GnuCOBOL Programmer’s Guide

Table of Contents

GnuCOBOL Programmer’s Guide

This manual documents the July2020 build of GnuCOBOL 3.1 RC-1.



1. Introduction

This document describes the syntax, semantics and use of the COBOL programming language as implemented by GnuCOBOL, formerly known as OpenCOBOL.

The original principal developers of GnuCOBOL were Keisuke Nishida and Roger While. Since then, many members of the community have been involved in its development.

This document is intended to serve as a fully functional reference and user’s guide, suitable for both those readers learning COBOL for the first time as a training tool, as well as those already familiar with another dialect of COBOL.

A separate manual — containing only the details of the GnuCOBOL implementation and designed for experienced COBOL programmers — has been taken from this guide. That document (GnuCOBOL Quick Reference) contains no training subject matter.

Other documents that should be read is the gnucobol.pdf found in the doc directory of the compiler sources and the file NEWS supplied with the source code of the GnuCOBOL compiler, in the top-level directory. There you will find the latest COBOL language features that have been added, some of which may not be in this document due to time constraints. If you find any, please report it as a bug for the Programmer’s Guide so that it can be fixed.

Yet another document which delves deeper in to the compiler that is a must read, is the FAQ available via the GnuCOBOL Manuals and Guides, although it could do with a wee clean up to ease reading and finding required information.



1.1. Additional Reference Sources

For those wishing to learn COBOL for the first time, Gary can strongly recommend the following resources.

If you like to hold a book in your hands, I strongly recommend Murach’s Structured COBOL, by Mike Murach, Anne Prince and Raul Menendez (2000) - ISBN 9781890774059. Mike Murach and his various writing partners have been writing outstanding COBOL textbooks for decades. It’s an excellent book for those familiar with the concepts of programming in other languages, but unfamiliar with COBOL.

Would you prefer a web-based tutorial? Try the University of Limerick (Ireland) - COBOL web site.

In addition there is the GnuCOBOL FAQ — which has now exceeded 1,400 pages — available as HTML or a downloadable .pdf file.

Along with every release of the compiler sources is the file NEWS. It contains up to the minute updates regarding the compiler and additional COBOL language elements which may well not be yet included in this manual.



1.2. Introducing COBOL

If you already know a programming language other than COBOL, chances are that language is Java, C or C++. You will find COBOL much different from those; sometimes the differences are a good thing and sometimes they aren’t. The thing to remember about COBOL is this: it was designed to solve business problems.

COBOL, first introduced to the programming public in 1959, was the very first programming language to become standardized (in 1960). This meant that a standard-compliant COBOL program written on computer “A” made by company “B” would be able to be compiled and executed on computer “X” made by company “Y” with very few, if any, changes. This may not seem like such a big deal today, but it was a radical departure from all programming languages that came before it and even many that came after it.

The name COBOL actually says it all — COBOL is an acronym that stands for “(CO)mmon (B)usiness (O)riented (L)anguage”. Note the fact that the word “common” comes before all others. The word “business” is a close second. Therein lies the key to COBOL’s success.



1.2.1. Why YOU Should Learn COBOL

Despite statements from industry “insiders”, the COBOL programming language is not dead, even though newer and so-called “modern” languages like Java, C#, .NET, Ruby on Rails and so on appear to have become the languages of choice in the Information Technology world. These languages have become popular because they address the following desired requirements for “modern” programming:

  1. They conform to the principles of Object-Oriented Programming (OOP). This is desired for one major reason — it facilitates “code re-usability”, thus improving the productivity of programmers by allowing them to re-use previously written (and debugged) code in new applications. For one reason or another, COBOL is perceived as being weak in this regard. It isn’t (especially today), as we’ll see in the next section, but perception is important.
  2. Those languages aren’t limited to mainframe computers, as COBOL is perceived to be. Some, like .NET and Ruby, aren’t even available on mainframes. The “modern” programming languages were designed and intended for use on the full variety of computer platforms, from shirt-pocket computers (i.e. smart phones) up to the most massive of supercomputers.
  3. There are several excellent commercially available COBOL implementations available for non-mainframe systems (Micro Focus COBOL, AccuCOBOL, NetCOBOL and Elastic COBOL, just to name a few), including Windows and UNIX/Linux systems. These aren’t cheap, however.
  4. Universities love the “Modern” languages. In the U.S., 73% of colleges lack even one COBOL course on their curricula. COBOL, it appears, is no longer “cool” enough for students to fill a classroom.

Just because COBOL doesn’t traditionally support objects, classes, and the like doesn’t mean that its “procedural” approach to computing isn’t valuable — after all, it runs 70% of the worlds business transactions, and does so:


Today’s IT managers and business leaders are faced with a challenging dilemma — how do you maintain the enormous COBOL code base that is still running their businesses when academia has all but abandoned the language they need their people to use to keep the wheels rolling? The problem is compounded by the fact that those programmers that are skilled in COBOL are retiring and taking their knowledge with them. In some markets, this appears to be having an inflationary effect on the cost of resources (COBOL programmers) whose supply is becoming smaller and smaller. The pressure to update applications to make use of more up-to-date graphical user interfaces is also perceived as a reason to abandon COBOL in favour of GUI-friendly languages such as Java.

Businesses are addressing the COBOL challenge in different ways:

  1. By undertaking so-called “modernization projects”, where existing applications are either rewritten in “modern” languages or replaced outright with purchased packages. Most of these businesses are using such activities as an excuse to abandon “expensive” mainframes in favour of (presumably) less-expensive “open systems” (mid frame/server) solutions.
  2. Many times these businesses are finding the cost of the system/networking engineering, operational management and monitoring and risk management (i.e. disaster recovery) infrastructures necessary to support truly mission-critical applications to be so high that the “less-expensive” solution really isn’t; in these cases the mainframe may remain the best option, thus leaving COBOL in play and businesses seeking another solution for at least part of their application base.
  3. Training their own COBOL programmers. Since colleges, universities and technical schools have lost interest in doing so, many businesses have undertaken the task of “growing their own” new crop of COBOL programmers. Fear of being pigeon-holed into a niche technology is a factor inhibiting many of today’s programmers from willingly volunteering for such training.
  4. By moving the user-interface onto the desktop; such efforts involve running modern-language front-end clients on user desktops (or laptops or smart phones, etc.) with COBOL programs providing server functionality on mainframe or midframe platforms, providing all the database and file “heavy lifting” on the back-end. Solutions like this provide users with the user-interfaces they want/need while still leveraging COBOL’s strengths on (possibly) downsized legacy mainframe or midframe systems.

It’s probably a true that an IT professional can no longer afford to allow COBOL to be the only wrench in their toolbox, but with a massive code base still in production now and for the foreseeable future, adding COBOL to a multi-lingual curriculum vitae (CV) and/or resume (yes — they ARE different) is not a bad thing at all. Knowing COBOL as well as the language du-jour will make you the smartest person in the room when the discussion of migrating the current “legacy” environment to a “modern” implementation comes around.

You’ll find COBOL an easy language to learn and a FAR EASIER language to master than many of the “modern” languages.

The whole reason you’re reading this is that you’ve discovered GnuCOBOL — another implementation of COBOL in addition to those mentioned earlier. The distinguishing characteristic of GnuCOBOL versus those others is that GnuCOBOL is FREE open-source and therefore FREE to obtain and use. It is community-enhanced and community-supported. Later in this document (see So What is GnuCOBOL?), you’ll begin to learn more about this COBOL implementation’s capabilities.



1.2.2. Programmer Productivity

Throughout the history of computer programming, the search for new ways to improve of the productivity of programmers has been a major consideration. Other than hobbyists, programming is an activity performed for money, and businesses abhor spending anything more than is absolutely necessary; even government agencies try to spend as little money on projects as is absolutely necessary.

The amount of programming necessary to accomplish a given task — including rework needed by any errors found during testing (testing is sometimes jokingly defined as: that time during which an application is actually in production, allowing users to discover the problems) is the measure of programmer productivity. Anything that reduces that effort will therefore reduce the time spent in such activities therefore reducing the expense of same. When the expense of programming is reduced, programmer productivity is increased.

Sometimes the quest for improved programmer productivity (and therefore reduced programming expense) has taken the form of introducing new features in programming languages, or even new languages altogether. Sometimes it has resulted in new ways of using the existing languages.

While many technological and procedural developments have made evolutionary improvements to programmer productivity, each of the following three events has been responsible for revolutionary improvements:


While GnuCOBOL supports few of the OOP programming constructs defined by the COBOL2002 and COBOL2014 standards, it supports every aspect of the ANSI 85 standard and therefore fully meets the needs of points #1 and #2, above. With its supported feature set (see So What is GnuCOBOL?), it provides significant programmer productivity capabilities.



1.3. So What is GnuCOBOL?

GnuCOBOL is a free and open sourced COBOL compiler and runtime environment, written using the C programming language. GnuCOBOL is typically distributed in source-code form, and must then be built for your computer’s operating system using the system’s C compiler and loader. While originally developed for the UNIX and Linux operating systems, GnuCOBOL has also been successfully built for computers running OSX and Windows utilizing the UNIX-emulation features of such tools as Cygwin and MinGW. Also see the GNU website for more information at.

The MinGW approach is a personal favourite with the author of this manual because it creates a GnuCOBOL compiler and runtime library that require only a single MinGW DLL to be available for the GnuCOBOL compiler, runtime library and user programs. That DLL is freely distributable under the terms of the GNU General Public License. A MinGW build of GnuCOBOL fits easily on and runs from a 128MB flash drive with no need to install any software onto the Windows computer that will be using it. Some functionality of the language, dealing with the sharing of files between concurrently executing GnuCOBOL programs and record locking on certain types of files, is sacrificed however as the underlying operating system routines needed to implement them aren’t available to Windows and aren’t provided by MinGW. The current version for MinGW is available at the download link along with various other platforms at the GnuCOBOL download website.

GnuCOBOL has also been built as a truly native Windows application utilizing Microsoft’s freely-downloadable Visual Studio Express package to provide the C compiler and linker/loader. This approach does not lend itself well to a “portable” distribution.

The GnuCOBOL compiler generates C code from your COBOL programs; that C code is then automatically compiled and linked using your system’s C compiler (typically, but not limited to, gcc).

GnuCOBOL fully supports much of the ANSI 85 standard for COBOL (the only major exclusion is the Communications Module) and also supports some of the components of the COBOL2002 and COBOL2014 standards, such as the SCREEN SECTION (see SCREEN SECTION), table-based SORT (see Table SORT) and user-defined functions. There are others with more being added almost weekly.



2. COBOL Fundamentals

This chapter describes the syntax, semantics and usage of the COBOL programming language as implemented by the current version of GnuCOBOL. For the rest of this document the Language is spelt as COBOL to ease reading however the compiler name retains the mixed case of GnuCOBOL.

This document is intended to serve as a full-function reference and user’s guide suitable for both those readers learning COBOL for the first time as usage as a training tool, as well as those already familiar with some dialects of the COBOL language.

A separate manual exists that just contains the details of the Cobol grammar as implemented in GnuCOBOL, which is designed strictly for experienced COBOL programmers and this is taken from this guide. This does NOT contain any training subject matter.

These extra manuals are: GnuCOBOL Quick Reference containing just the COBOL semantics / grammar in a short document while the other, GnuCOBOL Sample Programs, shows detailed example Cobol programs with indication of syntax used in each program.

For each implementation of the GnuCOBOL compiler the supplied files NEWS should also be read for any last minute updates along with files README and INSTALL for building the compiler.



2.1. The COBOL Language - The Basics



2.1.1. Language Reserved Words

Cobol programs consist of a sequence of words and symbols. Words, which consist of sequences of letters (upper- and/or lower-case), digits, dashes (‘-’) and/or underscores (‘_’) may have a pre-defined, specific, meaning to the compiler or may be invented by the programmer for his/her purposes.

The GnuCOBOL language specification defines over 1130 Reserved Words — words to which the compiler assigns a special meaning. This list and number applies to the default list which covers many implementations and that it is possible to limit the list to either a specific implementation via -std=xyz[-strict] or to manually unreserve words if they are used in existing sources as user-defined words.

Programmers may use a reserved word as part of a word they are creating themselves, but may not create their own word as an exact duplicate (without regard to case) of a COBOL reserved word. Note that a reserved word includes all classes, such as intrinsic functions, mnemonics names, system routines and reserved words. The list of reserved words can be changed by adding or removing specific words for a given compile or as a default by use of the steering command -std and -conf. See the specific config files that are by default, held in /usr/local/share/gnucobol/config. Also using the option ‘FUNCTION ALL INTRINSIC’, will add another 100+ reserved words. These can be modified to match the requirements of a business or project team but be warned that these are updated when a new version of the compiler is built so might be more prudent to create your own configuation based on an existing one but with a different name.

In addition, you can add and/or remove reserved words by adding one of these options to cobc to add -freserved-words=value or -freserved=word or, to remove, -fnot-reserved=word. As well as -freserved=word:alias to create an alias for a word as well as -fnot-register=word or -fregister=word to remove or add, a special register word.

See Appendix B - Reserved Word List, for a complete list of GnuCOBOL reserved words .

For any given version of GnuCOBOL you can also list the full current set of reserved words by running cobc with --list-reserved, --list-intrinsic, --list-system as well as --list-mnemonics. Again subject to variation depending on usage of the --std line command.



2.1.2. User-Defined Words

When you write GnuCOBOL programs, you’ll need to create a variety of words to represent various aspects of the program, the program’s data and the external environment in which the program will run. This will include internal names by which data files will be referenced, data item names and names of executable logic procedures.

User-defined words may be composed from the characters ‘A’ through ‘Z’ (upper- and/or lower-case), ‘0’ through ‘9’, dash (‘-’) and underscore (‘_’). User-defined words may neither start nor end with hyphen or underscore characters.

Other programming languages provide the programmer with a similar capability of creating their own words (names) for parts of a program; COBOL is somewhat unusual when compared to other languages in that user-defined words may start with a digit.

With the exception of logic procedure names, which may consist entirely of nothing but digits, user-defined words must contain at least one letter.



2.1.3. Case Insensitivity

All COBOL implementations allow the use of both upper and lower case letters in program coding. GnuCOBOL is completely insensitive to the case used when writing reserved words or user-defined names. Thus, AAAAA, aaaaa, Aaaaa and AaAaA are all the same word as far as GnuCOBOL is concerned.

The only time the case used does matter is within quoted character strings, where character values will be exactly as coded.

By convention throughout this document, COBOL reserved words will be shown entirely in UPPER-CASE while those words that were created by a programmer will be represented by tokens in mixed or lower case.

This isn’t a bad practice to use in actual programs, as it leads to programs where it is much easier to distinguish reserved words from user-defined ones!



2.1.4. Readability of Programs

Critics of COBOL frequently focus on the wordiness of the language, often citing the case of a so-called “Hello World” program as the “proof” that COBOL is so much more tedious to program in than more “modern” languages. This tedium is cited as such a significant impact to programmer productivity that, in their opinions, COBOL can’t go away quickly enough.

Here are two different “Hello World” applications, one written in Java and the second in GnuCOBOL. First, the Java version:

    Class HelloWorld {
        public static void main(String[] args) {
            System.out.println("Hello World!");
        }
    }

And here is the same program, written in GnuCOBOL:

    IDENTIFICATION DIVISION.
    PROGRAM-ID. HelloWorld.
    PROCEDURE DIVISION.
        DISPLAY "Hello World!".

Both of the above programs could have been written on a single line, if desired, and both languages allow a programmer to use (or not use) indentation as they see fit to improve program readability. Sounds like a tie so far.

Let’s look at how much more “wordy” COBOL is than Java. Count the characters in the two programs. The Java program has 95 (not counting carriage returns and any indentation). The COBOL program has 89 (again, not counting carriage returns and indentation)! Technically, it could have been only 65 because the IDENTIFICATION DIVISION. header is actually optional. Clearly, “Hello World” doesn’t look any more concise in Java than it does in COBOL.

Let’s look at a different problem. Surely a program that asks a user to input a positive integer, generates the sum of all positive integers from 1 to that number and then prints the result will be MUCH shorter and MUCH easier to understand when coded in Java than in COBOL, right?

You can be the judge. First, the Java version:

    import java.util.Scanner;
    public class sumofintegers {
        public static void main(String[] arg) {
            System.out.println("Enter a positive integer");
            Scanner scan=new Scanner(System.in);
            int n=scan.nextInt();
            int sum=0;
            for (int i=1;i<=n;i++) {
                sum+=i;
            }
            System.out.println("The sum is "+sum);
        }
    }

And now for the COBOL version:

    IDENTIFICATION DIVISION.
    PROGRAM-ID. SumOfIntegers.
    DATA DIVISION.
    WORKING-STORAGE SECTION.
    01 n   BINARY-LONG.
    01 i   BINARY-LONG.
    01 sum BINARY-LONG VALUE 0.
    PROCEDURE DIVISION.
    DISPLAY "Enter a positive integer"
    ACCEPT n
    PERFORM VARYING i FROM 1 BY 1 UNTIL i > n
        ADD i TO sum
    END-PERFORM
    DISPLAY "The sum is " sum.

My familiarity with COBOL may be prejudicing my opinion, but it doesn’t appear to me that the Java code is any simpler than the COBOL code. In case you’re interested in character counts, the Java code comes in at 278 (not counting indentation characters). The COBOL code is 298 (274 without the IDENTIFICATION DIVISION. header).

Despite what you’ve seen here, the more complex the programming logic being implemented, the more concise the Java code will appear to be, even compared to 2002-standard COBOL. That conciseness comes with a price though — program code readability. Java (or C or C++ or C#) programs are generally intelligible only to trained programmers. COBOL programs can, however, be quite understandable by non-programmers. This is actually a side-effect of the “wordiness” of the language, where COBOL statements use natural English words to describe their actions. This inherent readability has come in handy many times throughout my career when I’ve had to learn obscure business (or legal) processes by reading the COBOL program code that supports them.

The “modern” languages, like Java, also have their own “boilerplate” infrastructure overhead that must be coded in order to write the logic that is necessary in the program. Take for example the public static void main(String[] arg) and import java.util.Scanner; statements. The critics tend to forget about this when they criticize COBOL for its structural “overhead”.

When it first was developed, COBOL’s easily-readable syntax made it profoundly different from anything that had been seen before. For the first time, it was possible to specify logic in a manner that was — at least to some extent — comprehensible even to non-programmers. Take for example, the following code written in FORTRAN — a language developed only a year before COBOL:

    EXT = PRICE * IQTY
    INVTOT = INVTOT + EXT

With its original limitation on the length of variable names (one- to six-character names comprised of a letter followed by up to five letters and/or digits), its implicit rule that variables were automatically created as real (floating-point) unless their name started with a letter in the range I-N, and its use of algebraic notation to express actions being taken, FORTRAN wasn’t a particularly readable language, even for programmers. Compare this with the equivalent COBOL code:

    MULTIPLY price BY quantity GIVING extended-amount
    ADD extended-amount TO invoice-total

Clearly, even a non-programmer could at least conceptually understand what was going on! Over time, languages like FORTRAN evolved more robust variable names, and COBOL introduced a more formula-based syntactical capability for arithmetic operations, but FORTRAN was never as readable as COBOL.

Because of its inherent readability, I would MUCH rather be handed an assignment to make significant changes to a COBOL program about which I know nothing than to be asked to do the same with a C, C++, C# or Java program.

Those that argue that it is too boring / wasteful / time-consuming / insulting (pick one) to have to code a COBOL program “from scratch” are clearly ignorant of the following facts:



2.1.5. Divisions Organize Programs

COBOL programs are structured into four major areas of coding, each with its own purpose. These four areas are known as divisions.

Each division may consist of a variety of sections and each section consists of one or more paragraphs. A paragraph consists of sentences, each of which consists of one or more statements.

This hierarchical structure of program components standardizes the composition of all COBOL programs. Much of this manual describes the various divisions, sections, paragraphs and statements that may comprise any COBOL program. COPY statement (see COPY)



2.1.6. Copybooks

A Copybook is a segment of program code that may be utilized by multiple programs simply by having those programs use the COPY statement to import that code. This code may define files, data structures or procedural code.

Today’s current programming languages have a statement (usually, this statement is named “import”, “include” or “#include”) that performs this same function. What makes the COBOL copybook feature different than the “include” facility in newer languages, however, is the fact that the COPY statement can edit the imported source code as it is being copied. This capability makes copybook libraries extremely valuable to making code reusable. Also see section 3. Compiler Directing Facility commands COPY and REPLACE.



2.1.7. Structured Data

A contiguous area of storage within the memory space of a program that may be referenced, by name, in a COBOL program is referred to as a Data Item. Other programming languages use the term variable, property or attribute to describe the same thing.

COBOL introduced the concept of structured data. The principle of structured data in COBOL is based on the idea of being able to group related and contiguously-allocated data items together into a single aggregate data item, called a Group Item. For example, a 35-character ’Employee-Name’ group item might consist of a 20-character ’Last-Name’ followed by a 14-character ’First-Name’ and a 1-character ’Middle-Initial’.

A data item that isn’t itself formed from other data items is referred to in COBOL as an Elementary Item. In the previous example, ’Last-Name’, ’First-Name’ and ’Middle-Initial’ are all elementary items.



2.1.8. Files

One of COBOL’s strengths is the wide variety of data files it is capable of accessing. GnuCOBOL programs, like those created with other COBOL implementations, need to have the structure of any files they will be reading and/or writing described to them. The highest-level characteristic of a file’s structure is defined by specifying the organization of the file, as follows:

ORGANIZATION LINE SEQUENTIAL

These are files with the simplest of all internal structures. Their contents are structured simply as a series of identically- or differently-sized data records, each terminated by a special end-of-record delimiter character. An ASCII line-feed character (hexadecimal 0A) is the end-of-record delimiter character used by any UNIX or pseudo-UNIX (MinGW, Cygwin, OSX) GnuCOBOL build. A truly native Windows build would use a carriage-return, line-feed (hexadecimal 0D0A) sequence.

Records must be read from or written to these files in a purely sequential manner. The only way to read (or write) record number 100 would be to have read (or written) records number 1 through 99 first.

When the file is written to by a GnuCOBOL program, the delimiter sequence will be automatically appended to each data record as it is written to the file. A WRITE (see WRITE) to this type of file will be done as if a BEFORE ADVANCING 1 LINE clause were specified on the WRITE, if no ADVANCING clause is coded.

When the file is read, the GnuCOBOL runtime system will strip the trailing delimiter sequence from each record. The data will be padded (on the right) with spaces if the data just read is shorter than the area described for data records in the program. If the data is too long, it will be truncated and the excess will be lost.

These files should not be defined to contain any exact binary data fields because the contents of those fields could inadvertently have the end-of-record sequence as part of their values — this would confuse the runtime system when reading the file, and it would interpret that value as an actual end-of-record sequence.

LINE ADVANCING

These are files with an internal structure similar to that of a line sequential file. These files are defined (without an explicit ORGANIZATION specification) using the LINE ADVANCING clause on their SELECT statement (see SELECT).

When this kind of file is written to by a GnuCOBOL program, an end-of-record delimiter sequence will be automatically added to each data record as it is written to the file. A WRITE to this type of file will be done as if an AFTER ADVANCING 1 LINE clause were specified on the WRITE, if no ADVANCING clause is coded.

Like line sequential files, these files should not be defined to contain any exact binary data fields because the contents of those fields could inadvertently have the end-of-record sequence as part of their values — this would confuse the runtime system when reading the file, and it would interpret that value as an actual end-of-record sequence.

ORGANIZATION SEQUENTIAL

These files also have a simple internal structure. Their contents are structured simply as an arbitrarily-long sequence of data characters. This sequence of characters will be treated as a series of fixed-length records simply by logically splitting the sequence of characters up into fixed-length segments, each as long as the maximum record size defined in the program. There are no special end-of-record delimiter characters in the file and when the file is written to by a GnuCOBOL program, no delimiter sequence is appended to the data.

Records in this type of file are all the same physical length, except possibly for the very last record in the file, which may be shorter than the others. If variable-length logical records are defined to the program, the space occupied by each physical record in the file will occupy the space described by the longest record description in the program.

So, if a file contains 1275 characters of data, and a program defines the structure of that file as containing 100-character records, then the file contents will consist of twelve (12) 100-character records with a final record containing only 75 characters.

It would appear that it should be possible to locate and process any record in the file directly simply by calculating its starting character position based upon the program-defined record size. Even so, however, records must be still be read or written to these files in a purely sequential manner. The only way to read (or write) record number 100 would be to have read (or written) records number 1 through 99 first.

When the file is read, the data is transferred into the program exactly as it exists in the file. In the event that a short record is read as the very last record, that record will be padded (to the right) with spaces.

Care must be taken that programs reading such a file describe records whose length is exactly the same as that used by the program that created the file. For example, the following shows the contents of a SEQUENTIAL file created by a program that wrote five 6-character records to it. The ‘A’, ‘B’, … values reflect the records that were written to the file:

AAAAAA
BBBBBB
CCCCCC
DDDDDD
EEEEEE

Now, assume that another program reads this file, but describes 10-character records rather than 6. Here are the records that program will read:

AAAAAABBBB
BBCCCCCCDD
DDDDEEEEEE

There may be times where this is exactly what you were looking for. More often than not, however, this is not desirable behaviour. Suggestion: use a copybook to describe the record layouts of any file; this guarantees that multiple programs accessing that file will “see” the same record sizes and layouts by coding a COPY statement (see COPY) to import the record layout(s) rather than hand-coding them.

These files can contain exact binary data fields. Because there is no character sequence that constitutes an end-of-record delimiter, the contents of record fields are irrelevant to the reading process.

ORGANIZATION RELATIVE

The contents of these files consist of a series of fixed-length data records prefixed with a four-byte record header. The record header contains the length of the data, in bytes. The byte-count does not include the four-byte record header.

Records in this type of file are all the same physical length. If variable-length logical records are defined to the program, the space occupied by each physical record in the file will occupy the maximum possible space, and the logical record length field will contain the number of bytes of data in the record that are actually in use.

This file organization was defined to accommodate either sequential or random processing. With a RELATIVE file, it is possible to read or write record 100 directly, without having to have first read or written records 1-99. The GnuCOBOL runtime system uses the program-defined maximum record size to calculate a relative byte position in the file where the record header and data begin, and then transfers the necessary data to or from the program.

When the file is written by a GnuCOBOL program, no delimiter sequence is appended to the data, but a record-length field is added to the beginning of each physical record.

When the file is read, the data is transferred into the program exactly as it exists in the file.

Care must be taken that programs reading such a file describe records whose length is exactly the same as that used by the programs that created the file. It won’t end well if the GnuCOBOL runtime library interprets a four-byte ASCII character string as a record length when it transfers data from the file into the program!

Suggestion: use a copybook to describe the record layouts of any file; this guarantees that multiple programs accessing that file will “see” the same record sizes and layouts by coding a COPY statement (see COPY) to import the record layout(s) rather than hand-coding them.

These files can contain exact binary data fields. The contents of record fields are irrelevant to the reading process as there is no end-of-record delimiter.

ORGANIZATION INDEXED

This is the most advanced file structure available to GnuCOBOL programs. It’s not possible to describe the physical structure of such files because that structure will vary depending upon which advanced file-management facility was included into the GnuCOBOL build you will be using (Berkeley Database [BDB], VBISAM, etc.). We will — instead — discuss the logical structure of the file.

There will be multiple structures stored for an INDEXED file. The first will be a data component, which may be thought of as being similar to the internal structure of a relative file. Data records may not, however, be directly accessed by their record number as would be the case with a relative file, nor may they be processed sequentially by their physical sequence in the file.

The remaining structures will be one or more index components. An index component is a data structure that (somehow) enables the contents of a field, called a primary key, within each data record (a customer number, an employee number, a product code, a name, etc.) to be converted to a record number so that the data record for any given primary key value can be directly read, written and/or deleted. Additionally, the index data structure is defined in such a manner as to allow the file to be processed sequentially, record-by-record, in ascending sequence of the primary key field values. Whether this index structure exists as a binary-searchable tree structure (b-tree), an elaborate hash structure or something else is pretty much irrelevant to the programmer — the behaviour of the structure will be as it was just described. The actual mechanism used will depend upon the advanced file-management package was included into your GnuCOBOL implementation when it was built.

The runtime system will not allow two records to be written to an indexed file with the same primary key value.

The capability exists for an additional field to be defined as what is known as an alternate key. Alternate key fields behave just like primary keys, allowing both direct and sequential access to record data based upon the alternate key field values, with one exception. That exception is the fact that alternate keys may be allowed to have duplicate values, depending upon how the alternate key field is described to the GnuCOBOL compiler.

There may be any number of alternate keys, but each key field comes with a disk space penalty as well as an execution time penalty. As the number of alternate key fields increases, it will take longer and longer to write and/or modify records in the file.

These files can contain exact binary data fields. The contents of record fields are irrelevant to the reading process as there is no end-of-record delimiter.

All files are initially described to a GnuCOBOL program using a SELECT statement (see SELECT). In addition to defining a name by which the file will be referenced within the program, the SELECT statement will specify the name and path by which the file will be known to the operating system along with its organization, locking and sharing attributes.

A file description in the FILE SECTION (see FILE SECTION) will define the structure of records within the file, including whether or not variable-length records are possible and, if so, what the minimum and maximum length might be. In addition, the file description entry can specify file I/O block sizes.



2.1.9. Table Handling

Other programming languages have arrays; COBOL has tables. They’re basically the same thing. There are two special statements that exist in the COBOL language — SEARCH and SEARCH ALL — that make finding data in a table easy.

SEARCH searches a table sequentially, stopping only when either a table entry matching one of any number of search conditions is found, or when all table entries have been checked against the search criteria and none matched any of those criteria.

SEARCH ALL performs an extremely fast search against a table sorted by a key field contained in each table entry. The algorithm used for such a search is a binary search. The algorithm ensures that only a small number of entries in the table need to be checked in order to find a desired entry or to determine that the desired entry doesn’t exist in the table. The larger the table, the more effective this search becomes. For example, a binary search of a table containing 32,768 entries will locate a particular entry or determine the entry doesn’t exist by looking at no more than fifteen (15) entries! The algorithm is explained in detail in the documentation of the SEARCH ALL statement (see SEARCH ALL).

Finally, COBOL has the ability to perform in-place sorts of the data that is found in a table.



2.1.10. Sorting and Merging Data

The COBOL language includes a powerful SORT statement that can sort large amounts of data according to arbitrarily complex key structures. This data may originate from within the program or may be contained in one or more external files. The sorted data may be written automatically to one or more output files or may be processed, record-by-record in the sorted sequence.

A companion statement — MERGE — can combine the contents of multiple files together, provided those files are all pre-sorted in a similar manner according to the same key structure. The resulting output will consist of the contents of all of the input files, merged together and sequenced according to the common key structure(s). The output generated by a MERGE statement may be written automatically to one or more output files or may be processed internally by the program.

A special form of the SORT statement also exists just to sort the data that resides in a table. This is particularly useful if you wish to use SEARCH ALL against the table.



2.1.11. String Manipulation

There have been programming languages designed specifically for the processing of text strings, and there have been programming languages designed for the sole purpose of performing high-powered numerical computations. Most programming languages fall somewhere in the middle.

COBOL is no exception, although it does include some very powerful string manipulation capabilities; GnuCOBOL actually has even more string-manipulation capabilities than many other COBOL implementations. The following summarizes GnuCOBOL’s string-processing capabilities:

Concatenate two or more strings
Conversion of a numeric time or date to a formatted character string
Convert a binary value to its corresponding character in the program’s character set
Convert a character string to lower-case
Convert a character string to upper-case
Convert a character string to only printable characters
Convert a character to its numeric value in the program’s character set
Count occurrences of sub strings in a larger string
Decode a formatted numeric string back to a numeric value
Determine the length of a string or data-item capable of storing strings
Extract a sub string from a string based on its starting character position and length
Format a numeric item for output, including thousands-separators (‘,’ in the USA), currency symbols (‘$’ in the USA), decimal points, credit/Debit Symbols, Leading Or Trailing Sign Characters
Justification (left, right or centred) of a string field
Monoalphabetic substitution of one or more characters in a string with different characters
Parse a string, breaking it up into sub strings based upon one or more delimiting character sequences1
Removal of leading or trailing spaces from a string
Substitution of a single sub string with another of the same length, based upon the sub strings starting character position and length
Substitution of one or more sub strings in a string with replacement sub strings of the same length, regardless of where they occur
Substitution of one or more sub strings in a string with replacement sub strings of a potentially different length, regardless of where they occur


2.1.12. Screen Formatting Features

The COBOL2002 standard formalizes extensions to the COBOL language that allow for the definition and processing of text-based screens, as is a typical function on mainframe and midframe computers as well as on many point-of-sale (i.e. “cash register”) systems. GnuCOBOL implements virtually all the screen-handling features described by COBOL2002.

These features allow fields to be displayed at specific row/column positions, various colors and video attributes to be assigned to screen fields and the pressing of specific function keys (F1, F2, …) to be detectable. All of this takes place through the auspices of the SCREEN SECTION (see SCREEN SECTION) and special formats of the ACCEPT statement (see ACCEPT) and the DISPLAY statement (see DISPLAY).

The COBOL2002 standard, and therefore GnuCOBOL, only covers textual user interface (TUI) screens (those comprised of ASCII characters presented using a variety of visual attributes) and not the more-advanced graphical user interface (GUI) screen design and processing capabilities built into most modern operating systems. There are subroutine-based packages available that can do full GUI presentation — most of which may be called by GnuCOBOL programs, with a moderate research time investment (Tcl/Tk, for example) — but none are currently included with GnuCOBOL.



2.1.12.1. A Sample Screen

A Sample Screen Produced by a GnuCOBOL Program:

================================================================================
 GCic (2014/01/02 11:24) GnuCOBOL 2.1 23NOV2013 Interactive Compilation
+------------------------------------------------------------------------------+
: Filename: GCic.cbl                                                           :
: Folder:   E:\Programs\GCic\2013-11-23                                        :
+------------------------------------------------------------------------------+
 Set/Clr Switches Via F1-F9; Set Config Via F12; ENTER Key Compiles; ESC Quits
+------------------------------------------------------------------------------+
: F1  Assume WITH DEBUGGING MODE  F6 >"FUNCTION" Is Optional      : Current    :
: F2  Procedure+Statement Trace   F7 >Enable All Warnings         : Config:    :
: F3  Make a Library (DLL)        F8  Source Is Free-Format       : DEFAULT    :
: F4  Execute If Compilation OK   F9 >No COMP/BINARY Truncation   :            :
: F5  Listing Off                                                 :            :
+------------------------------------------------------------------------------+
 Extra "cobc" Switches, If Any ("-save-temps=xxx" Prevents Listings):
+------------------------------------------------------------------------------+
: ____________________________________________________________________________ :
: ____________________________________________________________________________ :
+------------------------------------------------------------------------------+
 Program Execution Arguments, If Any:
+------------------------------------------------------------------------------+
: ____________________________________________________________________________ :
: ____________________________________________________________________________ :
+------------------------------------------------------------------------------+
 GCic for Windows/MinGW Copyright (C) 2009-2014, Gary L. Cutler, GPL
================================================================================

The above screen was produced by the GnuCOBOL Interactive Compiler, or GCic. See GCic in GnuCOBOL Sample Programs, for the source and cross-reference listing of this program. PDF versions of this document will include an actual graphical image of this sample screen.

Screens are defined in the screen section of the data division. Once defined, screens are used at run-time via the ACCEPT and DISPLAY statements.



2.1.12.2. Color Palette and Video Attributes

GnuCOBOL supports the following visual attribute specifications in the SCREEN SECTION (see SCREEN SECTION):

Color

Eight (8) different colors may be specified for both the background (screen) and foreground (text) color of any row/column position on the screen. Colors are specified by number, although a copybook supplied with all GnuCOBOL distributions (screenio.cpy) defines COB-COLOR-xxxxxx names for the various colors so they may be specified as a more meaningful name rather than a number. The eight colors, by number, with the constant names defined in screenio.cpy, are as follows:

Black

COB-COLOR-BLACK

Blue

COB-COLOR-BLUE

Green

COB-COLOR-GREEN

Cyan

COB-COLOR-CYAN

Red

COB-COLOR-RED

Magenta

COB-COLOR-MAGENTA

Yellow

COB-COLOR-YELLOW

White

COB-COLOR-WHITE

Text Brightness

There are three possible brightness levels supported for text — lowlight (dim), normal and highlight (bright). Not all GnuCOBOL implementations will support all three (some treat lowlight the same as normal). The deciding factor as to whether two or three levels are supported lies with the version of the curses package that is being used. This is a utility screen-IO package that is included into the GnuCOBOL run-time library when the GnuCOBOL software is built.

As a general rule of thumb, Windows implementations support two levels while Unix ones support all three.

Blinking

This too is a video feature that is dependent upon the curses package built into your version of GnuCOBOL. If blinking is enabled in that package, text displayed in fields defined in the screen section as being blinking will endlessly cycle between the brightest possible setting (highlight) and an “invisible” setting where the text color matches that of the field background color. A Windows build, which generally uses the “pcurses” package, will uses a brighter-than-normal background color to signify “blinking”.

Reverse Video

This video attribute simply swaps the foreground and background colors and display options.

Field Outlining

It is possible, if supported by the curses package being used, to draw borders on the top, left and/or bottom edges of a field.

Secure Input

If desired, screen fields used as input fields may defined as “secure” fields, where each input character (regardless of what was actually typed) will appear as an asterisk (*) character. The actual character whose key was pressed will still be stored into the field in the program, however. This is very useful for password or account number fields.

Prompt Character

Input fields may have any character used as a fill character. These fill characters provide a visual indication of the size of the input field, and will automatically be transformed into spaces when the input field is processed by the program. If no such character is defined for an input field, an underscore (‘_’) will be assumed.



2.1.13. Report Writer Features

GnuCOBOL includes an implementation of the Report Writer Control System, or RWCS. The reportwriter module is now fully implemented as of version 3.0. This is a standardized, optional add-on feature to the COBOL language which automates much of the mechanics involved in the generation of printed reports by:

  1. Controlling the pagination of reports, including:
    1. The automatic production of a one-time notice on the first page of the report (report heading).
    2. The production of zero or more header lines at the top of every page of the report (page heading).
    3. The production of zero or more footer lines at the bottom of every page of the report (page footing).
    4. The automatic numbering of printed pages.
    5. The formatting of those report lines that make up the main body of the report (detail).
    6. Full awareness of where the “pen” is about to “write” on the current page, automatically forcing an eject to a new page, along with the automatic generation of a page footer to close the old page and/or a page header to begin the new one.
    7. The production of a one-time notice at the end of the last page of a report (report footing).
  2. Performing special reporting actions based upon the fact that the data being used to generate the report has been sorted according to one or more key fields:
    1. Automatically suppressing the presentation of one or more fields of data from the detail group when the value(s) of the field(s) duplicate those of the previously generated detail group. Fields such as these are referred to as group-indicate fields.
    2. Automatically causing suppressed detail group-indicate fields to re-appear should a detail group be printed on a new page.
    3. Recognizing when control fields on the report — fields tied to those that were used as SORT statement (see SORT) keys — have changed. This is known as a control break. The RWCS can automatically perform the following reporting actions when a control break occurs:
      • Producing a footer, known as a control footing after the detail lines that shared the same old value for the control field.
      • Producing a header, known as a control heading before the detail lines that share the same new value for the control field.
  3. Perform data summarise, as follows:
    1. Automatically generating subtotals in control and/or report footings, summarizing values of any fields in the detail group.
    2. Automatically generating crossfoot totals in detail groups. These would be sums of two or more values presented in the detail group.

The REPORT SECTION (see REPORT SECTION) documentation explores the description of reports and the PROCEDURE DIVISION (see PROCEDURE DIVISION) chapter documents the various language statements that actually produce reports. Before reading these, you might find it helpful to read Report Writer Usage, which is dedicated to putting the pieces together for you.



2.1.14. Data Initialization

There are three ways in which data division data gets initialized.

  1. When a program or subprogram is first executed, much of the data in its data division will be initialized as follows:

    The various sections of the data division each have their own rules as to when the actions described above will occur — consult the documentation on those sections for additional information.

    These default initialization rules can vary quite substantially from one COBOL implementation to another. For example, it is quite common for data division storage to be initialized to all binary zeros except for those data items where VALUE clauses are present. Take care when working with applications originally developed for another COBOL implementation to ensure that GnuCOBOL’s default initialization rules won’t prove disruptive.

  2. A programmer may use the INITIALIZE statement (see INITIALIZE) to initialise any group or elementary data item at any time. This statement provides far more initialization options than just the simple rules stated above.
  3. When the ALLOCATE statement (see ALLOCATE) statement is used to allocate a data item or to simply allocate an area of storage of a size specified on the ALLOCATE, that allocation may occur with or without initialization, as per the programmer’s needs.


2.1.15. Syntax Diagram Conventions

Syntax of the GnuCOBOL language will be described in special syntax diagrams using the following syntactical-description techniques:

MANDATORY-RESERVED-WORD
~~~~~~~~~~~~~~~~~~~~~~~

Reserved words of the COBOL language will appear in UPPER-CASE. When they appear underlined, as this one is, they are required reserved words.

OPTIONAL-RESERVED-WORD

When reserved words appear without underlining, as this one is, they are optional; such reserved words are available in the language syntax merely to improve readability — their presence or absence has no effect upon the program.

ABBREVIATION
~~~~

When only a portion of a reserved word is underlined, it indicates that the word may either be coded in its full form or may be abbreviated to the portion that is underlined.

substitutable-items

Generic terms representing user-defined substitutable items will be shown entirely in lower-case in syntax diagrams. When such items are referenced in text, they will appear as substitutable-items.

Complex-Syntax-Clause

Items appearing in Mixed Case within a syntax diagram represent complex clauses of other syntax elements that may appear in that position. Some COBOL syntax gets quite complicated, and using a convention such as this significantly reduces the complexity of a syntax diagram. When such items are referenced in text, they will appear as Complex-Syntax-Clause.

[ ]

Square bracket meta characters on syntax diagrams document language syntax that is optional. The [] characters themselves should not be coded. If a syntax diagram contains ‘a [b] c’, the ‘a’ and ‘c’ syntax elements are mandatory but the ‘b’ element is optional.

|

Vertical bar meta characters on syntax diagrams document simple choices. The | character itself should not be coded. If a syntax diagram contains ‘a|b|c’, exactly one of the items ‘a’, ‘b’ or ‘c’ must be selected.

{ xxxxxx }
{ yyyyyy }
{ zzzzzz }

A vertical list of items, bounded by multiple brace characters, is another way of signifying a choice between a series of items where exactly one item must be selected. This form is used to show choices when one or more of the selections is more complex than just a single word, or when there are too many choices to present horizontally with ‘|’ meta characters.

| xxxxxx |
| yyyyyy |
| zzzzzz |

A vertical list of items, bounded by multiple vertical bar characters, signifies a choice between a series of items where one or more of the choices could be selected.

...

The ... meta character sequence signifies that the syntax element immediately preceding it may be repeated. The ... sequence itself should not be coded. If a syntax diagram contains a b... c, syntax element ‘a’ must be followed by at least one ‘b’ element (possibly more) and the entire sequence must be terminated by a ‘c’ syntax element.

{ }

The braces (‘{’ and ‘}’) meta characters may be used to group a sequence of syntax elements together so that they may be treated as a single entity. The {} characters themselves should not be coded. These are typically used in combination with the ‘|’ or ‘...’ meta characters.

$*^()-+=:"'<,>./

Any of these characters appearing within a syntax diagram are to be interpreted literally, and are characters that must be coded — where allowed — in the statement whose format is being described. Note that a ‘.’ character is a literal character that must be coded on a statement whereas a ‘...’ symbol is the meta character sequence described above.



2.1.16. Format of Program Source Lines

Prior to the COBOL2002 standard, source statements in COBOL programs were structured around 80-column punched cards. This means that each source line in a COBOL program consisted of five different “areas”, defined by their column number(s).

As of the COBOL2002 standard, a second mode now exists for COBOL source code statements — in this mode of operation, COBOL statements may each be up to 255 characters long, with no specific requirements as to what should appear in which columns.

Of course, in keeping with the long-standing COBOL tradition of maintaining backwards compatibility with older standards, programmers (and, of course, compliant COBOL compilers) are capable of working in either mode. It is even possible to switch back and forth in the same program. The terms Fixed Format Mode and Free Format Mode are used to refer to these two modes of source code formatting.

The GnuCOBOL compiler (cobc) supports both of these source line format modes, defaulting to Fixed Format Mode lacking any other information.

The compiler can be instructed to operate in either mode in any of the following four ways:

  1. Using a compiler option switch — use the -fixed switch to start in Fixed Format Mode (remember that this is the default) or the -free switch to start in Free Format Mode.
  2. You may use the SOURCEFORMAT AS FIXED and SOURCEFORMAT AS FREE clauses of the >>SET CDF directive (see >>SET) within your source code to switch to Fixed or Free Format Mode, respectively.
  3. You may use the >>FORMAT IS FIXED and FORMAT IS FREE clauses of the >>DEFINE CDF directive (see >>DEFINE) within your source code to switch to Fixed or Free Format Mode, respectively.
  4. You may use the >>SOURCE CDF directive (see >>SOURCE) to switch to Free Format Mode (>>SOURCE FORMAT IS FREE) or Fixed Format Mode (>>SOURCE FORMAT IS FIXED.

Using methods 2-4 above, you may switch back and forth between the two formats at will.

The last three options above are all equivalent; all three are supported by GnuCOBOL so that source code compatibility may be maintained with a wide variety of other COBOL implementations. With all three, if the compiler is currently in Fixed Format Mode, the >> must begin in column 8 or beyond, provided no part of the directive extends past column 72. If the compiler is currently in Free Format Mode, the >> may appear in any column, provided no part of the directive extends past column 255.

Depending upon which source format mode the compiler is in, you will need to follow various rules for the format mode currently in effect. These rules are presented in the upcoming paragraphs.

The following discussion presents the various components of every GnuCOBOL source line record when the compiler is operating in Fixed Format Mode. Remember that this is the default mode for the GnuCOBOL compiler.

1-6

Sequence Number Area

Historically, back in the days when punched-cards were used to submit COBOL program source to a COBOL compiler, this part of a COBOL statement was reserved for a six-digit sequence number. While the contents of this area are ignored by COBOL compilers, it existed so that a program actually punched on 80-character cards could — if the card deck were dropped on the floor — be run through a card sorter machine and restored to its proper sequence. Of course, this isn’t necessary today; if truth be told, it hasn’t been necessary for a long time.

See Marking Changes in Programs, for discussion of a valuable use to which the sequence number area may be put today.

7

Indicator Area

Column 7 serves as an indicator in which one of five possible values will appear — space, D (or d), - (dash), / or *. The meanings of these characters are as follows:

space

No special meaning — this is the normal character that will appear in this area.

D/d

The line contains a valid GnuCOBOL statement that is normally treated as a comment unless the program is being compiled in debugging mode.

*

The line is a comment.

/

The line is a comment that will also force a page eject in the compilation listing. While GnuCOBOL will honour such a line as a comment, it will not form-feed any generated listing.

-

The line is a continuation of the previous line. These are needed only when an alphanumeric literal (quoted character string), reserved word or user-defined word are being split across lines.

8-11

Area A

Language DIVISION, SECTION and paragraph section headers must b egin in Area A, as must the level numbers 01, 77 in data description entries and the FD and SD file and SORT description headers.

12-72

Area B

All other COBOL programming language components are coded in these columns.

73-80

Program Name Area

This is another obsolete area of COBOL statements. This part of every statement also hails back to the day when programs were punched on cards; it was expected that the name of the program (or at least the first 8 characters of it) would be punched here so that — if a dropped COBOL source deck contained more than one program — that handy card sorter machine could be used to first separate the cards by program name and then sort them by sequence number. Today’s COBOL compilers (including GnuCOBOL) simply ignore anything past column 72.

See Marking Changes in Programs, for discussion of a valuable use to which the program name area may be put today.



2.1.17. Program Structure

Complete GnuCOBOL Program Syntax
=======================================================================

 [ IDENTIFICATION DIVISION. ]
   ~~~~~~~~~~~~~~~~~~~~~~~
   PROGRAM-ID|FUNCTION-ID.  name-1 [ Program-Options ] .
   ~~~~~~~~~~ ~~~~~~~~~~~
 [ ENVIRONMENT DIVISION. ]
   ~~~~~~~~~~~ ~~~~~~~~
 [ CONFIGURATION SECTION. ]
   ~~~~~~~~~~~~~ ~~~~~~~
 [ SOURCE-COMPUTER.         Compilation-Computer-Specification . ]
   ~~~~~~~~~~~~~~~
 [ OBJECT-COMPUTER.         Execution-Computer-Specification . ]
   ~~~~~~~~~~~~~~~
 [ REPOSITORY.              Function-Specification... . ]
   ~~~~~~~~~~
 [ SPECIAL-NAMES.           Program-Configuration-Specification . ]
   ~~~~~~~~~~~~~
 [ INPUT-OUTPUT SECTION. ]
   ~~~~~~~~~~~~ ~~~~~~~
 [ FILE-CONTROL.            General-File-Description... . ]
   ~~~~~~~~~~~~
 [ I-O-CONTROL.             File-Buffering-Specification... . ]
   ~~~~~~~~~~~
 [ DATA DIVISION. ]
   ~~~~~~~~~~~~~
 [ FILE SECTION.            Detailed-File-Description... . ]
   ~~~~~~~~~~~~
 [ WORKING-STORAGE SECTION. Permanent-Data-Definition... . ]
   ~~~~~~~~~~~~~~~ ~~~~~~~
 [ LOCAL-STORAGE SECTION.   Temporary-Data-Definition... . ]
   ~~~~~~~~~~~~~ ~~~~~~~
 [ LINKAGE SECTION.         Subprogram-Argument-Description... . ]
   ~~~~~~~ ~~~~~~~
 [ REPORT SECTION.          Report-Description... . ]
   ~~~~~~ ~~~~~~~
 [ SCREEN SECTION.          Screen-Layout-Definition... . ]
   ~~~~~~ ~~~~~~~
   PROCEDURE DIVISION [ { USING Subprogram-Argument...      } ]
   ~~~~~~~~~ ~~~~~~~~   { ~~~~~                             }
                        { CHAINING Main-Program-Argument... }
                          ~~~~~~~~
                      [   RETURNING identifier-1 ] .
 [ DECLARATIVES. ]        ~~~~~~~~~
   ~~~~~~~~~~~~
 [ Event-Handler-Routine... . ]
 [ END DECLARATIVES. ]
   ~~~ ~~~~~~~~~~~~
   General-Program-Logic
 [ Nested-Subprogram... ]
 [ END PROGRAM|FUNCTION name-1 ]
   ~~~ ~~~~~~~ ~~~~~~~~

=======================================================================

Each program consists of up to four Divisions (major groupings of sections, paragraphs and descriptive or procedural coding that all relate to a common purpose), named Identification, Environment, Data and Procedure.

  1. Not all divisions are needed in every program, but they must be specified in the order shown when they are used.
  2. The following points pertain to the identification division
  3. The following points pertain to the environment division:
  4. The following points pertain to the data division:
  5. The following points pertain to the procedure division:
  6. A single file of COBOL source code may contain:
  7. Subprogram ‘B’ may be nested inside program ‘A’ by including program B’s source code at the end of program A’s procedure division without an intervening END PROGRAM A. or END FUNCTION A. statement. For now, that’s all that will be said about nesting. See Independent vs Contained vs Nested Subprograms, for more information.
  8. Regardless of how many programs comprise a single GnuCOBOL source file, only a single output executable program will be generated from that source file when the file is compiled.


2.1.18. Comments

The following information describes how comments may be embedded into GnuCOBOL program source to provide documentation.

Comment TypeSource Mode — Description
Blank LinesFIXED — Blank lines may be inserted as desired.

FREE — Blank lines may be inserted as desired.

Full-line commentsFIXED — An entire source line will be treated as a comment (and will be ignored by the compiler) by coding an asterisk (‘*’) in column seven (7).

FREE — An entire source line will be treated as a comment (and will be ignored by the compiler) by coding the sequence ‘*>’, starting in any column, as the first non-blank characters on the line.

Full-line comments with form-feedFIXED — An entire source line will be treated as a comment by coding a slash (‘/’) in column seven (7). Many COBOL compilers will also issue a form-feed in the program listing so that the ‘/’ line is at the top of a new page. The GnuCOBOL compiler does not support this form-feed behaviour.

The GnuCOBOL Interactive Compiler, or GCic, does support this form-feed behaviour when it generates program source listings! See GCic in GnuCOBOL Sample Programs, for the source and cross-reference listing (produced by GCic) of this program — you can see the effect of ‘/’ there.

FREE — There is no Free Source Mode equivalent to ‘/’.

Partial-line commentsFIXED — Any text following the character sequence ‘*>’ on a source line will be treated as a comment. The ‘*’ must appear in column seven (7) or beyond.

FREE — Any text following the character sequence ‘*>’ on a source line will be treated as a comment. The ‘*’ may appear in any column.

Comments that may be treated as code, typically for debugging purposesFIXED — By coding a ‘D’ in column 7 (upper- or lower-case), an otherwise valid GnuCOBOL source line will be treated as a comment by the compiler.

FREE — By specifying the character sequence ‘>>D (upper- or lower-case) as the first non-blank characters on a source line, an otherwise valid GnuCOBOL source line will be treated as a comment by the compiler.

Debugging statements may be compiled either by specifying the -fdebugging-line switch on the GnuCOBOL compiler or by adding the WITH DEBUGGING MODE clause to the SOURCE-COMPUTER paragraph.



2.1.19. Literals

Literals are constant values that will not change during the execution of a program. There are two fundamental types of literals — numeric and alphanumeric.



2.1.19.1. Numeric LiteralsA numeric literal



2.1.19.2. Alphanumeric Literals

An alphanumeric literal

An alphanumeric literal is not valid for use in arithmetic expressions unless it is first converted to its numeric computational equivalent; there are three numeric conversion intrinsic functions built into GnuCOBOL that can perform this conversion — NUMVAL (see NUMVAL), NUMVAL-C (see NUMVAL-C) and NUMVAL-F (see NUMVAL-F).

Alphanumeric literals may take any of the following forms:

Alphanumeric literals too long to fit on a single line may be continued to the next line in one of two ways:

  1. If you are using Fixed Format Mode, the alphanumeric literal can be run right up to and including column 72. The literal may then be continued on the next line anywhere after column 11 by coding another quote or apostrophe (whichever was used to begin the literal originally). The continuation line must also have a hyphen (-)
         1         2         3         4         5         6         7   
1234567890123456789012345678901234567890123456789012345678901234567890123
 
       01  LONG-LITERAL-VALUE-DEMO     PIC X(60) VALUE "This is a long l
      -                                                "ong literal that
      -                                                " must be continu
      -                                                "ed.".
  1. Regardless of whether the compiler is operating in Fixed or Free Format Mode, GnuCOBOL allows alphanumeric literals to be broken up into separate fragments. These fragments have their own beginning and ending quote/apostrophe characters and are “glued together” at compilation time using ‘&
         1         2         3         4         5         6         7   
1234567890123456789012345678901234567890123456789012345678901234567890123
 
      01  LONG-LITERAL-VALUE-DEMO      PIC X(60) VALUE "This is a" &
                                        " long literal that must " &
                                                    "be continued.".

If your program is using Free Format Mode, there’s less need to continue long alphanumeric literals because statements may be as long as 255 characters.

Numeric literals may be split across lines just as alphanumeric literals are, using either of the above techniques and both reserved and user-defined words can be split across lines too (using the first technique). The continuation of numeric literals and user-defined/reserved words is provided merely to provide compatibility with older COBOL versions and programs, but should not be used with new programs — it just makes for ugly-looking programs.



2.1.19.3. Figurative Constants

Figurative constants are reserved words that may be used as literals anywhere the figurative constants value could be interpreted as an arbitrarily long sequence of the characters in question. When a specific length is required, such as would be the case with an argument to a subprogram, a figurative constant may not be used. Thus, the following are valid uses of figurative constants:


05 FILLER                PIC 9(10) VALUE ZEROS.
   ...
MOVE SPACES TO Employee-Name

But this is not:


CALL "SUBPGM" USING SPACES

The following are the GnuCOBOL figurative constants and their respective equivalent values.

ZERO

This figurative constant has a value of numeric 0 (zero). ZEROS and ZEROES are both synonyms of ZERO.

SPACE

This figurative constant has a value of one or more space characters. SPACES is a synonym of SPACE.

QUOTE

This figurative constant has a value of one or more double-quote characters ("). QUOTES is a synonym of QUOTE.

LOW-VALUE

This figurative constant has a value of one or more of whatever character occupies the lowest position in the program’s collating sequence as defined in the OBJECT-COMPUTER (see OBJECT-COMPUTER) paragraph or — if no such specification was made — in whatever default character set the program is using (typically, this is the ASCII character set). LOW-VALUES is a synonym of LOW-VALUE.

When the character set in use is ASCII with no collating sequence modifications, the LOW-VALUES figurative constant value is the ASCII NUL character. Because character sets can be redefined, however, you should not rely on this fact. Use the NULL figurative constant instead.

HIGH-VALUE

This figurative constant has a value of one or more of whatever character occupies the highest position in the program’s collating sequence as defined in the OBJECT-COMPUTER paragraph or — if no such specification was made — in whatever default character set the program is using (typically, this is the ASCII character set). HIGH-VALUES is a synonym of HIGH-VALUE.

NULL

A character comprised entirely of zero-bits (regardless of the programs collating sequence).

Programmers may create their own figurative constants via the SYMBOLIC CHARACTERS (see Symbolic-Characters-Clause) clause of the SPECIAL-NAMES (see SPECIAL-NAMES) paragraph.



2.1.20. Punctuation

A comma (‘,’)

The use of comma characters can cause confusion to a COBOL compiler if the DECIMAL POINT IS COMMA clause is used in the SPECIAL-NAMES (see SPECIAL-NAMES) paragraph, as might be the case in Europe. The following statement, which calls a subroutine passing it two arguments (the numeric constants 1 and 2):

CALL "SUBROUTINE" USING 1,2

Would — with DECIMAL POINT IS COMMA in effect — actually be interpreted as a subroutine call with 1 argument (the non-integer numeric literal whose value is 1 and 2 tenths). For this reason, it is best to always follow a comma with a space.

The period character (‘.’)

The rules for where and when periods are needed in the procedure division are somewhat complicated. See Use of Periods, for the details.



2.1.21. Interfacing to Other Environments

Through the CALL statement, COBOL programs may invoke other COBOL programs serving as subprograms. This is quite similar to cross-program linkage capabilities provided by other languages. In GnuCOBOL’s case, the CALL facility is powerful enough to be tailored to the point where a GnuCOBOL program can communicate with operating system, database management and run-time library APIs, even if they weren’t written in COBOL themselves. See GnuCOBOL Main Programs CALLing C Subprograms, for an example of how a GnuCOBOL program could invoke a C-language subprogram, passing information back and forth between the two.

The fact that GnuCOBOL supports a full-featured two-way interface with C-language programs means that — even if you cannot access a library API directly — you could always do so via a small C “wrapper” program that is CALLed by a GnuCOBOL program.



2.2. The COBOL Language - Advanced Techniques



2.2.1. Table References

COBOL uses parenthesis to specify the subscripts used to reference table entries (tables in COBOL are what other programming languages refer to as arrays).

For example, observe the following data structure which defines a 4 column by 3 row grid of characters:

01  GRID.
     05 GRID-ROW OCCURS 3 TIMES.
        10 GRID-COLUMN OCCURS 4 TIMES.
            15 GRID-CHARACTER       PIC X(1).

If the structure contains the following grid of characters:

A B C D
E F G H
I J K L

Then GRID-CHARACTER (2, 3) references the ‘G’ and GRID-CHARACTER (3, 2) references the ‘J’.

Subscripts may be specified as numeric (integer) literals, numeric (integer) data items, data items created with any of the picture-less integer USAGE (see USAGE) specifications, USAGE INDEX data items or arithmetic expressions resulting in a non-zero integer value.

In the above examples, a comma is used as a separator character between the two subscript values; semicolons (;) are also valid subscript separator characters, as are spaces! The use of a comma or semicolon separator in such a situation is technically optional, but by convention most COBOL programmers use one or the other. The use of no separator character (other than a space) is not recommended, even though it is syntactically correct, as this practice can lead to programmer-unfriendly code. It isn’t too difficult to read and understand GRID-CHARACTER(2 3), but it’s another story entirely when trying to comprehend GRID-CHARACTER(I + 1 J / 3) (instead of GRID-CHARACTER(I + 1, J / 3)). The compiler accepts it, but too much of this would make my head hurt.



2.2.2. Qualification of Data Names

COBOL allows data names to be duplicated within a program, provided references to those data names may be made in such a manner as to make those references unique through a process known as qualification.

To see qualification at work, observe the following segments of two data records defined in a COBOL program:

01  EMPLOYEE.                     01  CUSTOMER.
    05 MAILING-ADDRESS.               05 MAILING-ADDRESS.
       10 STREET        PIC X(35).       10 STREET        PIC X(35).
       10 CITY          PIC X(15).       10 CITY          PIC X(15).
       10 STATE         PIC X(2).        10 STATE         PIC X(2).
       10 ZIP-CODE.                      10 ZIP-CODE.
          15 ZIP-CODE-5 PIC 9(5).           15 ZIP-CODE-5 PIC 9(5).
          15 FILLER     PIC X(4).           15 FILLER     PIC X(4).

Now, let’s deal with the problem of setting the CITY portion of an EMPLOYEEs MAILING-ADDRESS to ‘Philadelphia’. Clearly, MOVE 'Philadelphia' TO CITY cannot work because the compiler will be unable to determine which of the two CITY fields you are referring to.

In an attempt to correct the problem, we could qualify the reference to CITY as MOVE 'Philadelphia' TO CITY OF MAILING-ADDRESS.

Unfortunately that too is insufficient because it still insufficiently specifies which CITY is being referenced. To truly identify which specific CITY you want, you’d have to code MOVE 'Philadelphia' TO CITY OF MAILING-ADDRESS OF EMPLOYEE.

Now there can be no confusion as to which CITY is being changed. Fortunately, you don’t need to be quite so specific; COBOL allows intermediate and unnecessary qualification levels to be omitted. This allows MOVE 'Philadelphia' TO CITY OF EMPLOYEE to do the job nicely.

If you need to qualify a reference to a table, do so by coding something like identifier-1 OF identifier-2 ( subscript(s) ).

The reserved word IN may be used in lieu of OF.



2.2.3. Reference Modifiers

Reference Modifier (Format 1) Syntax
=======================================================================

 identifier-1 [ OF|IN identifier-2 ] [ (subscript...) ] (start:[ length ])
                ~~ ~~

=======================================================================
Reference Modifier (Format 2) Syntax
=======================================================================

 intrinsic-function-reference (start:[ length ])

=======================================================================

The COBOL 1985 standard introduced the concept of a reference modifier to facilitate references to only a portion of a data item; GnuCOBOL fully supports reference modification.

The start value indicates the starting character position being referenced (character position values start with 1, not 0 as is the case in some programming languages) and length specifies how many characters are wanted.

If no length is specified, a value equivalent to the remaining character positions from start to the end of identifier-1 or to the end of the value returned by the function will be assumed.

Both start and length may be specified as integer numeric literals, integer numeric data items or arithmetic expressions with an integer value.

Here are a few examples:

CUSTOMER-LAST-NAME (1:3)

References the first three characters of CUSTOMER-LAST-NAME.

CUSTOMER-LAST-NAME (4:)

References all character positions of CUSTOMER-LAST-NAME from the fourth onward.

FUNCTION CURRENT-DATE (5:2)

References the current month as a 2-digit number in character form. See CURRENT-DATE, for more information.

Hex-Digits (Nibble + 1:1)

Assuming that Nibble is a numeric data item with a value in the range 0-15, and Hex-Digits is a PIC X(16) item with a value of 0123456789ABCDEF, this converts that numeric value to a hexadecimal digit.

Table-Entry (6) (7:5)

References characters 7 through 11 (5 characters in total) in the 6th occurrence of Table-Entry.

Reference modification may be used anywhere an identifier is legal, including serving as the receiving field of statements like MOVE (see MOVE), STRING (see STRING) and ACCEPT (see ACCEPT), to name a few.



2.2.4. Arithmetic Expressions

Arithmetic-Expression Syntax
=======================================================================

 Unary-Expression-1 { **|^ } Unary-Expression-2
                    {  *|/ }
                    {  +|- }

=======================================================================
Unary-Expression Syntax
=======================================================================

 { [ +|- ] { ( Arithmetic-Expression-1 )          } }
 {         { [ LENGTH OF ] { identifier-1       } } }
 {         {   ~~~~~~ ~~   { literal-1          } } }
 {         {               { Function-Reference } } }
 { Arithmetic-Expression-2                          }

=======================================================================

Arithmetic expressions are formed using four categories of operations — exponentiation, multiplication & division, addition & subtraction, and sign specification.

In complex expressions composed of multiple operators and operands, a precedence of operation applies whereby those operations having a higher precedence are computed first before operations with a lower precedence.

As is the case in almost any other programming language, the programmer is always free to use pairs of parenthesis to enclose sub-expressions of complex expressions that are to be evaluated before other sub-expressions rather than let operator precedence dictate the sequence of evaluation.

In highest to lowest order of precedence, here is a discussion of each category of operation:

Level 1 (Highest) — Unary Sign Specification (+ and - with a single argument)

The unary “minus” (-) operator returns the arithmetic negation of its single argument, effectively returning as its value the product of its argument and -1.

The unary “plus” (+) operator returns the value of its single argument, effectively returning as its value the product of its argument and +1.

Level 2 — Exponentiation (** or ^)

The value of the left argument is raised to the power indicated by the right argument. Non-integer powers are allowed. The ^ and ** operators are both supported to provide compatibility with programs written for other COBOL implementations.

Level 3 — Multiplication (*) and division (/)

The * operator computes the product of the left and right arguments while the / operator computes the value of the left argument divided by the value of the right argument. If the right argument has a value of zero, expression evaluation will be prematurely terminated before a value is generated. This may cause program failure at run-time.

A sequence of multiple 3rd-level operations (A * B / C, for example) will evaluate in strict left-to-right sequence if no parenthesis are used to control the order of evaluation.

Level 4 — Addition (+) or subtraction (+)

The + operator calculates the sum of the left and right arguments while the - operator computes the value of the right argument subtracted from that of the left argument.

A sequence of multiple 4th-level operations (A - B + C, for example) will evaluate in strict left-to-right sequence if no parenthesis are used to control the order of evaluation.

The syntactical rules of COBOL, allowing a dash (-) character in data item names, can lead to some ambiguity.

01  C        PIC 9 VALUE 5.
01  D        PIC 9 VALUE 2.
01  C-D      PIC 9 VALUE 7.
01  I        PIC 9 VALUE 0.
…
COMPUTE I=C-D+1

The COMPUTE (see COMPUTE) statement will evaluate the arithmetic expression C-D+1 and then save that result in I.

What value will be stored in I? The number 4, which is the result of subtracting the value of D (2) from the value of C (5) and then adding 1? Or, will it be the number 8, which is the value of adding 1 to the value of data item C-D (7)?

The right answer is 8 — the value of data item C-D plus 1! Hopefully, that was the intended result.

The GnuCOBOL compiler actually went through the following decision-making logic when generating code for the COMPUTE Statement:

  1. Is there a data item named C-D defined? If so, use its value for the character sequence C-D.
  2. If there is no C-D data item, then are there C and D data items? If not, the COMPUTE statement is in error. If there are, however, then code will be generated to subtract the value of D from C and add 1 to the result.

Had there been at least one space to the left and/or the right of the -, there would have been no ambiguity — the compiler would have been forced to use the individual C and D data items.

To avoid any possible ambiguity, as well as to improve program readability, it’s considered good COBOL programming practice to always code at least one space to both the left and right of every operator in arithmetic expressions as well as the = sign on a COMPUTE.

Here are some examples of how the precedence of operations affects the results of arithmetic expressions (all examples use numeric literals, to simplify the discussion).

ExpressionResultNotes
3 * 4 + 113* has precedence over +
4 * 2 ^ 3 - 10222^3 is 8 (^ has precedence over *), times 4 is 32, minus 10 is 22.
(4 * 2) ^ 3 - 10502Parenthesis provide for a recursive application of the arithmetic expression rules, effectively allowing you to alter the precedence of operations. 4 times 2 is 8 (the use of parenthesis “trumps” the exponentiation operator, so the multiplication happens first); 8 ^ 3 is 512, minus 10 is 502.
5 / 2.5 + 7 * 2 - 1.1515.35Integer and non-integer operands may be freely intermixed

Of course, arithmetic expression operands may be numeric data items (any USAGE except POINTER or PROGRAM POINTER) as well as numeric literals.



2.2.5. Conditional Expressions

Conditional expressions are expressions which identify the circumstances under which a program may take an action or cease taking an action. As such, conditional expressions produce a value of TRUE or FALSE.

There are seven types of conditional expressions, as discussed in the following sections.



2.2.5.1. Condition Names

These are the simplest of all conditions. Observe the following code:

05  SHIRT-SIZE               PIC 99V9.
    88 TINY                  VALUE 0 THRU 12.5
    88 XS                    VALUE 13 THRU 13.5.
    88 S                     VALUE 14, 14.5.
    88 M                     VALUE 15, 15.5.
    88 L                     VALUE 16, 16.5.
    88 XL                    VALUE 17, 17.5.
    88 XXL                   VALUE 18, 18.5.
    88 XXXL                  VALUE 19, 19.5.
    88 VERY-LARGE            VALUE 20 THRU 99.9.

The condition names TINY, XS, S, M, L, XL, XXL, XXXL and VERY-LARGE will have TRUE or FALSE values based upon the values within their parent data item (SHIRT-SIZE).

A program wanting to test whether or not the current SHIRT-SIZE value can be classified as XL could have that decision coded as a combined condition (the most complex type of conditional expression), as either:

IF SHIRT-SIZE = 17 OR SHIRT-SIZE = 17.5

- or -

IF SHIRT-SIZE = 17 OR 17.5

Or it could simply utilize the condition name XL as follows:

IF XL


2.2.5.2. Class Conditions

Class-Condition Syntax
=======================================================================

 identifier-1 IS [ NOT ] { NUMERIC          }
                   ~~~   { ~~~~~~~          }
                         { ALPHABETIC       }
                         { ~~~~~~~~~~       }
                         { ALPHABETIC-LOWER }
                         { ~~~~~~~~~~~~~~~~ }
                         { ALPHABETIC-UPPER }
                         { ~~~~~~~~~~~~~~~~ }
                         { OMITTED          }
                         { ~~~~~~~          }
                         { class-name-1     }

=======================================================================

Class conditions evaluate the type of data that is currently stored in a data item.

  1. The NUMERIC class test considers only the characters ‘0’, ‘1’, … , ‘9’ to be numeric; only a data item containing nothing but digits will pass a NUMERIC class test. Spaces, decimal points, commas, currency signs, plus signs, minus signs and any other characters except the digit characters will all fail NUMERIC class tests.
  2. The ALPHABETIC class test considers only upper-case letters, lower-case letters and spaces to be alphabetic in nature.
  3. The ALPHABETIC-LOWER and ALPHABETIC-UPPER class conditions consider only spaces and the respective type of letters to be acceptable in order to pass such a class test.
  4. The NOT option reverses the TRUE/FALSE value of the condition.
  5. Note that what constitutes a “letter” (or upper/lower case too, for that manner) may be influenced through the use of CHARACTER CLASSIFICATION specifications in the OBJECT-COMPUTER (see OBJECT-COMPUTER) paragraph.
  6. Only data items whose USAGE (see USAGE) is either explicitly or implicitly defined as DISPLAY may be used in NUMERIC or any of the ALPHABETIC class conditions.
  7. Some COBOL implementations disallow the use of group items or PIC A items with NUMERIC class conditions and the use of PIC 9 items with ALPHABETIC class conditions. GnuCOBOL has no such restrictions.
  8. The OMITTED class condition is used when it is necessary for a subprogram to determine whether or not a particular argument was passed to it. In such class conditions, identifier-1 must be a linkage section item defined on the USING clause of the subprograms PROCEDURE DIVISION header. See PROCEDURE DIVISION USING, for additional information.

The class-name-1 option allows you to test for a user-defined class. Here’s an example. First, assume the following SPECIAL-NAMES (see SPECIAL-NAMES) definition of the user-defined class ‘Hexadecimal’:

SPECIAL-NAMES.
    CLASS Hexadecimal IS '0' THRU '9', 'A' THRU 'F', 'a' THRU 'f'.

Now observe the following code, which will execute the 150-Process-Hex-Value procedure if Entered-Value contains nothing but valid hexadecimal digits:

    IF Entered-Value IS Hexadecimal
        PERFORM 150-Process-Hex-Value
    END-IF


2.2.5.3. Sign Conditions

Sign-Condition Syntax
=======================================================================

 identifier-1 IS [ NOT ] { POSITIVE }
                   ~~~   { ~~~~~~~~ }
                         { NEGATIVE }
                         { ~~~~~~~~ }
                         { ZERO     }
                           ~~~~

=======================================================================

Sign conditions evaluate the numeric state of a data item defined with a PICTURE (see PICTURE) and/or USAGE (see USAGE) that supports numeric values.

  1. A POSITIVE or NEGATIVE class condition will be TRUE only if the value of identifier-1 is strictly greater than or less than zero, respectively.
  2. A ZERO class condition can be passed only if the value of identifier-1 is exactly zero.
  3. The NOT option reverses the TRUE/FALSE value of the condition.


2.2.5.4. Switch-Status Conditions

In the SPECIAL-NAMES paragraph, an external switch name can be associated with one or more condition names. These condition names may then be used to test the ON/OFF status of the external switch.

Here are the relevant sections of code in a program named testprog, which is designed to simply announce if SWITCH-1 is on:

…
ENVIRONMENT DIVISION.
SPECIAL-NAMES.
    SWITCH-1 ON STATUS IS Switch-1-Is-ON.
…
PROCEDURE DIVISION.
…
    IF Switch-1-Is-ON
        DISPLAY "Switch 1 Is On"
    END-IF
…

The following are two different command window sessions — the left on a Unix/Cygwin/OSX system and the right on a windows system — that will set the switch on and then execute the testprog program. Notice how the message indicating that the program detected the switch was set is displayed in both examples:

$ COB_SWITCH_1=ON           C:>SET COB_SWITCH_1=ON
$ export COB_SWITCH_1       C:>testprog
$ ./testprog                Switch 1 Is On
Switch 1 Is On              C:>
$


2.2.5.5. Relation Conditions

Relation-Condition Syntax
=======================================================================

 { identifier-1            } IS [ NOT ] RelOp { identifier-2            }
 { literal-1               }      ~~~         { literal-2               }
 { arithmetic-expression-1 }                  { arithmetic-expression-2 }
 { index-name-1            }                  { index-name-2            }

=======================================================================
RelOp Syntax
=======================================================================

 { EQUAL TO                 }
 { ~~~~~                    }
 { EQUALS                   }
 { ~~~~~~                   }
 { GREATER THAN             }
 { ~~~~~~~                  }
 { GREATER THAN OR EQUAL TO }
 { ~~~~~~~      ~~ ~~~~~    }
 { LESS THAN                }
 { ~~~~                     }
 { LESS THAN OR EQUAL TO    }
 { ~~~~      ~~ ~~~~~       }
 { =                        }
 { >                        }
 { >=                       }
 { <                        }
 { <=                       }

=======================================================================

These conditions evaluate how two different values "relate" to each other.

  1. When comparing one numeric value to another, the USAGE (see USAGE) and number of significant digits in either value are irrelevant as the comparison is performed using the actual algebraic values.
  2. When comparing strings, the comparison is made based upon the program’s collating sequence. When the two string arguments are of unequal length, the shorter is assumed to be padded (on the right) with a sufficient number of spaces as to make the two strings of equal length. String comparisons take place on a corresponding character-by-character basis, left to right, until the TRUE/FALSE value for the relation test can be established. Characters are compared according to their relative position in the program’s COLLATING SEQUENCE (as defined in SPECIAL-NAMES (see SPECIAL-NAMES)), not according to the bit-pattern values the characters have in storage.
  3. By default, the program’s COLLATING SEQUENCE will, however, be based entirely on the bit-pattern values of the various characters.
  4. There is no functional difference between using the wordy version (IS EQUAL TO, IS LESS THAN, …) versus the symbolic version (=, <, …) of the actual relation operators.


2.2.5.6. Combined Conditions

Combined Condition Syntax
=======================================================================

 [ ( ] Condition-1 [ ) ] { AND } [ ( ] Condition-2 [ ) ]
                         { ~~~ }
                         { OR  }
                         { ~~  }

=======================================================================

A combined condition is one that computes a TRUE/FALSE value from the TRUE/FALSE values of two other conditions (which could themselves be combined conditions).

  1. If either condition has a value of TRUE, the result of ORing the two together will result in a value of TRUE. ORing two FALSE conditions will result in a value of FALSE.
  2. In order for AND to yield a value of TRUE, both conditions must have a value of TRUE. In all other circumstances, AND produces a FALSE value.
  3. When chaining multiple, similar conditions together with the same operator (OR/AND), and left or right arguments have common subjects, it is possible to abbreviate the program code. For example:
    IF ACCOUNT-STATUS = 1 OR ACCOUNT-STATUS = 2 OR ACCOUNT-STATUS = 7
    

    Could be abbreviated as:

    IF ACCOUNT-STATUS = 1 OR 2 OR 7
    
  4. Just as multiplication takes precedence over addition in arithmetic expressions, so does AND take precedence over OR in combined conditions. Use parenthesis to change this precedence, if necessary. For example:
    FALSE AND FALSE OR TRUE AND TRUE

    Evaluates to TRUE

    (FALSE AND FALSE) OR (TRUE AND TRUE)

    Evaluates to TRUE (since AND has precedence over OR) - this is identical to the previous example

    (FALSE AND (FALSE OR TRUE)) AND TRUE

    Evaluates to FALSE



2.2.5.7. Negated Conditions

Negated Condition Syntax
=======================================================================

 NOT Condition-1
 ~~~

=======================================================================

A condition may be negated by prefixing it with the NOT operator.

  1. The NOT operator has the highest precedence of all logical operators, just as a unary minus sign (which “negates” a numeric value) is the highest precedence arithmetic operator.
  2. Parenthesis must be used to explicitly signify the sequence in which conditions are evaluated and processed if the default precedence isn’t desired. For example:
    NOT TRUE AND FALSE AND NOT FALSE

    Evaluates to FALSE AND FALSE AND TRUE which evaluates to FALSE

    NOT (TRUE AND FALSE AND NOT FALSE)

    Evaluates to NOT (FALSE) which evaluates to TRUE

    NOT TRUE AND (FALSE AND NOT FALSE)

    Evaluates to FALSE AND (FALSE AND TRUE) which evaluates to FALSE



2.2.6. Use of Periods

All COBOL implementations distinguish between sentences and statements in the procedure division. A Statement is a single executable COBOL instruction. For example, these are all statements:

MOVE SPACES TO Employee-Address
ADD 1 TO Record-Counter
DISPLAY "Record-Counter=" Record-Counter

Some COBOL statements have a scope of applicability associated with them where one or more other statements can be considered to be part of or related to the statement in question. An example of such a situation might be the following, where the interest on a loan is being calculated and displayed at 4% interest if the loan balance is under $10,000, and 4.5% otherwise. (WARNING: the following code has an error!):

IF Loan-Balance < 10000
    MULTIPLY Loan-Balance BY 0.04 GIVING Interest
ELSE
    MULTIPLY Loan-Balance BY 0.045 GIVING Interest
DISPLAY "Interest Amount = " Interest

In this example, the IF statement actually has a scope that can include two sets of associated statements: one set to be executed when the IF (see IF) condition is TRUE, and another if it is FALSE.

Unfortunately, there’s a problem with the above. A human being looking at that code would probably infer that the DISPLAY (see DISPLAY) statement, because of its lack of indentation, is to be executed regardless of the TRUE/FALSE value of the IF condition. Unfortunately, the compiler (any COBOL compiler) won’t see it that way because it really couldn’t care less what sort of indentation, if any, is used. In fact, any COBOL compiler would be just as happy to see the code written like this:

IF Loan-Balance < 10000 MULTIPLY Loan-balance
BY 0.04 GIVING Interest ELSE MULTIPLY
Loan-Balance BY 0.045 GIVING Interest DISPLAY
"Interest Amount = " Interest

How then do we inform the compiler that the DISPLAY statement is outside the scope of the IF?

That’s where sentences come in.

A COBOL Sentence is defined as any arbitrarily long sequence of statements, followed by a period (.) character. The period character is what terminates the scope of a set of statements. Therefore, our example should have been coded like this:

IF Loan-Balance < 10000
    MULTIPLY Loan-Balance BY 0.04 GIVING Interest
ELSE
    MULTIPLY Loan-Balance BY 0.045 GIVING Interest.
DISPLAY "Interest Amount = " Interest

See the period at the end of the second MULTIPLY (see MULTIPLY)? That is what terminates the scope of the IF, thus making the DISPLAY statement’s execution completely independent of the TRUE/FALSE status of the IF.



2.2.7. Use of VERB/END-VERB Constructs

Prior to the 1985 COBOL standard, using a period character was the only way to signal the end of a statement’s scope.

Unfortunately, this caused some problems. Take a look at this code:

IF A = 1
    IF B = 1
        DISPLAY "A & B = 1"
ELSE *> This ELSE has a problem!
    IF B = 1
        DISPLAY "A NOT = 1 BUT B = 1"
    ELSE
        DISPLAY "NEITHER A NOR B = 1".

The problem with this code is that indentation — so critical to improving the human-readability of a program — can provide an erroneous view of the logical flow. An ELSE is always associated with the most-recently encountered IF; this means the emphasized ELSE will be associated with the IF B = 1 statement, not the IF A = 1 statement as the indentation would appear to imply.

This sort of problem led to a band-aid solution being added to the COBOL language: the NEXT SENTENCE clause:

IF A = 1
    IF B = 1
        DISPLAY "A & B = 1"
    ELSE
        NEXT SENTENCE
ELSE
    IF B = 1
        DISPLAY "A NOT = 1 BUT B = 1"
    ELSE
        DISPLAY "NEITHER A NOR B = 1".

NEXT SENTENCE informs the compiler that if the B = 1 condition is false, control should fall into the first statement that follows the next period.

With the 1985 standard for COBOL, a much more elegant solution was introduced. Any COBOL Verb (the first reserved word of a statement) that needed such a thing was allowed to use an END-verb construct to end its scope without disrupting the scope of any other statement it might have been in. Any COBOL 85 compiler would have allowed the following solution to our problem:

IF A = 1
    IF B = 1
        DISPLAY "A & B = 1"
    END-IF
ELSE
    IF B = 1
        DISPLAY "A NOT = 1 BUT B = 1"
    ELSE
        DISPLAY "NEITHER A NOR B = 1".

This new facility made the period almost obsolete, as our program segment would probably be coded like this today:

IF A = 1
    IF B = 1
        DISPLAY "A & B = 1"
    END-IF
ELSE
    IF B = 1
        DISPLAY "A NOT = 1 BUT B = 1"
    ELSE
        DISPLAY "NEITHER A NOR B = 1"
    END-IF
END-IF

COBOL (GnuCOBOL included) still requires that each procedure division paragraph contain at least one sentence if there is any executable code in that paragraph, but a popular coding style is now to simply code a single period right before the end of each paragraph.

The standard for the COBOL language shows the various END-verb clauses are optional because using a period as a scope-terminator remains legal.

If you will be porting existing code over to GnuCOBOL, you’ll find it an accommodating facility capable of conforming to whatever language and coding standards that code is likely to use. If you are creating new GnuCOBOL programs, however, I would strongly counsel you to use the END-verb structures in those programs.



2.2.8. Concurrent Access to Files

The manipulation of data files is one of the COBOL language’s great strengths. There are features built into COBOL to deal with the possibility that multiple programs may be attempting to access the same file concurrently. Multiple program concurrent access is dealt with in two ways — file sharing and record locking.

Not all GnuCOBOL implementations support file sharing and record-locking options. Whether they do or not depends upon the operating system they were built for and the build options that were used when the specific GnuCOBOL implementation was generated.



2.2.8.1. File Sharing

GnuCOBOL controls concurrent-file access at the highest level through the concept of file sharing, enforced when a program attempts to open a file. This is accomplished via a UNIX operating-system routine called fcntl. That module is not currently supported by Windows and is not present in the MinGW Unix-emulation package. GnuCOBOL builds created using a MinGW environment will be incapable of supporting file-sharing controls — files will always be shared in such environments. A GnuCOBOL build created using the Cygwin environment on Windows would have access to fcntl and therefore will support file sharing. Of course, actual Unix builds of GnuCOBOL, as well as OSX builds, should have no issues because fcntl should be available.

Any limitations imposed on a successful OPEN (see OPEN) will remain in place until your program either issues a CLOSE (see CLOSE) against the file or the program terminates.

File sharing is controlled through the use of a SHARING clause:

    SHARING WITH { ALL OTHER }
    ~~~~~~~      { ~~~       }
                 { NO OTHER  }
                 { ~~        }
                 { READ ONLY }
                   ~~~~ ~~~~

This clause may be used either in the file’s SELECT statement (see SELECT), on the OPEN statement (see OPEN) which initiates your program’s use of the file, or both. If a SHARING option is specified in both places, the specifications made on the OPEN statement will take precedence over those from the SELECT statement.

Here are the meanings of the three options:

ALL OTHER

When your program opens a file with this sharing option in effect, no restrictions will be placed on other programs attempting to OPEN the file after your program did. This is the default sharing mode.

NO OTHER

When your program opens a file with this sharing option in effect, your program announces that it is unwilling to allow any other program to have any access to the file as long as you are using that file; OPEN attempts made in other programs will fail with a file status of 37 (PERMISSION DENIED) until such time as you CLOSE (see CLOSE) the file.

READ ONLY

Opening a file with this sharing option indicates you are willing to allow other programs to OPEN the file for input while you have it open. If they attempt any other OPEN, theirs will fail with a file status of 37. Of course, your program may fail if someone else got to the file first and opened it with a sharing option that imposed file-sharing limitations.

If the SELECT of a file is coded with a FILE STATUS clause, OPEN failures — including those induced by sharing failures — will be detectable by the program and a graceful recovery (or at least a graceful termination) will be possible. If no such clause was coded, however, a runtime message will be issued and the program will be terminated.



2.2.8.2. Record Locking

Record-locking is supported by advanced file-management software built-in to the GnuCOBOL implementation you are using. This software provides a single point-of-control for access to files — usually ORGANIZATION INDEXED files. One such runtime package capable of doing this is the Berkeley Database (BDB) package — a package frequently used in GnuCOBOL builds to support indexed files.

The various I/O statements your program can execute are capable of imposing limitations on access by other concurrently-executing programs to the file record they just accessed. These limitations are syntactically imposed by placing a lock on the record using a LOCK clause. Other records in the file remain available, assuming that file-sharing limitations imposed at the time the file was opened didn’t prevent access to the entire file.

  1. If the GnuCOBOL build you are using was configured to use the Berkeley Database (BDB) package for indexed file I/O, record locking will be available by using the DB_HOME run-time environment variable.
  2. If the SELECT (see SELECT) statement or file OPEN (see OPEN) specifies SHARING WITH NO OTHER, record locking will be disabled.
  3. If the file’s SELECT contains a LOCK MODE IS AUTOMATIC clause, every time a record is read from the file, that record is automatically locked. Other programs may access other records within the file, but not a locked record.
  4. If the file’s SELECT contains a LOCK MODE IS MANUAL clause, locks are placed on records only when a READ statement executed against the file includes a LOCK clause (this clause will be discussed shortly).
  5. If the LOCK ON clause is specified in the file’s SELECT, locks (either automatically or manually acquired) will continue to accumulate as more and more records are read, until they are explicitly released. This is referred to as multiple record locking.

    Locks acquired vie multiple record locking remain in-effect until the program holding the lock…

  6. If the LOCK ON clause is not specified, then the next I/O statement your program executes, except for START (see START), will release the lock. This is referred to as single record locking.
  7. A LOCK clause, which may be coded on a READ (see READ), REWRITE (see REWRITE) or WRITE statement (see WRITE) looks like this:
        { IGNORING LOCK    }
        { ~~~~~~~~ ~~~~    }
        { WITH [ NO ] LOCK }
        {        ~~   ~~~~ }
        { WITH KEPT LOCK   }
        {      ~~~~ ~~~~   }
        { WITH IGNORE LOCK }
        {      ~~~~~~ ~~~~ }
        { WITH WAIT        }
               ~~~~
    

    The WITH [ NO ] LOCK option is the only one available to REWRITE or WRITE statements.

    The meanings of the various record locking options are as follows:

    IGNORING LOCK
    WITH IGNORE LOCK

    These options (which are synonymous) inform GnuCOBOL that any locks held by other programs should be ignored.

    WITH LOCK

    Access to the record by other programs will be denied.

    WITH NO LOCK

    The record will not be locked. This is the default for all statements.

    WITH KEPT LOCK

    When single record locking is in effect, as a new record is accessed, locks held for previous records are released. By using this option, not only is the newly accessed record locked (as WITH LOCK would do), but prior record locks will be retained as well. A subsequent READ without the KEPT LOCK option will release all “kept” locks, as will the UNLOCK statement.

    WITH WAIT

    This option informs GnuCOBOL that the program is willing to wait for a lock held (by another program) on the record being read to be released.

    Without this option, an attempt to read a locked record will be immediately aborted and a file status of 51 will be returned.

    With this option, the program will wait for a preconfigured time for the lock to be released. If the lock is released within the preconfigured wait time, the read will be successful. If the preconfigured wait time expires before the lock is released, the read attempt will be aborted and a 51 file status will be issued.



3. CDF - Compiler Directing Facility

The Compiler Directing Facility, or CDF, is a means of controlling the compilation of GnuCOBOL programs. CDF provides a mechanism for dynamically setting or resetting certain compiler switches, introducing new source code from one or more source code libraries, making dynamic source code modifications and conditionally processing or ignoring source statements altogether. This is accomplished via a series of special CDF statements and directives that will appear in the program source code.

When the compiler is operating in Fixed Format Mode, all CDF statements must begin in column eight (8) or beyond.

There are two types of supported CDF statements in GnuCOBOL — Text Manipulation Statements and Compiler Directives.

The CDF text manipulation statements COPY and REPLACE are used to introduce new code into programs either with or without changes, or may be used to modify existing statements already in the program. Text manipulation statements are always terminated with a period.

CDF directives, denoted by the presence of a >> character sequence as part of the statement name itself, influence the process of program compilation.

Compiler directives are never terminated with a period.

The compiler command-line option -D offers additional control (see cobc - The GnuCOBOL Compiler).



3.1. >>CALL-CONVENTION

CDF >>CALL-CONVENTION Syntax
=======================================================================

 >>CALL-CONVENTION    { COBOL   }
 ~~~~~~~~~~~~~~~~~    { EXTERN  }
                      { STDCALL }
                      { STATIC  } 

=======================================================================

This directive instructs the compiler how to treat references to program names and may be used to determine other details for interacting with a function or program. There are four options with COBOL being the default.

COBOL

The program name is treated as a COBOL word that maps to the externalised name program to be called, cancelled or referenced in the program-address-identifier, applying the same mapping rules as for a program name for which no AS phrase is specified. (The is the default.)

EXTERN

The program name is treated as an external reference.

STDCALL

[more info needed]

STATIC

The program name is called as a included element and not dynamically which is the normal default.



3.2. COPY

CDF COPY Statement Syntax
=======================================================================

 COPY copybook-name
 ~~~~
 [ IN|OF library-name ]
   ~~ ~~
 [ SUPPRESS PRINTING ]
   ~~~~~~~~
 [ REPLACING { Phrase-Clause | String-Clause }... ] .
   ~~~~~~~~~

=======================================================================
CDF COPY Phrase-Clause Syntax
=======================================================================

 { ==pseudo-text-1== } BY { ==pseudo-text-2== }
 { identifier-1      } ~~ { identifier-2      }
 { literal-1         }    { literal-2         }
 { word-1            }    { word-2            }

=======================================================================
CDF COPY String-Clause Syntax
=======================================================================

 [ LEADING|TRAILING ] ==partial-word-1== BY ==partial-word-2==
   ~~~~~~~ ~~~~~~~~                      ~~

=======================================================================
  1. COPY statements are used to import copybooks (see Copybooks) into a program.
  2. COPY statements may be used anywhere within a COBOL program where the code contained within the copybook would be syntactically valid.
  3. The optional SUPPRESS clause (with or without the optional PRINTING reserved word) is valid syntactically but is non-functional. It is supported to facilitate compatibility with source code written for other versions of COBOL.
  4. There is no difference between the use of the word IN and the word OF — use the one you prefer.
  5. A period is absolutely mandatory at the end of every COPY statement, even if the statement occurs within the scope of another one where a period might appear disruptive, such as within the scope of an IF (see IF) statement. This mandatory period at the end of the statement does not, however, affect the statement scope in which the COPY occurs.
  6. Both pseudo-text-2 and partial-word-2 may be null.
  7. All COPY statements are located and the contents of the corresponding copybooks inserted into the program source code before the actual compilation process begins. If a copybook contains a COPY statement, the copybook insertion process will be repeated to resolve the embedded COPY. This will continue until no unresolved COPY statements remain. At that point, actual program compilation will begin.
  8. See Locating Copybooks, for the specific rules on how copybooks are located by the compiler.
  9. The optional REPLACING clause allows for one or more of either of the following kinds of text replacements to be made:
    Phrase-Clause

    Replacement of one or more complete reserved words, user-defined identifiers or literals; the following points apply to this option:

    • This option cannot be used to replace part of a word, identifier or literal.
    • Whatever precedes the BY will be referred to here as the search string.
    • Single-item search strings can be specified by coding the identifier-1, literal-1 or word-1 being replaced.
    • Multiple-item search strings can be specified using the ==pseudo-text-1== option. For example, to replace all occurrences of UPON PRINTER, you would specify ==UPON PRINTER==.
    • The replacement string, which follows the BY, may be specified using any of the four options.
    • If the replacement string is a multiple-item phrase or is to be deleted altogether, you must use the ==pseudo-text-2== option. If pseudo-text-2 is null (in other words, the replacement text is specified as ====), all encountered occurrences of the search string will be deleted.
    String-Clause

    Using this, you may replace character sequences that occur at the beginning (see LEADING) or end (see TRAILING) of reserved or user-defined words. For example, to change all words of the form "0100-xxxxxx" to "020-xxxxxx", code LEADING ==0100-== BY ==020-==. To simply remove all "0100-" prefixes from words, code LEADING ==0100-== BY ====.



3.3. REPLACE

CDF REPLACE Statement (Format 1) Syntax
=======================================================================

 REPLACE [ ALSO ] { Phrase-Clause | String-Clause }... .
 ~~~~~~~   ~~~~

=======================================================================
CDF REPLACE Statement (Format 2) Syntax
=======================================================================

 REPLACE [ LAST ] OFF .
 ~~~~~~~   ~~~~   ~~~

=======================================================================
CDF REPLACE Phrase-Clause Syntax
=======================================================================

 { ==pseudo-text-1== } BY { ==pseudo-text-2== }
                       ~~

=======================================================================
CDF REPLACE String-Clause Syntax
=======================================================================

 [ LEADING|TRAILING ] ==partial-word-1== BY ==partial-word-2==
   ~~~~~~~ ~~~~~~~~                      ~~

=======================================================================
  1. The REPLACE statement provides a mechanism for changing all or part of one or more GnuCOBOL statements.
  2. A period is absolutely mandatory at the end of every REPLACE statement (either format), even if the statement occurs within the scope of another one where a period might appear disruptive (such as within the scope of an IF (see IF) statement; the period will not, however, affect the statement scope in which the REPLACE occurs.
  3. The following points apply to Format 1 of the REPLACE statement:
    1. Format 1 of the REPLACE statement can be used to make changes to program source code in much the same way as the REPLACING option of the COPY statement can, via these options:
      Phrase-Clause

      Replace one or more complete reserved words, user-defined identifiers or literals; the following points apply to this option:

      • This option cannot be used to replace part of a word, identifier or literal.
      • Whatever precedes the BY will be referred to here as the search string.
      • Search strings on REPLACE are always specified using the ==pseudo-text-1== option. For example, to replace all occurrences of UPON PRINTER, you would specify ==UPON PRINTER==.
      • The replacement string, which follows the BY, is specified using the ==pseudo-text-2== option. If pseudo-text-2 is null (in other words, the replacement text is specified as ====), all encountered occurrences of the search string will be deleted.
      String-Clause

      Using this, you may replace character sequences that occur at the beginning (see LEADING) or end (see TRAILING) of reserved or user-defined words. For example, to change all words of the form "0100-xxxxxx" to "020-xxxxxx", code LEADING ==0100-== BY ==020-==. To simply remove all "0100-" prefixes from words, code LEADING ==0100-== BY ====.

    2. Once a Format 1 REPLACE statement is encountered in the currently-compiling source file, Replace Mode becomes active, and the change(s) specified by that statement will be automatically made on all subsequent source statements the compiler reads from the file.
    3. Replace Mode remains in-effect — continuing to make source code changes — until another Format 1 REPLACE is encountered, the end of currently compiling program source file is reached or a Format 2 REPLACE statement is encountered.
    4. When a Format 1 REPLACE statement with the ALSO keyword is encountered without Replace Mode being currently active, the effect will be as if the ALSO had not been specified. If Replace Mode already was in effect, the effect will be to “push” the current change specification(s) onto the top of a stack and add the specification(s) of the new statement to those that were already in effect.
    5. When a Format 1 REPLACE without the ALSO keyword is encountered, any stacked change specification(s), if any, will be discarded and the currently in-effect change specification(s), if any, will be replaced by those of the new statement.
    6. When the end of the currently-compiling source file is reached, Replace Mode is deactivated and any stacked replace specifications will be discarded — compilation of the next source file (if any) will begin with Replace Mode inactive and no change specification(s) on the stack.
  4. The following points apply to Format 2 of the REPLACE statement:
    1. If Replace Mode is currently inactive, the Format 2 REPLACE statement will be ignored.
    2. If Replace Mode is currently active, a REPLACE OFF. will deactivate Replace Mode and discard any replace specification(s) on the stack. The compiler will henceforth operate as if no REPLACE had ever been encountered, until such time as another Format 1 REPLACE is encountered.
    3. If Replace Mode is currently active, a REPLACE LAST OFF. will replace the current replace specification(s) with those popped off the top of the stack. If there were no replace specification(s) on the stack, the effect will be as if a REPLACE OFF. had been coded.


3.4. >>DEFINE

CDF >>DEFINE Directive Syntax
=======================================================================

 >>DEFINE [ CONSTANT ] cdf-variable-1 AS { OFF                    }
 ~~~~~~~~   ~~~~~~~~                     { ~~~                    }
                                         { literal-1 [ OVERRIDE ] }
                                         {             ~~~~~~~~   }
                                         { PARAMETER [ OVERRIDE ] }
                                           ~~~~~~~~~   ~~~~~~~~

=======================================================================

Use the >>DEFINE CDF directive to create CDF variables and (optionally) assign them either literal or environment variable values.

  1. The reserved word AS is optional and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program.
  2. CDF variables defined in this way become undefined once an END PROGRAM or END FUNCTION directive is encountered in the input source.
  3. The >>DEFINE CDF directive is one way to create CDF variables that may be processed by other CDF statements such as >>IF (see >>IF). The >>SET CDF directive (see >>SET) provides another way to create them.
  4. CDF variable names follow the rules for standard GnuCOBOL user-defined names, and may not duplicate any CDF reserved word. CDF variable names may duplicate COBOL reserved words, provided the CONSTANT option is not specified, but such names are not recommended.
  5. The CONSTANT option is valid only in conjunction with literal-1. When CONSTANT is specified, the CDF variable that is created may be used within your regular COBOL code as if it were a literal value. Without this option, the CDF variable may only be referenced on other CDF statements. The OFF option is used to create a variable without assigning it any value.
  6. The PARAMETER option is used to create a variable whose value is that of the environment variable of the same name. Note that this value assignment occurs at compilation time, not program execution time.
  7. In the absence of the OVERRIDE option, cdf-variable-1 must not yet have been defined. When the OVERRIDE option is specified, cdf-variable-1 will be created with the specified value, if it had not yet been defined. If it had already been defined, it will be redefined with the new value.


3.5. >>IF

CDF >>IF Directive Syntax
=======================================================================

 >>IF CDF-Conditional-Expression-1
 ~~~~     [ Program-Source-Lines-1 ]

 [ >>ELIF CDF-Conditional-Expression-2
   ~~~~~~ [ Program-Source-Lines-2 ] ]...

 [ >>ELSE
   ~~~~~~ [ Program-Source-Lines-3 ] ]

 >>END-IF
 ~~~~~~~~

=======================================================================
CDF-Conditional-Expression Syntax
=======================================================================

 { cdf-variable-1 } IS [ NOT ] { DEFINED                      }
 { literal-1      }      ~~~   { ~~~~~~~                      }
                               { SET                          }
                               { ~~~                          }
                               { CDF-RelOp { cdf-variable-2 } }
                               {           { literal-2      } }

=======================================================================
CDF-RelOp Syntax
=======================================================================

 >=    or    GREATER THAN OR EQUAL TO
             ~~~~~~~      ~~ ~~~~~
 >     or    GREATER THAN
             ~~~~~~~
 <=    or    LESS THAN OR EQUAL TO
             ~~~~      ~~ ~~~~~
 <     or    LESS THAN
             ~~~~
 =     or    EQUAL TO
             ~~~~~
 <>    or    EQUAL TO (with "NOT")
             ~~~~~

=======================================================================

The >>IF CDF directive causes the GnuCOBOL compiler to process or ignore COBOL source statements, CDF text-manipulation statements and/or CDF directives depending upon the value of one or more conditional expressions based upon CDF variables.

  1. The reserved words IS, THAN and TO are optional and may be omitted. The presence or absence of these words has no effect on the program.
  2. Each >>IF directive must be terminated by an >>END-IF directive.
  3. There may be any number of >>ELIF clauses following an >>IF, including zero.
  4. There may no more than one >>ELSE clause following an >>IF. When >>ELSE is used, it must follow the >>IF and all >>ELIF clauses.
  5. Only one of the Program-Source-Lines-n block of statements that lie within the scope of the >>IF>>END-IF may be processed by the compiler. Which one (if any) that gets processed will be decided as follows:
    1. Each CDF-Conditional-Expression-n will be evaluated, in turn, in the sequence in which they are coded in the >>IF statement and any >>ELIF clauses that may be present until one evaluates to TRUE. Once one of them evaluates to TRUE, the Program-Source-Lines-n block of code that corresponds to the TRUE CDF-Conditional-Expression-n will be one that is processed. All others within the >>IF->>END-IF scope will be ignored.
    2. If no CDF-Conditional-Expression evaluates to TRUE, and there is an >>ELSE clause, the Program-Source-Lines-3 block of statements following the >>ELSE clause will be processed by the compiler and all others within the >>IF->>END-IF scope will be ignored.
    3. If no CDF-Conditional-Expression-n evaluates to TRUE and there is no >>ELSE clause, then none of the Program-Source-Lines-n block of statements within the >>IF->>END-IF scope will be processed by the compiler.
    4. If the Program-Source-Lines-n> statement block selected for processing is empty, no error results — there will just be no code generated from the >>IF->>END-IF structure.
  6. A Program-Source-Lines-n block may contain any valid COBOL or CDF code.
  7. The following points pertain to any CDF-Conditional-Expression-n:
    1. The DEFINED option tests for whether cdf-variable-1 has been defined, but not yet assigned a value (>>DEFINE … OFF); use the NOT option to test for the variable not being defined.
    2. The SET option tests for whether cdf-variable-1 has been given a value, either via a >>SET statement or via a >>DEFINE without the OFF option.
    3. Two CDF variables, two literals or a single CDF variable and a single literal may be compared against each other using a relational operator. Unlike the standard GnuCOBOL IF statement (see IF), multiple comparisons cannot be ANDed or ORed together; you may nest a second >>IF inside the first, however, to simulate an AND and an OR may be simulated via the >>ELIF option.
    4. The <> symbol stands for NOT EQUAL TO.


3.6. >>SET

CDF >>SET Directive Syntax
=======================================================================

 >>SET { [ CONSTANT ] cdf-variable-1 literal-1 ] }
 ~~~~~ {   ~~~~~~~~                              }
       { SOURCEFORMAT AS FIXED|FREE              }
       { ~~~~~~~~~~~~    ~~~~~ ~~~~              }
       { NOFOLDCOPYNAME                          }
       { ~~~~~~~~~~~~~~                          }
       { FOLDCOPYNAME AS UPPER|LOWER             }
         ~~~~~~~~~~~~    ~~~~~ ~~~~~

=======================================================================

The >>SET CDF directive provides an alternate means of performing the actions of the >>DEFINE and >>SOURCE directives, as well as a means of controlling the compiler’s -free switch, -fixed switch and -ffold-copy switch from within program source code.

  1. The reserved word AS is optional (only on the SOURCEFORMAT and FOLDCOPYNAME clauses) and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program.
  2. CDF variables defined in this way become undefined once an END PROGRAM or END FUNCTION directive is encountered in the input source.
  3. The FOLDCOPYNAME option provides the equivalent of specifying the compiler -ffold-copy=xxx switch, where xxx is either UPPER or LOWER.
  4. The NOFOLDCOPYNAME option turns off the effect of either the >>SET FOLDCOPYNAME statement or the compiler -ffold-copy=xxx switch.
  5. If the CONSTANT option is used, literal-1 must also be used. This option provides another means of defining constants that may be used anywhere in the program that a literal could be specified.
  6. The remaining options of the >>SET CDF directive provide equivalent functionality to the >>DEFINE and >>SOURCE directives, as follows:
    >>SET cdf-variable-1

    >>DEFINE cdf-variable-1 AS OFF

    >>SET cdf-variable-1 AS literal-1

    >>DEFINE cdf-variable-1 AS literal-1

    >>SET CONSTANT cdf-variable-1 literal-1

    >>DEFINE CONSTANT cdf-variable-1 literal-1

    >>SET SOURCEFORMAT AS FIXED

    >>SOURCE FORMAT IS FIXED

    >>SET SOURCEFORMAT AS FREE

    >>SOURCE FORMAT IS FREE

    >>SET XFD literal-1

    [to do]

    >>SET Micro-Focus-Directive

    [to do]



3.7. >>SOURCE

CDF >>SOURCE Directive Syntax
=======================================================================

 >>SOURCE FORMAT IS FIXED|FREE|VARIABLE
 ~~~~~~~~           ~~~~~ ~~~~ ~~~~~~~~

=======================================================================

The >>SOURCE CDF directive puts the compiler into FIXED or FREE source-code format mode. This, in effect, provides yet another mechanism for controlling the compiler’s -free switch and -fixed switch.

  1. The reserved words FORMAT and IS are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program.
  2. You may switch between FIXED and FREE mode as desired.
  3. You may also use the >>SET CDF directive to perform this function.
  4. If the compiler is already in the specified mode, this statement will have no effect.


3.8. >>TURN

CDF >>TURN Directive Syntax
=======================================================================

 >>TURN { exception-name-1 [ file-name-1 ]... }...
 ~~~~~~
    { OFF                           }
    { ~~~                           }
    { CHECKING ON [ WITH LOCATION ] }
      ~~~~~~~~ ~~        ~~~~~~~~

=======================================================================

The directive will (de-)activate exception checks.



3.9. >>D

CDF >>D Directive Syntax
=======================================================================

 >>D
 ~~~

=======================================================================

The directive removes all floating debug lines if debug mode not active. Otherwise will ignore the directive part of the line.



3.10. >>DISPLAY

CDF >>DISPLAY Directive Syntax
=======================================================================

 >>DISPLAY source-text [ VCS = version-string ]
 ~~~~~~~~~               ~~~

=======================================================================

The directive is a v1.0 extension and will display messages during compilation.



3.11. >>PAGE

CDF >>PAGE Directive Syntax
=======================================================================

 >>PAGE
 ~~~~~~

=======================================================================

The directive allows usage of the IBM paging controls EJECT, SKIP1, SKIP2, SKIP3 and TITLE.



3.12. >>LISTING

CDF >>LISTING Directive Syntax
=======================================================================

 >>LISTING  {ON}
 ~~~~~~~~~  {OFF}

=======================================================================

The directive allows the program listing to be de-(activated).



3.13. >>LEAP-SECONDS

CDF >>LEAP-SECONDS Directive Syntax
=======================================================================

 >>LEAP-SECONDS
 ~~~~~~~~~~~~~~

The >>LEAP-SECONDS CDF directive is syntactically recognized but is otherwise non-functional.


=======================================================================

Allows for more than 60 seconds per minute.



3.14. $ Directives

CDF $ Directive Syntax
=======================================================================

 $ (Dollar) Directives - Active.

 These directives are active and have the same function as ones starting with >>:

 $DEFINE
 $DISPLAY ON|OFF
 $IF
 $ELIF
 $ELSE
 $ELSE-IF
 $END
 $SET

 It is recommend to use the standard directives only instead of the MF directives
 (when possible) as these have a a higher chance for being portable.

 $ (Dollar) Directives - Not Active.
 These are NOT active and will produce a warning message:

 $DISPLAY VCS ...

 Recognised but otherwise ignored.

 @OPTIONS options-text

 Additional Micro-Focus directives accepted :

 ADDRSV | ADD-RSV literal-1
 ADDSYN | ADD-SYN literal-1 = literal-2
 ASSIGN  "EXTERNAL" | "DYNAMIC"
 BOUND
 CALLFH  literal-1
 COMP1  |  COMP-1  "BINARY" | "FLOAT"
 FOLDCOPYNAME | FOLD-COPY-NAME  AS "UPPER" | "LOWER"
 MAKESYN  |  MAKE-SYN
 NOBOUND  |  NO-BOUND
 NOFOLDCOPYNAME  |  NOFOLD-COPY-NAME  |  NO-FOLD-COPY-NAME
 OVERRIDE  literal-1 = literal-2
 REMOVE  literal-1
 SOURCEFORMAT | SOURCE-FORMAT "FIXED" | "FREE" | "VARIABLE"
 SSRANGE "2"
 NOSSRANGE  |  NO-SSRANGE

=======================================================================

Offers support for MF Compiler Directives.



3.15. Predefined compilation variables

GnuCOBOL defines compilation variables when various conditions are true. If the condition associated with a variable is false, the variable is not defined.

DEBUG

The -d debug flag is specified.

EXECUTABLE

Module being compiled contains the main program.

GCCOMP

The size of a COMP item is determined according to the GnuCOBOL scheme where for a picture of length:

1 - 2

item = 1 byte

3 - 4

item = 2 bytes

5 - 9

item = 4 bytes

10 - 18

item = 8 bytes

GNUCOBOL

GnuCOBOL is compiling the source unit.

HOSTSIGNS

A signed packed decimal item’s value may be considered NUMERIC if sign = X"F".

IBMCOMP

The size of a COMP item is determined according to the IBM scheme, where for a PICTURE of length:

1 - 4

item = 2 bytes

5 - 9

item = 4 bytes

10 - 18

item = 8 bytes

MODULE

The element being compiled does not contain the main program.

NOHOSTSIGNS

A signed packed decimal item’s value may not be considered NUMERIC if sign = X"F".

NOIBMCOMP

The size of a COMP item is not determined according to the IBM scheme.

NOSTICKY-LINKAGE

Sticky linkage (linkage section items remaining allocated between invocations) is not active.

NOTRUNC

Numeric data items are truncated according to their internal representation.

P64

Pointers are greater than 32 bits.

STICKY-LINKAGE

Sticky linkage (linkage section items remaining allocated between invocations) is active.

TRUNC

Numeric data items are truncated according to their PICTURE clauses.

While still supported, this may well be removed in the future and should not be used. See GCCOMP and GNUCOBOL instead:

OCCOMP

The size of a COMP item is determined according to the GnuCOBOL scheme, where for a PICTURE of length:

1 - 2

item = 1 byte

3 - 4

item = 2 bytes

5 - 9

item = 4 bytes

10 - 18

item = 8 bytes

OPENCOBOL

GnuCOBOL is compiling the source unit.



4. IDENTIFICATION DIVISION

IDENTIFICATION DIVISION Syntax
=======================================================================

[{ IDENTIFICATION } DIVISION. ]
 { ~~~~~~~~~~~~~~ } ~~~~~~~~
 { ID             }
   ~~
 { PROGRAM-ID.  } { program name } .
 { ~~~~~~~~~~   } { literal-1    } [ AS { literal-2 } ] [ Type-clause ] .
 { FUNCTION-ID. } { literal-3 } [ AS literal-4 ] .
   ~~~~~~~~~~~    { function-name } .
 { OPTIONS. }
   ~~~~~~~
 [ DEFAULT ROUNDED MODE IS {AWAY-FROM-ZERO         }
   ~~~~~~~ ~~~~~~~         {NEAREST-AWAY-FROM-ZERO }
                           {NEAREST-EVEN           }
                           {NEAREST-TOWARDS-ZERO   }
                           {PROHIBITED             }
                           {TOWARDS-GREATER        }
                           {TOWARDS-LESSER         }
                           {TRUNCATION             }]
 [ ENTRY-CONVENTION IS {COBOL   }
   ~~~~~~~~~~~~~~~~    {EXTERN  }
                       {STDCALL }]
 [ AUTHOR.        comment-1. ]
   ~~~~~~
 [ DATE-COMPILED. comment-2. ]
   ~~~~~~~~~~~~~
 [ DATE-MODIFIED. comment-3. ]
   ~~~~~~~~~~~~~
 [ DATE-WRITTEN.  comment-4. ]
   ~~~~~~~~~~~~
 [ INSTALLATION.  comment-5. ]
   ~~~~~~~~~~~~
 [ REMARKS.       comment-6. ]
   ~~~~~~~
 [ SECURITY.      comment-7. ]
   ~~~~~~~~

The AUTHOR, DATE-COMPILED, DATE-MODIFIED, DATE-WRITTEN, INSTALLATION, REMARKS and SECURITY paragraphs are supported by GnuCOBOL only to provide compatibility with programs written for the ANS1974 (or earlier) standards. As of the ANS1985 standard, these clauses have become obsolete and should not be used in new programs.


=======================================================================
PROGRAM-ID Type Clause Syntax
=======================================================================

 IS [ COMMON ] [ INITIAL|RECURSIVE PROGRAM ]
      ~~~~~~     ~~~~~~~ ~~~~~~~~~

=======================================================================

The identification division provides basic identification of the program by giving it a name and optionally defining some high-level characteristics via the eight pre-defined paragraphs that may be specified.

  1. The paragraphs shown above may be coded in any sequence.
  2. The reserved words AS, IS and PROGRAM are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program.
  3. A Type Clause may be coded only when PROGRAM-ID is specified. If one is coded, either COMMON, COMMON INITIAL or COMMON RECURSIVE must be specified.
  4. While the actual IDENTIFICATION DIVISION or ID DIVISION header is optional, the PROGRAM-ID / FUNCTION-ID paragraphs are not; only one or the other, however, may be coded.
  5. The compiler’s -Wobsolete switch will cause the GnuCOBOL compiler to issue warnings messages if these (or any other obsolete syntax) is used in a program.
  6. If specified, literal-1 must be an actual alphanumeric literal and may not be a figurative constant.
  7. The PROGRAM-ID and FUNCTION-ID paragraphs serve to identify the program to the external (i.e. operating system) environment. If there is no AS clause present, the program-id will serve as that external identification. If there is an AS clause specified, that specified literal will serve as the external identification. For the remainder of this document, that "external identification" will be referred to as the primary entry-point name.
  8. The INITIAL, COMMON and RECURSIVE words are used only within subprograms serving as subroutines. Their purposes are as follows:
    1. COMMON should be used only within subprograms that are nested subprograms. A nested subprogram declared as COMMON may be called from any nested program in the source file being compiled, not just those "above" it in the nesting structure.
    2. The RECURSIVE clause, if any, will cause the compiler to generate different object code for the subprogram that will enable it to invoke itself and to properly return back to the program that invoked it.

      User-defined functions (i.e. FUNCTION-ID) are always recursive.

    3. The INITIAL clause, if specified, guarantees the subprogram will be in its initial (i.e. compiled) state each and every time it is executed, not just the first time.


5. ENVIRONMENT DIVISION

ENVIRONMENT DIVISION Syntax
=======================================================================

   ENVIRONMENT DIVISION.
   ~~~~~~~~~~~ ~~~~~~~~
 [ CONFIGURATION SECTION. ]
   ~~~~~~~~~~~~~ ~~~~~~~~
 [ SOURCE-COMPUTER.         Compilation-Computer-Specification . ]
   ~~~~~~~~~~~~~~~
 [ OBJECT-COMPUTER.         Execution-Computer-Specification . ]
   ~~~~~~~~~~~~~~~
 [ SPECIAL-NAMES.           Program-Configuration-Specification . ]
   ~~~~~~~~~~~~~
 [ REPOSITORY.              Function-Specification... . ]
   ~~~~~~~~~~
 [ INPUT-OUTPUT SECTION. ]
   ~~~~~~~~~~~~ ~~~~~~~
 [ FILE-CONTROL.            General-File-Description... . ]
   ~~~~~~~~~~~~
 [ I-O-CONTROL.             File-Buffering Specification... . ]
   ~~~~~~~~~~~

=======================================================================

This division defines the external computer environment in which the program will be operating. This includes defining any files that the program may be .



5.1. CONFIGURATION SECTION

CONFIGURATION SECTION Syntax
=======================================================================

   CONFIGURATION SECTION.
   ~~~~~~~~~~~~~ ~~~~~~~
 [ SOURCE-COMPUTER. Compilation-Computer-Specification . ]
   ~~~~~~~~~~~~~~~
 [ OBJECT-COMPUTER. Execution-Computer-Specification . ]
   ~~~~~~~~~~~~~~~
 [ SPECIAL-NAMES.   Program-Configuration-Specification . ]
   ~~~~~~~~~~~~~
 [ REPOSITORY.      Function-Specification... . ]
   ~~~~~~~~~~

=======================================================================

This section defines the computer system upon which the program is being compiled and executed and also specifies any special environmental configuration or compatibility characteristics.

  1. The four paragraphs in this section may be specified in any order but if not in this order, a warning will be issued.
  2. The configuration section is not allowed in a nested subprogram. A nested program inherits the configuration section settings of its parent program.
  3. If none of the features provided by the configuration section are required by a program, the entire CONFIGURATION SECTION. header may be omitted from the program.


5.1.1. SOURCE-COMPUTER

SOURCE-COMPUTER Syntax
=======================================================================

 SOURCE-COMPUTER. computer-name [ WITH DEBUGGING MODE ] .
 ~~~~~~~~~~~~~~~                       ~~~~~~~~~ ~~~~

=======================================================================

This paragraph defines the computer upon which the program is being compiled and provides one way in which debugging code embedded within the program may be activated.

  1. The reserved word WITH is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. This paragraph is not allowed in a nested subprogram. A nested program inherits the SOURCE-COMPUTER settings of its parent program.
  3. The value specified for computer-name is irrelevant, provided it is a valid COBOL word that does not match any GnuCOBOL reserved word. The computer-name value may include spaces. This need not match the computer-name used with the OBJECT-COMPUTER paragraph, if any.
  4. The DEBUGGING MODE clause, if present, will inform the compiler that debugging lines (those with a ‘D’ in column 7 if Fixed Source Mode is in effect, or those prefixed with a >>D if Free Source Mode is in effect) — normally treated as comments — are to be compiled.
  5. Even without the DEBUGGING MODE clause, it is still possible to compile debugging lines. Debugging lines may also be compiled by specifying the -fdebugging-line switch to the GnuCOBOL compiler.


5.1.2. OBJECT-COMPUTER

OBJECT-COMPUTER Syntax
=======================================================================

 OBJECT-COMPUTER.  [ computer-name ]
 ~~~~~~~~~~~~~~~
 [ MEMORY SIZE IS integer-1 WORDS|CHARACTERS ]
   ~~~~~~ ~~~~              ~~~~~ ~~~~~~~~~~
 [ PROGRAM COLLATING SEQUENCE IS alphabet-name-1 ]
           ~~~~~~~~~
 [ SEGMENT-LIMIT IS integer-2 ]
   ~~~~~~~~~~~~~
 [ CHARACTER CLASSIFICATION IS { locale-name-1  } ]
             ~~~~~~~~~~~~~~    { LOCALE         }
                               { ~~~~~~         }
                               { USER-DEFAULT   }
                               { ~~~~~~~~~~~~   }
                               { SYSTEM-DEFAULT }
                                 ~~~~~~~~~~~~~~
 .

The MEMORY SIZE and SEGMENT-LIMIT clauses are syntactically recognized but are otherwise non-functional.


=======================================================================

This paragraph describes the computer upon which the program will execute.

  1. The computer-name, if specified, must immediately follow the OBJECT-COMPUTER paragraph name. The remaining clauses may be coded in any sequence.
  2. The reserved words CHARACTER, IS, PROGRAM and SEQUENCE are optional and may be omitted. The presence or absence of these words has no effect on the program.
  3. The value specified for computer-name, if any, is irrelevant provided it is a valid COBOL word that does not match any GnuCOBOL reserved word. The computer-name may include spaces. This need not match the computer-name used with the SOURCE-COMPUTER paragraph, if any.
  4. The OBJECT-COMPUTER paragraph is not allowed in a nested subprogram. A nested program inherits the OBJECT-COMPUTER settings of its parent program.
  5. The COLLATING SEQUENCE clause allows you to specify a customized character collating sequence to be used when alphanumeric values are compared to one another. Data will still be stored in the character set native to the computer, but the logical sequence in which characters are ordered for comparison purposes can be altered from that defined by the computer’s native character set. The alphabet-name-1 you specify needs to be defined in the SPECIAL-NAMES (see SPECIAL-NAMES) paragraph.
  6. If no COLLATING SEQUENCE clause is specified, the collating sequence implied by the character set native to the computer (usually ASCII) will be used.
  7. The optional CLASSIFICATION clause may be used to specify a locale for the environment in which the program will execute, for the purpose of influencing the upper-case and lower-case mappings of characters for the UPPER-CASE (see UPPER-CASE) and LOWER-CASE (see LOWER-CASE) intrinsic functions and the classification of characters for the ALPHABETIC, ALPHABETIC-LOWER and ALPHABETIC-UPPER class tests. The definitions of these classes is taken from the cultural convention specification (LC_CTYPE) from the specified locale.

    The meanings of the four locale specifications are as follows:

    1. locale-name-1 references a LOCALE (see SPECIAL-NAMES) definition.
    2. The keyword LOCALE refers to the current locale (in effect at the time the program is executed)
    3. The keyword USER-DEFAULT references the default locale specified for the user currently executing this program.
    4. The keyword SYSTEM-DEFAULT denotes the default locale specified for the computer upon which the program is executing.
  8. Absence of a CLASSIFICATION clause will cause character classification to occur according to the rules for the computer’s native character set (ASCII, EBCDIC, etc.).


5.1.3. SPECIAL-NAMES

SPECIAL-NAMES Syntax
=======================================================================

 SPECIAL-NAMES.
 ~~~~~~~~~~~~~
  [ CALL-CONVENTION integer-1 IS mnemonic-name-1 ]
    ~~~~~~~~~~~~~~~
  [ CONSOLE IS CRT ]
    ~~~~~~~    ~~~
  [ CRT STATUS IS identifier-1 ]
    ~~~ ~~~~~~
  [ CURRENCY SIGN IS literal-1 ]
    ~~~~~~~~ ~~~~
  [ CURSOR IS identifier-2 ]
    ~~~~~~
  [ DECIMAL-POINT IS COMMA ]
    ~~~~~~~~~~~~~    ~~~~~
  [ EVENT STATUS IS identifier-3 ]
    ~~~~~ ~~~~~~
  [ LOCALE locale-name-1 IS literal-2 ]...
    ~~~~~~
  [ NUMERIC SIGN IS TRAILING SEPARATE ]
    ~~~~~~~ ~~~~    ~~~~~~~~ ~~~~~~~~
  [ SCREEN CONTROL IS identifier-4 ]
    ~~~~~~ ~~~~~~~
  [ device-name-1 IS mnemonic-name-2 ]...

  [ feature-name-1 IS mnemonic-name-3 ]...

  [ Alphabet-Clause ]...

  [ Class-Definition-Clause ]...

  [ Switch-Definition-Clause ]...

  [ Symbolic-Characters-Clause ]...
  .

The EVENT STATUS and SCREEN CONTROL clauses are syntactically recognized but are otherwise non-functional.


=======================================================================
Alphabet-Name-Clause, Class-Definition-Clause,
Switch-Definition-Clause and Symbolic-Characters-Clause
are discussed in detail in the next four sections.

The SPECIAL-NAMES paragraph provides a means for specifying various program and operating environment configuration options.

  1. The various clauses that may be specified within the SPECIAL-NAMES paragraph may be coded in any order.
  2. The reserved word IS is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  3. The SPECIAL-NAMES paragraph is not allowed in a nested subprogram. A nested program inherits the SPECIAL-NAMES settings of its parent program.
  4. Only the final clause specified within this paragraph should be terminated with a period.
  5. The CALL-CONVENTION clause allows a decimal integer, representing a series of ON/OFF switch settings, to be associated with a mnemonic name which may then be coded on a CALL statement (see CALL). The switch settings defined by this mnemonic will then control how the linkage to a subroutine invoked by the CALL statement that references mnemonic-name-1 will be handled.
  6. The CONSOLE IS CRT clause, if specified, will cause a DISPLAY statement lacking an explicit UPON clause to be treated as a DISPLAY screen-data-item statement (see DISPLAY screen-data-item), and any ACCEPT statement lacking a FROM clause to be treated as a ACCEPT screen-data-item statement (see ACCEPT screen-data-item).
  7. If the CRT STATUS clause is not specified, an implicit COB-CRT-STATUS identifier (with a PICTURE 9(4)) will be allocated for the purpose of receiving screen ACCEPT statuses. If CRT STATUS is specified, then identifier-1 must be defined in the program as a PICTURE 9(4) field.
  8. The CURRENCY SIGN clause may be used to redefine the character to be used as a currency sign in a PICTURE (see PICTURE) clause. The default currency sign is a dollar-sign (‘$’). You may specify any character except 0-9, A-Z, a-z, +, -, ,, ., *, /, ;, (, ), =, \\, quote (‘"’) or space.
  9. The CURSOR IS clause allows you to specify a 4- or 6-character data item into which the cursor screen location at the time a screen ACCEPT is satisfied. The value will be returned as rrcc or rrrccc, depending upon the length of the specified identifier-2, where rr and rrr represent the row number (starting at zero) and cc and ccc represent the column number (also starting at zero). There is no default data item allocated for this data if the CURSOR IS clause is not specified, and it is the programmer’s responsibility to define identifier-2 if the clause is specified.
  10. The DECIMAL POINT IS COMMA clause reverses the definition of the ‘,’ and ‘.’ characters when they are used as PICTURE editing symbols and within numeric literals. This can have unwanted side-effects - see Punctuation.
  11. The LOCALE clause may be used to associate external OS-defined locale names (literal-2) with an internal name (locale-name-1) that may then be referenced within the program. Locale names are defined by the Operating System and/or C compiler GnuCOBOL will be utilizing on your computer.
  12. The following is the list of possible locale codes, for example, that would be available on a Windows computer running a GnuCOBOL version that was built utilizing the MinGW Unix-emulator and the GNU C compiler (gcc):
    A

    af_ZA, am_ET, ar_AE, ar_BH, ar_DZ, ar_EG, ar_IQ, ar_JO, ar_KW, ar_LB, ar_LY, ar_MA, ar_OM, ar_QA, ar_SA, ar_SY, ar_TN, ar_YE, arn_CL, as_IN, az_Cyrl_AZ, az_Latn_AZ

    B

    ba_R, be_BY, bg_BG, bn_IN bo_BT, bo_CN, br_FR, bs_Cyrl_BA, bs_Latn_BA

    C

    ca_ES, cs_CZ, cy_GB

    D

    da_DK, de_AT, de_CH, de_DE, de_LI, de_LU, dsb_DE, dv_MV

    E

    el_GR, en_029, en_AU, en_BZ, en_CA, en_GB, en_IE, en_IN, en_JM, en_MY en_NZ, en_PH, en_SG, en_TT, en_US, en_ZA, en_ZW, es_AR, es_BO, es_CL, es_CO, es_CR, es_DO, es_EC, es_ES, es_GT, es_HN, es_MX, es_NI, es_PA, es_PE, es_PR, es_PY, es_SV, es_US, es_UY es_VE, et_EE, eu_ES

    F

    fa_IR, fi_FI, fil_PH, fo_FO, fr_BE, fr_CA, fr_CH, fr_FR, fr_LU, fr_MC, fy_NL

    G

    ga_IE, gbz_AF, gl_ES, gsw_FR, gu_IN

    H

    ha_Latn_NG, he_IL, hi_IN, hr_BA, hr_HR, hu_HU, hy_AM

    I

    id_ID, ig_NG, ii_CN, is_IS, it_CH, it_IT, iu_Cans_CA, iu_Latn_CA

    J

    ja_JP

    K

    ka_GE, kh_KH, kk_KZ, kl_GL, kn_IN, ko_KR, kok_IN, ky_KG

    L

    lb_LU, lo_LA, lt_LT, lv_LV

    M

    mi_NZ, mk_MK, ml_IN, mn_Cyrl_MN, mn_Mong_CN moh_CA, mr_IN, ms_BN, ms_MY, mt_MT

    N

    nb_NO, ne_NP, nl_BE, nl_NL, nn_NO, ns_ZA

    O

    oc_FR, or_IN

    P

    pa_IN, pl_PL, ps_AF, pt_BR, pt_PT

    Q

    qut_GT, quz_BO, quz_EC, quz_PE

    R

    rm_CH, ro_RO, ru_RU, rw_RW

    S

    sa_IN, sah_RU, se_FI, se_NO se_SE, si_LK, sk_SK, sl_SI, sma_NO, sma_SE, smj_NO, smj_SE, smn_FI, sms_FI, sq_AL, sr_Cyrl_BA, sr_Cyrl_CS, sr_Latn_BA, sr_Latn_CS, sv_FI, sv_SE, sw_KE syr_SY

    T

    ta_IN, te_IN, tg_Cyrl_TJ, th_TH tk_TM, tmz_Latn_DZ, tn_ZA, tr_IN, tr_TR, tt_RU

    U

    ug_CN, uk_UA, ur_PK, uz_Cyrl_UZ, uz_Latn_UZ

    V

    vi_VN

    W

    wen_DE, wo_SN

    X

    xh_ZA

    Y

    yo_NG

    Z

    zh_CN, zh_HK, zh_MO, zh_SG, zh_TW, zu_ZA

  13. The NUMERIC SIGN TRAILING SEPARATE specification causes all signed numeric USAGE DISPLAY data items to be created as if the SIGN IS TRAILING SEPARATE CHARACTER clause was included in their definitions.
  14. The device-name-1 IS mnemonic-name-2 clause allows you to specify an alternate name (device-name-1) for one of the built-in GnuCOBOL device name mnemonic-name-2. The list of device names built-into GnuCOBOL, and the physical device associated with that name, are as follows:
    CONSOLE

    This is the (screen-mode) display of the PC or Unix system.

    STDIN
    SYSIN
    SYSIPT

    These devices (they are all synonymous) represent standard system input (pipe 0). On a PC or UNIX system, this is typically the keyboard. The contents of a file may be delivered to a GnuCOBOL program for access via one of these device names by adding the sequence ‘0< filename’ to the end of the programs execution command.

    PRINTER
    STDOUT
    SYSLIST
    SYSLST
    SYSOUT

    These devices (they are all synonymous) represent standard system output (pipe 1). On a PC or UNIX system, this is typically the display. Output sent to one of these devices by a GnuCOBOL program can be sent to a file by adding the sequence ‘1> filename’ to the end of the programs execution command.

    STDERR
    SYSERR

    These devices (they are synonymous) represent standard system error output (pipe 2). On a PC or UNIX system, this is typically the display. Output sent to one of these devices by a GnuCOBOL program can be sent to a file by adding the sequence ‘2> filename’ to the end of the programs execution command.

  15. The feature-name-1 IS mnemonic-name-3 clause allow for mnemonic names to be assigned to up to the 13 printer channel (i.e. vertical page positioning) position feature names Cnn (nn=01-12) and CSP. Once a channel position has been assigned a mnemonic name, statements of the form WRITE record-name AFTER ADVANCING mnemonic-name-3 may be coded to write the specified print record at the channel position assigned to mnemonic-name-3.

    Printers supporting channel positioning are generally mainframe-type line printers. When writing to printers that do not support channel positioning, a formfeed will be issued to the printer.

    The CSP positioning option stands for “No Spacing”. Testing on a MinGW build of GnuCOBOL shows that this too results in a formfeed being issued.



5.1.3.1. Alphabet-Name-Clause

SPECIAL-NAMES Alphabet-Clause Syntax
=======================================================================

 ALPHABET alphabet-name-1 IS { ASCII             }
 ~~~~~~~~                    { ~~~~~             }
                             { EBCDIC            }
                             { ~~~~~~            }
                             { NATIVE            }
                             { ~~~~~~            }
                             { STANDARD-1        }
                             { ~~~~~~~~~~        }
                             { STANDARD-2        }
                             { ~~~~~~~~~~        }
                             { Literal-Clause... }

=======================================================================
SPECIAL-NAMES ALPHABET Literal-Clause Syntax
=======================================================================

 literal-1 [ { THRU|THROUGH literal-2 } ]
             { ~~~~ ~~~~~~~           }
             { {ALSO literal-3}...    }
                ~~~~

=======================================================================

The ALPHABET clause relates alphabet-name-1 to a specified character code set or collating sequence, including one you define yourself using the literal-1 option.

  1. The reserved word IS is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. The reserved words THRU and THROUGH are interchangeable.
  3. GnuCOBOL considers ASCII, STANDARD-1 and STANDARD-2 to be interchangeable.
  4. NATIVE specifies the system default character set.
  5. The following points apply to using the literal-n specifications to compose a custom character set:
    1. The literal-n values are either integers or alphanumeric quoted characters. These represent a single character in the NATIVE character set, either by its actual text value (alphanumeric quoted character) or by ordinal position in the NATIVE character set (integer),
    2. The sequence in which characters are defined in this clause specifies the relative order those characters should have when comparisons are made using this alphabet.
    3. Character positions in this list do not affect the actual binary storage values used for the characters. Binary values will still be those of the NATIVE character set.
    4. You may specify any of the figurative constants SPACE, SPACES, ZERO, ZEROS, ZEROES, QUOTE, QUOTES, HIGH-VALUE, HIGH-VALUES, LOW-VALUE or LOW-VALUES for any of the literal-1, literal-2 or literal-3 specifications.
  6. Once you have defined an alphabet name, that alphabet name may be used on specifications in CODE-SET, COLLATING SEQUENCE, or SYMBOLIC CHARACTERS clauses elsewhere in the program.


5.1.3.2. Class-Definition-Clause

SPECIAL-NAMES Class-Definition-Clause Syntax
=======================================================================

 CLASS class-name-1 IS { literal-1 [ THRU|THROUGH literal-2 ] }...
 ~~~~~                               ~~~~ ~~~~~~~

=======================================================================
  1. The reserved word IS is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. The reserved words THRU and THROUGH are interchangeable.
  3. Both literal-1 and literal-2 must be alphanumeric literals of length 1.
  4. The literal(s) specified on this clause define the possible characters that may be found in a data item’s value in order to be considered part of the class.
  5. For example, the following defines a class called Hexadecimal, the definition of which specifies the only characters that may be present in an alphanumeric data item if that data item is to be part of the Hexadecimal class:
    CLASS Hexadecimal IS '0' THRU '9'
                         'A' THRU 'F'
                         'a' THRU 'f'
    
  6. Once class Hexadecimal has been defined, program code could then use a statement such as IF input-item IS Hexadecimal to determine if the value of characters in a data item are valid according to that class.


5.1.3.3. Switch-Definition-Clause

SPECIAL-NAMES Switch-Definition-Clause Syntax
=======================================================================

 switch-name-1 [ IS mnemonic-name-1 ]

   [ ON STATUS IS condition-name-1 ]
     ~~
   [ OFF STATUS IS condition-name-2 ]
     ~~~

=======================================================================

The switch-definition clause associates a condition-name with a run-time execution switch so that the status of that switch may be tested from within a program.

  1. The reserved words IS and STATUS are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The valid switch-name-1 names are SWITCH-n (n = 0-36).
  3. If the program is compiled with the -fsyntax-extension switch, the switch names SWn (n = 0-15) are also valid; they correspond to SWITCH-0 through SWITCH-15, respectively as well as SWITCH-16 through SWITCH-36, SWITCH 0 through SWITCH 26 and SWITCH A through SWITCH Z.
  4. At execution time, each switch will be associated with a COB_SWITCH_n run-time environment variable, where n will have the value ‘0’ through ‘15’. Any of these sixteen environment variables that have the value ON (regardless of upper- or lower-case value) will be considered to be set “on”. Any of these sixteen environment variables having no value at all or a value other than ON will be considered OFF.
  5. Each specified switch must have at least one of a IS mnemonic-name-1, ON STATUS or an OFF STATUS option defined for it, otherwise there will be no way to reference the switch from within a GnuCOBOL program.
  6. The IS mnemonic-name-1 syntax provides a means for setting the switch to either an ON or OFF value via the SET statement (see SET).
  7. The ON STATUS and OFF STATUS syntax provides a way of associating a condition-name with either the on or off status of the switch, so that status may be tested at execution time via the IF statement (see IF).


5.1.3.4. Symbolic-Characters-Clause

SPECIAL-NAMES-Symbolic-Characters-Clause Syntax
=======================================================================

 SYMBOLIC CHARACTERS
 ~~~~~~~~
   { symbolic-character-1... IS|ARE integer-1... }...

   [ IN alphabet-name-1 ]
     ~~

=======================================================================

This clause may be used to define your own figurative constants.

  1. The reserved words ARE, CHARACTERS and IS are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. There must be exactly as many integer-1 values specified as there are
    symbolic-character-1 names.

  3. Each symbolic character name will be associated with the corresponding integer-1th character in the alphabet named in the IN clause. The integer values are selecting characters from the alphabet by their ordinal position and not by their numeric value; thus, an integer of 15 will select the 15th character in the specified alphabet, regardless of the actual numeric value of the bit pattern that constitutes that character.
  4. If no alphabet-name-1 is specified, the systems native character set will be assumed.
  5. The following two code examples define the same set of figurative constant names for five ASCII control characters (assuming that ASCII is the system’s native character set). The two examples are identical in their effects, even though the way the figurative constants are defined is different.
    Individually
    SYMBOLIC CHARACTERS NUL IS 1
                        SOH IS 2
                        BEL IS 8
                        DC1 IS 18
                        DC2 IS 19
    
    Respectively
    SYMBOLIC CHARACTERS NUL SOH BEL DC1 DC2
                    ARE   1   2   8  18  19
    


5.1.4. REPOSITORY

REPOSITORY Syntax
=======================================================================

 REPOSITORY.
 ~~~~~~~~~~
    FUNCTION { function-prototype-name-1 [ AS literal-1 ] }...
    ~~~~~~~~ {                             ~~             }
             { intrinsic-function-name-1 [ AS literal-2 ] }
             {                             ~~             }
             { intrinsic-function-name-2 INTRINSIC        }
             { ALL INTRINSIC             ~~~~~~~~~        }
               ~~~ ~~~~~~~~~

=======================================================================

The REPOSITORY paragraph provides a way to control access to the various built-in intrinsic functions and any user defined functions that your program will be using.

  1. The REPOSITORY paragraph is not allowed in a nested subprogram. A nested program inherits the REPOSITORY settings of its parent program.
  2. The INTRINSIC clause allows you to flag one or more (or ALL) built-in intrinsic functions as being usable without the need to code the keyword FUNCTION in front of the function names.
  3. As an alternative to using the ALL INTRINSIC clause, you may instead compile your GnuCOBOL programs using the -fintrinsics=ALL switch.
  4. The function-prototype-name-1 option is required to specify the name of a user-defined function your program will be using. Optionally, should you desire, you may specify an alias name by which you will reference that user-defined function. Should you wish, you may also use the AS clause to provide an alias name for a built-in intrinsic function.
  5. The following example
    REPOSITORY.
        FUNCTION ALL INTRINSIC.
        FUNCTION MY-FUNCTION-1.
        FUNCTION MY-FUNCTION-2 AS "MF2".
        FUNCTION STANDARD-DEVIATION AS "SIGMA".
    

A special note about user-defined functions — because you must name a user-defined function that your program will be using in the REPOSITORY paragraph, you may always reference that function from your program’s procedure division without needing to use the FUNCTION keyword.



5.2. INPUT-OUTPUT SECTION

INPUT-OUTPUT SECTION Syntax
=======================================================================

 [ INPUT-OUTPUT SECTION. ]
   ~~~~~~~~~~~~ ~~~~~~~
 [ FILE-CONTROL. ]
   ~~~~~~~~~~~~
     [ SELECT-Statement... ]

 [ I-O-CONTROL. ]
   ~~~~~~~~~~~
     [ MULTIPLE-FILE-Statement ]

     [ SAME-RECORD-Statement ]

=======================================================================

The INPUT-OUTPUT section provides for the definition of any files the program will be accessing as well as control of the I/O buffering process against those files through the FILE-CONTROL and I-O-CONTROL paragraphs, respectively.

  1. As the diagram shows, there are three types of statements that may occur in the two paragraphs of this section. If none of the statements are coded in a particular paragraph, the paragraph itself may be omitted, otherwise it is required.
  2. If neither paragraph is coded, the INPUT-OUTPUT SECTION. header itself may be omitted, otherwise it is normally required.
  3. If the compiler configuration file (see Compiler Configuration Files) you are using has relaxed-syntax-check set to ‘yes’, the FILE-CONTROL and I-O-CONTROL paragraphs may be specified without the INPUT-OUTPUT SECTION header having been coded.
  4. If both statement types are coded in the I-O-CONTROL paragraph, the order in which those statements are coded is irrelevant.


5.2.1. SELECT

SELECT Statement Syntax
=======================================================================

 SELECT [ [ NOT ] OPTIONAL ] file-name-1
 ~~~~~~     ~~~   ~~~~~~~~
 [ ASSIGN { TO    } [{ EXTERNAL }] [{ DISC|DISK      }] [{ identifier-1 }] ]
   ~~~~~~ { USING }  { ~~~~~~~~ }   { ~~~~ ~~~~      }   { word-1       }
                     { DYNAMIC  }   { DISPLAY        }   { literal-1    }
                       ~~~~~~~      { ~~~~~~~        }
                                    { KEYBOARD       }
                                    { ~~~~~~~~       }
                                    { LINE ADVANCING }
                                    { ~~~~ ~~~~~~~~~ }
                                    { PRINTER        }
                                    { ~~~~~~~        }
                                    { RANDOM         }
                                    { ~~~~~~         }
                                    { TAPE           }
                                      ~~~~
 [ COLLATING SEQUENCE IS alphabet-name-1 ]
   ~~~~~~~~~
 [ FILE|SORT ] STATUS IS identifier-2 [ identifier-3 ] ]
   ~~~~ ~~~~   ~~~~~~
 [ LOCK MODE IS { MANUAL|AUTOMATIC                                } ]
   ~~~~         { ~~~~~~ ~~~~~~~~~                                }
                { EXCLUSIVE [ WITH { LOCK ON MULTIPLE RECORDS } ] }
                  ~~~~~~~~~        { ~~~~ ~~ ~~~~~~~~ ~~~~~~~ }
                                   { LOCK ON RECORD           }
                                   { ~~~~ ~~ ~~~~~~           }
                                   { ROLLBACK                 }
                                   { ~~~~~~~~                 }
 [ ORGANIZATION Clause ]
   ~~~~~~~~~~~~
 [ ORGANISATION Clause ]
   ~~~~~~~~~~~~
 [ RECORD DELIMITER IS STANDARD-1 ]
   ~~~~~~ ~~~~~~~~~    ~~~~~~~~~~
 [ RESERVE integer-1 AREAS ]
   ~~~~~~~
 [ SHARING WITH { ALL OTHER } ]
   ~~~~~~~      { ~~~       }
                { NO OTHER  }
                { ~~        }
                { READ ONLY }
                  ~~~~ ~~~~

The COLLATING SEQUENCE, RECORD DELIMITER, RESERVE and ALL OTHER clauses are syntactically recognized but are otherwise non-functional.


=======================================================================

The SELECT statement creates a definition of a file and links that COBOL definition to the external operating system environment.

  1. The reserved words AREAS, IS, MODE, OTHER, SEQUENCE, TO, USING and WITH are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. After file-name-1, the various clauses may be coded in any sequence.
  3. A period must follow the last coded clause.
  4. The OPTIONAL clause, to be used only for files that will be used to provide input data to the program, indicates the file may or may not actually be available at run-time. Attempts to OPEN an OPTIONAL file when the file does not exist will receive a special non-fatal file status value (see status 05 in the list of file status values below) indicating the file is not available; a subsequent attempt to READ that file will return an AT END (end-of-file) condition. Optionally, files may be designated as NOT OPTIONAL, if desired. This is useful when specifying the compiler’s -foptional-file switch, which automatically makes all files OPTIONAL except for those explicitly declared as NOT OPTIONAL.
  5. The file-name-1 value that you specify will be the name by which you will reference the file within your program. This name should be formed according to the rules for user-defined names (see User-Defined Words).
  6. The optional ASSIGN clause specifies how — at runtime, when file-name-1 is opened — either a logical device (STDIN, STDOUT) or a file anywhere in one of the currently-mounted file systems will be associated with file-name-1, as follows:
    1. There are three components to the ASSIGN clause:
      Type

      EXTERNAL, DYNAMIC or neither

      Device

      the list of device choices

      Locator

      shown as a choice between identifier-1, word-1 and literal-1.

    2. ASSIGN TO DISC file-name-1 will be assumed if there is no ASSIGN clause on a SELECT.
    3. If an ASSIGN clause is coded without a Device, the device DISC will be assumed.
    4. If a Locator clause is coded, the COBOL file file-name-1 will be attached to a data file within any file system that is mounted and available to the executing program at the time file-name-1 is opened. How that file is identified varies, depending upon the specified Locator, as follows:
      1. If literal-1 is coded, the value of the literal will serve as the File Location String that will identify the data file.
      2. If identifier-1 is coded, the value of the identifier will serve as the File Location String that will identify the data file.
      3. If word-1 (a syntactically valid word not duplicating a reserved or user-defined word) is coded, and a Type is EXTERNAL, then word-1 itself will serve as the File Location String that will identify the data file. If, however, a Type of EXTERNAL was not specified, the compiler will create a PIC X(1024) data item named word-1 within the program; the contents of that data item at the time the program opens file-name-1 will then serve as the File Location String that will identify the data file.
      4. File Location Strings will be discussed shortly.
    5. If no Locator is coded, file-name-1 will be attached to a logical device or a file based upon the specified (or implied) Device, as follows:
      1. DISC or DISK will assume an attachment to a file named file-name-1 in whatever directory is current at the time the file is opened.
      2. DISPLAY will assume an attachment to the STDOUT logical device; these files should only be used for output.
      3. KEYBOARD will assume an attachment to the STDIN logical device; these files should only be used for input.
      4. PRINTER will assume an attachment to the LPT1 logical device/port; these files should only be used for output.
      5. RANDOM or TAPE will behave exactly as DISC does. These two additional Devices are provided to facilitate the compilation of COBOL source from other COBOL implementations.
    6. The LINE ADVANCING device requires that a Locator be specified; these files should only be used for output. A COBOL Line Advancing file will allow carriage-control characters such as line-feeds and form-feeds to be written to the attached operating system file, via the ADVANCING clause of the WRITE statement (see WRITE).
    7. File Location Strings are used (at runtime) to identify the path and filename to the data file that must be attached to file-name-1 when that file is opened.
    8. If the compiler configuration file (see Compiler Configuration Files) you used to compile the program with had a filename-mapping value of yes, the GnuCOBOL runtime system will first attempt to identify a currently-defined environment variable whose value will serve as the data file’s path and filename, as follows:
      1. If the compiler configuration file (see Compiler Configuration Files) (see Compiler Configuration Files) you used to compile the program specified mf as the assign-clause value, then the File Locator String will be interpreted according to Microfocus COBOL rules — namely, everything before the last ‘-’ in the File Locator String will be ignored; the characters after the last ‘-’ will be treated as the base of an environment variable name. If there is no ‘-’ character in the File Locator String then the entire File Locator String will serve as the base of an environment variable name. This is the default behaviour for every config file except ibm.
      2. If, on the other hand, the compiler configuration file (see Compiler Configuration Files) you used to compile the program specified mf as the assign-clause value, then the File Locator String will be interpreted according to according to IBM COBOL rules — namely, the File Locator String is expected to be of the form S-xxx or AS-xxx, in which case the xxx will be treated as the base of an environment variable name. If there is no ‘-’ character in the File Locator String then the entire File Locator String will serve as the base of an environment variable name.
      3. Once an environment variable name base (let’s refer to it as bbbb) has been determined, the runtime system will look for the first one of the following environment variables that exists, in this sequence:
        DD_bbbb
        dd_bbbb
        bbbb
        

        Windows systems are case-insensitive with regard to environment variables, so there is no difference between the first two when using a GnuCOBOL implementation built for either Windows/MinGW or native Windows.

        If an environment variable was found, its value will serve as the path and filename to the data file.

    9. If no environment variable was found, or the configuration file (see Compiler Configuration Files) used to compile the program had a filename-mapping value of NO, then the File Locator String value will serve as the path and filename to the data file.
    10. Paths and file names may be specified on an absolute (C:\\Data\\datafile.dat, /Data/datafile.dat, …) or relative to the current directory (Data\\datafile.dat, Data/datafile.dat, …) basis. If no directory name is included (datafile.dat), the file must be in the current directory.
  7. The FILE STATUS or SORT STATUS clause (they are both equivalent and only one or the other, if any, should be specified) is used to specify the name of a two-digit numeric data item into which an I/O status code will be saved after every I/O verb that is executed against the file. This does not actually allocate the data item — you must define the item yourself somewhere in the data division. Note that the following list is not definitive: more can be added and any tests should include one for non zeros as a catch all. Possible status codes that can be returned to a FILE STATUS data item are as follows:
    00

    Success

    02

    Success (Duplicate Record Key Written)

    04

    Success (Incomplete)

    05

    Success (Optional File Not Found)

    07

    Success (No Unit)

    10

    End of file reached if reading forward or beginning-of-file reached if reading backward

    14

    Out of key range

    21

    Key invalid

    22

    Key already exists

    23

    Key not found

    24

    Key boundary violation

    30

    Permanent I/O error

    31

    Inconsistent filename

    34

    Boundary violation

    35

    File not found

    37

    Permission denied

    38

    Closed with lock

    39

    Conflicting attribute

    41

    File already open

    42

    File not open

    43

    Read not done

    44

    Record overflow

    46

    Read error

    47

    OPEN INPUT denied (insufficient permissions to read file)

    48

    OPEN OUTPUT denied (insufficient permissions to write to file)

    49

    OPEN I-O denied (insufficient permissions to read and/or write file)

    51

    Record locked

    52

    End of page

    57

    LINAGE bad specification (I-O linage)

    61

    File sharing failure

    71

    Bad character

    91

    File not available

  8. The SHARING clause defines the conditions under which the program will be willing (or not) to allow other programs executing at the same time to access the file. See File Sharing, for the details.
  9. The LOCK clause defines how concurrent access to the file will be managed on a record-by-record basis. See Record Locking, for the details.
  10. For syntax details for the ORGANIZATION clause, see next group of paragraphs.
  11. A SELECT statement without an ORGANIZATION explicitly coded will be handled as if the following ORGANIZATION clause had been specified:
    ORGANIZATION IS SEQUENTIAL
    ACCESS MODE IS SEQUENTIAL
    


5.2.1.1. ORGANIZATION SEQUENTIAL

ORGANIZATION SEQUENTIAL Clause Syntax
=======================================================================

 [ ORGANIZATION|ORGANISATION IS ] RECORD BINARY SEQUENTIAL
   ~~~~~~~~~~~~ ~~~~~~~~~~~~                    ~~~~~~~~~~
    [ ACCESS MODE IS SEQUENTIAL ]
      ~~~~~~         ~~~~~~~~~~

=======================================================================

Files declared as ORGANIZATION SEQUENTIAL will consist of records with no explicit end-of-record delimiter character sequences; records in such files are “delineated” by a calculated byte-offset (based on the maximum record length) into the file.

  1. The reserved words BINARY, IS, MODE and RECORD are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved words ORGANIZATION and ORGANISATION are interchangeable.
  3. The phrase ORGANIZATION IS (and its internationalized alternative, ORGANISATION IS) is optional to provide compatibility with those (few) COBOL implementations that consider ORGANIZATION to be optional. Most COBOL implementations do require the word ORGANIZATION, so it should be used in new programs.
  4. These files cannot be prepared with any standard text-editing or word processing software as all such programs will embed delimiter characters at the end of records (use ORGANIZATION IS LINE SEQUENTIAL instead).
  5. These files may contain either USAGE DISPLAY or USAGE COMPUTATIONAL (of any variety) data since no binary data sequence can be accidentally interpreted as an end-of-record delimiter.
  6. While records in a ORGANIZATION SEQUENTIAL file may be defined as having variable-length records, the file will be structured in such a manner as to reserve space for each record equal to the size of the largest possible record, based on the file’s description in the FILE SECTION.
  7. The ACCESS MODE SEQUENTIAL clause is optional because, if absent, it will be assumed anyway for this type of file. The internal structure of these files is such that they can only be processed in a sequential manner; in order to read the 100th record in such a file, for example, you first must read records 1 through 99.
  8. Sequential files are processed using the following statements:


5.2.1.2. ORGANIZATION LINE SEQUENTIAL

ORGANIZATION LINE SEQUENTIAL Clause Syntax
=======================================================================

 [ ORGANIZATION|ORGANISATION IS ] LINE SEQUENTIAL
   ~~~~~~~~~~~~ ~~~~~~~~~~~~      ~~~~ ~~~~~~~~~~
    [ ACCESS MODE IS SEQUENTIAL ]
      ~~~~~~         ~~~~~~~~~~
    [ PADDING CHARACTER IS literal-1 | identifier-1 ]
      ~~~~~~~

The PADDING CHARACTER clause is syntactically recognized but is otherwise non-functional.


=======================================================================

Files declared as ORGANIZATION LINE SEQUENTIAL will consist of records terminated by an end-of-record delimiter character or character sequence.

  1. The reserved words CHARACTER, IS and MODE are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved words ORGANIZATION and ORGANISATION are interchangeable.
  3. The phrase ORGANIZATION IS (and its internationalized alternative, ORGANISATION IS) is optional to provide compatibility with those (few) COBOL implementations that consider that word to be optional. Most COBOL implementations do require the word ORGANIZATION, so it should be used in new programs.
  4. This is the only ORGANIZATION valid for files that are assigned to the PRINTER device.
  5. These files may be created with any standard text-editing or word processing software capable of writing text files. Such files should not contain any USAGE COMPUTATIONAL or BINARY (of any variety) data since such fields could accidentally contain byte sequences that could be interpreted as an end-of-record delimiter.
  6. Both fixed- and variable-length record formats are supported.
  7. The end-of-record delimiter sequence will be X‘0A (an ASCII line-feed character) or a X‘0D0A (an ASCII carriage-return + line-feed sequence). The former is used on Unix implementations of GnuCOBOL (including Windows/MinGW, Windows/Cygwin and OSX implementations) while the latter would be used with native Windows implementations.
  8. When reading a LINE SEQUENTIAL file, records in excess of the size implied by the file’s description in the FILE SECTION will be truncated while records shorter than that size will be padded to the right with SPACES.
  9. The ACCESS MODE SEQUENTIAL clause is optional because, if absent, it will be assumed anyway for this type of file. The internal structure of these files is such that the data can only be processed in a sequential manner; in order to read the 100th record in such a file, for example, you first must read records 1 through 99.
  10. Files assigned to PRINTER or CONSOLE should be specified as ORGANIZATION LINE SEQUENTIAL.
  11. Line Sequential files are processed using the following statements:


5.2.1.3. ORGANIZATION RELATIVE

ORGANIZATION RELATIVE Clause Syntax
=======================================================================

 [ ORGANIZATION|ORGANISATION IS ] RELATIVE
   ~~~~~~~~~~~~ ~~~~~~~~~~~~      ~~~~~~~~
    [ ACCESS MODE IS { SEQUENTIAL } ]
      ~~~~~~         { ~~~~~~~~~~ }
                     { DYNAMIC    }
                     { ~~~~~~~    }
                     { RANDOM     }
                       ~~~~~~
    [ RELATIVE KEY IS identifier-1 ]
      ~~~~~~~~

=======================================================================

These files are files with an internal organization such that records may be processed in a sequential manner based upon their physical location in the file or in a random manner by allowing records to be read, written or updated by specifying the relative record number in the file.

  1. The reserved words IS, KEY and MODE are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved words ORGANIZATION and ORGANISATION are interchangeable.
  3. The phrase ORGANIZATION IS (and its internationalized alternative, ORGANISATION IS) is optional to provide compatibility with those (few) COBOL implementations that consider that word to be optional. Most COBOL implementations do require the word ORGANIZATION, so it should be used in new programs.
  4. ORGANIZATION RELATIVE files cannot be assigned to the CONSOLE, DISPLAY, LINE ADVANCING or PRINTER devices.
  5. The RELATIVE KEY clause is optional only if ACCESS MODE SEQUENTIAL is specified.
  6. While an ORGANIZATION RELATIVE file may be defined as having variable-length records, the file will be structured in such a manner as to reserve space for each record equal to the size of the largest possible record as defined by the file’s description in the FILE SECTION.
  7. ACCESS MODE SEQUENTIAL, the default ACCESS MODE if none is specified, indicates that the records of the file will be processed in a sequential manner, according to their physical sequence in the file.
  8. ACCESS MODE RANDOM means that records will be processed in random sequence by specifying their record number in the file every time the file is read or written.
  9. ACCESS MODE DYNAMIC indicates the program may switch back and forth between SEQUENTIAL and RANDOM mode during execution. The file starts out initially in SEQUENTIAL mode when first opened but the program may use the START statement (see START) to switch between sequential and random access.
  10. The RELATIVE KEY data item is a numeric data item that cannot be defined as a field within records of this file. Its purpose is to return the current relative record number of a relative file that is being processed in SEQUENTIAL access mode and to serve as a key that specifies the relative record number to be read or written when processing a relative file in RANDOM access mode.
  11. Relative files are processed using the following statements:


5.2.1.4. ORGANIZATION INDEXED

ORGANIZATION INDEXED Clause Syntax
=======================================================================

 [ ORGANIZATION|ORGANISATION IS ] INDEXED
   ~~~~~~~~~~~~ ~~~~~~~~~~~~      ~~~~~~~
    [ ACCESS MODE IS { SEQUENTIAL } ]
      ~~~~~~         { ~~~~~~~~~  }
                     { DYNAMIC    }
                     { ~~~~~~~    }
                     { RANDOM     }
                       ~~~~~~
    [ RECORD KEY IS { [ data-name-1       ]
      ~~~~~~
                    { [ record-key-name-1 ]
                      [ =|{SOURCE IS} data-name-2 ] ... ] }
                           ~~~~~~
    [ ALTERNATE RECORD KEY IS { [ data-name-3       ]
      ~~~~~~~~~ ~~~~~~
                              { [ record-key-name-2 ]
                                [ =|{SOURCE IS} data-name-4 ] ... ] }
                                     ~~~~~~
                              [ WITH DUPLICATES ] ]...
                                     ~~~~~~~~~~
                              [ SUPPRESS WHEN ALL literal     ]
                                ~~~~~~~~~~~~~~~~~
                              [ SUPPRESS WHEN SPACES | ZEROES ]
                                ~~~~~~~~~~~~~~~~~~~~   ~~~~~~

=======================================================================

Indexed files, like relative files, may have their records processed in either a sequential or random manner. Unlike relative files, however, the actual location of a record in an indexed file is calculated automatically based upon the value(s) of one or more alphanumeric fields within records of the file. For example, an indexed file containing product data might use the product identification code as a record key. This means you may read, write or update the A6G4328th record or the Z8X7723th record directly, based upon the product id value of those records!

  1. The reserved words IS, KEY and MODE are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved words ORGANIZATION and ORGANISATION are interchangeable.
  3. The phrase ORGANIZATION IS (and its internationalized alternative, ORGANISATION IS) is optional to provide compatibility with those (few) COBOL implementations that consider that word to be optional. Most COBOL implementations do require the word ORGANIZATION, so it should be used in new programs.
  4. ORGANIZATION INDEXED files cannot be assigned to CONSOLE, DISPLAY, KEYBOARD, LINE ADVANCING or PRINTER.
  5. ACCESS MODE SEQUENTIAL, the default ACCESS MODE if none is specified, indicates that the records of the file will be processed in a sequential manner with respect to the values of the RECORD KEY or the ALTERNATE RECORD KEY most-recently referenced on a START statement (see START).
  6. ACCESS MODE RANDOM means that records will be processed in random sequence by accessing the record with specific record key or alternate record key values.
  7. ACCESS MODE DYNAMIC allows the file will be processed either in RANDOM or SEQUENTIAL mode; the program may switch between the two modes as needed. The START statement is used to make the switch between modes.
  8. The RECORD KEY clause defines the field within the record used to provide the primary access to records within the file. No two records in the file will be allowed to have the same PRIMARY KEY field value. The SOURCE IS clause is for use with Split Keys.
  9. The ALTERNATE RECORD KEY clause, if used, defines an additional field within the record that provides an alternate means of directly accessing records or an additional field by which the file’s contents may be processed sequentially. You have the choice of allowing records to have duplicate alternate key values, if necessary.
  10. There may be multiple ALTERNATE RECORD KEY clauses, each defining an additional alternate key for the file.
  11. Usage of the SUPPRESS WHEN clause is used when Sparse Keys are required which may take the form for a literal or spaces or zeroes.
  12. Indexed files are processed using the following statements:


5.2.2. SAME RECORD AREA

I-O-CONTROL SAME AREA Syntax
=======================================================================

 SAME { SORT-MERGE } AREA FOR file-name-1... .
 ~~~~ { ~~~~~~~~~~ }
      { SORT       }
      { ~~~~       }
      { RECORD     }
        ~~~~~~

The SAME SORT-MERGE and SAME SORT clauses are syntactically recognized but are otherwise non-functional.


=======================================================================

The SAME RECORD AREA clause allows you to specify that multiple files should share the same input and output memory buffers.

  1. The reserved words AREA and FOR are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. This statement must be terminated with a period.
  3. While coding only a single file name (the repeated file-name-1 item) is syntactically valid, this statement will have no effect upon the program unless at least two files are specified.
  4. The effect of this statement will be to cause the specified files to share the same I/O buffer in memory. These buffers can sometimes get quite large, and by having multiple files share the same buffer memory you may significantly cut down the amount of memory the program is using (thus making “room” for more procedural code or data). If you do use this feature, take care to ensure that no more than one of the specified files are ever OPEN simultaneously.


5.2.3. MULTIPLE FILE

I-O-CONTROL MULTIPLE FILE Syntax
=======================================================================

 MULTIPLE FILE TAPE CONTAINS
 ~~~~~~~~
    { file-name-1 [ POSITION integer-1 ] }...
                    ~~~~~~~~
    .

The MULTIPLE FILE TAPE clause is obsolete and is therefore recognized but not functional.


=======================================================================


6. DATA DIVISION

DATA DIVISION Syntax
=======================================================================

   DATA DIVISION.
   ~~~~ ~~~~~~~~
 [ FILE SECTION.
   ~~~~ ~~~~~~~
   { File/Sort-Description [ { FILE-SECTION-Data-Item } ]... }... ]
   {                         { 01-Level-Constant      }      }
   {                         { 78-Level-Constant      }      }
   { 01-Level-Constant                                       }
   { 78-Level-Constant                                       }
 [ WORKING-STORAGE SECTION.
   ~~~~~~~~~~~~~~~ ~~~~~~~
   [ { WORKING-STORAGE-SECTION-Data-Item } ]... ]
     { 01-Level-Constant                 }
     { 78-Level-Constant                 }
 [ LOCAL-STORAGE SECTION.
   ~~~~~~~~~~~~~ ~~~~~~~
   [ { LOCAL-STORAGE-SECTION-Data-Item } ]... ]
     { 01-Level-Constant               }
     { 78-Level-Constant               }
 [ LINKAGE SECTION.
   ~~~~~~~ ~~~~~~~
   [ { LINKAGE-SECTION-Data-Item } ]... ]
     { 01-Level-Constant         }
     { 78-Level-Constant         }
 [ REPORT SECTION.
   ~~~~~~ ~~~~~~~
   { Report-Description [ { Report-Group-Definition } ]... }... ]
   {                      { 01-Level-Constant       }      }
   {                      { 78-Level-Constant       }      }
   { 01-Level-Constant                                     }
   { 78-Level-Constant                                     }
 [ SCREEN SECTION.
   ~~~~~~ ~~~~~~~
   [ { SCREEN-SECTION-Data-Item } ]... ]
     { 01-Level-Constant        }
     { 78-Level-Constant        }

=======================================================================

All data used by any COBOL program must be defined in one of the six sections of the data division, depending upon the purpose of the data.

  1. If no data will be described in one of the data division sections, that section header may be omitted.
  2. If no data division sections are needed, the DATA DIVISION. header itself may be omitted.
  3. If more than one section is needed in the data division (a common situation), the sections must be coded in the sequence they are presented above.


6.1. Data Definition Principles

GnuCOBOL data items, like those of other COBOL implementations, are described in a hierarchical manner. This accommodates the fact that data items frequently need to be able to be broken up into subordinate items. Take for example, the following logical layout of a portion of a data item named Employee:

                           Employee
                               |                     Additional
              :----------------:----------------:--> Data Items ...
              |                                 |
        Employee-name                    Employment-Dates
              |                                 |
    :---------:-------------:           :-------:-------:
    |         |             |           |               |
Last-Name First-Name Middle-Initial From-Date        To-Date
                                        |               |
                                   :----:----:     :----:----:
                                   |    |    |     |    |    |
                                 Year Month Day  Year Month Day

The Employee data item consists of two subordinate data items — an Employee-Name and an Employment-Dates data item (presumably there would be a lot of others too, but we don’t care about them right now). As the diagram shows, each of those data items are, in turn, broken down into subordinate data items. This hierarchy of data items can get rather deep, and GnuCOBOL, like other COBOL implementations, can handle up to 49 levels of such hierarchical structures.

As was presented earlier (see Structured Data), a data item that is broken down into other data items is referred to as a group item, while one that isn’t broken down is called an elementary item.

COBOL uses the concept of a level number to indicate the level at which a data item occurs in a data structure such as the example shown above. When these data items are defined, they are all defined together with a number in the range 1-49 specified in front of their names. Over the years, a convention has come to exist among COBOL programmers that level numbers are always coded as two-digit numbers — they don’t need to be specified as two-digit numbers, but every example you see in this document will take that approach!

The data item at the top, also referred to as a record, always has a level number of 01. After that, you may assign level numbers as you wish (01–02–03–04…, 01–05–10–15…, etc.), as long as you follow these simple rules:

  1. Every data item at the same level of a hierarchy diagram such as the one you see here (if you were to make one, which you rarely will, if ever, once you get used to this concept) must have the same level number.
  2. Every new level uses a level number that is strictly greater than the one used in the parent (next higher) level.
  3. When describing data hierarchies, you may never use a level number greater than 49 (except for 66, 77, 78 and 88 which have very special meanings (see Special Data Items).

So, the definition of these data items in a GnuCOBOL program would go something like this:

    01  Employee
        05 Employee-Name
           10 Last-Name
           10 First-Name
           10 Middle-Initial
        05 Employment-Dates
           10 From-Date
              15 Year
              15 Month
              15 Day
           10 To-Date
              15 Year
              15 Month
              15 Day

The indentation is purely at the discretion of the programmer to make things easier for humans to read (the compiler couldn’t care less). Historically, COBOL implementations that required Fixed Format Mode source programs required that the 01 level number begin in Area A and that everything else begins in Area B. GnuCOBOL only requires that all data definition syntax occur in columns 8-72. In Free Format Mode, of course, there aren’t even those limitations.

Did you notice that there are two each of Year, Month and Day data names defined? That’s perfectly legal, provided that each can be uniquely qualified so as to be distinct from the other. Take for example the Year items. One is defined as part of the From-Date data item while the other is defined as part of the To-Date data item. In COBOL, we would actually code references to these two data items as either Year OF From-Date and Year OF To-Date or Year IN From-Date and Year IN To-Date (COBOL allows either IN or OF to be used). Since these references would clarify any confusion to us as to which Year might be referenced, the GnuCOBOL compiler won’t be confused either.

The coding example shown above is incomplete; it only describes the data item names and their hierarchical relationships to one other. In addition, any valid data item definitions will also need to describe what type of data is to be contained in a data item (Numeric? Alphanumeric? Alphabetic?), how much data can be held in the data item and a multitude of other characteristics.

When group items are being defined, subordinate items may be assigned the “name”   FILLER. There may be any number of FILLER items defined within a group item. A data item named FILLER cannot be referenced directly; these items are generally used to specify an unused portion of the total storage allocated to a group item. Note that it is possible that the name of the group item itself might be specified as FILLER if there is no need to ever refer directly to the group structure itself.



6.2. FILE SECTION

FILE SECTION Syntax
=======================================================================

 [ FILE SECTION.
   ~~~~ ~~~~~~~
   { File/Sort-Description [ { FILE-SECTION-Data-Item } ]... }... ]
   {                         { 01-Level-Constant      }      }
   {                         { 78-Level-Constant      }      }
   { 01-Level-Constant                                       }
   { 78-Level-Constant                                       }

=======================================================================

Every file that has been referenced by a SELECT statement (see SELECT) must also be described in the file section of the data division.

Files destined for use as sort/merge work files must be described with a Sort/Merge File Description (SD) while every other file is described with a File Description (FD). Each of these descriptions will almost always be followed with at least one record description.



6.2.1. File/Sort-Description

File/Sort-Description Syntax
=======================================================================

 FD|SD file-name-1 [ IS EXTERNAL|GLOBAL ]
 ~~ ~~                  ~~~~~~~~ ~~~~~~
 [ BLOCK CONTAINS [ integer-1 TO ] integer-2 CHARACTERS|RECORDS ]
   ~~~~~                      ~~             ~~~~~~~~~~ ~~~~~~~
 [ CODE-SET IS alphabet-name-1 ]
   ~~~~~~~~
 [ DATA { RECORD IS   } identifier-1... ]
   ~~~~ { ~~~~~~      }
        { RECORDS ARE }
          ~~~~~~~
 [ LABEL { RECORD IS   } OMITTED|STANDARD ]
   ~~~~~ { ~~~~~~      } ~~~~~~~ ~~~~~~~~
         { RECORDS ARE }
           ~~~~~~~
 [ LINAGE IS integer-3 | identifier-2 LINES
   ~~~~~~
     [ LINES AT BOTTOM integer-4 | identifier-3 ]
                ~~~~~~
     [ LINES AT TOP integer-5 | identifier-4 ]
                ~~~
     [ WITH FOOTING AT integer-6 | identifier-5 ] ]
            ~~~~~~~
 [ RECORD { CONTAINS [ integer-7 TO ] integer-8 CHARACTERS   } ]
   ~~~~~~ {                      ~~                          }
          { IS VARYING IN SIZE                               }
          {    ~~~~~~~                                       }
          {     [ FROM [ integer-7 TO ] integer-8 CHARACTERS }
          {                        ~~                        }
          {         DEPENDING ON identifier-6 ]              }
                    ~~~~~~~~~
 [ RECORDING MODE IS recording-mode ]
   ~~~~~~~~~
 [ { REPORT IS   } report-name-1... ]
   { ~~~~~~      }
   { REPORTS ARE }
     ~~~~~~~
 [ VALUE OF implementor-name-1 IS literal-1 | identifier-7 ] .
   ~~~~~ ~~

The BLOCK CONTAINS, DATA RECORD, LABEL RECORD, RECORDING MODE and VALUE OF clauses are syntactically recognized but are obsolete and non-functional. These clauses should not be coded in new programs.


=======================================================================
  1. The reserved words ARE, AT, CHARACTERS (RECORD clause only), CONTAINS, FROM, IN, IS, ON and WITH are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program.
  2. The terms RECORD IS and RECORDS ARE are interchangeable.
  3. The terms REPORT IS and REPORTS ARE are interchangeable.
  4. Only files intended for use as work files for either the SORT (see SORT) or MERGE (see MERGE) statements should be coded with an SD — all others should be defined with a FD.
  5. The sequence in which files are defined via FD or SD, as compared to the sequence in which their SELECT statements were coded, is irrelevant.
  6. The name specified as file-name-1 must exactly match the name specified on the file’s SELECT statement.
  7. The CODE-SET clause allows a custom alphabet, defined in the SPECIAL-NAMES (see SPECIAL-NAMES) paragraph, to be associated with a file. This clause is valid only when used with sequential or line sequential files.
  8. The LINAGE clause may only be specified in the FD of a sequential or line sequential file. If used with a sequential file, the organization of that file will be implicitly changed to line sequential. The various components of the LINAGE clause define the layout of printed pages as follows:
    LINES AT TOP

    Number of unused (i.e. left blank) lines at the top of every page. The default if this if not specified is zero.

    LINES AT BOTTOM

    Number of unused (i.e. left blank) lines at the bottom of every page. The default if this if not specified is zero.

    LINAGE IS n LINES

    Total number of used/usable lines on the page.

    The sum of the previous three specifications should be the total number of possible lines available on one printed page.

    FOOTING AT

    Line number beyond which nothing may be printed except for any footing that is to appear on every page. The default for this if not specified is zero, meaning there will be no footings. This value cannot be larger than the LINAGE IS n LINES value.

  9. This page structure — once defined — can be automatically enforced by the WRITE statement (see WRITE).
  10. Specifying a LINAGE clause in an FD will cause the LINAGE-COUNTER special register to be created for the file. This automatically-created data item will always contain the current relative line number on the page being prepared which will serve as the starting point for a WRITE statement.
  11. The RECORD CONTAINS and RECORD IS VARYING clauses are ignored (with a warning message issued) when used with line sequential files. With other file organizations, these mutually-exclusive clauses define the length of data records within the file. The data item specified as identifier-6 must be defined within one of the record descriptions of file-name-1.
  12. The REPORT IS clause announces to the compiler that the file will be dedicated to the Report Writer Control System (RWCS); the clause names one or more reports, each to be described in the report section. The following special rules apply when the REPORT clause is used:
    1. The clause may only be specified in the FD of a sequential or line sequential file. If used with a sequential file, the organization of that file will be implicitly changed to line sequential.
    2. The FD cannot be followed by record descriptions. Detailed descriptions of data to be printed to the file will be defined in the REPORT SECTION (see REPORT SECTION).
    3. If a LINAGE clause is also specified, Values specified for LINAGE IS and FOOTING AT will be ignored. The values of LINES AT BOTTOM and LINES AT TOP, if any, will be honoured.
  13. The following special rules apply only to sort/merge work files:
    1. Sort/merge work files should be assigned to DISK (or DISC) on their SELECT statements.
    2. Sorts and merges will be performed in memory, if the amount of data being sorted allows.
    3. Should actual disk work files be necessary due to the amount of data being sorted or merged, they will be automatically allocated to disk in a folder defined by:
      • The TMPDIR run-time environment variable (see Run Time Environment Variables)
      • The TMP run-time environment variable
      • The TEMP run-time environment variable

      (in that order).

    4. These disk files will be automatically purged upon SORT or MERGE termination. They will also be purged if the program terminates abnormally before the SORT or MERGE finishes. Should you ever need to know, temporary sort/merge work files will be named cob*.tmp.
    5. If you specify a specific filename in the sort/merge work file’s SELECT, it will be ignored.
  14. See Data Description Clauses, for information on the EXTERNAL and GLOBAL options.


6.2.2. FILE-SECTION-Data-Item

FILE-SECTION-Data-Item Syntax
=======================================================================

 level-number [ identifier-1 | FILLER ] [ IS GLOBAL|EXTERNAL ]
                               ~~~~~~        ~~~~~~ ~~~~~~~~
 [ BLANK WHEN ZERO ]
   ~~~~~      ~~~~
 [ JUSTIFIED RIGHT ]
   ~~~~
 [ OCCURS [ integer-1 TO ] integer-2 TIMES
   ~~~~~~             ~~
        [ DEPENDING ON identifier-2 ]
          ~~~~~~~~~
        [ ASCENDING|DESCENDING KEY IS identifier-3 ]
          ~~~~~~~~~ ~~~~~~~~~~
        [ INDEXED BY identifier-4 ] ]
          ~~~~~~~
 [ PICTURE IS picture-string ]
   ~~~
 [ REDEFINES identifier-5 ]
   ~~~~~~~~~
 [ SIGN IS LEADING|TRAILING [ SEPARATE [CHARACTER] ] ]
   ~~~~    ~~~~~~~ ~~~~~~~~   ~~~~~~~~
 [ SYNCRONIZED|SYNCHRONISED [ LEFT|RIGHT ] ]
   ~~~~        ~~~~           ~~~~ ~~~~~
 [ USAGE IS data-item-usage ] . [ FILE-SECTION-Data-Item ]...
   ~~~~~

The LEFT and RIGHT (SYNCRONIZED) clauses are syntactically recognized but are otherwise non-functional.


=======================================================================

Every sort file description (SD or FD) must be followed by at least one 01-level data item, except for file descriptions containing the REPORT IS clause. These 01-level data items, in turn, may be broken down into subordinate group and elementary items. An 01-level data item defined here in the file section is also known as a Record, even if it is an elementary item, provided that elementary item lacks the CONSTANT attribute.

  1. The reserved words BY, IS, KEY, ON and WHEN are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program.
  2. The reserved words SYNCRONIZED and SYNCRONIZED are interchangeable. Both may be abbreviated to SYNC.
  3. The reserved word PICTURE may be abbreviated to PIC.
  4. As the syntax diagram shows, the definition of a FILE-SECTION-Data-Item is a recursive one in that there may be any number of such specifications coded following a FD or SD. The first such specification must have a level number of 01, and will describe a specific format of data record within the file. Specifications that follow that one may have level numbers greater than 01, in which case they are defining a hierarchical breakdown of the record. The definition of a record is terminated when one of the following occurs:
    Another 01-level item is found

    signifies the start of another record layout for the file.

    Another FD or SD is found

    marks the completion of the detailed description of the file and begins another.

    A division or section header is found

    also marks the completion of the detailed description of the file and signifies the end of the file section as well.

  5. Every FILE-SECTION-Data-Item description must be terminated with a period.
  6. If there are multiple record descriptions present for a given FD or SD, the one with the longest length will define the size of the record buffer into which a READ statement (see READ) or a RETURN statement (see RETURN) will deliver data read from the file and from which a WRITE statement (see WRITE) or RELEASE statement (see RELEASE) statement will obtain the data to be written to the file.
  7. The various 01-level record descriptions for a file description implicitly share that one common record buffer (thus, they provide different ways to view the structure of data that can exist within the file). Record buffers can be shared between files by using the SAME RECORD AREA (see SAME RECORD AREA) clause.
  8. The only valid level numbers are 01-49, 66, 77, 78 and 88. Level numbers 66, 77, 78 and 88 all have special uses — See Special Data Items, for details.
  9. Not specifying an identifier-1 or FILLER immediately after the level number has the same effect as if FILLER were specified. A data item named FILLER cannot be referenced directly; these items are generally used to specify an unused portion of the total storage allocated to a group item or to describe a group item whose contents which will only be referenced using the names of those items that belong to it.
  10. EXTERNAL cannot be combined with GLOBAL or REDEFINES.
  11. File section data buffers (and therefore all 01-level record layouts defined in the file section) are initialized to all binary zeros when the program is loaded into storage.
  12. See Data Description Clauses, for information on the usage of the various data description clauses.


6.3. WORKING-STORAGE SECTION

WORKING-STORAGE-SECTION-Data-Item Syntax
=======================================================================

 level-number [ identifier-1 | FILLER ] [ IS GLOBAL | EXTERNAL ]
                               ~~~~~~        ~~~~~~   ~~~~~~~~
 [ BASED ]
   ~~~~~
 [ BLANK WHEN ZERO ]
   ~~~~~      ~~~~
 [ JUSTIFIED RIGHT ]
   ~~~~
 [ OCCURS [ integer-1 TO ] integer-2 TIMES
   ~~~~~~             ~~
       [ DEPENDING ON identifier-2 ]
         ~~~~~~~~~
       [ ASCENDING|DESCENDING KEY IS identifier-3 ]
         ~~~~~~~~~ ~~~~~~~~~~
       [ INDEXED BY identifier-4 ] ]
         ~~~~~~~
 [ PICTURE IS picture-string ]
   ~~~
 [ REDEFINES identifier-5 ]
   ~~~~~~~~~
 [ SIGN IS LEADING|TRAILING [ SEPARATE CHARACTER ] ]
   ~~~~    ~~~~~~~ ~~~~~~~~   ~~~~~~~~
 [ SYNCRONIZED|SYNCHRONISED [ LEFT|RIGHT ] ]
   ~~~~        ~~~~           ~~~~ ~~~~~
 [ USAGE IS data-item-usage ]
   ~~~~~
 [ VALUE IS [ ALL ] literal-1 ] . [ WORKING-STORAGE-SECTION-Data-Item ]...
   ~~~~~      ~~~

The LEFT and RIGHT (SYNCRONIZED) clauses are syntactically recognized but are otherwise non-functional.


=======================================================================

The working-storage section is used to describe data items that are not part of files, screens or reports and whose data values persist throughout the execution of the program.

  1. The reserved words BY, CHARACTER, IS, KEY, ON, RIGHT (JUSTIFIED), TIMES and WHEN are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program.
  2. The reserved words SYNCRONIZED and SYNCHRONISED are interchangeable. Both may be abbreviated as SYNC.
  3. The reserved word PICTURE may be abbreviated to PIC.
  4. The reserved word JUSTIFIED may be abbreviated to JUST.
  5. As the syntax diagram shows, the definition of a WORKING-STORAGE-SECTION-Data-Item is a recursive one in that there may be any number of such specifications coded following one another. The first such specification must have a level number of 01. Specifications that follow that one may have level numbers greater than 01, in which case they are defining a hierarchical breakdown of a record. The definition of a record is terminated when one of the following occurs:
  6. Every WORKING-STORAGE-SECTION-Data-Item description must be terminated with a period.
  7. The only valid level numbers are 01-49, 66, 77, 78 and 88. Level numbers 01 through 49 are used to define data items that may be part of a hierarchical structure. Level number 01 can also be used to define a constant — an item with an unchangeable value specified at compilation time.
  8. Level numbers 66, 77, 78 and 88 all have special uses — See Special Data Items, for details.
  9. Not specifying an identifier-1 or FILLER immediately after the level number has the same effect as if FILLER were specified. A data item named FILLER cannot be referenced directly; these items are generally used to specify an unused portion of the total storage allocated to a group item or to describe a group item whose contents which will only be referenced using the names of those items that belong to it.
  10. Data items defined within the working-storage section are automatically initialized once — as the program in which the data is defined is loaded into memory. Subprograms may be loaded into memory more than once (see the CANCEL statement (see CANCEL)), in which case initialization will happen each time they are loaded. See Data Initialization, for a discussion of the initialization rules.
  11. See Data Description Clauses, for information on the usage of the various data description clauses.


6.4. LOCAL-STORAGE SECTION

LOCAL-STORAGE-SECTION-Data-Item Syntax
=======================================================================

 level-number [ identifier-1 | FILLER ] [ IS GLOBAL|EXTERNAL ]
                               ~~~~~~        ~~~~~~ ~~~~~~~~
 [ BASED ]
   ~~~~~
 [ BLANK WHEN ZERO ]
   ~~~~~      ~~~~
 [ JUSTIFIED RIGHT ]
   ~~~~
 [ OCCURS [ integer-1 TO ] integer-2 TIMES
   ~~~~~~             ~~
       [ DEPENDING ON identifier-2 ]
         ~~~~~~~~~
       [ ASCENDING|DESCENDING KEY IS identifier-3 ]
         ~~~~~~~~~ ~~~~~~~~~~
       [ INDEXED BY identifier-4 ] ]
         ~~~~~~~
 [ PICTURE IS picture-string ]
   ~~~
 [ REDEFINES identifier-5 ]
   ~~~~~~~~~
 [ SIGN IS LEADING|TRAILING [ SEPARATE CHARACTER ] ]
   ~~~~    ~~~~~~~ ~~~~~~~~   ~~~~~~~~
 [ SYNCRONIZED|SYNCHRONISED [ LEFT|RIGHT ] ]
   ~~~~        ~~~~           ~~~~ ~~~~~
 [ USAGE IS data-item-usage ]
   ~~~~~
 [ VALUE IS [ ALL ] literal-1 ] . [ LOCAL-STORAGE-SECTION-Data-Item ]...
   ~~~~~      ~~~

The LEFT and RIGHT (SYNCRONIZED) clauses are syntactically recognized but are otherwise non-functional.


=======================================================================

The local-storage section is similar to working-storage, but describes data within a subprogram that will be dynamically allocated and initialized (automatically) each time the subprogram is executed. See Data Initialization, for the rules of data initialization.

  1. The reserved words BY, CHARACTER IS, KEY, ON, RIGHT (JUSTIFIED), TIMES and WHEN are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program.
  2. The reserved words SYNCRONIZED and SYNCHRONISED are interchangeable. Both may be abbreviated as SYNC.
  3. The reserved word PICTURE may be abbreviated to PIC.
  4. The reserved word JUSTIFIED may be abbreviated to JUST.
  5. As the syntax diagram shows, the definition of a LOCAL-STORAGE-SECTION-Data-Item is a recursive one in that there may be any number of such specifications coded following one another. The first such specification must have a level number of 01. Specifications that follow that one may have level numbers greater than 01, in which case they are defining a hierarchical breakdown of a record. The definition of a record is terminated when one of the following occurs:
  6. Every LOCAL-STORAGE-SECTION-Data-Item description must be terminated with a period.
  7. The only valid level numbers are 01-49, 66, 77, 78 and 88. Level numbers 01 through 49 are used to define data items that may be part of a hierarchical structure. Level number 01 can also be used to define a constant — an item with an unchangeable value specified at compilation time.
  8. Level numbers 66, 77, 78 and 88 all have special uses — See Special Data Items, for details.
  9. Not specifying an identifier-1 or FILLER immediately after the level number has the same effect as if FILLER were specified. A data item named FILLER cannot be referenced directly; these items are generally used to specify an unused portion of the total storage allocated to a group item or to describe a group item whose contents which will only be referenced using the names of those items that belong to it.
  10. Local-storage cannot be used in nested subprograms.
  11. See Data Description Clauses, for information on the usage of the various data description clauses.


6.5. LINKAGE SECTION

LINKAGE-SECTION-Data-Item Syntax
=======================================================================

 level-number [ identifier-1 | FILLER ] [ IS GLOBAL|EXTERNAL ]
                               ~~~~~~        ~~~~~~ ~~~~~~~~
 [ ANY LENGTH ]
   ~~~ ~~~~~~
 [ BASED ]
   ~~~~~
 [ BLANK WHEN ZERO ]
   ~~~~~      ~~~~
 [ JUSTIFIED RIGHT ]
   ~~~~
 [ OCCURS [ integer-1 TO ] integer-2 TIMES
   ~~~~~~             ~~
       [ DEPENDING ON identifier-3 ]
         ~~~~~~~~~
       [ ASCENDING|DESCENDING KEY IS identifier-4 ]
         ~~~~~~~~~ ~~~~~~~~~~
       [ INDEXED BY identifier-5 ] ]
         ~~~~~~~
 [ PICTURE IS picture-string ]
   ~~~
 [ REDEFINES identifier-6 ]
   ~~~~~~~~~
 [ SIGN IS LEADING|TRAILING [ SEPARATE CHARACTER ] ]
   ~~~~    ~~~~~~~ ~~~~~~~~   ~~~~~~~~
 [ SYNCRONIZED|SYNCHRONISED [ LEFT|RIGHT ] ]
   ~~~~        ~~~~           ~~~~ ~~~~~
 [ USAGE IS data-item-usage ] . [ LINKAGE-SECTION-Data-Item ]...
   ~~~~~

The LEFT and RIGHT (SYNCRONIZED) clauses are syntactically recognized but are otherwise non-functional.


=======================================================================

The linkage section describes data within a subprogram that serves as either input arguments to or output results from the subprogram.

  1. The reserved words BY, CHARACTER, IS, KEY, ON and WHEN are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program.
  2. The reserved words SYNCRONIZED and “SYNCHRONISED” are interchangeable. Both may be abbreviated as SYNC.
  3. The reserved word PICTURE may be abbreviated to PIC.
  4. The reserved word JUSTIFIED may be abbreviated to JUST.
  5. As the syntax diagram shows, the definition of a LINKAGE-SECTION-Data-Item is a recursive one in that there may be any number of such specifications coded following one another. The first such specification must have a level number of 01. Specifications that follow that one may have level numbers greater than 01, in which case they are defining a hierarchical breakdown of a record. The definition of a record is terminated when one of the following occurs:
  6. Every LINKAGE-SECTION-Data-Item description must be terminated with a period.
  7. The only valid level numbers are 01-49, 66, 77, 78 and 88. Level numbers 01 through 49 are used to define data items that may be part of a hierarchical structure. Level number 01 can also be used to define a constant — an item with an unchangeable value specified at compilation time.
  8. Level numbers 66, 77, 78 and 88 all have special uses — See Special Data Items, for details.
  9. It is expected that:
    1. A linkage section should occur only within a subprogram. The compiler will not prevent its use in a main program, however.
    2. All 01-level data items described within a subprogram’s linkage section should appear in a PROCEDURE DIVISION USING (see PROCEDURE DIVISION USING) or as arguments on an ENTRY statement.
    3. Each 01-level data item described within a subprogram’s linkage section should correspond to an argument passed on a CALL statement (see CALL) or an argument on a function call to the subprogram.
  10. Not specifying an identifier-1 or FILLER immediately after the level number has the same effect as if FILLER were specified. A data item named FILLER cannot be referenced directly; these items are generally used to specify an unused portion of the total storage allocated to a group item or to describe a group item whose contents which will only be referenced using the names of those items that belong to it. In the linkage section, 01-level data items cannot be named FILLER.
  11. No storage is allocated for data defined in the linkage section; the data descriptions there are merely defining storage areas that will be passed to the subprogram by a calling program. Therefore, any discussion of the default initialization of such data is irrelevant. It is possible, however, to manually allocate linkage section data items that aren’t subprogram arguments via the ALLOCATE statement (see ALLOCATE) statement. In such cases, initialization will take place as per the documentation of that statement.
  12. See Data Description Clauses, for information on the usage of the various data description clauses.


6.6. REPORT SECTION

REPORT SECTION Syntax
=======================================================================

 [ REPORT SECTION.
   ~~~~~~ ~~~~~~~
   { Report-Description [ { Report-Group-Definition } ]... }... ]
   {                      { 01-Level-Constant       }      }
   {                      { 78-Level-Constant       }      }
   { 01-Level-Constant                                     }
   { 78-Level-Constant                                     }

=======================================================================
Report-Description (RD) Syntax
=======================================================================

 RD report-name [ IS GLOBAL ]
 ~~                  ~~~~~~
 [ CODE IS literal-1 | identifier-1 ]
   ~~~~
 [ { CONTROL IS   } { FINAL        }... ]
   { ~~~~~~~      } { ~~~~~        }
   { CONTROLS ARE } { identifier-2 }
     ~~~~~~~~
 [ PAGE [ { LIMIT IS   } ] [ { literal-2    } LINES ]
   ~~~~   { ~~~~~      }     { identifier-3 } ~~~~
          { LIMITS ARE }
            ~~~~~~
       [ literal-3 | identifier-4 COLUMNS|COLS ]
                                  ~~~~~~~ ~~~~
       [ HEADING IS literal-4 | identifier-5 ]
         ~~~~~~~
       [ FIRST DE|DETAIL IS literal-5 | identifier-6 ]
         ~~~~~ ~~ ~~~~~~
       [ LAST CH|{CONTROL HEADING} IS literal-6 | identifier-7 ]
         ~~~~ ~~  ~~~~~~~ ~~~~~~~
       [ LAST DE|DETAIL IS literal-7 | identifier-8 ]
         ~~~~ ~~ ~~~~~~
       [ FOOTING IS literal-8 | identifier-9 ] ] .
         ~~~~~~~

=======================================================================

This section describes the layout of printed reports as well as many of the functional aspects of the generation of reports that will be produced via the Report Writer Control System. It is important to maintain the order of these clauses and ensure that all fields defined or referenced with this section are actually defined in the WORKING-STORAGE SECTION and not elsewhere.

  1. The reserved words ARE and IS are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The phrases CONTROL IS and CONTROLS ARE are interchangeable, as are the PAGE LIMIT and PAGE LIMITS phrases.
  3. The reserved word LINES may be abbreviated as LINE.
  4. The reserved word COLUMNS may be abbreviated as COLS.
  5. Each report referenced on a REPORT IS clause (see File/Sort-Description) must be described with a report description (RD).
  6. See GLOBAL, for information on the GLOBAL option.
  7. Please see Report Writer Features, if you have not read it already. It will familiarize you with the Report Writer terminology that follows.
  8. The following rules pertain to the PAGE LIMITS clause:
    1. If no PAGE LIMITS clause is specified, the entire report will be generated as if it consists of a single arbitrarily long page.
    2. All literals (literal-2 through literal-8) must be numeric with non-zero positive integer values.
    3. All identifiers (identifier-2 through identifier-8) must be numeric, unedited with non-zero positive integer values.
    4. Any value specified for literal-2 or identifier-2 will define the total number of available lines on any report page, not counting any unused margins at the top and/or bottom of the page (defined by the LINES AT TOP and LINES AT BOTTOM values specified on the LINAGE clause of the FD this RD is linked to — see File/Sort-Description).
    5. Any value specified for literal-3 or identifier-3 will be ignored.
    6. The HEADING clause defines the first line number at which a report heading or page heading may be presented.
    7. The FIRST DETAIL clause defines the first line at which a detail group may be presented.
    8. The LAST CONTROL HEADING clause defines the last line at which any line of a control heading may be presented.
    9. The LAST DETAIL clause defines the last line at which any line of a detail group may be presented.
    10. The FOOTING clause defines the last line at which any line of a control footing group may be presented.
    11. The following rules establish default values for the various PAGE LIMIT clauses, assuming there is one:
      HEADING

      default is one (1)

      FIRST DETAIL HEADING

      value is used

      LAST CONTROL HEADING

      value from LAST DETAIL or, if that is absent, the value from FOOTING or, if that too is absent, the value from PAGE LIMIT

      LAST DETAIL

      value from FOOTING or, if that is absent, the value from PAGE LIMIT

      FOOTING

      value from LAST DETAIL or, if that is absent, the value from PAGE LIMIT

    12. For the values specified on a PAGE LIMIT clause to be valid, all of the following must be true:
      • FIRST DETAILHEADING
      • LAST CONTROL HEADINGFIRST DETAIL
      • LAST DETAILLAST CONTROL HEADING
      • FOOTINGLAST DETAIL
  9. The following rules pertain to the CONTROL clause:
    1. If there is no CONTROL clause, the report will contain no control breaks; this implies that there can be no CONTROL HEADING or CONTROL FOOTING report groups defined for this RD.
    2. Include the reserved word FINAL if you want to include a special control heading before the first detail line is generated (CONTROL HEADING FINAL) or after the last detail line is generated (CONTROL FOOTING FINAL).
    3. If you specify FINAL, it must be the first control break named in the RD.
    4. Any identifier-9 specifications included on the CONTROL clause are referencing data names defined in any data division section except for the report section.
    5. There must be a CONTROL HEADING and/or CONTROL FOOTING report group defined in the report section for each identifier-9.
    6. At execution time:
      • Each time a GENERATE statement (see GENERATE) is executed against a detail report group defined for this RD, the RWCS will check the contents of each identifier-2 data item; whenever an identifier-9’s value has changed since the previous GENERATE, a control break condition will be in effect for that identifier-2.
      • Once the list of control breaks has been determined, the CONTROL FOOTING for each identifier-2 having a control break (if any such report group is defined) will be presented.
      • Next, the CONTROL HEADING for each identifier-2 having a control break (if any such report group is defined) will be presented.
      • The CONTROL FOOTING and CONTROL HEADING report groups will be presented in the sequence in which they are listed on the CONTROL clause.
      • Only after this processing has occurred will the detail report group specified on the GENERATE be presented.
  10. Each RD will have the following allocated for it:
    1. The PAGE-COUNTER special register (see Special Registers), which will contain the current report page number.
      • This register will be set to a value of 1 when an INITIATE statement (see INITIATE) is executed for the report and will be incremented by 1 each time the RWCS starts a new page of the report.
      • References to PAGE-COUNTER within the report section will be implicitly qualified with the name of the report to which the report group referencing the register belongs.
      • References to PAGE-COUNTER in the procedure division must be qualified with the appropriate report name if there are multiple RDs defined.
    2. The LINE-COUNTER special register, which will contain the current line number on the current page.
  11. The RD must be followed by at least one 01-level report group definition.


6.6.1. Report Group Definitions

Report-Group-Definition Syntax
=======================================================================

 01 [ identifier-1 ]

 [ LINE NUMBER IS { integer-1 [ [ ON NEXT PAGE ] } ]
   ~~~~           {                  ~~~~ ~~~~   }
                  { +|PLUS integer-1             }
                  {   ~~~~                       }
                  { ON NEXT PAGE                 }
                       ~~~~ ~~~~
 [ NEXT GROUP IS { [ +|PLUS ] integer-2  } ]
   ~~~~ ~~~~~    {     ~~~~              }
                 { NEXT|{NEXT PAGE}|PAGE }
                   ~~~~  ~~~~ ~~~~  ~~~~
 [ TYPE IS { RH|{REPORT HEADING}                      } ]
   ~~~~    { ~~  ~~~~~~ ~~~~~~~                       }
           { PH|{PAGE HEADING}                        }
           { ~~  ~~~~ ~~~~~~~                         }
           { CH|{CONTROL HEADING} FINAL|identifier-2  }
           { ~~  ~~~~~~~ ~~~~~~~  ~~~~~               }
           { DE|DETAIL                                }
           { ~~ ~~~~~~                                }
           { CF|{CONTROL FOOTING} FINAL|identifier-2  }
           { ~~  ~~~~~~~ ~~~~~~~  ~~~~~               }
           { PF|{PAGE FOOTING}                        }
           {  ~~ ~~~~ ~~~~~~~                         }
           { RF|{REPORT FOOTING}                      }
             ~~  ~~~~~~ ~~~~~~~
 . [ REPORT-SECTION-Data-Item ]...

=======================================================================

The syntax shown here documents how a report group is defined to a report. This syntax is valid only in the report section, and only then after an RD.

  1. The reserved words IS, NUMBER and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The RH and REPORT HEADING terms are interchangeable, as are PH and PAGE HEADING, CH and CONTROL HEADING, DE and DETAIL, CF and CONTROL FOOTING, PF and PAGE FOOTING as well as RF and REPORT FOOTING.
  3. The report group being defined will be a part of the most-recently coded RD.
  4. The TYPE (see TYPE) clause specifies the type of report group being defined.
  5. The level number used for a report group definition must be 01.
  6. The optional identifier-1 specification assigns a name to this report group so that the group may be referenced either by a GENERATE statement or on a USE BEFORE REPORTING.
  7. No two report groups in the same report (RD) may named with the same identifier-1. There may, however, be multiple identifier-1 definitions in different reports. In such instances, references to identifier-1 must be qualified by the report name.
  8. There may only be one report heading, report footing, final control heading, final control footing, page heading and page footing defined per report.
  9. Report group declarations must be followed by at least one REPORT-SECTION-Data-Item with a level number in the range 02-49.
  10. See Data Description Clauses, for information on the usage of the various data description clauses.


6.6.2. REPORT SECTION Data Items

REPORT-SECTION-Data-Item Syntax
=======================================================================

 level-number [ identifier-1 ]

 [ BLANK WHEN ZERO ]
   ~~~~~      ~~~~
 [ COLUMN [ { NUMBER IS   } ] [ +|PLUS ] integer-1 ]
   ~~~      { ~~~~~~      }       ~~~~
            { NUMBERS ARE }
              ~~~~~~~
 [ GROUP INDICATE ]
   ~~~~~ ~~~~~~~~
 [ JUSTIFIED RIGHT ]
   ~~~~
 [ LINE NUMBER IS { integer-2 [ [ ON NEXT PAGE ] } ]
   ~~~~           { +|PLUS integer-2 ~~~~ ~~~~   }
                  {   ~~~~                       }
                  { ON NEXT PAGE                 }
                       ~~~~ ~~~~
 [ OCCURS [ integer-3 TO ] integer-4 TIMES
   ~~~~~~             ~~
     [ DEPENDING ON identifier-2 ]
       ~~~~~~~~~
     [ STEP integer-5 ]
       ~~~~
     [ VARYING identifier-3 FROM { identifier-4 } BY { identifier-5 } ]
       ~~~~~~~              ~~~~ { integer-6    } ~~ { integer-7    }
 [ PICTURE IS picture-string ]
   ~~~
 [ PRESENT WHEN condition-name ]
   ~~~~~~~ ~~~~
 [ SIGN IS LEADING|TRAILING [ SEPARATE CHARACTER ] ]
   ~~~~    ~~~~~~~ ~~~~~~~~   ~~~~~~~~
 [ { SOURCE IS literal-1|identifier-6 [ ROUNDED ]                   } ]
   { ~~~~~~                             ~~~~~~~                     }
   { SUM OF { identifier-7 }... [ { RESET ON FINAL|identifier-8 } ] }
   { ~~~    { literal-2    }      { ~~~~~    ~~~~~              }   }
   { VALUE IS [ ALL ] literal-3   { UPON identifier-9           }   }
     ~~~~~      ~~~                 ~~~~
 . [ REPORT-SECTION-Data-Item ]...

=======================================================================

Data item descriptions describing the report lines and fields that make up the substance of a report group immediately follow the definition of that group.

  1. The reserved words IS, NUMBER, OF, ON, RIGHT, TIMES and WHEN (BLANK) are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved word COLUMN may be abbreviated as COL.
  3. The reserved word JUSTIFIED may be abbreviated as JUST.
  4. The reserved word PICTURE may be abbreviated as PIC.
  5. The SOURCE (see SOURCE), SUM (see SUM) and VALUE (see VALUE) clauses, valid only on an elementary item, are mutually-exclusive of each other.
  6. Group items (those without PICTURE clauses) are frequently used to describe entire lines of a report, while elementary items (those with a picture clause) are frequently used to describe specific fields of information on the report. When this coding convention is being used, group items will have LINE (see LINE) clauses and no COLUMN (see COLUMN) clauses while elementary items will be specified the other way around.
  7. See Data Description Clauses, for information on the usage of the various data description clauses.


6.7. SCREEN SECTION

SCREEN-SECTION-Data-Item Syntax
=======================================================================

 level-number [ identifier-1 | FILLER ]
                               ~~~~~~
 [ AUTO | AUTO-SKIP | AUTOTERMINATE ] [ BELL | BEEP ]
   ~~~~   ~~~~~~~~~   ~~~~~~~~~~~~~     ~~~~   ~~~~
 [ BACKGROUND-COLOR|BACKGROUND-COLOUR IS integer-1 | identifier-2 ]
   ~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~
 [ BLANK LINE|SCREEN ] [ ERASE EOL|EOS ]
   ~~~~~ ~~~~ ~~~~~~     ~~~~~ ~~~ ~~~
 [ BLANK WHEN ZERO ] [ JUSTIFIED RIGHT ]
   ~~~~~      ~~~~     ~~~~
 [ BLINK ] [ HIGHLIGHT | LOWLIGHT ] [ REVERSE-VIDEO ]
   ~~~~~     ~~~~~~~~~   ~~~~~~~~     ~~~~~~~~~~~~~
 [ COLUMN NUMBER IS [ +|PLUS ] integer-2 | identifier-3 ]
   ~~~                  ~~~~
 [ FOREGROUND-COLOR|FOREGROUND-COLOUR IS integer-3 | identifier-4 ]
   ~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~
 [ { FROM literal-1 | identifier-5 } ]
   { ~~~~                          }
   { TO identifier-5               }
   { ~~                            }
   { USING identifier-5            }
   { ~~~~~                         }
   { VALUE IS [ ALL ] literal-1    }
     ~~~~~      ~~~
 [ FULL | LENGTH-CHECK ] [ REQUIRED | EMPTY-CHECK ] [ SECURE | NO-ECHO ]
   ~~~~   ~~~~~~~~~~~~     ~~~~~~~~   ~~~~~~~~~~~     ~~~~~~   ~~~~~~~
 [ LEFTLINE ] [ OVERLINE ] [ UNDERLINE ]
   ~~~~~~~~     ~~~~~~~~     ~~~~~~~~~
 [ LINE NUMBER IS [ +|PLUS ] integer-4 | identifier-6 ]
   ~~~~               ~~~~
 [ OCCURS integer-5 TIMES ]
   ~~~~~~
 [ PICTURE IS picture-string ]
   ~~~
 [ PROMPT [ CHARACTER IS literal-2 | identifier-7 ]
   ~~~~~~   ~~~~~~~~~
 [ SIGN IS LEADING|TRAILING [ SEPARATE CHARACTER ] ]
   ~~~~    ~~~~~~~ ~~~~~~~~   ~~~~~~~~
 . [ SCREEN-SECTION-Data-Item ]...

=======================================================================

The screen section describes the screens to be displayed during terminal/console I-O.

  1. The reserved words CHARACTER (SEPARATE clause), IS, NUMBER, RIGHT, TIMES and WHEN are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved word COLUMN may be abbreviated as COL.
  3. The reserved word PICTURE may be abbreviated as PIC.
  4. The following sets of reserved words are interchangeable:
  5. Data items defined in the screen section describe input, output or combination screen layouts to be used with ACCEPT screen-data-item statement (see ACCEPT screen-data-item) or DISPLAY screen-data-item statement (see DISPLAY screen-data-item) statements. These screen layouts may define the entire available screen area or any subset of it.
  6. The term available screen area is a nebulous one in those environments where command-line shell sessions are invoked within a graphical user-interface environment, as will be the case on Windows, OSX and most Unix/Linux systems — these environments allow command-line session windows to exist with a variable number of available screen rows and columns. When you are designing GnuCOBOL screens, you need to do so with an awareness of the logical screen row/column geometry the program will be executing within.
  7. Data items with level numbers 01 (Constants), 66, 78 and 88 may be used in the screen section; they have the same syntax, rules and usage as they do in the other data division sections.
  8. Without LINE (see LINE) or COLUMN (see COLUMN) clauses, screen section fields will display on the console window beginning at whatever line/column coordinate is stated or implied by the ACCEPT screen-data-item or DISPLAY screen-data-item statement that presents the screen item. After a field is presented to the console window, the next field will be presented immediately following that field.
  9. A LINE clause explicitly stated in the definition of a screen section data item will override any LINE clause included on the ACCEPT screen-data-item or DISPLAY screen-data-item statement that presents that data item to the screen. The same is true of COLUMN clauses.
  10. The Tab and Back-Tab (Shift-Tab on most keyboards) keys will position the cursor from field to field in the line/column sequence in which the fields occur on the screen at execution time, regardless of the sequence in which they were defined in the screen section.
  11. See Data Description Clauses, for information on the usage of the various data description clauses.


6.8. Special Data Items



6.8.1. 01-Level Constants

01-Level-Constant Syntax
=======================================================================

 01 constant-name-1 CONSTANT [ IS GLOBAL ]
                    ~~~~~~~~      ~~~~~~
   { AS { literal-1                           } } .
   {    { { BYTE-LENGTH } OF { identifier-1 } } }
   {    { { ~~~~~~~~~~~ }    { usage-name   } } }
   {    { { LENGTH      }                     } }
   {        ~~~~~~                              }
   { FROM CDF-variable-name-1                   }
     ~~~~

=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, SCREEN.

The 01-level constant is one of four types of compilation-time constants that can be declared within a program. The other three types are >>DEFINE CDF directive (see >>DEFINE) constants, >>SET CDF directive (see >>SET) constants and 78-level constants (see 78-Level Data Items).

  1. The reserved words AS, IS and OF are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. See GLOBAL, for information on the GLOBAL option.
  3. This particular type of constant declaration provides the ability to determine the length of a data item or the storage size associated with a particular numeric USAGE (see USAGE) type — something not possible with the other types of constants.
  4. Constants defined in this way become undefined once an END PROGRAM or END FUNCTION is encountered in the input source.
  5. Data descriptions of this form do not actually allocate any storage — they merely define a name (constant-name-1) that may be used anywhere a numeric literal (see BYTE-LENGTH or LENGTH options) or a literal of the same type as literal-1 may be used.
  6. The constant-name-1 name may not be referenced on a CDF directive.
  7. Care must be taken that constant-name-1 does not duplicate any other data item name that has been defined in the program as references to that data item name will refer to the constant and not the data item. The GnuCOBOL compiler will not issue a warning about this condition.
  8. The value specified for usage-name may be any USAGE that does not use a PICTURE (see PICTURE) clause. These would be any of BINARY-C-LONG, BINARY-CHAR, BINARY-DOUBLE, BINARY-LONG, BINARY-SHORT, COMP-1 (or COMPUTATIONAL-1), COMP-2 (or COMPUTATIONAL-2), FLOAT-DECIMAL-16, FLOAT-DECIMAL-34, FLOAT-LONG, FLOAT-SHORT, POINTER, or PROGRAM-POINTER.
  9. The BYTE-LENGTH clause will produce a numeric value for constant-name-1 identical to that which would be returned by the BYTE-LENGTH intrinsic function executed against identifier-1 or a data item declared with a USAGE of usage-name.
  10. The LENGTH clause will produce a numeric value for constant-name-1 identical to that which would be returned by the LENGTH intrinsic function executed against identifier-1 or a data item declared with a USAGE of usage-name.

Here is the listing of a GnuCOBOL program that uses 01-level constants to display the length (in bytes) of the various picture-less usage types.

    IDENTIFICATION DIVISION.
    PROGRAM-ID. Usage Lengths.
    DATA DIVISION.
    WORKING-STORAGE SECTION.
    01  Len-BINARY-C-LONG    CONSTANT AS LENGTH OF BINARY-C-LONG.
    01  Len-BINARY-CHAR      CONSTANT AS LENGTH OF BINARY-CHAR.
    01  Len-BINARY-DOUBLE    CONSTANT AS LENGTH OF BINARY-DOUBLE.
    01  Len-BINARY-LONG      CONSTANT AS LENGTH OF BINARY-LONG.
    01  Len-BINARY-SHORT     CONSTANT AS LENGTH OF BINARY-SHORT.
    01  Len-COMP-1           CONSTANT AS LENGTH OF COMP-1.
    01  Len-COMP-2           CONSTANT AS LENGTH OF COMP-2.
    01  Len-FLOAT-DECIMAL-16 CONSTANT AS LENGTH OF FLOAT-DECIMAL-16.
    01  Len-FLOAT-DECIMAL-34 CONSTANT AS LENGTH OF FLOAT-DECIMAL-34.
    01  Len-FLOAT-LONG       CONSTANT AS LENGTH OF FLOAT-LONG.
    01  Len-FLOAT-SHORT      CONSTANT AS LENGTH OF FLOAT-SHORT.
    01  Len-POINTER          CONSTANT AS LENGTH OF POINTER.
    01  Len-PROGRAM-POINTER  CONSTANT AS LENGTH OF PROGRAM-POINTER.
    PROCEDURE DIVISION.
    000-Main.
        DISPLAY "On this system, with this build of GnuCOBOL, the"
        DISPLAY "PICTURE-less USAGE's have these lengths (in bytes):"
        DISPLAY " "
        DISPLAY "BINARY-C-LONG:    " Len-BINARY-C-LONG
        DISPLAY "BINARY-CHAR:      " Len-BINARY-CHAR
        DISPLAY "BINARY-DOUBLE:    " Len-BINARY-DOUBLE
        DISPLAY "BINARY-LONG:      " Len-BINARY-LONG
        DISPLAY "BINARY-SHORT:     " Len-BINARY-SHORT
        DISPLAY "COMP-1:           " Len-COMP-1
        DISPLAY "COMP-2:           " Len-COMP-2
        DISPLAY "FLOAT-DECIMAL-16: " Len-FLOAT-DECIMAL-16
        DISPLAY "FLOAT-DECIMAL-34: " Len-FLOAT-DECIMAL-34
        DISPLAY "FLOAT-LONG:       " Len-FLOAT-LONG
        DISPLAY "FLOAT-SHORT:      " Len-FLOAT-SHORT
        DISPLAY "POINTER:          " Len-POINTER
        DISPLAY "PROGRAM-POINTER:  " Len-PROGRAM-POINTER
        STOP RUN
        .

The output of this program, on a Windows 7 system with a 32-bit MinGW build of GnuCOBOL is:

    On this system, with this build of GnuCOBOL, the
    PICTURE-less USAGE's have these lengths (in bytes):

    BINARY-C-LONG:    4
    BINARY-CHAR:      1
    BINARY-DOUBLE:    8
    BINARY-LONG:      4
    BINARY-SHORT:     2
    COMP-1:           4
    COMP-2:           8
    FLOAT-DECIMAL-16: 8
    FLOAT-DECIMAL-34: 16
    FLOAT-LONG:       8
    FLOAT-SHORT:      4
    POINTER:          4
    PROGRAM-POINTER:  4


6.8.2. 66-Level Data Items

66-Level-Data-Item Syntax
=======================================================================

 66 identifier-1 RENAMES identifier-2 [ THRU|THROUGH identifier-3 ] .
                 ~~~~~~~                ~~~~ ~~~~~~~

=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE

A 66-level data item regroups previously defined items by specifying alternative, possibly overlapping, groupings of elementary data items.

  1. The reserved words THRU and THROUGH are interchangeable.
  2. A level-66 data item cannot rename a level-66, level-01, level-77, or level-88 data item.
  3. There may be multiple level-66 data items that rename data items contained within the same 01-level record description.
  4. All RENAMES entries associated with one logical record must immediately follow that record’s last data description entry.


6.8.3. 77-Level Data Items

77-Level-Data-Item Syntax
=======================================================================

 77 identifier-1 [ IS GLOBAL|EXTERNAL ]
                      ~~~~~~ ~~~~~~~~
 [ BASED ]
   ~~~~~
 [ BLANK WHEN ZERO ]
   ~~~~~      ~~~~
 [ JUSTIFIED RIGHT ]
   ~~~~
 [ PICTURE IS picture-string ]
   ~~~
 [ REDEFINES identifier-5 ]
   ~~~~~~~~~
 [ SIGN IS LEADING|TRAILING [ SEPARATE CHARACTER ] ]
   ~~~~    ~~~~~~~ ~~~~~~~~   ~~~~~~~~
 [ SYNCRONIZED|SYNCHRONISED [ LEFT|RIGHT ] ]
   ~~~~        ~~~~           ~~~~ ~~~~~
 [ USAGE IS data-item-usage ]
   ~~~~~
 [ VALUE IS [ ALL ] literal-1 ] .
   ~~~~~      ~~~

The LEFT and RIGHT (SYNCRONIZED) clauses are syntactically recognized but are otherwise non-functional.


=======================================================================

This syntax is valid in the following sections: WORKING-STORAGE, LOCAL-STORAGE, LINKAGE

The intent of a 77-level item is to be able to create a stand-alone elementary data item.

  1. The reserved words CHARACTER, IS, RIGHT (JUSTIFIED) and WHEN are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved word JUSTIFIED may be abbreviated as JUST, the reserved word PICTURE may be abbreviated as PIC and the reserved words SYNCRONIZED and SYNCHRONISED may be abbreviated as SYNC.
  3. New programs requiring a stand-alone elementary item should be coded to use a level number of 01 rather than 77.
  4. See Data Description Clauses, for information on the usage of the various data description clauses.


6.8.4. 78-Level Data Items

78-Level-Constant Syntax
=======================================================================

 78 constant-name-1 VALUE IS literal-1 .
                    ~~~~~

=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, SCREEN

The 78-level constant is one of four types of compilation-time constants that can be declared within a program. The other three types are >>DEFINE CDF directive (see >>DEFINE) constants, >>SET CDF directive (see >>SET) constants and 01-level constants (see 01-Level Constants).

  1. The reserved word IS is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. Constants defined in this way become undefined once an END PROGRAM or END FUNCTION is encountered in the input source.
  3. Data descriptions of this form do not actually allocate any storage — they merely define a name (constant-name-1) that may be used anywhere a literal of the same type as literal-1 may be used.
  4. The constant-name-1 name may not be referenced on a CDF directive.
  5. Care must be taken that constant-name-1 does not duplicate any other data item name that has been defined in the program as references to that data item name will refer to the constant and not the data item. The GnuCOBOL compiler will not issue a warning about this condition.


6.8.5. 88-Level Data Items

88-Level-Data-Item Syntax
=======================================================================

 88 condition-name-1 { VALUE IS   } {literal-1 [ THRU|THROUGH literal-2 ]}...
                     { ~~~~~      }              ~~~~ ~~~~~~~
                     { VALUES ARE }
                       ~~~~~~

   [ WHEN SET TO FALSE IS literal-3 ] .
                 ~~~~~

=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT, SCREEN

Condition names are Boolean (i.e. TRUE / FALSE) data items that receive their TRUE and FALSE values based upon the values of the non 88-level data item whose definition they immediately follow.

  1. The reserved words ARE, IS, SET and TO are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved words THRU and THROUGH are interchangeable.
  3. Condition names are always defined subordinate to another (non 88-level) data item. That data item must be an elementary item. Whenever the parent data item assumes one of the values specified on the 88-level item’s VALUE (see VALUE) clause, condition-name-1 will take on the value of TRUE.
  4. Condition names do not occupy any storage.
  5. The optional THROUGH clause allows a range of possible TRUE values to be specified.
  6. Whenever the parent data item assumes any value except one of the values specified on condition-name-1’s VALUE clause, condition-name-1 will take on the value of FALSE.
  7. Executing the statement SET condition-name-1 TO TRUE will cause condition-name-1’s parent data item to take on the first value specified on condition-name-1’s VALUE clause.
  8. Executing the statement SET condition-name-1 TO FALSE will cause condition-name-1’s parent data item to take on the value specified on condition-name-1’s FALSE clause. If condition-name-1 does not have a FALSE clause, the SET (see SET) statement will generate an error message at compilation time.
  9. See Condition Names, for more information.


6.9. Data Description Clauses



6.9.1. ANY LENGTH

ANY LENGTH Attribute Syntax
=======================================================================

 ANY LENGTH
 ~~~ ~~~~~~

=======================================================================

This syntax is valid in the following sections: LINKAGE

Data items declared with the ANY LENGTH attribute have no fixed compile-time length. Such items may only be defined in the linkage section of a subprogram as they may only serve as subroutine argument descriptions. These items must have a PICTURE (see PICTURE) clause that specifies exactly one A, X or 9 symbol.

  1. The ANY LENGTH and BASED (see BASED) clauses cannot be used together in the same data item description.


6.9.2. AUTO

AUTO Attribute Syntax
=======================================================================

 AUTO
 ~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

A field whose description includes this attribute will cause the cursor to automatically advance to the next input-enabled field of a screen if the field is completely filled with input data.

  1. The AUTO, AUTO-SKIP (see AUTO-SKIP) and AUTOTERMINATE (see AUTOTERMINATE) clauses are interchangeable, and may not be used together in the same data item description.


6.9.3. AUTO-SKIP

AUTO-SKIP Attribute Syntax
=======================================================================

 AUTO-SKIP
 ~~~~~~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

A field whose description includes this attribute will cause the cursor to automatically advance to the next input-enabled field of a screen if the field is completely filled with input data.

  1. The AUTO (see AUTO), AUTO-SKIP and AUTOTERMINATE (see AUTOTERMINATE) clauses are interchangeable, and may not be used together in the same data item description.


6.9.4. AUTOTERMINATE

AUTOTERMINATE Attribute Syntax
=======================================================================

 AUTOTERMINATE
 ~~~~~~~~~~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

A field whose description includes this attribute will cause the cursor to automatically advance to the next input-enabled field of a screen if the field is completely filled with input data.

  1. The AUTO (see AUTO), AUTO-SKIP (see AUTO-SKIP) and AUTOTERMINATE clauses are interchangeable, and may not be used together in the same data item description.


6.9.5. BACKGROUND-COLOR

BACKGROUND-COLOR Attribute Syntax
=======================================================================

 BACKGROUND-COLOR|BACKGROUND-COLOUR IS integer-1 | identifier-1
 ~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

This clause is used to specify the screen background color of the screen data item or the default screen background color of subordinate items if used on a group item.

  1. The reserved word IS is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. The reserved words BACKGROUND-COLOR and BACKGROUND-COLOUR are interchangeable.
  3. You specify colors by number (0-7), or by using the constant names provided in the screenio.cpy copybook (provided with all GnuCOBOL source distributions).
  4. Colors may also be specified using a numeric non-edited identifier whose value is in the range 0-7.

For composite DISPLAY’s, the attributes are always only applied to the previous source-item but the following also allows a change by variable or literal i.e.

DISPLAY "Name: "   BACKGROUND-COLOR COB-YELLOW
         NAME-VAR  BACKGROUND-COLOR COB-BLACK
END-DISPLAY

See Color Palette and Video Attributes, for more information on screen colors and video attributes.



6.9.6. BASED

BASED Attribute Syntax
=======================================================================

 BASED
 ~~~~~

=======================================================================

This syntax is valid in the following sections: WORKING-STORAGE, LOCAL-STORAGE, LINKAGE

Data items declared with BASED are allocated no storage at compilation time. At run-time, the ALLOCATE (see ALLOCATE) or SET ADDRESS (see SET ADDRESS) statements are used to allocate space for and (optionally) initialize such items.

  1. The BASED and ANY LENGTH (see ANY LENGTH) clauses cannot be used together in the same data item description.
  2. The BASED clause may only be used on level 01 and level 77 data items.


6.9.7. BEEP

BEEP Attribute Syntax
=======================================================================

 BEEP
 ~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

  1. The BEEP and BELL (see BELL) clauses are interchangeable, and may not be used together in the same data item description.
  2. Use this clause to cause an audible tone to occur when the screen item is DISPLAYed.


6.9.8. BELL

BELL Attribute Syntax
=======================================================================

 BELL
 ~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

  1. The BEEP (see BEEP) and BELL clauses are interchangeable, and may not be used together in the same data item description.
  2. Use this clause to cause an audible tone to occur when the screen item is DISPLAYed.


6.9.9. BLANK

BLANK Attribute Syntax
=======================================================================

 BLANK LINE|SCREEN
 ~~~~~ ~~~~ ~~~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

This clause will blank out either the entire screen (BLANK SCREEN) or just the line upon which data is about to be displayed (BLANK LINE).

  1. Blanked-out areas will have their foreground and background colors set to the attributes of the field containing the BLANK clause.
  2. This clause is useful when one screen section item is being displayed over the top of a previously-displayed one.


6.9.10. BLANK WHEN ZERO

BLANK-WHEN-ZERO Attribute Syntax
=======================================================================

 BLANK WHEN ZERO
 ~~~~~      ~~~~

=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT, SCREEN

This clause will cause that item’s value to be automatically transformed into spaces if a value of 0 is ever MOVEd to the item.

  1. The reserved word WHEN is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. This clause may only be used on a PIC 9 data item with a USAGE (see USAGE) of DISPLAY.


6.9.11. BLINK

BLINK Attribute Syntax
=======================================================================

 BLINK
 ~~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

The BLINK clause modifies the visual appearance of the displayed field by making the field contents blink.

See Color Palette and Video Attributes, for more information on screen colors and video attributes.



6.9.12. COLUMN

COLUMN (REPORT SECTION) Clause Syntax
=======================================================================

 COLUMN [ { NUMBER IS   } ] [ +|PLUS ] integer-1 ]
 ~~~      { NUMBERS ARE }       ~~~~

=======================================================================
COLUMN (SCREEN SECTION) Clause Syntax
=======================================================================

 COLUMN NUMBER IS [ +|PLUS ] integer-2 | identifier-3 ]
 ~~~                  ~~~~

=======================================================================

This syntax is valid in the following sections: REPORT, SCREEN

The COLUMN clause provides the means of stating in which column a field should be presented on the console window (screen section) or a report (report section).

  1. The reserved words ARE, IS, NUMBER and NUMBERS are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved word COLUMN may be abbreviated as COL.
  3. The line location of a report section or screen section field will be determined by the LINE (see LINE) clause.
  4. The value of integer-1 must be 1 or greater.
  5. If identifier-1 is used to specify either an absolute or relative column position, identifier-1 must be defined as a numeric item of any USAGE (see USAGE) other than COMPUTATIONAL-1 or COMPUTATIONAL-2, without editing symbols. The value of identifier-1 at the time the screen data item is presented must be 1 or greater. Note that a COMPUTATIONAL-1 or COMPUTATIONAL-2 identifier will be accepted by the compiler, but will produce unpredictable results at run-time.
  6. The column coordinate of a field may be stated on an absolute basis (i.e. COLUMN 5) or on a relative basis based upon the end of the previously-presented field (i.e. COLUMN PLUS 1).
  7. The symbol ‘+’ may be used in lieu of the word PLUS, if desired; if symbol ‘+’ is used, however, there must be at least one space separating it from integer-1. Failure to include this space will cause the symbol ‘+’ sign to be simply treated as part of integer-1 and will treat the COLUMN clause as an absolute column specification rather than a relative one.
  8. Using relative column positioning (COLUMN PLUS) has slightly different behaviour depending upon the section in which the clause is used, as follows:
    1. When used on a report section data item, COLUMN PLUS will position the start of the new field’s value such that there are integer-1 blank columns between the end of the previous field and the beginning of this field.

      If a report data item’s description includes the SOURCE (see SOURCE), SUM (see SUM) or VALUE (see VALUE) clause but has no COLUMN clause, COLUMN PLUS 1 will be assumed.

    2. When used on a screen section data item, COLUMN PLUS will position the new field so that it begins exactly integer-1 or identifier-1 characters past the last character of the previous field. Thus, COLUMN PLUS 1 will leave no blank positions between the end of the previous field and the start of this one.

      If a screen data item’s description includes the FROM (see FROM), TO (see TO), USING (see USING) or VALUE (see VALUE) clause but has no COLUMN clause, the new screen field will begin at the column coordinate of the last character of the previous field.



6.9.13. CONSTANT

CONSTANT Attribute Syntax
=======================================================================

 CONSTANT
 ~~~~~~~~

=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, SCREEN

This option signifies that the 01-level data item in whose declaration CONSTANT is specified will be treated as a symbolic name for a literal value, usable wherever a literal of the appropriate type could be used.

  1. The value of a data item defined as a constant cannot be changed at run-time. In fact, it is not syntactically acceptable to use such a data item as the destination field of any procedure division statement that stores a value.
  2. See 01-Level Constants, for additional information.


6.9.14. EMPTY-CHECK

EMPTY-CHECK Attribute Syntax
=======================================================================

 EMPTY-CHECK
 ~~~~~~~~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

This clause forces the user to enter data into the field it is specified on (or into all subordinate input-capable fields if EMPTY-CHECK is specified on a group item).

  1. The EMPTY-CHECK and REQUIRED (see REQUIRED) clauses are interchangeable, and may not be used together in the same data item description.
  2. In order to take effect, the user must first move the cursor into the field having this clause in its definition.
  3. The ACCEPT screen-data-item statement (see ACCEPT screen-data-item) will ignore the Enter key and any other cursor-moving keystrokes that would cause the cursor to move to another screen item unless data has been entered into the field. Function keys will still be allowed to terminate the ACCEPT.
  4. In order to be functional, this attribute must be supported by the underlying “curses” package your GnuCOBOL implementation was built with. As of this time, the “PDCurses” package (used for native Windows or MinGW builds) does not support EMPTY-CHECK.


6.9.15. ERASE

ERASE Clause Syntax
=======================================================================

 ERASE EOL|EOS
 ~~~~~ ~~~ ~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

ERASE will blank-out screen contents from the location where the screen data item whose description contains this clause will be displayed, forward until the end of the screen (ERASE EOS)

  1. Erased areas will have their foreground and background colors set to the attributes of the field containing the ERASE clause.
  2. This clause is useful when one screen section item is being displayed over the top of a previously-displayed one.

See Color Palette and Video Attributes, for more information on screen colors and video attributes.



6.9.16. EXTERNAL

EXTERNAL Attribute Syntax
=======================================================================

 EXTERNAL
 ~~~~~~~~

=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE

This clause marks a data item description, FD or SD see File/Sort-Description as being shareable with other programs executed from the same execution thread.

  1. By specifying the EXTERNAL clause on either an FD or an SD, the file description is capable of being shared between all programs executed from the same execution thread, provided an EXTERNAL clause is coded with the file’s description in each program requiring it. This sharing allows the file to be opened, read and/or written and closed in different programs. This sharing applies to the record descriptions subordinate to the file description too.
  2. By specifying the EXTERNAL clause on the description of a data item, the data item is capable of being shared between all programs executed from the same execution thread, provided the data item is coded (with an EXTERNAL clause) in each program requiring it.
  3. The following points apply to the specification of EXTERNAL in a data item’s definition:
    1. The EXTERNAL clause may only be specified at the 77 or 01 level.
    2. An EXTERNAL item must have a data name and that name cannot be FILLER.
    3. EXTERNAL cannot be combined with BASED (see BASED), GLOBAL (see GLOBAL) or REDEFINES (see REDEFINES).


6.9.17. FALSE

FALSE Clause Syntax
=======================================================================

 WHEN SET TO FALSE IS literal-1
             ~~~~~

=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT, SCREEN

This clause, which may only appear on the definition of a level-88 condition name, is used to specify the value of the data item that serves as the parent of the level-88 condition name that will force the condition name to assume a value of FALSE.

  1. The reserved words IS, SET, TO and WHEN are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. See 88-Level Data Items, or See Condition Names, for more information.


6.9.18. FOREGROUND-COLOR

FOREGROUND-COLOR Attribute Syntax
=======================================================================

 FOREGROUND-COLOR|FOREGROUND-COLOUR IS integer-1 | identifier-1
 ~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

This clause is used to specify the color of text within a screen data item or the default text color of subordinate items if used on a group item.

  1. The reserved word IS is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. The reserved words FOREGROUND-COLOR and FOREGROUND-COLOUR are interchangeable.
  3. You specify colors by number (0-7), or by using the constant names provided in the screenio.cpy copybook (which is provided with all GnuCOBOL source distributions).
  4. Colors may also be specified using a numeric non-edited identifier whose value is in the range 0-7.

See Color Palette and Video Attributes, for more information on screen colors and video attributes.



6.9.19. FROM

FROM Clause Syntax
=======================================================================

 FROM literal-1 | identifier-5
 ~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

This clause is used to specify either the data item a screen section field is to obtain its value from when the screen is displayed, or a literal that will specify the value of that same field.

  1. The FROM, TO (see TO), USING (see USING) and VALUE (see VALUE) clauses are mutually-exclusive in any screen section data item’s definition.


6.9.20. FULL

FULL Attribute Syntax
=======================================================================

 FULL
 ~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

The FULL clause forces the user to enter data into the field it is specified on (or into all subordinate input-capable fields if specified on a group item) sufficient to fill every character position of the field.

  1. The FULL and LENGTH-CHECK (see LENGTH-CHECK) clauses are interchangeable, and may not be used together in the same data item description.
  2. In order for this clause to take effect at execution time, the user must move the cursor into the field having this clause in its definition.
  3. The ACCEPT screen-data-item statement (see ACCEPT screen-data-item) will ignore the Enter key and any other cursor-moving keystrokes that would cause the cursor to move to another screen item unless the proper amount of data has been entered into the field. Function keys will still be allowed to terminate the ACCEPT, however.
  4. In order to be functional, this attribute must be supported by the underlying “curses” package your GnuCOBOL implementation was built with. As of this time, the “PDCurses” package (used for native Windows or MinGW builds) does not support FULL.


6.9.21. GLOBAL

GLOBAL Attribute Syntax
=======================================================================

 GLOBAL
 ~~~~~~

=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, REPORT

This clause marks a data item, 01-level constant, FD (see File/Sort-Description), SD (see File/Sort-Description) or an RD (see REPORT SECTION) as being shareable with any nested subprograms.

  1. By specifying the GLOBAL clause on the description of a file or a report, that description is capable of being shared between a program and any nested subprograms within it, provided the FD, SD or RD is coded (with a GLOBAL clause) in each nested subprogram requiring it. This sharing allows the file to be opened, read and/or written and closed or the report to be initiated or terminated in those programs. Separately compiled programs may not share a GLOBAL file description, but they may share an EXTERNAL (see EXTERNAL) file description. This sharing applies to the record descriptions subordinate to the file description and the report groups subordinate to the RD also.
  2. By specifying the GLOBAL clause on the description of a data item, the data item is capable of being shared between a program and any nested subprograms within it, provided the data item is coded (with a GLOBAL clause) in each program requiring it.
  3. The following points apply to the specification of GLOBAL in a data item’s definition:
    1. The GLOBAL clause may only be specified at the 77 or 01 level.
    2. A GLOBAL item must have a data name and that name cannot be FILLER.
    3. GLOBAL cannot be combined with EXTERNAL (see EXTERNAL), REDEFINES (see REDEFINES) or BASED (see BASED).


6.9.22. GROUP INDICATE

GROUP-INDICATE Attribute Syntax
=======================================================================

 GROUP INDICATE
 ~~~~~ ~~~~~~~~

=======================================================================

This syntax is valid in the following sections: REPORT

The GROUP INDICATE clause specifies that the data item in whose definition the clause appears will be presented only in very limited circumstances.

  1. This clause may only appear within a DETAIL report group (see TYPE).
  2. When this clause is present, the data item in question will be presented only under the following circumstances:
    1. On the first presentation of the detail group following the INITIATE (see INITIATE) of the report.
    2. On the first presentation of the detail group after every new page is started.
    3. On the first presentation of the detail group after any control break occurs.


6.9.23. HIGHLIGHT

HIGHLIGHT Attribute Syntax
=======================================================================

 HIGHLIGHT
 ~~~~~~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

This clause controls the intensity of text (FOREGROUND-COLOR (see FOREGROUND-COLOR)) by setting that intensity to its highest of three possible settings.

  1. This clause, along with LOWLIGHT (see LOWLIGHT), are intended to provide a three-level intensity scheme (LOWLIGHT … nothing (Normal) … HIGHLIGHT).

See Color Palette and Video Attributes, for more information on screen colors and video attributes.



6.9.24. JUSTIFIED

JUSTIFIED Attribute Syntax
=======================================================================

 JUSTIFIED RIGHT
 ~~~~


=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT, SCREEN

The presence of a JUSTIFIED RIGHT clause in a data item’s definition alters the manner in which data is stored into the field from the default ’left-justified, space filled’ behaviour to ’right justified, space filled’.

  1. The reserved word RIGHT is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. The reserved word JUSTIFIED may be abbreviated as JUST.
  3. This clause is valid only on alphabetic (PIC A) or alphanumeric (PIC X) data items.
  4. The presence or absence of this clause influences the behaviour of the MOVE (see MOVE) statement as well as the FROM (see FROM), SOURCE (see SOURCE) and USING (see USING) data item description clauses.
  5. If the value being stored into the field is the same length as the receiving field, the presence or absence of the JUSTIFIED RIGHT clause on that field’s description is irrelevant.
  6. The following examples illustrate the behaviour of the presence and absence of the JUSTIFIED RIGHT clause when the field size is different than that of the value being stored. In these examples, the symbol b represents a space.

    When the value is shorter than the field size:

    Without JUSTIFIEDWith JUSTIFIED
    01  A PIC X(6).
    MOVE @code{ABC} TO A
    
    01  A PIC X(6) JUSTIFIED RIGHT.
    MOVE @code{ABC} TO A
    
    ResultResult
    ABCbbbbbbABC

    When the value is longer than the field size:

    Without JUSTIFIEDWith JUSTIFIED
    01  A PIC X(6).
    MOVE 'ABCDEFGHI' TO A
    
    01  A PIC X(6) JUSTIFIED RIGHT.
    MOVE 'ABCDEFGHI' TO A
    
    ResultResult
    ABCDEFDEFGHI


6.9.25. LEFTLINE

LEFTLINE Attribute Syntax
=======================================================================

 LEFTLINE
 ~~~~~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

The LEFTLINE clause will introduce a vertical line at the left edge of a screen field.

  1. The LEFTLINE, OVERLINE (see OVERLINE) and UNDERLINE (see UNDERLINE) clauses may be used in any combination in a single field’s description.
  2. This clause is essentially non-functional when used within Windows command shell (cmd.exe) environments and running programs compiled using a GnuCOBOL implementation built using “PDCurses” (such as Windows/MinGW builds).
  3. Whether or not this clause operates on Cygwin or UNIX/Linux/OSX systems will depend upon the video attribute capabilities of the terminal output drivers and “curses” software being used.

See Color Palette and Video Attributes, for more information on screen colors and video attributes.



6.9.26. LENGTH-CHECK

LENGTH-CHECK Attribute Syntax
=======================================================================

 LENGTH-CHECK
 ~~~~~~~~~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

The LENGTH-CHECK clause forces the user to enter data into the field it is specified on (or into all subordinate input-capable fields if specified on a group item) sufficient to fill every character position of the field.

  1. The FULL (see FULL) and LENGTH-CHECK clauses are interchangeable, and may not be used together in the same data item description.
  2. In order for this clause to take effect at execution time, the user must move the cursor into the field having this clause in its definition.
  3. The ACCEPT screen-data-item statement (see ACCEPT screen-data-item) will ignore the Enter key and any other cursor-moving keystrokes that would cause the cursor to move to another screen item unless the proper amount of data has been entered into the field. Function keys will still be allowed to terminate the ACCEPT, however.
  4. In order to be functional, this attribute must be supported by the underlying “curses” package your GnuCOBOL implementation was built with. As of this time, the “PDCurses” package (used for native Windows or MinGW builds) does not support LENGTH-CHECK.


6.9.27. LINE

LINE (REPORT SECTION) Clause Syntax
=======================================================================

 LINE NUMBER IS { integer-2 [ [ ON NEXT PAGE ] }
 ~~~~           {                  ~~~~ ~~~~   }
                { +|PLUS integer-2             }
                {   ~~~~                       }
                { ON NEXT PAGE                 }
                     ~~~~ ~~~~

=======================================================================
LINE (SCREEN SECTION) Clause Syntax
=======================================================================

 [ LINE NUMBER IS [ +|PLUS ] integer-4 | identifier-6 ]
   ~~~~               ~~~~

=======================================================================

This syntax is valid in the following sections: REPORT, SCREEN

This clause provides a means of explicitly stating on which line a field should be presented on the console window (screen section) or on a report (report section).

  1. The reserved words IS, NUMBER and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The following points document the use of format 1 of the LINE clause:
    1. The column location of a report item will be determined by the COLUMN (see COLUMN) clause.
    2. The value of integer-1 must be 1 or greater.
    3. The report line number upon which the data item containing this clause along with any subordinate data items will be presented may be stated on an absolute basis (i.e. LINE 5) or on a relative basis based upon the previously-displayed line (i.e. LINE PLUS 1).
    4. The symbol ‘+’ may be used in lieu of the word PLUS, if desired; if ‘+’ is used, however, there must be at least one space separating it from integer-1. Failure to include this space will cause the ‘+’ to be simply treated as part of integer-1 and will treat the LINE clause as an absolute line specification rather than a relative one.
    5. The optional NEXT PAGE clause specifies that — regardless of whether or not the report group containing this clause could fit on the report page being currently generated, the report group will be forced to appear on a new page.
  3. The following points document the use for format 2 of the LINE clause:
    1. The column location of a screen section field is determined by the COLUMN (see COLUMN) clause.
    2. The value of integer-1 must be 1 or greater.
    3. If identifier-1 is used to specify either an absolute or relative column position, identifier-1 must be defined as a numeric item of any USAGE (see USAGE) other than COMPUTATIONAL-1 or COMPUTATIONAL-2, without editing symbols. The value of identifier-1 at the time the screen data item is presented must be 1 or greater. Note that a COMPUTATIONAL-1 or COMPUTATIONAL-2 identifier will be accepted by the compiler, but will produce unpredictable results at run-time.
    4. The screen line number upon which the data item containing this clause along with any subordinate data items will be displayed may be stated on an absolute basis (i.e. LINE 5) or on a relative basis based upon the previously-displayed line (i.e. LINE PLUS 1).
    5. The symbol ‘+’ may be used in lieu of the word PLUS, if desired; if ‘+’ is used, however, there must be at least one space separating it from integer-1. Failure to include this space will cause the ‘+’ to be simply treated as part of integer-1 and will treat the LINE clause as an absolute line specification rather than a relative one.
    6. If a screen data item’s description includes the FROM (see FROM), TO (see TO), USING (see USING) or VALUE (see VALUE) clause but has no LINE clause, the “current screen line” will be assumed.


6.9.28. LOWLIGHT

LOWLIGHT Attribute Syntax
=======================================================================

 LOWLIGHT
 ~~~~~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

The LOWLIGHT clause controls the intensity of text (FOREGROUND-COLOR) by setting that intensity to its lowest of three possible settings.

  1. This clause, along with HIGHLIGHT (see HIGHLIGHT), are intended to provide a three-level intensity scheme (LOWLIGHT … nothing (Normal) … HIGHLIGHT). In environments such as a Windows console where only two levels of intensity are supported, LOWLIGHT is the same as leaving this clause off altogether.

See Color Palette and Video Attributes, for more information on screen colors and video attributes.



6.9.29. NEXT GROUP

NEXT-GROUP Clause Syntax
=======================================================================

 NEXT GROUP IS { [ +|PLUS ] integer-2  }
 ~~~~ ~~~~~    {     ~~~~              }
               { NEXT|{NEXT PAGE}|PAGE }
                 ~~~~  ~~~~ ~~~~  ~~~~


=======================================================================

This syntax is valid in the following sections: REPORT

This clause defines any rules for where the next group to be presented on a report will begin, line-wise, with respect to the last line of the group in which this clause appears.

  1. The reserved word IS is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. The terms NEXT, NEXT PAGE and PAGE are interchangeable.
  3. A report group must contain at least one LINE NUMBER clause in order to also contain a NEXT GROUP clause.
  4. If the RD (see REPORT SECTION) in which the report group containing a NEXT GROUP clause does not contain a PAGE LIMITS clause, only the PLUS integer-1 option may be specified.
  5. The NEXT PAGE option cannot be used in a PAGE FOOTING.
  6. The NEXT GROUP option cannot be specified in either a REPORT HEADING or a PAGE HEADING.
  7. The effects of NEXT GROUP will be in addition to any line spacing defined by the next-presented group’s LINE NUMBER clause.


6.9.30. NO-ECHO

NO-ECHO Attribute Syntax
=======================================================================

 NO-ECHO
 ~~~~~~~


=======================================================================

This syntax is valid in the following sections: SCREEN

The NO-ECHO clause will cause all data entered into the field to appear on the screen as asterisks.

  1. The NO-ECHO and SECURE (see SECURE) clauses are interchangeable, and may not be used together in the same data item description.
  2. This clause may only be used on a field allowing data entry (a field containing either the USING (see USING) or TO (see TO) clause).

See Color Palette and Video Attributes, for more information on screen colors and video attributes.



6.9.31. OCCURS

OCCURS (REPORT SECTION) Clause Syntax
=======================================================================

 OCCURS [ integer-1 TO ] integer-2 TIMES
 ~~~~~~             ~~
   [ DEPENDING ON identifier-1 ]
     ~~~~~~~~~
   [ STEP integer-3 ]
     ~~~~
   [ VARYING identifier-2 FROM { identifier-3 } BY { identifier-4 } ]
     ~~~~~~~              ~~~~ { integer-4    } ~~ { integer-5    }

=======================================================================
OCCURS (SCREEN SECTION) Clause Syntax
=======================================================================

 OCCURS integer-2 TIMES
 ~~~~~~

=======================================================================
OCCURS (All Other Sections Clause Syntax
=======================================================================

 OCCURS [ integer-1 TO ] integer-2 TIMES
 ~~~~~~             ~~
      [ DEPENDING ON identifier-1 ]
        ~~~~~~~~~
      [ ASCENDING|DESCENDING KEY IS identifier-5... ]...
        ~~~~~~~~~ ~~~~~~~~~~
      [ INDEXED BY identifier-6 ]
        ~~~~~~~

=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT, SCREEN

The OCCURS clause is used to create a data structure called a table, where entries in that structure repeat multiple times.

  1. The reserved words BY (INDEXED), IS, KEY, ON and TIMES are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The value of integer-2 specifies how many entries will be allocated in the table.
  3. The following is an example of how a table might be defined:
    05 QUARTERLY-REVENUE OCCURS 4 TIMES PIC 9(7)V99.
    

    This will allocate the following:

    QUARTERLY-REVENUE(1)
    QUARTERLY-REVENUE(2)
    QUARTERLY-REVENUE(3)
    QUARTERLY-REVENUE(4)
    

    Each occurrence is referenced using the subscript syntax (a numeric literal, arithmetic expression or numeric identifier enclosed within parenthesis) shown above.

  4. The OCCURS clause may be used at the group level too, in which case the entire group structure repeats, as follows:
    05 GRP OCCURS 3 TIMES.
        10 A     PIC X(1).
        10 B     PIC X(1).
        10 C     PIC X(1).
    

    This would allow references to any of the following:

    GRP(1)   includes A(1), B(1) and C(1)
    GRP(2)   includes A(2), B(2) and C(2)
    GRP(3)   includes A(3), B(3) and C(3)
    

    or each A,B,C item could be referenced as follows:

    A(1)   character #1 of GRP(1)
    B(1)   character #2 of GRP(1)
    C(1)   character #3 of GRP(1)
    A(2)   character #1 of GRP(2)
    B(2)   character #2 of GRP(2)
    C(2)   character #3 of GRP(2)
    A(3)   character #1 of GRP(3)
    B(3)   character #2 of GRP(3)
    C(3)   character #3 of GRP(3)
    
  5. The optional DEPENDING ON clause can be added to an OCCURS to create a variable-length table. In such cases, the value of integer-1 specifies what the minimum number of entries in the table will be while integer-2 specifies the maximum. Such tables will be allocated out to the maximum size specified as integer-2. At execution time the value of identifier-1 will determine how many of the table elements are accessible.
  6. See the documentation of the SEARCH (see SEARCH), SEARCH ALL (see SEARCH ALL) and SORT (see SORT) statements for explanations of the KEY and INDEXED BY clauses.
  7. The OCCURS clause cannot be specified in a data description entry that has a level number of 01, 66, 77, or 88, although it is valid in data items described subordinate to an 01-level data item.
  8. The following points apply to an OCCURS used in the report section:
    1. The optional STEP clause defines an incrementation value that will be added to any absolute LINE (see LINE) or COLUMN (see COLUMN) number specifications that may be part of or subordinate to this data item’s definition.
    2. The optional VARYING clause defines an identifier that may be used as a subscript for the multiple occurrences of this or any subordinate data item should the SOURCE (see SOURCE) or SUM (see SUM) clause(s) on this or subordinate data items reference entries within the table. The identifier-2 data item is dynamically created as needed and cannot be referenced outside the scope of the report data item definition.
    3. The following two examples illustrate two different ways a report could include four quarters worth of sales figures in its detail lines — one doing things ’the hard way’ and one using the advanced OCCURS capabilities of STEP and VARYING. Both assume the definition of the following table exists in working-storage:
      05 SALES OCCURS 4 TIMES PIC 9(7)V99.

      First, the “Hard Way”:

      10 COL 7  PIC $(7)9.99 SOURCE SALES(1).
      10 COL 17 PIC $(7)9.99 SOURCE SALES(2).
      10 COL 27 PIC $(7)9.99 SOURCE SALES(3).
      10 COL 37 PIC $(7)9.99 SOURCE SALES(4).
      

      And then using STEP and VARYING:

      10 COL 7  OCCURS 4 TIMES STEP 10 VARYING QTR FROM 1 BY 1
                PIC $(7)9.99 SOURCE SALES(QTR).
      


6.9.32. OVERLINE

OVERLINE Attribute Syntax
=======================================================================

 OVERLINE
 ~~~~~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

The OVERLINE clause will introduce a horizontal line at the top edge of a screen field.

  1. The LEFTLINE (see LEFTLINE), OVERLINE and UNDERLINE (see UNDERLINE) clauses may be used in any combination in a single field’s description.
  2. This clause is essentially non-functional when used within Windows command shell (cmd.exe) environments and running programs compiled using a GnuCOBOL implementation built using “PDCurses” (such as Windows/MinGW builds).
  3. Whether or not this clause operates on Cygwin or UNIX/Linux/OSX systems will depend upon the video attribute capabilities of the terminal output drivers and “curses” software being used.

See Color Palette and Video Attributes, for more information on screen colors and video attributes.



6.9.33. PICTURE

PICTURE Clause Syntax
=======================================================================

 PICTURE IS picture-string
 ~~~

=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT, SCREEN

The picture clause defines the class (numeric, alphabetic or alphanumeric), size and format of the data that may be contained by the data item being defined. Sometimes this role is assisted by the USAGE (see USAGE) clause, and in a few instances will be assumed entirely by that clause.

  1. The reserved word IS is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. The reserved word PICTURE may be abbreviated as PIC. Most programmers prefer to use the latter.
  3. A picture clause may only be specified on an elementary item.
  4. A picture-string is a sequence of the special symbols ‘$’, ‘*’, ‘+’, ‘,’, ‘-’, ‘.’, ‘/’, ‘0’ (zero), ‘9’, ‘A’, ‘B’, CR, DB, ‘S’, ‘V’, ‘X’ and ‘Z’.
  5. In general, each picture symbol represents either a single character in storage or a single decimal digit. There are a few exceptions, and they will be discussed as needed.
  6. When a picture-string contains a repeated sequence of symbols — PIC 9999/99/99 — for example, the repetition can be specified using a parenthetic repeat count, as in PIC 9(4)/9(2)/9(2). Using repeat counts is optional and their use (or not) is entirely at the discretion of the programmer. Many programmers use repetition for small sequences (PIC XXX) and repeat counts for larger ones (PIC 9(9).
  7. This first set of picture symbols defines the basic data type of a data item. Each symbol represents a single character’s worth of storage.
    A

    Defines storage reserved for a single alphabetic character (‘A’-‘Z’, ‘a’-‘z’).

    N

    Defines storage reserved for a single character in the computer’s National Character set. Support for national character sets in GnuCOBOL is currently only partially implemented, and the compile- and run-time effect of using the ‘N’ picture symbol is the same as if X(2) had been coded, with the additional effect that such a field will qualify as a NATIONAL or NATIONAL-EDITED field on an INITIALIZE (see INITIALIZE) statement.

    X

    Defines storage reserved for a single alphanumeric character (any character).

    9

    Defines storage reserved for a single numeric digit character (‘0’-‘9’).

    Typically, only one kind of each of those symbols is used in the same picture clause, but that isn’t a requirement. Data items that, of the three symbols above, use nothing but ‘A’ picture symbols are known as Alphabetic Data Items while those that use ‘9’ picture symbols without any ‘A’ or ‘X’ symbols (or those that have a USAGE without a PICTURE) are known as Numeric Data Items. All other data items are referred to as Alphanumeric Data Items.

    If you need to allocate space for a data item whose format is two letters followed by five digits followed by three letters, you could use the picture-string AA99999AAA, A(2)9(5)A(3) XXXXXXXXXX or X(10). There is absolutely no functional difference whatsoever between the four — none of them provide any functionality the others do not. The first two probably make for better documentation of the expected field contents, but they don’t provide any run-time enforcement capabilities.

    As far as enforcement goes, however, both alphabetic and numeric picture strings do provide for both compile-time and run-time enforcement capabilities. In the case of compilation enforcement, the compiler can issue warning messages if you attempt to specify a non-numeric value for a numeric data item or if you attempt to MOVE (see MOVE) a non-numeric data item to one that is numeric. Similar capabilities exist for alphabetic data items. At run-time, you may use a special class test (see Class Conditions) to determine if the contents of a data item are entirely numeric or entirely alphabetic.

  8. The following picture symbols may be used with numeric data items.
    P

    Defines an implied digit position that will be considered to be a zero when the data item is referenced at run-time. This symbol is used to allow data items that will contain very large values to be allocated using less storage by assuming a certain number of trailing zeros (one per ‘P’) to exist at the end of values.

    The ‘P’ symbol is not allowed in conjunction with ‘N’.

    The ‘P’ symbol may only be used at the beginning or end of a picture clause.

    P’ is a repeatable symbol.

    All computations and MOVE (see MOVE) operations involving such a data item will behave as if the zeros were actually there.

    For example, let’s say you need to allocate a data item that contains however many millions of dollars of revenue your company has in gross revenues this year:

    01 Gross-Revenue PIC 9(9).

    In which case 9 characters of storage will be reserved. The values 000000000 through 999999999 will represent the gross-revenues. But, if only the millions are tracked (meaning the last six digits are always going to be 0), you could define the field as:

    01 Gross-Revenue PIC 9(3)P(6).

    Whenever Gross-Revenue is referenced in calculations, or whenever its value is moved to another data item, the value of Gross-Revenue will be treated as if it is nnn000000, where nnn is the actual value in storage.

    If you wanted to store the value 128 million into that field, you would do so as if the ‘P’s were ‘9’s:

    MOVE 128000000 TO Gross-Revenue
    

    A DISPLAY (see DISPLAY) of a data item containing ‘P’ symbols is a little strange. The value displayed will be what is actually in storage, but the total size of the displayed value will be as if the ‘P’ symbols had been ‘9’s. Thus, after the above statement established a value for Gross-Revenue, a DISPLAY Gross-Revenue would produce output of ‘000000128’.

    S

    This symbol, if used, must be the very first symbol in the PICTURE value. A ‘S’ indicates that the data item is Signed, meaning that negative values are possible for this data item. Without an ‘S’, any negative values stored into this data item via a MOVE or arithmetic statement will have the negative sign stripped from it (in effect becoming the absolute value).

    The ‘S’ symbol is not allowed in conjunction with ‘N’.

    The ‘S’ symbol may only occur once in a picture string. See SIGN IS, for further discussion of how negative values may be stored in a numeric data item.

    V

    This symbol is used to define where an implied decimal-point (if any) is located in a numeric item. Just as there may only be a single decimal point in a number so may there be no more than one ‘V’ in a PICTURE. Implied decimal points occupy no space in storage — they just specify how values are used. For example, if the value 1234 is in storage in a field defined as PIC 999V9, that value would be treated as 123.4 in any statements that referenced it.

    The ‘V’ symbol is not allowed in conjunction with ‘N’.

    The ‘V’ symbol may only occur once in a picture string.

  9. Any editing symbols introduced past this point will, if coded in the picture clause of an otherwise numeric data item, transform that data item from a numeric to a Numeric Edited data item. Numeric edited data items are treated as alphanumeric and may not serve either as table subscripts or as source arguments on an arithmetic statement.
  10. The following are the fixed insertion editing symbols that may be specified in a picture string. Each of these editing symbols will insert a special character into the field value at the position it is specified in the picture string. These editing symbols will each introduce one extra character into the total field size for each occurrence of the symbol in the picture string.
    B

    The ‘B’ editing symbol introduces a blank into the field value for each occurrence.

    Multiple ‘B’ symbols may be coded.

    The following example will format a ten digit number (presumably a telephone number) into a ‘### ### ####’ layout:

        ...
            05 Phone-Number       PIC 9(3)B9(3)B9(4).
        ...
            MOVE 5185551212 TO Phone-Number
            DISPLAY Phone-Number
    

    This code will display ‘518 555 1212’.

    0

    The ‘0’ (zero) editing symbol introduces one “0” character into the field value for each occurrence in the picture string.

    Multiple ‘0’ symbols may be coded.

    Here’s an example:

        ...
            05  Output-Item     PIC 909090909.
        ...
            MOVE 12345 TO Output-Item
            DISPLAY Output-Item
    

    The above will display ‘102030405’.

    /

    The ‘/’ editing symbol inserts one “/” character into the field value for each occurrence in the picture string.

    Multiple ‘/’ symbols may be coded.

    This editing symbol is most-frequently used to format dates, as follows:

        ...
            05  Year-Month-Day   PIC 9(4)/9(2)/9(2).
        ...
            MOVE 20140207 TO Year-Month-Day
            DISPLAY Year-Month-Day
    

    This example displays ‘2014/02/07’.

  11. The following are the numeric formatting symbols that may be specified in a picture string. Each of these editing symbols will insert special characters into the field value to present numbers in a “friendly” format. These editing symbols will each introduce one extra character into the total field size for each occurrence of the symbol in the picture string. Numeric fields whose picture clause contains these characters may neither be used as source fields in any calculation nor may they serve as source fields for the transfer of data values to any data item other than an alphanumeric field.
    .

    The ‘.’ symbol inserts a decimal point into a numeric field value. When the contents of a numeric data item sending field are moved into a receiving data item whose picture clause contains the ‘.’ editing symbol, implied (‘V’) or actual decimal point in the sending data item or literal, respectively, will be aligned with the ‘.’ symbol in the receiving field. Digits are then transferred from the sending to the receiving field outward from the sending field’s ‘V’ or ‘.’, truncating sending digits if there aren’t enough positions in the receiving field. Any digit positions in the receiving field that don’t receive digits from the sending field, if any, will be set to 0.

    The ‘.’ symbol is not allowed in conjunction with ‘N’.

    An example will probably help:

        ...
        05  Source-Field   PIC 9(2)V9 VALUE 7.2.
        05  Dest-Field     PIC 9(5).9(2).
        ...
        MOVE 1234567.89 TO Dest-Field
        DISPLAY Dest-Field
        MOVE 19 TO Dest-Field
        DISPLAY Dest-Field
        MOVE Source-Field TO Dest-Field
        DISPLAY Dest-Field
    

    The example will display three results — ‘34567.89’, ‘00019.00’ and ‘00007.20’.

    Both data item definitions appear to have two decimal points in their picture clauses. They actually don’t, because the last character of every data item definition is always a period — the period that ends the definition.

    ,

    The ‘,’ symbol serves as a thousands separator. Many times, you’ll see large numbers formatted with these symbols — for example, 123,456,789. This can be accomplished easily by adding thousands separator symbols to a picture string. Thousands separator symbols that aren’t needed will behave as if they were ‘9’s.

    The ‘,’ symbol is not allowed in conjunction with ‘N’.

    Here’s an example:

        ...
        05  My-Lottery-Winnings   PIC 9(3),9(3),9(3).
        ...
        MOVE 12345 TO My-Lottery-Winnings
        DISPLAY My-Lottery-Winnings
    

    The value ‘0000012,345’ (a very disappointing one for my retirement plans, but a good thousands separator demo) will be displayed. Notice how, since the first comma wasn’t needed due to the meagre amount I won, it behaved like another ‘9’.

    If desired, you may reverse the roles of the ‘.’ and ‘,’ editing symbols by specifying DECIMAL POINT IS COMMA in the SPECIAL-NAMES (see SPECIAL-NAMES) paragraph.

  12. The following are insertion symbols. They are used to insert an extra character (two in the case of CR and DB) to signify the sign (positive or negative) of the numeric value that is moved into the field whose picture string contains one of these symbols, or the fact that the data item represents a currency (money) amount. Only one of the ‘+’, ‘-’, CR or DB symbols may be used in a picture clause. In this context, when any of these symbols are used in a picture-string, they must be at the end. The ‘+’, ‘-’ and/or currency symbols may also be used as floating editing symbols at the beginning of the picture-string — a subject that will be covered in the next numbered paragraph.
    +

    If the value of the numeric value moved into the field is positive (0 or greater), a ‘+’ character will be inserted. If the value is negative (less than 0), a ‘-’ character is inserted.

    The ‘+’ symbol is not allowed in conjunction with ‘N’.

    -

    If the value of the numeric value moved into the field is positive (0 or greater), a space will be inserted. If the value is negative (less than 0), a ‘-’ character is inserted.

    The ‘-’ symbol is not allowed in conjunction with ‘N’.

    CR

    This symbol is coded as the two characters ‘C’ and ‘R’. If the value of the numeric value moved into the field is positive (0 or greater), two spaces will be inserted. If the value is negative (less than 0), the characters CR (credit) are inserted.

    The CR symbol is not allowed in conjunction with ‘N’.

    DB

    This symbol is coded as the two characters ‘D’ and ‘B’. If the value of the numeric value moved into the field is positive (0 or greater), two spaces will be inserted. If the value is negative (less than 0), the characters DB (debit) are inserted.

    The DB symbol is not allowed in conjunction with ‘N’.

    $

    Regardless of the value moved into the field, this symbol will insert the currency symbol into the data item’s value in the position where it occurs in the picture-string (see SPECIAL-NAMES).

    The ‘$’ symbol is not allowed in conjunction with ‘N’.

  13. These editing symbols are known as floating replacement symbols. These symbols may occur in sequences before any ‘9’ editing symbols in the picture-string of a numeric data item. Using these symbols transforms that numeric data item into a numerid edited data item, which can no longer be used in calculations or subscripts.
  14. Each of the following symbols behave like a ‘9’, until such point as all digits in the numeric value are exhausted and leading zeros are about to be inserted. In effect, these editing symbols define what should happen to those leading zero.
    $

    Of those currency symbols that correspond to character positions in which leading zeros reside, the right-most will have its ‘0’ value replaced by the currency symbol in-effect for the program (see SPECIAL-NAMES). Any remaining leading zero values occupying positions described by this symbol will be replaced by spaces.

    The ‘$’ symbol is not allowed in conjunction with ‘N’.

    Any currency symbol coded to the right of a ‘.’ will be treated exactly like a ‘9’.

    *

    This symbol is referred to as a check protection symbol. All check-protection symbols that correspond to character positions in which leading zeros reside will have their ‘0’ values replaced by ‘*’.

    The ‘*’ symbol is not allowed in conjunction with ‘N’.

    Any check-suppression symbol coded to the right of a ‘.’ will be treated exactly like a ‘9’.

    +

    Of those ‘+’ symbols that correspond to character positions in which leading zeros reside, the right-most will have its ‘0’ value replaced by a ‘+’ if the value in the data item is zero or greater or a ‘-’ otherwise. Any remaining leading zero values occupying positions described by this symbol will be replaced by spaces. You cannot use both ‘+’ and ‘-’ in the same picture-string.

    The ‘+’ symbol is not allowed in conjunction with ‘N’.

    Any ‘+’ symbol coded to the right of a ‘.’ will be treated exactly like a ‘9’.

    -

    Of those ‘-’ symbols that correspond to character positions in which leading zeros reside, the right-most will have its ‘0’ value replaced by a space if the value in the data item is zero or greater or a ‘-’ otherwise. Any remaining leading zero values occupying positions described by this symbol will be replaced by spaces. You cannot use both ‘+’ and ‘-’ in the same picture-string.

    The ‘-’ symbol is not allowed in conjunction with ‘N’.

    Any ‘-’ symbol coded to the right of a ‘.’ will be treated exactly like a ‘9’.

    Z

    All ‘Z’ symbols that correspond to character positions in which leading zeros reside will have their ‘0’ values replaced by spaces.

    Any zero-suppression symbol coded to the right of a ‘.’ will be treated exactly like a ‘9’.

    Z’ and ‘*’ should not be coded in the same picture-string

    +’ and ‘-’ should not be coded in the same picture-string

    When multiple floating symbols are coded, even if there is only one of them used they will all be considered floating and will all be able to assume each other’s properties. For example, if a data item has a PIC +$ZZZZ9.99 picture-string, and a value of 1 is moved to that field at run-time, the resulting value will be (the b symbol represents a space) bbbb+$1.00. This is not consistent with many other COBOL implementations, where the result would have been +$bbbb1.00.

    Most other COBOL implementations reject the use of multiple occurrences of multiple floating editing symbols. For example, they would reject picture-strings such as +++$$$9.99, $$$ZZZ9.99 and so on. GnuCOBOL accepts these. Programmers creating GnuCOBOL programs should avoid such picture-strings if there is any likelihood that those programs may be used with other COBOL implementations.



6.9.34. PRESENT WHEN

PRESENT-WHEN Clause Syntax
=======================================================================

 PRESENT WHEN condition-name
 ~~~~~~~ ~~~~

=======================================================================

This syntax is valid in the following sections: REPORT

This clause names an existing Condition Name (see Condition Names) that will serve as a switch controlling the presentation or suppression of a report group.

  1. If the specified condition-name has a value of FALSE when a GENERATE statement (see GENERATE) causes a report group to be presented, the presentation of that group will be suppressed.
  2. If the condition-name has a value of TRUE, the group will be presented.
  3. See Condition Names, for more information.


6.9.35. PROMPT

PROMPT Clause Syntax
=======================================================================

 PROMPT [ CHARACTER IS literal-1 | identifier-1 ]
 ~~~~~~   ~~~~~~~~~


=======================================================================

This syntax is valid in the following sections: SCREEN

This clause defines the character that will be used as the fill-character for any input fields on the screen.

  1. The reserved word IS is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. The default prompt character, should no CHARACTER specification be coded, or should the PROMPT clause be absent altogether, is an underscore (‘_’).
  3. Prompt characters will be automatically transformed into spaces upon input.

See Color Palette and Video Attributes, for more information on screen colors and video attributes.



6.9.36. PROTECTED

PROTECTED Attribute Syntax
=======================================================================

 PROTECTED SIZE IS { identifier }
 ~~~~~~~~  ~~~~    { integer    }

=======================================================================

This syntax is valid in the following sections: SCREEN

  1. The PROTECTED extended clause will effect the specified field to be limited in size, regardless of the picture size.2
  2. The SIZE phrase specifies the size (length) of the field. After the ACCEPT or DISPLAY is finished, the cursor is placed immediately after the field defined by this clause, unless this would place the cursor outside of the current terminal window. In this case, the cursor is wrapped around to the beginning of the next line (scrolling the window if necessary).
  3. If the SIZE phrase is not used, then the field length defaults to the size of the item being accepted or displayed. If the CONVERT phrase is used, however, then the size of the field depends on the data type of the item and the verb being used.
    1. If the DISPLAY verb is executing, then the size is the same as if the CONVERT phrase were not specified except for numeric items. For numeric items, the size is the number of digits in the item, plus one if it is not an integer, plus one if it is signed. The remaining cases cover the size when an ACCEPT statement is used.
    2. If the item is numeric or numeric edited, then the size is the number of digits in the item, plus one if it is not an integer, plus one if it is signed.
    3. If the item is alphanumeric edited, then the size is set to the number of ‘A’ or ‘X’ positions specified in its PICTURE clause.
    4. For all other data types, the field size is set to the size of the item (same as if CONVERT were not specified).
  4. Note that the OUTPUT phrase changes the way in which the default field size is computed. See that heading above for details. Also note that the OUTPUT phrase affects only the way items are displayed on the screen; the internal format of accepted data is not affected.
  5. Note that you cannot supply the CONVERT phrase in the Screen Section. Thus the size of a Screen Section field is always the size of its screen entry unless the SIZE phrase is specified.


6.9.37. REDEFINES

REDEFINES Clause Syntax
=======================================================================

 REDEFINES identifier-1
 ~~~~~~~~~

=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE

The REDEFINES clause causes the data item in who’s definition the REDEFINES clause is specified (hereafter referred to as the redefines object) to occupy the same physical storage space as identifier-1 (hereafter referred to as the redefines subject).

  1. The following rules must all be followed in order to use REDEFINES:
    1. The level number of both the subject and object data items must be the same.
    2. The level numbers of both the subject and object data items cannot be 66, 78 or 88.
    3. If N represents the level number of the object, then no other data items with level number N may be defined between the subject and object data items unless they too are REDEFINES of the subject.
    4. If N represents the level number of the object, then no other data items with a level number numerically less than N may be defined between the subject and object data items.
    5. The total allocated size of the subject data item must be the same as the total allocated size of the object data item.
    6. No OCCURS (see OCCURS) clause may be part of the definition of either the subject or object data items. Either or both, however, may be group items that contain data items with OCCURS clauses.
    7. No VALUE (see VALUE) clause may be defined on the object data item, and no data items subordinate to the object data item may have VALUE clauses, with the exception of level-88 condition names.


6.9.38. RENAMES

RENAMES Clause Syntax
=======================================================================

 RENAMES identifier-1 [ THRU|THROUGH identifier-2
 ~~~~~~~                ~~~~ ~~~~~~~

=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE

The RENAMES clause regroups previously defined items by specifying alternative, possibly overlapping, groupings of elementary data items.

  1. The reserved words THRU and THROUGH are interchangeable.
  2. You must use the level number 66 for data description entries that contain the RENAMES clause.
  3. The identifier-1 and identifier-2 data items, along with all data items defined between those two data items in the program source, must all be contained within the same 01-level record description.
  4. See 66-Level Data Items, for additional information on the RENAMES clause.


6.9.39. REQUIRED

REQUIRED Attribute Syntax
=======================================================================

 REQUIRED
 ~~~~~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

This clause forces the user to enter data into the field it is specified on (or into all subordinate input-capable fields if REQUIRED is specified on a group item).

  1. The EMPTY-CHECK (see EMPTY-CHECK) and REQUIRED clauses are interchangeable, and may not be used together in the same data item description.
  2. In order to take effect, the user must first move the cursor into the field having this clause in its definition.
  3. The ACCEPT screen-data-item statement (see ACCEPT screen-data-item) will ignore the Enter key and any other cursor-moving keystrokes that would cause the cursor to move to another screen item unless data has been entered into the field. Function keys will still be allowed to terminate the ACCEPT.
  4. In order to be functional, this attribute must be supported by the underlying “curses” package your GnuCOBOL implementation was built with. As of this time, the “PDCurses” package (used for native Windows or MinGW builds) does not support REQUIRED.


6.9.40. REVERSE-VIDEO

REVERSE-VIDEO Attribute Syntax
=======================================================================

 REVERSE-VIDEO
 ~~~~~~~~~~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

The REVERSE-VIDEO attribute swaps the specified or implied FOREGROUND-COLOR (see FOREGROUND-COLOR) and BACKGROUND-COLOR (see BACKGROUND-COLOR) attributes for the field whose definition contains this clause (or all subordinate fields if used on a group item).

See Color Palette and Video Attributes, for more information on screen colors and video attributes.



6.9.41. SECURE

SECURE Attribute Syntax
=======================================================================

 SECURE
 ~~~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

This clause will cause all data entered into the field to appear on the screen as asterisks.

  1. The NO-ECHO (see NO-ECHO) and SECURE clauses are interchangeable, and may not be used together in the same data item description.
  2. This clause may only be used on a field allowing data entry (a field containing either the USING (see USING) or TO (see TO) clause).

See Color Palette and Video Attributes, for more information on screen colors and video attributes.



6.9.42. SIGN IS

SIGN-IS Clause Syntax
=======================================================================

 SIGN IS LEADING|TRAILING [ SEPARATE CHARACTER ]
 ~~~~    ~~~~~~~ ~~~~~~~~   ~~~~~~~~

=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT, SCREEN

This clause, allowable only for USAGE DISPLAY numeric data items, specifies how an ‘S’ symbol will be interpreted in a data item’s picture clause.

  1. The reserved words CHARACTER and IS are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. Without the SEPARATE CHARACTER option, the sign of the data item’s value will be encoded by transforming the last (see TRAILING) or first (see LEADING) digit as follows:
    First/Last DigitValue For PositiveValue for Negative
    00p
    11q
    22r
    33s
    44t
    55u
    66v
    77w
    88x
    99y
  3. If the SEPARATE CHARACTER clause is used, then an actual ‘+’ or ‘-’ character will be inserted into the field’s value as the first (LEADING) or last (TRAILING) character. Note that having this character embedded within the data item’s storage does not prevent the data item from being used as a source field in arithmetic operations.
  4. When SEPARATE CHARACTER is specified, the ‘S’ symbol in the data item’s PICTURE must be counted when determining the data item’s size.
  5. Neither the presence of an encoded digit (see above) nor an actual ‘+’ or ‘-’ character embedded within the data item’s storage prevents the data item from being used as a source field in arithmetic operations.


6.9.43. SOURCE

SOURCE Clause Syntax
=======================================================================

 SOURCE IS literal-1 | identifier-1 [ ROUNDED ]
 ~~~~~~                               ~~~~~~~

=======================================================================

This syntax is valid in the following sections: REPORT

This clause logically attaches a report section data item to another data item defined elsewhere in the data division.

  1. The reserved word IS is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. When the report group containing this clause is presented, the value of the specified numeric literal or identifier will be automatically moved to the report data item prior to presentation.
  3. The specified identifier may be defined anywhere in the data division, but if it is defined in the report section it may only be PAGE-COUNTER, LINE-COUNTER or a SUM (see SUM) counter.
  4. The PICTURE (see PICTURE) of the report data item must be such that it would be legal to MOVE (see MOVE) the specified literal or identifier to a data item with that PICTURE.
  5. The ROUNDED option comes into play should the number of digits to the right of an actual or assumed decimal point be different between the specified literal or identifier value (the “source value”) and the PICTURE specified for the field in whose definition the SOURCE clause appears (the “target field”). Without ROUNDED, excess digits in the source value will simply be truncated to fit the target field. With ROUNDED, the source value will be arithmetically rounded to fit the target field. See ROUNDED, for information on the NEAREST-AWAY-FROM-ZERO rounding rule, which is the one that will apply.


6.9.44. SUM OF

SUM-OF Clause Syntax
=======================================================================

 SUM OF { identifier-7 }... [ { RESET ON FINAL|identifier-8 } ]
 ~~~    { literal-2    }      { ~~~~~    ~~~~~              }
                              { UPON identifier-9           }
                                ~~~~

=======================================================================

This syntax is valid in the following sections: REPORT

The SUM clause establishes a summation counter whose value will be arithmetically calculated whenever the field is presented.

  1. The reserved words OF and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The SUM clause may only appear in a CONTROL FOOTING report group.
  3. If the data item in which the SUM clause appears has been assigned its own identifier name, and that name is not FILLER, then that data item is referred to as a sum counter.
  4. All identifier-7 data items must be non-edited numeric in nature.
  5. If any identifier-7 data item is defined in the report section, it must be a sum counter.
  6. Any identifier-7 data items that are sum counters must either be defined in the same report group as the data item in which this SUM clause appears or they must be defined in a report data item that exists at a lower level in this report’s control hierarchy. See Control Hierarchy, for additional information.
  7. The PICTURE of the report data item in who’s description this SUM clause appears in must be such that it would be legal to MOVE (see MOVE) the specified identifier-7 or literal-2 value to a data item with that PICTURE.
  8. The following points apply to the UPON option:
    1. The data item identifier-9 must be the name of a detail group specified in the same report as the control footing group in which this SUM clause appears.
    2. The presence of an UPON clause limits the SUM clause to adding the specified numeric literal or identifier value into the sum counter only when a GENERATE identifier-9 statement is executed.
    3. If there is no UPON clause specified, the value of identifier-7 or literal-2 will be added into the sum counter whenever a GENERATE (see GENERATE) of any detail report group in the report is executed.
    4. If there is only a single detail group in the report’s definition, the UPON clause is meaningless.
  9. The following points apply to the RESET option:
    1. If the RESET option is coded, FINAL or identifier-8 (whichever is coded on the RESET) must be one of the report’s control breaks specified on the CONTROLS clause.
    2. If there is no RESET option coded, the sum counter will be reset back to zero after each time the control footing containing the SUM clause is presented. This is the typical behaviour that would be expected.
    3. If, however, you want to reset the SUM counter only when the control footing for a control break higher in the control hierarchy is presented, specify that higher control break on the RESET option.


6.9.45. SYNCRONIZED

SYNCRONIZED Syntax
=======================================================================

 SYNCRONIZED|SYNCHRONISED [ LEFT|RIGHT ]
 ~~~~        ~~~~           ~~~~ ~~~~~

The LEFT and RIGHT (SYNCRONIZED) clauses are syntactically recognized but are otherwise non-functional.


=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE

This optional clause optimizes the storage of binary numeric items to store them in such a manner as to make it as fast as possible for the CPU to fetch them.

  1. The reserved words SYNCRONIZED and SYNCHRONISED are interchangeable, and may be abbreviated as SYNC.
  2. If the SYNCRONIZED clause is coded on anything but a numeric data item with a USAGE (see USAGE) that specifies storage of data in a binary form, the SYNCRONIZED clause will be ignored.
  3. Synchronization is performed (by the compiler) as follows:
    1. If the binary item occupies one byte of storage, no synchronization is performed.
    2. If the binary item occupies two bytes of storage, the binary item is allocated at the next half-word boundary.
    3. If the binary item occupies four bytes of storage, the binary item is allocated at the next word boundary.
    4. If the binary item occupies four bytes of storage, the binary item is allocated at the next word boundary.


6.9.46. TO

TO Clause Syntax
=======================================================================

 TO identifier-5
 ~~

=======================================================================

This syntax is valid in the following sections: SCREEN

This clause logically attaches a screen section data item to another data item defined elsewhere in the data division.

  1. The TO clause is used to define a data-entry field with no initial value; when a value is entered, it will be saved to the specified identifier.
  2. The FROM (see FROM), TO, USING (see USING) and VALUE (see VALUE) clauses are mutually-exclusive in any screen section data item’s definition.


6.9.47. TYPE

TYPE Clause Syntax
=======================================================================

 [ TYPE IS { RH|{REPORT HEADING}                      } ]
   ~~~~    { ~~  ~~~~~~ ~~~~~~~                       }
           { PH|{PAGE HEADING}                        }
           { ~~  ~~~~ ~~~~~~~                         }
           { CH|{CONTROL HEADING} FINAL|identifier-2  }
           { ~~  ~~~~~~~ ~~~~~~~  ~~~~~               }
           { DE|DETAIL                                }
           { ~~ ~~~~~~                                }
           { CF|{CONTROL FOOTING} FINAL|identifier-2  }
           { ~~  ~~~~~~~ ~~~~~~~  ~~~~~               }
           { PF|{PAGE FOOTING}                        }
           {  ~~ ~~~~ ~~~~~~~                         }
           { RF|{REPORT FOOTING}                      }
             ~~  ~~~~~~ ~~~~~~~

=======================================================================

This syntax is valid in the following sections: REPORT

This clause defines the type of report group that is being defined for a report.

  1. This clause is required on any 01-level data item definitions (other than 01-level constants) in the report section. This clause is invalid on any other report section data item definitions.
  2. There may be a maximum of one (1) report group per RD defined with a TYPE of REPORT HEADING, PAGE HEADING, PAGE FOOTING and REPORT FOOTING.
  3. There must be either a CONTROL HEADING or a CONTROL FOOTING or both specified for each entry specified on the CONTROLS ARE clause of the RD.
  4. The various report groups that constitute a report may be defined in any order.
  5. See RWCS Lexicon, for a description of the seven different types of report groups.


6.9.48. UNDERLINE

UNDERLINE Attribute Syntax
=======================================================================

 UNDERLINE
 ~~~~~~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

The UNDERLINE clause will introduce a horizontal line at the bottom edge of a screen field.

  1. The LEFTLINE (see LEFTLINE), OVERLINE (see OVERLINE) and UNDERLINE clauses may be used in any combination in a single field’s description.
  2. This clause is essentially non-functional when used within Windows command shell (cmd.exe) environments and running programs compiled using a GnuCOBOL implementation built using “PDCurses” (such as Windows/MinGW builds).
  3. Whether or not this clause operates on Cygwin or UNIX/Linux/OSX systems will depend upon the video attribute capabilities of the terminal output drivers and “curses” software being used.

See Color Palette and Video Attributes, for more information on screen colors and video attributes.



6.9.49. USAGE

USAGE Clause Syntax
=======================================================================

 USAGE IS data-item-usage
 ~~~~~

=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT

The USAGE clause defines the format that will be used to store the value of a data item.

  1. The reserved word IS is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. The following table summarizes the various USAGE specifications available in GnuCOBOL.

    BINARY
    ~~~~~~

    Range of Values:Defined by the quantity of ‘9’s and the presence or absence of an ‘S’ in the PICTURE
    Storage Format:Compatible Binary Integer
    Negative Values Allowed?:If PICTURE contains ‘S
    PICTURE Used?:Yes

    BINARY-C-LONG [ SIGNED ]
    ~~~~~~~~~~~~~

    Same as BINARY-DOUBLE SIGNED

    BINARY-C-LONG UNSIGNED
    ~~~~~~~~~~~~~ ~~~~~~~~

    Range of Values:Typically 0 – 4,294,967,295
    Storage Format:Native Binary Integer
    Negative Values Allowed?:No
    PICTURE Used?:No

    BINARY-CHAR [ SIGNED ]
    ~~~~~~~~~~~

    Range of Values:-128 – 127
    Storage Format:Native Binary Integer
    Negative Values Allowed?:Yes
    PICTURE Used?:No

    BINARY-CHAR UNSIGNED
    ~~~~~~~~~~~ ~~~~~~~~

    Range of Values:0 – 255
    Storage Format:Native Binary Integer
    Negative Values Allowed?:No
    PICTURE Used?:No

    BINARY-DOUBLE [ SIGNED ]
    ~~~~~~~~~~~~~

    Range of Values:-9,223,372,036,854,775,808 – 9,223,372,036,854,775,807
    Storage Format:Native Binary Integer
    Negative Values Allowed?:Yes
    PICTURE Used?:No

    BINARY-DOUBLE UNSIGNED
    ~~~~~~~~~~~~~ ~~~~~~~~

    Range of Values:0 – 18,446,744,073,709,551,615
    Storage Format:Native Binary Integer
    Negative Values Allowed?:No
    PICTURE Used?:No

    BINARY-INT
    ~~~~~~~~~~

    Same as BINARY-LONG SIGNED

    BINARY-LONG [ SIGNED ]
    ~~~~~~~~~~~

    Range of Values:-2,147,483,648 – 2,147,483,647
    Storage Format:Native Binary Integer
    Negative Values Allowed?:Yes
    PICTURE Used?:No

    BINARY-LONG UNSIGNED
    ~~~~~~~~~~~ ~~~~~~~~

    Range of Values:0 – 4,294,967,295
    Storage Format:Native Binary Integer
    Negative Values Allowed?:No
    PICTURE Used?:No

    BINARY-LONG-LONG
    ~~~~~~~~~~~~~~~~

    Same as BINARY-DOUBLE SIGNED

    BINARY-SHORT [ SIGNED ]
    ~~~~~~~~~~~~

    Range of Values:-32,768 – 32,767
    Storage Format:Native Binary Integer
    Negative Values Allowed?:Yes
    PICTURE Used?:No

    BINARY-SHORT UNSIGNED
    ~~~~~~~~~~~~ ~~~~~~~~

    Range of Values:0 – 65,535
    Storage Format:Native Binary Integer
    Negative Values Allowed?:No
    PICTURE Used?:No

    COMPUTATIONAL
    ~~~~

    Same as BINARY

    COMP[UTATIONAL]-1
    ~~~~ ~~

    Same as FLOAT-SHORT

    COMP[UTATIONAL]-2
    ~~~~ ~~

    Same as FLOAT-LONG

    COMP[UTATIONAL]-3
    ~~~~ ~~

    Same as PACKED-DECIMAL

    COMP[UTATIONAL]-4
    ~~~~ ~~

    Same as BINARY

    COMP[UTATIONAL]-5
    ~~~~ ~~

    Range of Values:Depends on number of ‘9’s in the PICTURE and the binary-size setting of the configuration file used to compile the program
    Storage Format:Native Binary Integer
    Negative Values Allowed?:If PICTURE contains ‘S
    PICTURE Used?:Yes

    COMP[UTATIONAL]-6
    ~~~~ ~~

    Range of Values:Defined by the quantity of ‘9’s and the presence or absence of an ‘S’ in the PICTURE
    Storage Format:Unsigned Packed Decimal
    Negative Values Allowed?:No
    PICTURE Used?:Yes

    COMP[UTATIONAL]-X
    ~~~~ ~~

    Range of Values:If used with PIC X, allocates one byte of storage per ‘X’; range of values is 0 to max storable in that many bytes. If used with PIC 9, range of values depends on number of ‘9’s in PICTURE
    Storage Format:Native unsigned (X) or signed (9) Binary
    Negative Values Allowed?:If PICTURE 9 and contains ‘S
    PICTURE Used?:Yes

    DISPLAY
    ~~~~~~~

    Range of Values:Depends on PICTURE — One character per X, A, 9, period, $, Z, 0, *, S (if SEPARATE CHARACTER specified), +, - or B symbol in PICTURE; Add 2 more bytes if the DB or CR editing symbol is used
    Storage Format:Characters
    Negative Values Allowed?:If PICTURE contains ‘S
    PICTURE Used?:Yes

    FLOAT-DECIMAL-16
    ~~~~~~~~~~~~~~~~

    Range of Values:-9.999999999999999 * 10383 – 9.999999999999999 * 10384
    Storage Format:Native IEEE 754 Decimal64 Floating-point
    Negative Values Allowed?:Yes
    PICTURE Used?:No

    FLOAT-DECIMAL-34
    ~~~~~~~~~~~~~~~~

    Range of Values:-9.99999... * 106143 – 9.99999... * 106144
    Storage Format:Native IEEE 754 Decimal128 Floating-point
    Negative Values Allowed?:Yes
    PICTURE Used?:No

    FLOAT-LONG
    ~~~~~~~~~~

    Range of Values:Approximately -1.797693134862316 * 10308 – 1.797693134862316 * 10308
    Storage Format:Native IEEE 754 Binary64 Floating-point
    Negative Values Allowed?:Yes
    PICTURE Used?:No

    FLOAT-SHORT
    ~~~~~~~~~~~

    Range of Values:Approximately -3.4028235 * 1038 – 3.4028235 * 1038
    Storage Format:Native IEEE 754 Binary32
    Negative Values Allowed?:Yes
    PICTURE Used?:No

    INDEX
    ~~~~~

    Range of Values:0 to maximum address possible (32 or 64 bits)
    Storage Format:Native Binary Integer
    Negative Values Allowed?:No
    PICTURE Used?:No

    NATIONAL
    ~~~~~~~~

    USAGE NATIONAL, while syntactically recognized, is not supported by GnuCOBOL

    PACKED-DECIMAL
    ~~~~~~~~~~~~~~

    Range of Values:Defined by the quantity of ‘9’s and the presence or absence of an ‘S’ in the PICTURE
    Storage Format:Signed Packed Decimal
    Negative Values Allowed?:If PICTURE contains ‘S
    PICTURE Used?:Yes

    POINTER
    ~~~~~~~

    Range of Values:0 to maximum address possible (32 or 64 bits)
    Storage Format:Native Binary Integer
    Negative Values Allowed?:No
    PICTURE Used?:No

    PROCEDURE-POINTER
    ~~~~~~~~~~~~~~~~~

    Same as PROGRAM-POINTER

    PROGRAM-POINTER
    ~~~~~~~~~~~~~~~

    Range of Values:0 to maximum address possible (32 or 64 bits)
    Storage Format:Native Binary Integer
    Negative Values Allowed?:No
    PICTURE Used?:No

    SIGNED-INT
    ~~~~~~~~~~

    Same as BINARY-LONG SIGNED

    SIGNED-LONG
    ~~~~~~~~~~~

    Same as BINARY-DOUBLE SIGNED

    SIGNED-SHORT
    ~~~~~~~~~~~~

    Same as BINARY-SHORT SIGNED

    UNSIGNED-INT
    ~~~~~~~~~~~~

    Same as BINARY-LONG UNSIGNED

    UNSIGNED-LONG
    ~~~~~~~~~~~~~

    Same as BINARY-DOUBLE UNSIGNED

    UNSIGNED-SHORT
    ~~~~~~~~~~~~~~

    Same as BINARY-SHORT UNSIGNED
  3. Binary data (integer or floating-point) can be stored in either a Big-Endian or Little-Endian form.

    Big-endian data allocation calls for the bytes that comprise a binary item to be allocated such that the least-significant byte is the right-most byte. For example, a four-byte binary item having a value of decimal 20 would be big-endian allocated as 00000014 (shown in hexadecimal notation).

    Little-endian data allocation calls for the bytes that comprise a binary item to be allocated such that the least-significant byte is the left-most byte. For example, a four-byte binary item having a value of decimal 20 would be little-endian allocated as 14000000 (shown in hexadecimal notation).

    All CPUs are capable of understanding big-endian format, which makes it the most compatible form of binary storage across computer systems.

    Some CPUs — such as the Intel/AMD i386/x64 architecture processors used in most Windows PCs — prefer to process binary data stored in a little-endian format. Since that format is more efficient on those systems, it is referred to as the native binary format.

    On a system supporting only one format of binary storage (generally, that would be big-endian), the terms most efficient and native format are synonymous.

  4. Data items that have the UNSIGNED attribute explicitly coded, or DISPLAY, PACKED-DECIMAL, COMP-5, COMP-X items that do not have an ‘S’ symbol in their picture clause cannot preserve negative values that may be stored into them. Storing a negative value into such a field will actually result in the sign being stripped, essentially saving the absolute value in the data item.
  5. Packed-decimal (i.e. USAGE PACKED-DECIMAL, USAGE COMP-3 or USAGE COMP-6) data is stored as a series of bytes such that each byte contains two 4-bit fields, referred to as nibbles (since they comprise half a “byte”, they’re just “nibbles” — don’t groan, I don’t just make this stuff up!). Each nibble represents a ‘9’ in the PICTURE and each holds a single decimal digit encoded as its binary value (0 = 0000, 1 = 0001, … , 9 = 1001).

    The last byte of a PACKED-DECIMAL or COMP-3 data item will always have its left nibble corresponding to the last ‘9’ in the PICTURE and its right nibble reserved as a sign indicator. This sign indicator is always present regardless of whether or not the PICTURE included an ‘S’ symbol.

    The first byte of the data item will contain an unused left nibble if the PICTURE had an even number of ‘9’ symbols in it.

    The sign indicator will have a value of a hexadecimal A through F. Traditional packed decimal encoding rules call for hexadecimal values of F, A, C or E (“FACE”) in the sign nibble to indicate a positive value and B or D to represent a negative value (hexadecimal digits 0-9 are undefined). Testing with a Windows MinGW/GnuCOBOL implementation shows that — in fact — hex digit D represents a negative number and any other hexadecimal digit denotes a positive number. Therefore, a PIC S9(3) COMP-3 packed-decimal field with a value of -15 would be stored internally as a hexadecimal 015D in GnuCOBOL.

    If you attempt to store a negative number into a packed decimal field that has no ‘S’ in its PICTURE, the absolute value of the negative number will actually be stored.

    USAGE COMP-6 does not allow for negative values, therefore no sign nibble will be allocated. A USAGE COMP-6 data item containing an odd number of ‘9’ symbols in its PICTURE will leave its leftmost nibble unused.

  6. The USAGE specifications FLOAT-DECIMAL-16 and FLOAT-DECIMAL-34 will encode data using IEEE 754 Decimal64 and Decimal128 format, respectively. The former allows for up to 16 digits of exact precision while the latter offers 34. The phrase “exact precision” is used because the traditional binary renderings of decimal real numbers in a floating-point format (FLOAT-LONG and FLOAT-SHORT, for example) only yield an approximation of the actual value because many decimal fractions cannot be precisely rendered in binary. The Decimal64 and Decimal128 renderings, however, render decimal real numbers in encoded decimal form in much the same way that PACKED-DECIMAL renders a decimal integer in digit-by-digit decimal form. The exact manner in which this rendering is performed is complex (Wikipedia has an excellent article on the subject — just search for Decimal64).
  7. GnuCOBOL stores FLOAT-DECIMAL-16 and FLOAT-DECIMAL-34 data items using either Big-Endian or Little-Endian form, whichever is native to the system.
  8. The USAGE specifications FLOAT-LONG and FLOAT-SHORT use the IEEE 754 Binary64 and Binary32 formats, respectively. These are binary encodings of real decimal numbers, and as such cannot represent every possible value between the minimum and maximum values in the range for those usages. Wikipedia has an excellent article on the Binary64 and Binary32 encoding schemes — just search on Binary32 or Binary64.

    GnuCOBOL stores FLOAT-LONG and FLOAT-SHORT data items using either Big-Endian or Little-Endian form, whichever is native to the system.

  9. A USAGE clause specified at the group item level will apply that USAGE to all subordinate data items, except those that themselves have a USAGE clause.
  10. The only USAGE that is allowed in the report section is USAGE DISPLAY.


6.9.50. USING

USING Clause Syntax
=======================================================================

 USING identifier-1
 ~~~~~

=======================================================================

This syntax is valid in the following sections: SCREEN

This clause logically attaches a screen section data item to another data item defined elsewhere in the data division.

  1. When the screen item whose definition this clause is part of is displayed, the value currently in identifier-1 will be automatically moved into the screen item first.
  2. When the screen item whose definition this clause is part of (or its parent) is accepted, the current contents of the screen item will be saved back to identifier-1 at the conclusion of the ACCEPT.
  3. The FROM (see FROM), TO (see TO), USING and VALUE (see VALUE) clauses are mutually-exclusive in any screen section data item’s definition.


6.9.51. VALUE

VALUE (Condition Names) Clause Syntax
=======================================================================

 { VALUE IS   } {literal-1 [ THRU|THROUGH literal-2 ]}...
 { ~~~~~      }              ~~~~ ~~~~~~~
 { VALUES ARE }
   ~~~~~~

=======================================================================
VALUE (Other Data Items) Syntax
=======================================================================

 VALUE IS [ ALL ] literal-1
 ~~~~~      ~~~

=======================================================================

This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT, SCREEN

The VALUE clause is used to define condition names or to assign values (at compilation time) to data items.

  1. The reserved words ARE and IS are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. This clause cannot be specified on the same data item as a FROM (see FROM), TO (see TO) or USING (see USING) clause.
  3. The following points apply to using the VALUE clause in the definition of a condition name:
    1. The clauses VALUE IS and VALUES ARE are interchangeable.
    2. The reserved words THRU and THROUGH are interchangeable.
    3. See 88-Level Data Items, for a discussion of how this format of VALUE is used to create condition names.
    4. See Condition Names, for a discussion of how condition names are used.
  4. The following points apply to using the VALUE clause in the definition of any other data item:
    1. In this context, VALUE specifies an initial compilation-time value that will be assigned to the storage occupied by the data item in the program object code generated by the compiler.
    2. The VALUE clause is ignored on EXTERNAL (see EXTERNAL) data items or on any data items defines as subordinate to an EXTERNAL data item.
    3. This format of the VALUE clause may not be used anywhere in the description of an 01 item (or any of its subordinate items) serving as an FD or SD record description.
    4. If the optional ALL clause is used, it may only be used with an alphanumeric literal value; the value will be repeated as needed to completely fill the data item. Here are some examples with and without ALL (the symbol b denotes a space):
      PIC X(5) VALUE ‘A’      *> Abbbb
      PIC X(5) VALUE ALL ‘A’  *> AAAAA
      PIC 9(3) VALUE 1        *> 001
      PIC 9(3) VALUE ALL ‘1’  *> 111
      
    5. When used in the definition of a screen data item:
      1. A figurative constant may not be supplied as literal-1.
      2. Any FROM (see FROM), TO (see TO) or USING (see USING) clause in the same data item’s definition will be ignored.
      3. If there is no picture clause specified, the size of the screen data item will be the length of the literal-1 value.
      4. If there is no picture clause and the ALL option is specified, the ALL option will be ignored.
    6. Giving a table an initial, compile-time value is one of the trickier aspects of COBOL data definition. There are basically three standard techniques and a fourth that people familiar with other COBOL implementations but new to GnuCOBOL may find interesting. So, here are the three standard approaches:
      1. Don’t bother worrying about it at compile-time. Use the INITIALIZE (see INITIALIZE) to initialize all data item occurrences in a table (at run-time) to their data-type-specific default values (numerics: 0, alphabetic and alphanumerics: spaces).
      2. Initialize small tables at compile time by including a VALUE clause on the group item that serves as a parent to the table, as follows:
        05  SHIRT-SIZES          VALUE "S 14M 15L 16XL17".
            10 SHIRT-SIZE-TBL    OCCURS 4 TIMES.
               15 SST-SIZE       PIC X(2).
               15 SST-NECK       PIC 9(2).
        
      3. Initialize tables of almost any size at compilation time by utilizing the REDEFINES (see REDEFINES) clause:
        05  SHIRT-SIZE-VALUES.
            10 PIC X(4)          VALUE "S 14".
            10 PIC X(4)          VALUE "M 15".
            10 PIC X(4)          VALUE "L 16".
            10 PIC X(4)          VALUE XL17.
        05  SHIRT-SIZES          REDEFINES SHIRT-SIZE-VALUES.
            10 SHIRT-SIZE-TBL    OCCURS 4 TIMES.
               15 SST-SIZE       PIC X(2).
               15 SST-NECK       PIC 9(2).
        

        Admittedly, this table is much more verbose than the one shown with a group VALUE. What is good about this initialization technique, however, is that you can have as many FILLER and VALUE items as you need for a larger table, and those values can be as long as necessary!

    7. Many COBOL compilers do not allow the use of VALUE and OCCURS (see OCCURS) on the same data item; additionally, they don’t allow a VALUE clause on a data item subordinate to an OCCURS. GnuCOBOL, however, has neither of these restrictions!

      Observe the following example, which illustrates a fourth manner in which tables may be initialized in GnuCOBOL:

      05  X           OCCURS 6 TIMES.
          10 A        PIC X(1) VALUE '?'.
          10 B        PIC X(1) VALUE '%'.
          10 N        PIC 9(2) VALUE 10.
      

      In this example, all six ‘A’ items will be initialized to ‘?’, all six ‘B’ items will be initialized to ‘%’ and all six ‘N’ items will be initialized to 10. It’s not clear exactly how many times this sort of initialization will be useful, but it’s there if you need it.

  5. The FROM (see FROM), TO (see TO), USING (see USING) and VALUE clauses are mutually-exclusive in any screen section data item’s definition.


7. PROCEDURE DIVISION

PROCEDURE DIVISION Syntax
=======================================================================

   PROCEDURE DIVISION [ { USING Subprogram-Argument...     } ]
   ~~~~~~~~~ ~~~~~~~~   { ~~~~~                            }
                        { CHAINING Main-Program-Argument...}
                          ~~~~~~~~
                      [ RETURNING identifier-1 ] .
 [ DECLARATIVES. ]      ~~~~~~~~~
   ~~~~~~~~~~~~
 [ Event-Handler-Routine... . ]

 [ END DECLARATIVES. ]
   ~~~ ~~~~~~~~~~~~
   General-Program-Logic

 [ Nested-Subprogram... ]

 [ END PROGRAM|FUNCTION name-1 ]
   ~~~ ~~~~~~~ ~~~~~~~~

=======================================================================

The PROCEDURE DIVISION of any GnuCOBOL program marks the point where all executable code is written.



7.1. PROCEDURE DIVISION USING

PROCEDURE DIVISION Subprogram-Argument Syntax
=======================================================================

 [ BY { REFERENCE [ OPTIONAL ]                       } ] identifier-1
      { ~~~~~~~~~   ~~~~~~~~                         }
      { VALUE [ [ UNSIGNED ] SIZE IS { AUTO      } ] }
        ~~~~~     ~~~~~~~~   ~~~~    { ~~~~      }
                                     { DEFAULT   }
                                     { ~~~~~~~   }
                                     { integer-1 }

=======================================================================

The USING clause defines the arguments that will be passed to a GnuCOBOL program which is serving as a subprogram.

  1. The reserved words BY and IS are optional and may be omitted. The presence or absence of these words have no effect upon the program.
  2. The USING clause should only be used on the procedure division header of subprograms (subroutines or user-defined functions).
  3. The calling program will pass zero or more data items, known as arguments, to this subprogram — there must be exactly as many identifier-1 data items specified on the USING clause as the maximum number of arguments the subprogram will ever be passed.
  4. If a subprogram does not expect any arguments, it should not have a USING clause specified on its procedure division header.
  5. The order in which arguments are defined on the USING clause must correspond to the order in which those arguments will be passed to the subprogram by the calling program.
  6. The identifiers specified on the USING clause must be defined in the linkage section of the subprogram. No storage is actually allocated for those identifiers in the subprogram as the actual storage for them will exist in the calling program.
  7. A GnuCOBOL subprogram expects that all arguments to it will be one of two things:

    In the case of the former, the USING clause on the procedure division header should describe the argument via the BY REFERENCE clause — in the latter case, a BY VALUE specification should be coded. This allows the code generated by the compiler to properly reference the subprogram arguments at run-time.

  8. BY REFERENCE is the assumed default for the first USING argument should no BY clause be specified for it. Subsequent arguments will assume the BY specification of the argument prior to them should they lack a BY clause of their own.
  9. Changes made by a subprogram to the value of an argument specified on the USING clause will “be visible” to the calling program only if BY REFERENCE was explicitly specified or implicitly assumed for the argument on the subprogram’s procedure division header and the argument was passed to the subprogram BY REFERENCE by the calling program. See Subprogram Arguments, for additional information on the mechanics of how arguments are passed to subprograms.
  10. The optional SIZE clause allows you to specify the number of bytes a BY VALUE argument will occupy, with SIZE DEFAULT specifying 4 bytes (this is the default if no SIZE clause is used), SIZE AUTO specifying the size of the argument in the calling program and SIZE integer-1 specifying a specific byte count.
  11. The optional UNSIGNED keyword, legal only if SIZE AUTO or SIZE integer-1 are coded, will add the unsigned attribute to the argument’s specification in the C-language function header code generated for the subprogram. While not of any benefit when the calling program is a GnuCOBOL program, this can improve compatibility with a C-language calling program.
  12. The OPTIONAL keyword, legal only on BY REFERENCE arguments, allows calling programs to code OMITTED for that corresponding argument when they call this subprogram. See CALL. for additional information on this feature.


7.2. PROCEDURE DIVISION CHAINING

PROCEDURE DIVISION Main-Program-Argument Syntax
=======================================================================

 [ BY REFERENCE ] [ OPTIONAL ] identifier-1
      ~~~~~~~~~     ~~~~~~~~

=======================================================================

The CHAINING term provides one mechanism a programmer may use to retrieve command-line arguments passed to a program at execution time.

  1. PROCEDURE DIVISION CHAINING may only be coded in a main program (that is, the first program executed when a compiled GnuCOBOL compilation unit is executed). It cannot be used in any form of subprogram.
  2. The CHAINING clause defines arguments that will be passed to a main program from the operating system. The argument identifiers specified on the CHAINING clause will be populated by character strings comprised of the parameters specified to the program on the command line that executed it, as follows:
    1. When a GnuCOBOL program is executed from a command-line, the complete command line text will be broken into a series of tokens, where each token is identified as being a word separated from the others in the command text by at least one space. For example, if the command line was /usr/local/myprog THIS IS A TEST, there will be five tokens identified by the operating system — ‘/usr/local/myprog’, ‘THIS’, ‘IS’, ‘A’ and ‘TEST’.
    2. Multiple space-delimited tokens may be treated as a single token by enclosing them in quotes. For example, there are only three tokens generated from the command line C:\Pgms\myprog.exe ‘THIS IS A’ TEST — ‘C:\Pgms\myprog.exe’, ‘THIS IS A’ and ‘TEST’. When quote characters are used to create multi-word tokens, the quote characters themselves are stripped from the token’s value.
    3. Once tokens have been identified, the first one (the command) will be discarded; the rest will be stored into the CHAINING arguments when the program begins execution, with the 2nd token going to the 1st argument, the 3rd token going to the 2nd argument and so forth.
    4. If there are more tokens than there are arguments, the excess tokens will be discarded.
    5. If there are fewer tokens than there are arguments, the excess arguments will be initialized as if the INITIALIZE identifier-1 (see INITIALIZE) statement were executed.
    6. All identifiers specified on the CHAINING clause should be defined as PIC X, PIC A, group items (which are treated implicitly as PIC X) or as PIC 9 USAGE DISPLAY. The use of USAGE BINARY (or the like) data items as CHAINING arguments is not recommended as all command-line tokens will be retained in their original character form as they are moved into the argument data items.
    7. If an argument identifier is smaller in storage size than the token value to be stored in it, the right-most excess characters of the token value will be truncated as the value is moved in. Any JUSTIFIED RIGHT clause on such an argument identifier will be ignored.
    8. If an argument is larger in storage size than the token value to be stored in it, the token value will be moved into the argument identifier in a left-justified manner. unmodified-modified byte positions in the identifier will be space filled, unless the argument identifier is defined as PIC 9 USAGE DISPLAY, in which case unmodified bytes will be filled with ‘0’ characters from the systems native character set.

      This behaviour when the argument is defined as PIC 9 may be unacceptable, as an argument defined as PIC 9(3) but passed in a value of ‘1’ from the command line will receive a value of ‘100’, not ‘001’. Consider defining “numeric” command line arguments as PIC X and then using the NUMVAL intrinsic function (see NUMVAL) function to determine the proper numeric value.



7.3. PROCEDURE DIVISION RETURNING

PROCEDURE DIVISION RETURNING Syntax
=======================================================================

 RETURNING identifier-1
 ~~~~~~~~~

=======================================================================

The RETURNING clause on the PROCEDURE DIVISION header documents that the subprogram in which the clause appears will be returning a numeric value back to the program that called it.

  1. The RETURNING clause is optional within a subroutine, as not all subroutines return a value to their caller.
  2. The RETURNING clause is mandatory within a user-defined function, as all such must return a numeric result.
  3. The identifier-1 data item should be defined as a USAGE BINARY-LONG data item.
  4. Main programs that wish to “pass back” a return code value to the operating system when they exit do not use RETURNING - they do so simply by MOVEing a value to the RETURN-CODE special register.
  5. This is not the only mechanism that a subprogram may use to pass a value back to its caller. Other possibilities are:
    1. The subprogram may modify any argument that is specified as BY REFERENCE on its PROCEDURE DIVISION header. Whether the calling program can actually “see” any modifications depends upon how the calling program passed the argument to the subprogram. See CALL, for more information.
    2. A data item with the GLOBAL (see GLOBAL) attribute specified in its description in the calling program is automatically visible to and updatable by a subprogram nested with the calling program. See Independent vs Contained vs Nested Subprograms, for more information on subprogram nesting.
    3. A data item defined with the EXTERNAL (see EXTERNAL) attribute in a subprogram and the calling program (same name in both programs) is automatically visible to and updatable by both programs, even if those programs are compiled separately from one another.


7.4. PROCEDURE DIVISION Sections and Paragraphs

The procedure division is the only one of the COBOL divisions that allows you to create your own sections and paragraphs. These are collectively referred to as Procedures, and the names you create for those sections and paragraphs are called Procedure Names.

Procedure names are optional in the procedure division and — when used — are named entirely according to the needs and whims of the programmer.

Procedure names may be up to thirty one (31) characters long and may consist of letters, numbers, dashes and underscores. A procedure name may neither begin nor end with a dash (‘-’) or underscore (‘_’) character. This means that Main, 0100-Read-Transaction and 17 are all perfectly valid procedure names.

There are three circumstances under which the use of certain GnuCOBOL statements or options will require the specification of procedures. These situations are:

  1. When DECLARATIVES (see DECLARATIVES) are specified.
  2. When the ENTRY statement (see ENTRY) is being used.
  3. When any procedure division statement that references procedures is used. These statements are:


7.5. DECLARATIVES

DECLARATIVES Syntax
=======================================================================

section-name-1 SECTION.

 USE { [ GLOBAL ] AFTER STANDARD { EXCEPTION } PROCEDURE ON { INPUT       } }
 ~~~ {   ~~~~~~                  { ~~~~~~~~~ }              { ~~~~~       } }
     {                           { ERROR     }              { OUTPUT      } }
     {                             ~~~~~                    { ~~~~~~      } }
     {                                                      { I-O         } }
     { FOR DEBUGGING ON { procedure-name-1           }      { ~~~         } }
     {     ~~~~~~~~~    { ALL PROCEDURES             }      { EXTEND      } }
     {                  { ~~~ ~~~~~~~~~~             }      { ~~~~~~      } }
     {                  { REFERENCES OF identifier-1 }      { file-name-1 } }
     {                                                                      }
     { [ GLOBAL ] BEFORE REPORTING identifier-2                             }
     {   ~~~~~~   ~~~~~~ ~~~~~~~~~                                          }
     {                                                                      }
     { AFTER EC|{EXCEPTION CONDITION}                                       }
             ~~  ~~~~~~~~~ ~~~~~~~~~

The AFTER EXCEPTION CONDITION and AFTER EC clauses are syntactically recognized but are otherwise non-functional.


=======================================================================

The DECLARATIVES area of the procedure division allows the programmer to define a series of “trap” procedures (referred to as declarative procedures) capable of intercepting certain events that may occur at program execution time. The syntax diagram above shows the format of a single such procedure.

  1. The reserved words AFTER, FOR, ON, PROCEDURE and STANDARD are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. EC and EXCEPTION CONDITION are interchangeable.
  3. The declaratives area may contain any number of declarative procedures, but no two declarative procedures should be coded to trap the same event.
  4. The following points apply to the USE BEFORE REPORTING clause:
    1. identifier-2 must be a report group.
    2. At run-time, the declaratives procedure will be executed prior to the processing of the specified report group’s presentation; within the procedure you may take either of the following actions:
      • You may adjust the value(s) of any items referenced in SUM (see SUM) or SOURCE (see SOURCE) clauses in the report group.
      • You may execute the SUPPRESS (see SUPPRESS) statement to squelch the presentation of the specified report group altogether. Note that you will be suppressing this one specific instance of that group’s presentation and not all of them.
  5. The following points apply to the USE FOR DEBUGGING clause:
    1. This clause allows you to define a declarative procedure that will be invoked whenever…
      • identifier-1 is referenced on any statement.
      • procedure-name-1 is executed.
      • …any procedure is executed (ALL PROCEDURES).
    2. A USE FOR DEBUGGING declarative procedure will be ignored at compilation time unless WITH DEBUGGING MODE is specified in the SOURCE-COMPUTER (see SOURCE-COMPUTER) paragraph. Neither the compiler’s -fdebugging-line switch nor -debug switch will activate this feature.
    3. Any USE FOR DEBUGGING declarative procedures will be ignored at execution time unless the COB_SET_DEBUG run-time environment variable (see Run Time Environment Variables) has been set to a value of ‘Y’, ‘y’ or ‘1’.
    4. The typical use of a USE FOR DEBUGGING declarative procedure is to display the DEBUG-ITEM special register, which will be implicitly and automatically created in your program for you if WITH DEBUGGING MODE is active.

      The structure of DEBUG-ITEM will be as follows:

      01  DEBUG-ITEM.
          05 DEBUG-LINE      PIC X(6).
          05 FILLER          PIC X(1) VALUE SPACE.
          05 DEBUG-NAME      PIC X(31).
          05 FILLER          PIC X(1) VALUE SPACE.
          05 DEBUG-SUB-1     PIC S9(4) SIGN LEADING SEPARATE.
          05 FILLER          PIC X(1) VALUE SPACE.
          05 DEBUG-SUB-2     PIC S9(4) SIGN LEADING SEPARATE.
          05 FILLER          PIC X(1) VALUE SPACE.
          05 DEBUG-SUB-3     PIC S9(4) SIGN LEADING SEPARATE.
          05 FILLER          PIC X(1) VALUE SPACE.
          05 DEBUG-CONTENTS  PIC X(31).
      

      where…

      DEBUG-LINE

      … is the program line number of the statement that triggered the declaratives procedure.

      DEBUG-NAME

      … is the procedure name or identifier name that triggered the declaratives procedure.

      DEBUG-SUB-1

      … is the first subscript value (if any) for the reference of the identifier that triggered the declaratives procedure.

      DEBUG-SUB-2

      … is the second subscript value (if any) for the reference of the identifier that triggered the declaratives procedure.

      DEBUG-SUB-3

      … is the third subscript value (if any) for the reference of the identifier that triggered the declaratives procedure.

      DEBUG-CONTENTS

      … is a (brief) statement of the manner in which the procedure that triggered the declaratives procedure was executed or the first 31 characters of the value of the identifier whose reference triggered the declaratives procedure (the value after the statement was executed).

  6. The USE AFTER STANDARD ERROR PROCEDURE clause defines a declarative procedure invoked any time a failure is encountered with the specified I/O type (or against the specified file(s)).
  7. The GLOBAL (see GLOBAL) option, if used, allows a declarative procedure to be used across the program containing the USE statement and any subprograms nested within that program.
  8. Declarative procedures may not reference any other procedures defined outside the scope of DECLARATIVES.


7.6. Common Clauses on Executable Statements



7.6.1. AT END + NOT AT END

AT END Syntax
=======================================================================

 [ AT END imperative-statement-1 ]
      ~~~
 [ NOT AT END imperative-statement-2 ]
   ~~~    ~~~

=======================================================================

AT END clauses may be specified on READ (see READ), RETURN (see RETURN), SEARCH (see SEARCH) and SEARCH ALL (see SEARCH ALL) statements.

  1. The following points pertain to the use of these clauses on READ (see READ) and RETURN (see RETURN) statements:
    1. The AT END clause will — if present — cause imperative-statement-1 (see Imperative Statement) to be executed if the statement fails due to a file status of 10 (end-of-file). See File Status Codes, for a list of possible File Status codes.

      An AT END clause will not detect other non-zero file-status values.

      Use a DECLARATIVES (see DECLARATIVES) routine or an explicitly-declared file status field tested after the READ or RETURN to detect error conditions other than end-of-file.

    2. A NOT AT END clause will cause imperative-statement-2 to be executed if the READ or RETURN attempt is successful.
  2. The following points pertain to the use of these clauses on SEARCH (see SEARCH) and SEARCH ALL (see SEARCH ALL) statements:
    1. An AT END clause detects and handles the case where either form of table search has failed to locate an entry that satisfies the search conditions being used.
    2. The NOT AT END clause is not allowed on either form of table search.


7.6.2. CORRESPONDING

Three GnuCOBOL statements — ADD (see ADD CORRESPONDING), MOVE (see MOVE CORRESPONDING) and SUBTRACT (see SUBTRACT CORRESPONDING) support the use of a CORRESPONDING option:

ADD CORRESPONDING group-item-1 TO group-item-2
MOVE CORRESPONDING group-item-1 TO group-item-2
SUBTRACT CORRESPONDING group-item-1 FROM group-item-2

This option allows one or more data items within one group item (group-item-1 — the first named on the statement) to be paired with correspondingly-named (hence the name) in a second group item (group-item-2 — the second named on the statement). The contents of group-item-1 will remain unaffected by the statement while one or more data items within group-item-2 will be changed.

In order for data-item-1, defined subordinate to group item group-item-1 to be a corresponding match to data-item-2 which is subordinate to group-item-2, each of the following must be true:

  1. Both data-item-1 and data-item-2 must have the same name, and that name may not explicitly or implicitly be FILLER.
  2. Both data-item-1 and data-item-2
    1. …must exist at the same relative structural “depth” of definition within group-item-1 and group-item-2, respectively
    2. …and all “parent” data items defined within each group item must have identical (but non-FILLER) names.
  3. When used with a MOVE verb…
    1. …one of data-item-1 or data-item-2 (but not both) is allowed to be a group item
    2. …and it must be valid to move data-item-1 TO data-item-2.
  4. When used with ADD or SUBTRACT verbs, both data-item-1 and data-item-2 must be numeric, elementary, unedited items.
  5. Neither data-item-1 nor data-item-2 may be a REDEFINES (see REDEFINES) or RENAMES (see RENAMES) of another data item.
  6. Neither data-item-1 nor data-item-2 may have an OCCURS (see OCCURS) clause, although either may contain subordinate data items that do have an OCCURS clause (assuming rule 3a applies)

Observe the definitions of data items ‘Q’ and ‘Y’…

01  Q.                           01  Y.
    03 X.                            02 A         PIC X(1).
       05 A         PIC 9(1).        02 G1.
       05 G1.                           03 G2.
          10 G2.                           04 B   PIC X(1).
             15 B   PIC X(1).        02 C         PIC X(1).
       05 C.                         02 G3.
          10 FILLER PIC X(1).           03 G5.
       05 G3.                              04 D   PIC X(1).
          10 G4.                        03 G6     PIC X(1).
             15 D   PIC X(1).        02 E         PIC 9(1).
       05 E         PIC X(1).        02 F         PIC X(1).
       05 F         REDEFINES V1     02 G         PIC X(4).
                    PIC X(1).        02 H         OCCURS 4 TIMES
       05 G.                                      PIC X(1).
          10 G6     OCCURS 4 TIMES   66 I         RENAMES E.
                    PIC X(1).        02 J.
       05 H         PIC X(4).           03 K.
       05 I         PIC 9(1).              04 L.
       05 J.                                  05 M.
          10 K.
             15 M   PIC X(1).

The following are the valid CORRESPONDING matches, assuming the statement MOVE CORRESPONDING X TO Y is being executed (there are no valid corresponding matches for ADD CORRESPONDING or SUBTRACT CORRESPONDING because every potential match up violates rule #4):

A, B, C, G

The following are the CORRESPONDING match ups that passed rule #1 (but failed on another rule), and the reasons why they failed.

Data ItemFailure Reason
DFails due to rule #2b
EFails due to rule #3b
FFails due to rule #5
G1Fails due to rule #3a
G2Fails due to rule #3a
G3Fails due to rule #3a
G4Fails due to rule #1
G5Fails due to rule #1
G6Fails due to rule #6
HFails due to rule #6
IFails due to rule #5
JFails due to rule #3a
KFails due to rule #3a
LFails due to rule #1
MFails due to rule #2a


7.6.3. INVALID KEY + NOT INVALID KEY

INVALID KEY Syntax
=======================================================================

 [ INVALID KEY imperative-statement-1 ]
   ~~~~~~~
 [ NOT INVALID KEY imperative-statement-2 ]
   ~~~ ~~~~~~~

=======================================================================

INVALID KEY clauses may be specified on DELETE (see DELETE), READ (see Random READ), REWRITE (see REWRITE), START (see START) and WRITE (see WRITE) statements.

Specification of an INVALID KEY clause will allow your program to trap an I/O failure condition (with an I/O error code in the file’s FILE-STATUS (see SELECT) field) that has occurred due to a record-not-found condition and handle it gracefully by executing imperative-statement-1 (see Imperative Statement).

An optional NOT INVALID KEY clause will cause imperative-statement-2 to be executed if the statement’s execution was successful.



7.6.4. ON EXCEPTION + NOT ON EXCEPTION

ON EXCEPTION Syntax
=======================================================================

 [ ON EXCEPTION imperative-statement-1 ]
      ~~~~~~~~~
 [ NOT ON EXCEPTION imperative-statement-2 ]
   ~~~    ~~~~~~~~~

=======================================================================

EXCEPTION clauses may be specified on ACCEPT (see ACCEPT), CALL (see CALL) and DISPLAY (see DISPLAY) statements.

Specification of an exception clause will allow your program to trap a failure condition that has occurred and handle it gracefully by executing imperative-statement-1 (see Imperative Statement). If such a condition occurs at runtime without having one of these clauses specified, an error message will be generated (by the GnuCOBOL runtime library) to the SYSERR device (pipe 2). The program may also be terminated, depending upon the type and severity of the error.

An optional NOT ON EXCEPTION clause will cause imperative-statement-2 to be executed if the statement’s execution was successful.



7.6.5. ON OVERFLOW + NOT ON OVERFLOW

ON OVERFLOW Syntax
=======================================================================

 [ ON OVERFLOW imperative-statement-1 ]
      ~~~~~~~~
 [ NOT ON OVERFLOW imperative-statement-2 ]
   ~~~    ~~~~~~~~

=======================================================================

OVERFLOW clauses may be specified on CALL (see CALL), STRING (see STRING) and UNSTRING (see UNSTRING) statements.

An ON OVERFLOW clause will allow your program to trap a failure condition that has occurred and handle it gracefully by executing imperative-statement-1 (see Imperative Statement). If such a condition occurs at runtime without having one of these clauses specified, an error message will be generated (by the GnuCOBOL runtime library) to the SYSERR device (pipe 2). The program may also be terminated, depending upon the type and severity of the error.

An optional NOT ON OVERFLOW clause will cause imperative-statement-2 to be executed if the statement’s execution was successful.



7.6.6. ON SIZE ERROR + NOT ON SIZE ERROR

ON SIZE ERROR Syntax
=======================================================================

 [ ON SIZE ERROR imperative-statement-1 ]
      ~~~~ ~~~~~
 [ NOT ON SIZE ERROR imperative-statement-2 ]
   ~~~    ~~~~ ~~~~~

=======================================================================

SIZE ERROR clauses may be included on ADD (see ADD), COMPUTE (see COMPUTE), DIVIDE (see DIVIDE), MULTIPLY (see MULTIPLY) and SUBTRACT (see SUBTRACT) statements.

Including an ON SIZE ERROR clause on an arithmetic statement will allow your program to trap a failure of an arithmetic statement (either generating a result too large for the receiving field, or attempting to divide by zero) and handle it gracefully by executing imperative-statement-1 (see Imperative Statement). Field size overflow conditions occur silently, usually without any runtime messages being generated, even though such events rarely lend themselves to generating correct results. Division by zero errors, when no ON SIZE ERROR clause exists, will produce an error message (by the GnuCOBOL runtime library) to the SYSERR device (pipe 2) and will also abort the program.

An optional NOT ON SIZE ERROR clause will cause imperative-statement-2 to be executed if the arithmetic statement’s execution was successful.



7.6.7. ROUNDED

ROUNDED Syntax
=======================================================================

 ROUNDED [ MODE IS { AWAY-FROM-ZERO         }
 ~~~~~~~   ~~~~    { ~~~~~~~~~~~~~~         }
                   { NEAREST-AWAY-FROM-ZERO }
                   { ~~~~~~~~~~~~~~~~~~~~~~ }
                   { NEAREST-EVEN           }
                   { ~~~~~~~~~~~~           }
                   { NEAREST-TOWARD-ZERO    }
                   { ~~~~~~~~~~~~~~~~~~~    }
                   { PROHIBITED             }
                   { ~~~~~~~~~~             }
                   { TOWARD-GREATER         }
                   { ~~~~~~~~~~~~~~         }
                   { TOWARD-LESSER          }
                   { ~~~~~~~~~~~~~          }
                   { TRUNCATION             }
                     ~~~~~~~~~~

=======================================================================

GnuCOBOL provides for control over the final rounding process applied to the receiving fields on all arithmetic verbs. Each of the arithmetic statements (ADD (see ADD), COMPUTE (see COMPUTE), DIVIDE (see DIVIDE), MULTIPLY (see MULTIPLY) and SUBTRACT (see SUBTRACT)) statements allow an optional ROUNDED clause to be applied to each receiving data item.

The following rules apply to the rounding behaviour induced by this clause.

  1. Rounding only applies when the result being saved to a receiving field with a ROUNDED clause is a non-integer value.
  2. Absence of a ROUNDED clause is the same as specifying ROUNDED MODE IS TRUNCATION.
  3. Use of a ROUNDED clause without a MODE specification is the same as specifying ROUNDED MODE IS NEAREST-AWAY-FROM-ZERO.

The behaviour of the eight different rounding modes is defined in the following table. Note that a ‘’ indicates the last digit repeats. The examples assume an integer receiving field.

AWAY-FROM-ZERO

Rounding is to the nearest value of larger magnitude.

-3.510 ⇒ -4+3.510 ⇒ +4
-3.500 ⇒ -4+3.500 ⇒ +4
-3.499… ⇒ -4+3.499… ⇒ +4
-2.500 ⇒ -3+2.500 ⇒ +3
-2.499… ⇒ -3+2.499… ⇒ +3
NEAREST-AWAY-FROM-ZERO

Rounding is to the nearest value (larger or smaller). If two values are equally near, the value with the larger absolute value is selected.

-3.510 ⇒ -4+3.510 ⇒ +4
-3.500 ⇒ -4+3.500 ⇒ +4
-3.499… ⇒ -3+3.499… ⇒ +3
-2.500 ⇒ -3+2.500 ⇒ +3
-2.499… ⇒ -2+2.499… ⇒ +2
NEAREST-EVEN

Rounding is to the nearest value (larger or smaller). If two values are equally near, the value whose rightmost digit is even is selected. This mode is sometimes called “Banker’s rounding”.

-3.510 ⇒ -4+3.510 ⇒ +4
-3.500 ⇒ -4+3.500 ⇒ +4
-3.499… ⇒ -3+3.499… ⇒ +3
-2.500 ⇒ -2+2.500 ⇒ +2
-2.499… ⇒ -2+2.499… ⇒ +2
NEAREST-TOWARD-ZERO

Rounding is to the nearest value (larger or smaller). If two values are equally near, the value with the smaller absolute value is selected.

-3.510 ⇒ -4+3.510 ⇒ +4
-3.500 ⇒ -3+3.500 ⇒ +3
-3.499… ⇒ -3+3.499… ⇒ +3
-2.500 ⇒ -2+2.500 ⇒ +2
-2.499… ⇒ -2+2.499… ⇒ +2
PROHIBITED

No rounding is performed. If the value cannot be represented exactly in the desired format, the EC-SIZE-TRUNCATION condition (exception code 1005) is set (and may be retrieved via the ACCEPT (see ACCEPT FROM Runtime-Info) statement) and the results of the operation are undefined.

-3.510 ⇒ Undefined+3.510 ⇒ Undefined
-3.500 ⇒ Undefined+3.500 ⇒ Undefined
-3.499… ⇒ Undefined+3.499… ⇒ Undefined
-2.500 ⇒ Undefined+2.500 ⇒ Undefined
-2.499… ⇒ Undefined+2.499… ⇒ Undefined
TOWARD-GREATER

Rounding is toward the nearest value whose algebraic value is larger.

-3.510 ⇒ -3+3.510 ⇒ +4
-3.500 ⇒ -3+3.500 ⇒ +4
-3.499… ⇒ -3+3.499… ⇒ +4
-2.500 ⇒ -2+2.500 ⇒ +3
-2.499… ⇒ -2+2.499… ⇒ +3
TOWARD-LESSER

Rounding is toward the nearest value whose algebraic value is smaller.

-3.510 ⇒ -4+3.510 ⇒ +3
-3.500 ⇒ -4+3.500 ⇒ +3
-3.499… ⇒ -4+3.499… ⇒ +3
-2.500 ⇒ -3+2.500 ⇒ +2
-2.499… ⇒ -3+2.499… ⇒ +2
TRUNCATION

Rounding is to the nearest value whose magnitude is smaller.

-3.510 ⇒ -3+3.510 ⇒ +3
-3.500 ⇒ -3+3.500 ⇒ +3
-3.499… ⇒ -3+3.499… ⇒ +3
-2.500 ⇒ -2+2.500 ⇒ +2
-2.499… ⇒ -2+2.499… ⇒ +2


7.7. Special Registers

GnuCOBOL, like other COBOL dialects, includes a number of data items that are automatically available to a programmer without the need to actually define them in the data division. COBOL refers to such items as registers or special registers. The special registers available to a GnuCOBOL program are as follows:

COB-CRT-STATUS

PIC 9(4) — This is the default data item allocated for use by the ACCEPT screen-data-item statement (see ACCEPT screen-data-item), if no CRT STATUS (see SPECIAL-NAMES) clause was specified..

DEBUG-ITEM

Group Item — A group item in which debugging information generated by a USE FOR DEBUGGING section in the declaratives area of the procedure division will place information documenting why the USE FOR DEBUGGING procedure was invoked. Consult the DECLARATIVES (see DECLARATIVES) documentation for information on the structure of this register.

LINAGE-COUNTER

BINARY-LONG SIGNED — An occurrence of this register exists for each selected file having a LINAGE (see File/Sort-Description) clause. If there are multiple files whose file descriptions have LINAGE clauses, any explicit references to this register will require qualification (using OF file-name). The value of this register will be the current logical line number within the page body. The value of this register cannot be modified.

LINE-COUNTER

BINARY-LONG SIGNED — An occurrence of this register exists for each report defined in the program (via an RD (see REPORT SECTION)). If there are multiple reports, any explicit references to this register not made in the report section will require qualification (OF report-name). The value of this register will be the current logical line number on the current page. The value of this register cannot be modified.

NUMBER-OF-CALL-PARAMETERS

BINARY-LONG SIGNED — This register contains the number of arguments passed to a subroutine — the same value that would be returned by the C$NARG built-in system subroutine (see C$NARG). Its value will be zero when referenced in a main program. This register, when referenced from within a user-defined function, returns a value of one (‘1’) if the function has any number of arguments and a zero if it has no arguments.

PAGE-COUNTER

BINARY-LONG SIGNED — An occurrence of this register exists for each report having an RD (see REPORT SECTION). If there are multiple such reports, any explicit references to this register not made in the report section will require qualification ( OF report-name). The value of this register will be the current report page number. The value of this register cannot be modified.

RETURN-CODE

BINARY-LONG SIGNED — This register provides a numeric data item into which a subroutine may MOVE (see MOVE) a value (which will then be available to the calling program) prior to transferring control back to the program that called it, or into which a main program may MOVE a value before returning control to the operating system. Many built-in subroutines will return a value using this register. These values are — by convention — used to signify success (usually with a value of 0) or failure (usually with a non-zero value) of the process the program was attempting to perform. This register may also be modified by a subprogram as a result of that subprogram’s use of the RETURNING (see PROCEDURE DIVISION RETURNING) clause.

SORT-RETURN

BINARY-LONG SIGNED — This register is used to report the success/fail status of a RELEASE (see RELEASE) or RETURN (see RETURN) statement. A value of 0 is reported on success. A value of 16 denotes failure. An AT END (see AT END + NOT AT END) condition on a RETURN is not considered a failure.

WHEN-COMPILED

PIC X(16) — This register contains the date and time the program was compiled in the format ‘mm/dd/yyhh.mm.ss’. Note that only a two-digit year is provided.

LENGTH OF Syntax
=======================================================================

 LENGTH OF numeric-literal-1 | identifier-1
 ~~~~~~

=======================================================================

Alphanumeric literals and identifiers may optionally be prefixed with the LENGTH OF clause. The compile-time value generated by this clause will be the number of bytes in the alphanumeric literal or the defined size (in bytes) of the identifier.

  1. The reserved word OF is optional and may be omitted. The presence or absence of this word has no effect upon the program. Here is an example. The following two GnuCOBOL statements both display the same result (27):
    01  Demo-Identifier          PIC X(27).
    ...
        DISPLAY LENGTH OF "This is a LENGTH OF Example"
        DISPLAY LENGTH OF Demo-Identifier
    
  2. The LENGTH OF clause on a literal or identifier reference may generally be used anywhere a numeric literal might be specified, with the following exceptions:


7.8. GnuCOBOL Statements



7.8.1. ACCEPT



7.8.1.1. ACCEPT FROM CONSOLE

ACCEPT FROM CONSOLE Syntax
=======================================================================

   ACCEPT { identifier-1 }   [ FROM mnemonic-name-1 ]
   ~~~~~~                      ~~~~
          { OMITTED      }
            ~~~~~~~

 [ END-ACCEPT ]
   ~~~~~~~~~~

=======================================================================

This format of the ACCEPT statement is used to read a value from the console window or the standard input device and store it into a data item (identifier-1).

  1. If no FROM clause is specified, FROM CONSOLE is assumed.
  2. The specified mnemonic-name-1 must either be one of the built-in device names CONSOLE, STDIN, SYSIN or SYSIPT, or a user-defined (see SPECIAL-NAMES) mnemonic name attached to one of those four device names.
  3. Input will be read either from the console window (CONSOLE) or from the system-standard input (pipe 0 = STDIN, SYSIN or SYSIPT) and will be saved in identifier-1.
  4. If identifier-1 is a numeric data item, the character value read from the console or standard-input device will be parsed according to the rules for input to the NUMVAL intrinsic function (see NUMVAL), except that none of the trailing sign formats are honoured.


7.8.1.2. ACCEPT FROM COMMAND-LINE

ACCEPT FROM COMMAND-LINE Syntax
=======================================================================

   ACCEPT identifier-1
   ~~~~~~
          FROM { COMMAND-LINE                                }
          ~~~~ { ~~~~~~~~~~~~                                }
               { ARGUMENT-NUMBER                             }
               { ~~~~~~~~~~~~~~~                             }
               { ARGUMENT-VALUE                              }
               { ~~~~~~~~~~~~~~                              }
               { [ ON EXCEPTION imperative-statement-1 ]     }
               {      ~~~~~~~~~                              }
               { [ NOT ON EXCEPTION imperative-statement-2 ] }
 [ END-ACCEPT ]    ~~~    ~~~~~~~~~
   ~~~~~~~~~~

=======================================================================

This format of the ACCEPT statement is used to retrieve information from the program’s command line.

  1. The reserved word ON is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. When you accept from the COMMAND-LINE option, you will retrieve the entire set of arguments entered on the command line that executed the program, exactly as they were specified. Parsing that returned data into its meaningful information will be your responsibility.
  3. Using COMMAND-LINE or ARGUMENT-VALUE in a *nix based platform and that includes Linux, OSX, BSD and under windows running msys or MinGW etc, the shell process will expand any arguments that have a ‘*’ in the list — such as ‘a*’, ‘abc*.*’, etc. — and create a list of all files that match the pattern. To avoid this if not wanted, put all such argument within quotes, e.g., progundertest "a*" b c d "ef*" "*hg" and the text within quotes will be passed verbatim to the program (as in the example progundertest).
  4. By accepting from ARGUMENT-NUMBER, you will be asking the GnuCOBOL run-time system to parse the arguments from the command line and return the number of arguments found. Parsing will be conducted according to the following rules:
    1. Arguments will be separated by treating spaces and/or tab characters as the delimiters between arguments. The number of such delimiters separating two non-blank argument values is irrelevant.
    2. Strings enclosed in double-quote characters (‘"’) will be treated as a single argument, regardless of how many spaces or tab characters (if any) might be embedded within the quotation characters.
    3. On Windows systems, single-quote, or apostrophe, characters (‘'’) will be treated just like any other data character and will not delineate argument strings.
  5. By accepting from ARGUMENT-VALUE, you will be asking the GnuCOBOL run-time system to parse the arguments from the command line and return the “current” argument. You specify which argument number is “current” via the ARGUMENT-NUMBER option on the DISPLAY statement (see DISPLAY UPON COMMAND-LINE). Parsing of arguments will be conducted according to the rules set forth above.
  6. The optional ON EXCEPTION and NOT ON EXCEPTION clauses may be used to detect and react to the failure or success, respectively, of an attempt to retrieve an ARGUMENT-VALUE. See ON EXCEPTION + NOT ON EXCEPTION, for additional information.


7.8.1.3. ACCEPT FROM ENVIRONMENT

ACCEPT FROM ENVIRONMENT Syntax
=======================================================================

   ACCEPT identifier-1
   ~~~~~~
          FROM { ENVIRONMENT-VALUE            }
          ~~~~ { ~~~~~~~~~~~~~~~~~            }
               { ENVIRONMENT { literal-1    } }
               { ~~~~~~~~~~~ { identifier-1 } }
        [ ON EXCEPTION imperative-statement-1 ]
             ~~~~~~~~~
        [ NOT ON EXCEPTION imperative-statement-2 ]
          ~~~    ~~~~~~~~~
 [ END-ACCEPT ]
   ~~~~~~~~~~

=======================================================================

This format of the ACCEPT statement is used to retrieve environment variable values.

  1. The reserved word ON is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. By accepting from ENVIRONMENT-VALUE, you will be asking the GnuCOBOL run-time system to retrieve the value of the environment variable whose name is currently in the ENVIRONMENT-NAME register. A value may be placed into the ENVIRONMENT-NAME register using the ENVIRONMENT-NAME option of the DISPLAY statement (see DISPLAY UPON ENVIRONMENT-NAME).
  3. A simpler approach to retrieving an environment variables value is to use the ENVIRONMENT option, where you specify the environment variable whose value is to be retrieved right on the ACCEPT statement itself.
  4. The optional ON EXCEPTION and NOT ON EXCEPTION clauses may be used to detect and react to an attempt to retrieve the value of a non-existent environment variable or the successful retrieval of an environment variable’s value, respectively. See ON EXCEPTION + NOT ON EXCEPTION, for additional information.


7.8.1.4. ACCEPT screen-data-item

ACCEPT screen-data-item Syntax
=======================================================================

   ACCEPT { identifier-1 }
   ~~~~~~
          { OMITTED      }
            ~~~~~~~
                           [{ FROM EXCEPTION-STATUS }]
                              ~~~~ ~~~~~~~~~~~~~~~~
                           [{ FROM CRT ] [ MODE IS BLOCK ]}
                              ~~~~ ~~~     ~~~~    ~~~~~

          [ AT { | LINE NUMBER { integer-1    }                | } ]
            ~~ { | ~~~~        { identifier-2 }                | }
               { | COLUMN|COL|POSITION|POS NUMBER { integer-2    }
               { | ~~~~~~ ~~~ ~~~~~~~~ ~~~        { identifier-3 }
               {                                                 }
               { { integer-3    }                                }
               { { identifier-4 }                                }

          [ WITH [ Attribute-Specification ]...
            ~~~~
                 [ LOWER|UPPER ]
                   ~~~~~ ~~~~~
                 [ SCROLL { UP   } [ { integer-4    } LINE|LINES ] ]
                   ~~~~~~ { ~~   }   { identifier-5 }
                          { DOWN }
                            ~~~~
                 [ TIMEOUT|TIME-OUT AFTER { integer-5    } ]
                   ~~~~~~~ ~~~~~~~~       { identifier-6 }
                 [ CONVERSION ]
                   ~~~~~~~~~~
                 [ UPDATE ]
                   ~~~~~~
                 [ SIZE  { integer-6    } ]
                   ~~~~  { identifier-7 }
          [ ON EXCEPTION imperative-statement-1 ]
               ~~~~~~~~~
          [ NOT ON EXCEPTION imperative-statement-2 ]
            ~~~    ~~~~~~~~~
 [ END-ACCEPT ]
   ~~~~~~~~~~

The FROM CRT, MODE IS BLOCK and CONVERSION clauses are syntactically recognized but are otherwise non-functional.


=======================================================================

This format of the ACCEPT statement is used to retrieve data from a formatted console window screen.

  1. The reserved words AFTER, IS, NUMBER and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved words COLUMN, COL and POSITION are interchangeable.
  3. The reserved words TIMEOUT and TIME-OUT are interchangeable.
  4. If identifier-1 is defined in the SCREEN SECTION (see SCREEN SECTION), any AT, Attribute-Specification, LOWER, UPPER or SCROLL clauses will be ignored. In these cases, an implied DISPLAY (see DISPLAY screen-data-item) of identifier-1 will occur before input is accepted. Coding an explicit DISPLAY identifier-1 before an ACCEPT identifier-1 is redundant and will incur the performance penalty of painting the screen contents twice.
  5. The various AT clauses provide a means of positioning the cursor to a specific spot on the screen before the screen is read. One or the other (but not both) may be used, as follows:
    1. The LINE and COLUMN clauses provide one mechanism for specifying the line and column position to which the cursor will be positioned before allowing the user to enter data. In the absence of one or the other, a value of 1 will be assumed for the one that is missing. The author’s personal preference, however, is to explicitly code both.
    2. The literal-3 or identifier-4 value, if specified, must be a four- or six-digit value with the 1st half of the number indicating the line where the cursor should be positioned and the second half indicating the column. You may code only one of each clause on any ACCEPT.
  6. WITH options (including the various individual Attribute-Specifications) should be coded only once.
  7. The following Attribute-Specification clauses are allowed on the ACCEPT statement; these are the same as those allowed for SCREEN SECTION data items. A particular Attribute-Specification may be used only once in any ACCEPT:
  8. The SCROLL option will cause the entire contents of the screen to be scrolled UP or DOWN by the specified number of lines before any value is displayed on the screen. It is syntactically allowable to specify a SCROLL UP clause as well as a SCROLL DOWN clause. In such an instance, it is the last one specified that will be honoured. If no LINES specification is made, 1 LINE will be assumed.
  9. The TIMEOUT option will cause the ACCEPT to wait no more than the specified number of seconds for input. The wait count may be specified as a positive integer or a numeric data item with a positive value.
  10. The UPDATE option will enable the supplied data field to be updated having been displayed on screen prior to data being entered by overwriting, if needed. When this option is not used the input field is cleared prior to input and this is the default but can be changed by the use of compiler steering command -faccept-with-update that can be input when starting the compiler or included in the configuration file e.g., default.conf used when selected by default -std=default. For more information see cobc - The GnuCOBOL Compiler option switches) and Compiler Configuration Files.
  11. This format of the ACCEPT statement will be terminated by any of the following events:
    1. When the Enter key is pressed.
    2. Expiration of the TIMEOUT timer — this will be treated as if the Enter key had been pressed with no data being entered.
    3. When a function key (Fn) is pressed.
    4. The pressing of the PgUp or PgDn keys, if the COB_SCREEN_EXCEPTIONS run-time environment variable (see Run Time Environment Variables) is set to any non-blank value.
    5. The pressing of the Esc key if both the COB_SCREEN_ESC run-time environment variable as well as COB_SCREEN_EXCEPTIONS run-time environment variable are set to any non-blank value.
    6. The pressing of the Up-arrow, Down-Arrow or PrtSc (Print Screen) keys. These keys are not detectable on Windows systems, however.
  12. The following apply when identifier-1 is defined in the SCREEN SECTION:
    1. Alphanumeric data entered into identifier-1 or any screen data item subordinate to it must be consistent with the PICTURE (see PICTURE) clause of that item. This will be enforced at runtime by the ACCEPT statement.
    2. If identifier-1 or any screen data item subordinate to it are defined as numeric, entered data must be acceptable as NUMVAL intrinsic function (see NUMVAL) input (no decimal points are allowed, however). The value stored into the screen data item will be as if the input were passed to that function.
    3. If identifier-1 or any screen data item subordinate to it are defined as numeric edited, entered data must be acceptable as NUMVAL-C intrinsic function (see NUMVAL-C) input (again, no decimal points are allowed). The value stored into the screen data item will be as if the input were passed to that function.
  13. The following apply when identifier-1 is not defined in the SCREEN SECTION:
    1. Alphanumeric data entered into identifier-1 should be consistent with the PICTURE (see PICTURE) clause of that item, although that will not be enforced by the ACCEPT statement. You may use Class Conditions (see Class Conditions) after the data is accepted to enforce the data type.
    2. If identifier-1 is defined as numeric, entered data must be acceptable as NUMVAL intrinsic function (see NUMVAL) input (no decimal points are allowed, however). The value stored into identifier-1 will be as if the input were passed to that function.
    3. If identifier-1 is defined as numeric edited, entered data must be acceptable as NUMVAL-C intrinsic function (see NUMVAL-C) input (again, no decimal points are allowed). The value stored into identifier-1 will be as if the input were passed to that function.
  14. The optional ON EXCEPTION and NOT ON EXCEPTION clauses may be used to detect and react to the failure or success, respectively, of the screen I/O attempt. See ON EXCEPTION + NOT ON EXCEPTION, for additional information.

    After this format of the ACCEPT statement is executed, the program’s CRT STATUS (see SPECIAL-NAMES) identifier will be populated with one of the following:

    CodeMeaning
    0000ENTER key pressed
    1001–1064F1F64, respectively, were pressed
    2001PgUp was pressed
    2002PgDn was pressed
    2003Up-Arrow was pressed
    2004Down-Arrow was pressed
    2005Esc was pressed
    2006PrtSc (Print Screen) was pressed
    2007Tab
    2008Back Tab
    2009Key Left
    2010Key Right
    2011Insert Key on accept omitted
    2012Delete Key on accept omitted
    2013Backspace Key on accept omitted
    2014Home Key on accept omitted
    2015End Key on accept omitted
    2040-2095 Exception keys for Mouse Handling
    2040Mouse Move
    2041Left Pressed
    2042Left Released
    2043Left Dbl Click
    2044Mid Pressed
    2045Mid Released
    2046Mid Dbl Click
    2047Right Pressed
    2048Right Released
    2049Right Dbl Click
    2050Shift Move
    2051Shift Left Pressed
    2052Shift Left Released
    2053Shift Left Dbl Click
    2054Shift Mid Pressed
    2055Shift Mid Released
    2056-Shift Mid Dbl Click
    2057Shift Right Pressed
    2058Shift Right Released
    2059Shift Right Dbl Click
    2060Ctrl Move
    2061Ctrl Left Pressed
    2062Ctrl Left Released
    2063Ctrl Left Dbl Click
    2064Ctrl Mid Pressed
    2065Ctrl Mid Released
    2066Ctrl Mid Dbl Click
    2067Ctrl Right Pressed
    2068Ctrl Right Released
    2069Ctrl Right Dbl Click
    2070Alt Move
    2071Alt Left Pressed
    2072Alt Left Released
    2073-Alt Left Dbl Click
    2074Alt Mid Pressed
    2075Alt Mid Released
    2076Alt Mid Dbl Click
    2077Alt Right Pressed
    2078Alt Right Released
    2079Alt Right Dbl Click
    2080Wheel Up
    2081Wheel Down
    2082Wheel Left
    2083Wheel Right
    2084Shift Wheel Up
    2085Shift Wheel Down
    2086Shift Wheel Left
    2087Shift Wheel Right
    2088Ctrl Wheel Up
    2089Ctrl Wheel Down
    2090Ctrl Wheel Left
    2091Ctrl Wheel Right
    2092Alt Wheel Up
    2093Alt Wheel Down
    2094Alt Wheel Left
    2095Alt Wheel Right
    Input validation
    8000NO Field
    8001Time Out
    Other errors
    9000Fatal
    9001Max Field
  15. The actual key pressed to generate a function key (Fn) will depend on the type of terminal device you’re using (PC, Macintosh, VT100, etc.) and what type of enhanced display driver was configured with the version of GnuCOBOL you’re using.

    For example, on a GnuCOBOL build for a Windows PC using MinGW and “PDCurses”, F1F12 are the actual F-keys on the PC keyboard, F13F24 are entered by shifting the F-keys, F25F36 are entered by holding Ctrl while pressing an F-key and F37F48 are entered by holding Alt while pressing an F-key. On the other hand, a GnuCOBOL implementation built for Windows using Cygwin and NCurses treats the PCs F1F12 keys as the actual F1F12, while shifted F-keys will enter F11F20. With Cygwin/NCurses, Ctrl- and Alt-modified F-keys aren’t recognized, nor are Shift-F11 or Shift-F12.

    Mouse Key codes are populated only if mouse management has been enabled. To enable mouse it is first necessary to set COB_MOUSE_FLAGS (either externally via terminal command, or internally via SET ENVIRONMENT to the applicable ?mouse mask? (specifying which activities you wish the program to detect). Here is an example of setting the mask from a COBOL program:

    COPY screenio.cpy.
    
    01  mouse-flags PIC 9(4).
    
    ...
    
        COMPUTE mouse-flags = COB-AUTO-MOUSE-HANDLING
                            + COB-ALLOW-LEFT-DOWN
                            + COB-ALLOW-MIDDLE-DOWN
                            + COB-ALLOW-RIGHT-DOWN
    
        SET ENVIRONMENT "COB_MOUSE_FLAGS" TO mouse-flags.
    
    
  16. Once that has been done, every (extended) ACCEPT, will return a value in COB_CRT_STATUS reflecting mouse activity, when such activity occurs. The applicable values are shown in screenio.cpy under ?Exception keys for mouse handling?. If you define a variable in SPECIAL NAMES as follows:
    SPECIAL-NAMES.
       CURSOR IS data-name.   *> where data-name is PIC 9(4) or 9(6).
    
  17. The cursor or mouse position will be returned as well. The position is expressed as row and column (rrcc or rrrccc).
  18. Numeric keypad keys are not recognizable on Windows MinGW/PDCurses builds of GnuCOBOL, regardless of the number lock settings. Windows Cygwin/NCurses builds recognize numeric keypad inputs properly. Although not tested during the preparation of this documentation, I would expect native Windows builds using PDCurses to behave as MinGW builds do and native Unix builds using NCurses to behave as do Cygwin builds.
  19. The optional EXCEPTION-STATUS clause may be used to detect exceptions from a prior arithmetic verb such as COMPUTE to recover any errors produced. These are recovered using the function EXCEPTION-STATUS.


7.8.1.5. ACCEPT FROM DATE/TIME

ACCEPT FROM DATE/TIME Syntax
=======================================================================

   ACCEPT identifier-1 FROM { DATE [ YYYYMMDD ] }
   ~~~~~~              ~~~~ { ~~~~   ~~~~~~~~   }
                            { DAY [ YYYYDDD ]   }
                            { ~~~   ~~~~~~~     }
                            { DAY-OF-WEEK       }
                            { ~~~~~~~~~~~       }
 [ END-ACCEPT ]             { TIME              }
   ~~~~~~~~~~

=======================================================================

This format of the ACCEPT statement is used to retrieve the current system date, time or current day of the week and store it into a data item.

  1. The data retrieved from the system and the format in which it is structured will vary, as follows:
    SyntaxData RetrievedFormat
    DATECurrent date in Gregorian formyymmdd
    DATE YYYYMMDDCurrent date in Gregorian formyyyymmdd
    DAYCurrent date in Julian formyyddd
    DAY YYYYDDDCurrent date in Julian formyyyyddd
    TIMETime, including hundredths of a second (nn)hhmmssnn


7.8.1.6. ACCEPT FROM Screen-Info

ACCEPT FROM Screen-Info Syntax
=======================================================================

   ACCEPT identifier-1
   ~~~~~~
          FROM { LINES|LINE-NUMBER }
          ~~~~ { ~~~~~ ~~~~~~~~~~~ }
               { COLS|COLUMNS      }
               { ~~~~ ~~~~~~~      }
               { ESCAPE KEY        }
                 ~~~~~~ ~~~
 [ END-ACCEPT ]
   ~~~~~~~~~~

=======================================================================

This format of the ACCEPT statement is used to retrieve information about the console window or about the user’s interactions with it.

  1. The reserved words LINES and LINE-NUMBER are interchangeable.
  2. The reserved words COLS and COLUMNS are interchangeable.
  3. The following points pertain to the use of the LINES and COLUMNS options:
    1. The LINES and COLUMNS options will retrieve the respective components of the size of the console display.
    2. When the console is running in a windowed environment, this will be the sizing of the window in which the program is executing, in terms of horizontal (COLUMNS) or vertical (LINES) character counts — not pixels.
    3. When the system is not running a windowing environment, the physical console screen attributes will be returned.
    4. Values of 0 will be returned if GnuCOBOL was not generated to include screen I/O.
    5. See the documentation on the CBL_GET_SCR_SIZE built-in system subroutine (see CBL_GET_SCR_SIZE) for another way to retrieve this information.
  4. The ESCAPE KEY option may be used after the ACCEPT FROM Screen-Info statement (see ACCEPT FROM Screen-Info) has executed. The result returned will be the four-digit CRT STATUS (see SPECIAL-NAMES) identifier value. See CRT STATUS Codes, for the specific code values.


7.8.1.7. ACCEPT FROM Runtime-Info

ACCEPT FROM Runtime-Info Syntax
=======================================================================

   ACCEPT identifier-1
   ~~~~~~
          FROM { EXCEPTION STATUS }
          ~~~~ { ~~~~~~~~~ ~~~~~~ }
               { USER NAME        }
                 ~~~~ ~~~~
 [ END-ACCEPT ]
   ~~~~~~~~~~

=======================================================================

This format of the ACCEPT statement is used to retrieve run-time information such as the most-recent error exception code and the current user’s user name.

  1. The following points pertain to the use of the EXCEPTION STATUS option:
    1. identifier-1 must be defined as a PIC X(4) item.
    2. See Error Exception Codes, for a complete list of the exception codes and their meanings.
    3. An alternative to the use of ACCEPT FROM Runtime-Info is to use the EXCEPTION-STATUS intrinsic function (see EXCEPTION-STATUS).
  2. The following points pertain to the use of the USER NAME option:
    1. The returned result is the userid that was used to login to the system with, and not any actual first and/or last name of the user in question (unless, of course, that is the information used as a logon id). It is not the PID or UID numbers but the name associated with the UID under *nix based systems.
    2. identifier-1 should be defined large enough to receive the longest user-name on the system.
    3. If insufficient space is allocated, the returned value will be truncated.
    4. If excess space is allocated, the returned value will be padded with spaces (to the right).


7.8.1.8. ACCEPT OMITTED

ACCEPT OMITTED Syntax
=======================================================================

   ACCEPT OMITTED
   ~~~~~~

   1.  For console : See 6.17.1.1 (ACCEPT FROM CONSOLE Syntax)

   2.  For Screen  : See 6.17.1.4 (ACCEPT screen-data-item Syntax)

 [ END-ACCEPT ]
   ~~~~~~~~~~

=======================================================================

This format of the ACCEPT statement will wait for a keyboard event that terminates input; function keys, or Enter/Return, among others. CRT STATUS (COB-CRT-STATUS CRT STATUS (see SPECIAL-NAMES) if not explicitly defined) is set with the keycode, listed in copy/screenio.cpy. It also handles a few other keycode terminations not normally used to complete an extended accept.

  1. The following are examples of keycodes that can be used:
    COB-SCR-INSERT
    COB-SCR-DELETE
    COB-SCR-BACKSPACE
    COB-SCR-KEY-HOME
    COB-SCR-KEY-END
    
  2. You can used extended attributes, useful for setting timeouts or positioning.


7.8.1.9. ACCEPT FROM EXCEPTION-STATUS

ACCEPT FROM EXCEPTION-STATUS Syntax
=======================================================================

   ACCEPT exception-status-pic-9-4   FROM EXCEPTION-STATUS
   ~~~~~~                            ~~~~ ~~~~~~~~~~~~~~~~

 [ END-ACCEPT ]
   ~~~~~~~~~~

=======================================================================

This format of the ACCEPT statement will receive the status for any exceptions resulting from a previous valid verb.

  1. The following is an example of usage:
     In WS:
     01  exception-status  pic 9(4).
    ..
     In PD:
    
     ACCEPT unexpected-rounding  FROM EXCEPTION-STATUS
     IF unexpected-rounding NOT EQUAL "0000" THEN
        DISPLAY "Unexpected rounding. Code " unexpected-rounding
                 UPON SYSERR
     END-IF
    


7.8.2. ADD



7.8.2.1. ADD TO

ADD TO Syntax
=======================================================================

   ADD { literal-1    }...
   ~~~ { identifier-1 }

       TO { identifier-2
       ~~
          [ ROUNDED [ MODE IS { AWAY-FROM-ZERO         } ] ] }...
            ~~~~~~~   ~~~~    { ~~~~~~~~~~~~~~         }
                              { NEAREST-AWAY-FROM-ZERO }
                              { ~~~~~~~~~~~~~~~~~~~~~~ }
                              { NEAREST-EVEN           }
                              { ~~~~~~~~~~~~           }
                              { NEAREST-TOWARD-ZERO    }
                              { ~~~~~~~~~~~~~~~~~~~    }
                              { PROHIBITED             }
                              { ~~~~~~~~~~             }
                              { TOWARD-GREATER         }
                              { ~~~~~~~~~~~~~~         }
                              { TOWARD-LESSER          }
                              { ~~~~~~~~~~~~~          }
                              { TRUNCATION             }
                                ~~~~~~~~~~
     [ ON SIZE ERROR imperative-statement-1 ]
          ~~~~ ~~~~~
     [ NOT ON SIZE ERROR imperative-statement-2 ]
       ~~~    ~~~~ ~~~~~
 [ END-ADD ]
   ~~~~~~~

=======================================================================

This format of the ADD statement generates an intermediate arithmetic sum of the values of all identifier-1 and literal-1) items. The value of each identifier-2 will be replaced, in turn, by the sum of that identifier-2s value and the intermediate sum.

  1. The reserved words IS and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. Both identifier-1 and identifier-2 must be numeric unedited data items while literal-1 must be a numeric literal.
  3. An identifier-1 data item may also be coded as an identifier-2. Note, however, that the value of such a data item will therefore be included twice in the result.
  4. The contents of each identifier-1 will remain unchanged by this statement.
  5. The optional ROUNDED (see ROUNDED) clause available to each identifier-2 will control how non-integer results will be saved.
  6. The optional ON SIZE ERROR and NOT ON SIZE ERROR clauses may be used to detect and react to the failure or success, respectively, of an attempt to perform a calculation. In this case, failure is defined as being an identifier-2 with an insufficient number of digit positions available to the left of any implied decimal point. See ON SIZE ERROR + NOT ON SIZE ERROR, for additional information.


7.8.2.2. ADD GIVING

ADD GIVING Syntax
=======================================================================

   ADD { literal-1    }...
   ~~~ { identifier-1 }

     [ TO identifier-2 ]
       ~~
       GIVING { identifier-3
       ~~~~~~
         [ ROUNDED [ MODE IS { AWAY-FROM-ZERO         } ] ] }...
           ~~~~~~~   ~~~~    { ~~~~~~~~~~~~~~         }
                             { NEAREST-AWAY-FROM-ZERO }
                             { ~~~~~~~~~~~~~~~~~~~~~~ }
                             { NEAREST-EVEN           }
                             { ~~~~~~~~~~~~           }
                             { NEAREST-TOWARD-ZERO    }
                             { ~~~~~~~~~~~~~~~~~~~    }
                             { PROHIBITED             }
                             { ~~~~~~~~~~             }
                             { TOWARD-GREATER         }
                             { ~~~~~~~~~~~~~~         }
                             { TOWARD-LESSER          }
                             { ~~~~~~~~~~~~~          }
                             { TRUNCATION             }
                               ~~~~~~~~~~
     [ ON SIZE ERROR imperative-statement-1 ]
          ~~~~ ~~~~~
     [ NOT ON SIZE ERROR imperative-statement-2 ]
       ~~~    ~~~~ ~~~~~
 [ END-ADD ]
   ~~~~~~~

=======================================================================

This format of the ADD statement generates the arithmetic sum of the values of all identifier-1, literal-1) and identifier-2 (if any) items and then saves that sum to each identifier-3.

  1. The reserved words IS and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. Both identifier-1 and identifier-2 must be numeric unedited data items while literal-1 must be a numeric literal; identifier-3 may be either a numeric or numeric edited data item.
  3. An identifier-1 or identifier-2 data item may be used as an identifier-3, if desired.
  4. The contents of each identifier-1 and identifier-2 will remain unchanged by this statement, unless they happen to also be specified as an identifier-3.
  5. The current value in each identifier-3 at the start of the statement’s execution is irrelevant, since the contents of each identifier-3 will simply be replaced with the computed sum.
  6. The optional ROUNDED (see ROUNDED) clause available to each identifier-3 will control how non-integer results will be saved.
  7. The optional ON SIZE ERROR and NOT ON SIZE ERROR clauses may be used to detect and react to the failure or success, respectively, of an attempt to perform a calculation. In this case, failure is defined as being an identifier-3 with an insufficient number of digit positions available to the left of any implied decimal point. See ON SIZE ERROR + NOT ON SIZE ERROR, for additional information.


7.8.2.3. ADD CORRESPONDING

ADD CORRESPONDING Syntax
=======================================================================

   ADD CORRESPONDING identifier-1
   ~~~
       TO identifier-2
       ~~
     [ ROUNDED [ MODE IS { AWAY-FROM-ZERO         } ] ]
       ~~~~~~~   ~~~~    { ~~~~~~~~~~~~~~         }
                         { NEAREST-AWAY-FROM-ZERO }
                         { ~~~~~~~~~~~~~~~~~~~~~~ }
                         { NEAREST-EVEN           }
                         { ~~~~~~~~~~~~           }
                         { NEAREST-TOWARD-ZERO    }
                         { ~~~~~~~~~~~~~~~~~~~    }
                         { PROHIBITED             }
                         { ~~~~~~~~~~             }
                         { TOWARD-GREATER         }
                         { ~~~~~~~~~~~~~~         }
                         { TOWARD-LESSER          }
                         { ~~~~~~~~~~~~~          }
                         { TRUNCATION             }
                           ~~~~~~~~~~
     [ ON SIZE ERROR imperative-statement-1 ]
          ~~~~ ~~~~~
     [ NOT ON SIZE ERROR imperative-statement-2 ]
       ~~~    ~~~~ ~~~~~
 [ END-ADD ]
   ~~~~~~~

=======================================================================

This format of the ADD statement generates code equivalent to individual ADD TO (see ADD TO) statements for corresponding matches of data items found subordinate to the two identifiers.

  1. The reserved words IS and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. Both identifier-1 and identifier-2 must be group items.
  3. See CORRESPONDING, for information on how corresponding matches will be found between identifier-1 and identifier-2.
  4. The optional ROUNDED (see ROUNDED) clause available to each identifier-3 will control how non-integer results will be saved.
  5. The optional ON SIZE ERROR and NOT ON SIZE ERROR clauses may be used to detect and react to the failure or success, respectively, of an attempt to perform a calculation. In this case, failure is defined as being an identifier-3 with an insufficient number of digit positions available to the left of any implied decimal point. See ON SIZE ERROR + NOT ON SIZE ERROR, for additional information.


7.8.3. ALLOCATE

ALLOCATE Syntax
=======================================================================

 ALLOCATE { expression-1 CHARACTERS } [ { INITIALIZED } ]
 ~~~~~~~~ { identifier-1 ~~~~~~~~~~ }   { ~~~~~~~~~~~ }
                                        { INITIALISED }
     [ RETURNING identifier-2 ]           ~~~~~~~~~~~
       ~~~~~~~~~

=======================================================================

The ALLOCATE statement is used to dynamically allocate memory at run-time.

  1. The reserved words INITIALIZED and INITIALISED are interchangeable.
  2. Both identifier-1 and RETURNING identifier-2 may not be specified in the same statement.
  3. If used, expression-1 must be an arithmetic expression with a non-zero positive integer value.
  4. If used, identifier-1 should be an 01-level item defined in working-storage or local-storage with the BASED (see BASED) attribute. It may be an 01 item defined in the linkage section without the BASED attribute, but using such a data item is not recommended.
  5. If used, identifier-2 should be a POINTER (see USAGE) data item.
  6. The optional RETURNING clause will return the address of the allocated memory block into the specified USAGE POINTER identifier-2 data item. When this option is used, knowledge of the originally-requested size of the allocated memory block will be retained by the program in case a FREE (see FREE) statement is ever issued against identifier-2.
  7. When the identifier-1 option is used in conjunction with INITIALIZED (or its internationalized alternative INITIALISED), the allocated memory block will be initialized as if an INITIALIZE identifier-1 WITH FILLER ALL TO VALUE THEN TO DEFAULT (see INITIALIZE) were executed.
  8. When the expression-1 CHARACTERS option is used, INITIALIZED will initialize the allocated memory block to binary zeros. If INITIALIZED is not used, the initial contents of allocated memory will be left to whatever rules of memory allocation are in effect for the operating system the program is running under.
  9. There are two basic ways in which this statement is used. The simplest is:
    ALLOCATE My-01-Item
    

    With this form, a block of storage equal in size to the defined size of My-01-Item (which must have been defined with the BASED attribute) will be allocated. The address of that block of storage will become the base address of My-01-Item so that it and its subordinate data items become usable within the program.

    A second (and equivalent) approach is:

    ALLOCATE LENGTH OF My-01-Item CHARACTERS RETURNING The-Pointer
    SET ADDRESS OF My-01-Item TO The-Pointer
    
  10. With this form My-01-Item can either be defined with the BASED attribute or be defined in LINKAGE SECTION. Instead of LENGTH OF My-01-Item you may also use a size smaller to the maximum field size as long as you ensure that the complete field is never used.
  11. Referencing a BASED data item either before its storage has been allocated or after its storage has been released (via the FREE statement) will lead to “unpredictable results”. That’s how reference manuals and standards specifications talk about this situation. In the author’s experience, the results are all too predictable: the program aborts from an attempt to reference an unallocated area of memory.


7.8.4. ALTER

ALTER Syntax
=======================================================================

 ALTER procedure-name-1 TO PROCEED TO procedure-name-2
 ~~~~~                  ~~

=======================================================================

The ALTER statement was used in the early years of the COBOL language to edit the object code of a program at execution time, changing a GO TO (see Simple GO TO) statement to branch to a spot in the program different than where the GO TO statement was originally compiled for.

  1. The reserved words PROCEED and TO (the one after PROCEED) are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. procedure-name-1 must contain only a single statement, and that statement must be a simple GO TO.
  3. The effect of this statement will be as if the generated machine-language code for the GO TO statement in procedure-name-1 is changed so that the GO TO statement now transfers control to procedure-name-2, rather than to whatever procedure name was specified in the program source code.
  4. Support for the ALTER verb has been added to GnuCOBOL for the purpose of enabling GnuCOBOL to pass those National Institute of Standards and Technology (NIST) tests for the COBOL programming language that require support for ALTER.
  5. Because of the catastrophic effect this statement has on program readability and therefore the programmer’s ability to debug problems with program logic, the use of ALTER in new programs is STRONGLY discouraged.


7.8.5. CALL

CALL Syntax
=======================================================================

   CALL [ { STDCALL         } ] { literal-1    }
   ~~~~   { ~~~~~~~         }   { identifier-1 }
          { STATIC          }
          { ~~~~~~          }
          { mnemonic-name-1 }

        [ USING CALL-Argument... ]
          ~~~~~
        [ RETURNING|GIVING identifier-2 ]
          ~~~~~~~~~ ~~~~~~
        [ ON OVERFLOW|EXCEPTION imperative-statement-1 ]
             ~~~~~~~~ ~~~~~~~~~
        [ NOT ON OVERFLOW|EXCEPTION imperative-statement-2 ]
          ~~~    ~~~~~~~~ ~~~~~~~~~
 [ END-CALL ]
   ~~~~~~~~

=======================================================================
CALL Argument Syntax
=======================================================================

 [ BY { REFERENCE } ]
      { ~~~~~~~~~ }
      { CONTENT   }
      { ~~~~~~~   }
      { VALUE     }
        ~~~~~

      { OMITTED                                                   }
      { ~~~~~~~                                                   }
      { [ UNSIGNED ] [ SIZE IS { AUTO      } ] [ { literal-2    } }
          ~~~~~~~~     ~~~~    { ~~~~      }     { identifier-2 }
                               { DEFAULT   }
                               { ~~~~~~~   }
                               { integer-1 }

=======================================================================

The CALL statement is used to transfer control to a subroutine. See Sub-Programming, for the specifics of using subprograms with GnuCOBOL programs.

  1. The reserved words BY, IS and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved words EXCEPTION and OVERFLOW are interchangeable.
  3. The reserved words GIVING and RETURNING are interchangeable.
  4. The expectation is that the subroutine will eventually return control back to the calling program, at which point the CALLing program will resume execution starting with the statement immediately following the CALL. Subprograms are not required to return to their callers, however, and are free to halt program execution if they wish.
  5. The mnemonic-name-1 / STATIC / STDCALL option, if used, affects the linkage conventions that will be used to the subroutine being called, as follows:
    STATIC

    causes the linkage to the subroutine to be performed in such a way as to require the subroutine to be statically-linked with the calling program. Note that this enables static-linking to be used on a subroutine-by-subroutine selective basis.

    STDCALL

    allows system standard calling conventions (as opposed to GnuCOBOL calling conventions) to be used when calling a subroutine. The definition of what constitutes “system standard” may vary from operating system to operating system. Use of this requires special knowledge about the linkage requirements of subroutines you are intending to CALL. Subroutines written in GnuCOBOL do not need this option.

    mnemonic-name-1

    allows a custom defined calling convention to be used. Such mnemonic names are defined using the CALL-CONVENTION (see SPECIAL-NAMES) clause. That clause associates a decimal integer value with mnemonic-name-1 such that the individual bits set on or off in the binary equivalent of the integer affect linkage to the subroutine as described in the following chart. Those rows of the chart marked with a “No” in the Supported column represent bit positions (switch settings) in the integer value that are currently accepted (to provide compatibility to other COBOL implementations) if coded, but are otherwise unsupported.

    Note that bit 0 is the right-most bit in the binary value.

    BitSupportedMeaning if 0Meaning if 1
    0NoArguments will be passed in right-to-left sequenceArguments will be passed in left-to-right sequence.
    1NoThe calling program will flush processed arguments from the argument stack.The called program (subroutine) will flush processed arguments from the argument stack.
    2YesThe RETURN-CODE special register (see Special Registers) will be updated in addition to any RETURNING or GIVING data item.The RETURN-CODE special register will not be updated (but any RETURNING or GIVING data item still will).
    3YesIf CALL literal is used, the subroutine will be located and linked in with the calling program at compile time or may be dynamically located and loaded at execution time, depending on compiler switch settings and operating system capabilities.If CALL literal is used, the subroutine can only be located and linked with the calling program at compilation time.
    4NoOS/2 “OPTLINK” conventions will not be used to CALL the subprogram.OS/2 “OPTLINK” conventions will be used to CALL the subprogram.
    5NoWindows 16-bit “thunking” will not be in effect.Windows 16-bit “thunking” will be used to call the subroutine as a DLL.
    6YesThe STDCALL convention will not be used.The STDCALL convention, required to use the Microsoft Win32 API, will be used.

    Using the STATIC option on a CALL statement is equivalent to using CALL-CONVENTION 8 (only bit 3 set).

    Using the STDCALL option on a CALL statement is equivalent to using CALL CONVENTION 64 (only bit 6 set).

  6. The value of literal-1 or identifier-1 is the entry-point of the subprogram you wish to call.
  7. When you call a subroutine using identifier-1, you are forcing the runtime system to call a dynamically-loadable subprogram. The contents of identifier-1 will be the entry-point name within that module. If this is the first call to any entry-point within the module being made at run-time, the contents of identifier-1 must be the primary entry-point name of the module (which must also match the filename, minus any OS-mandated extension) of the executable file comprising the module).
  8. You can force the GnuCOBOL runtime system to pre-load all dynamically-loaded modules that could ever be called by the program, at the time the program starts executing. This is accomplished through the use of the COB_PRE_LOAD run-time environment variable (see Run Time Environment Variables). If used, this will only pre-load those modules invoked via CALL literal-1, as the runtime contents of identifier-1 cannot be predicted.
  9. If the subprogram being called is a GnuCOBOL program, and if that program had the INITIAL (see IDENTIFICATION DIVISION) attribute specified on its PROGRAM-ID clause, all of the subprogram’s data division data will be restored to its initial state each time the subprogram is executed, regardless of which entry-point within the subprogram is being referenced.

    This [re]-initialization behaviour will always apply to any subprogram’s local-storage (if any), regardless of the use (or not) of INITIAL.

  10. The USING clause defines a list of arguments that may be passed from the calling program to the subprogram. The manner in which any given argument is passed to the subroutine depends upon the BY clause (if any) coded (or implied) for that argument, as follows:
    BY REFERENCE

    passes the address of the argument to the subprogram. If the subprogram changes the contents of that argument, the change will be “visible” to the calling program.

    BY CONTENT

    passes the address of a copy of the argument to the subprogram. If the subprogram changes the value of such an argument, the change only affects the copy back in the calling program, not the original version.

    BY VALUE

    passes the actual numeric value of the literal or identifiers contents as the argument. This feature exists to provide compatibility with C, C++ and other languages and would not normally be used when calling GnuCOBOL subprograms. Only numeric literals or numeric data items should be passed in this manner.

    If an argument lacks a BY clause, the most-recently encountered BY specification on that CALL statement will be assumed. If the first argument specified on a CALL lacks a BY clause, BY REFERENCE will be assumed.

  11. No more than 251 arguments may be passed to a subroutine, unless the GnuCOBOL compiler was built with a specifically different argument limit specified for it. If you have access to the GnuCOBOL source code, you may adjust this limit by changing the value of the COB_MAX_FIELD_PARAMS in the call.c file (found in the libcob folder) as well as the last shown #if MAX_CALL_FIELD_PARAMS statement before you run make to build the compiler and run-time library.
  12. The RETURNING clause allows you to specify a numeric data item into which the subroutine should return a numeric value. If you use this clause on the CALL, the subroutine should include a RETURNING (see PROCEDURE DIVISION RETURNING) clause on its procedure division header. Of course, a subroutine may pass a value of any kind back in any argument passed BY REFERENCE.
  13. The optional ON OVERFLOW and NOT ON OVERFLOW clauses (or ON EXCEPTION and NOT ON EXCEPTION — they are interchangeable) may be used to detect and react to the failure or success, respectively, of an attempt to CALL the subroutine. Failure, in this context, is defined as the inability to either locate or load the object code of the subroutine at execution time. See ON OVERFLOW + NOT ON OVERFLOW, for additional information.
  14. Call also supports using an entry point stored in a PROGRAM-POINTER, avoiding the dynamic runtime lookup. GnuCOBOL keeps a cache of lookups during a program run. Repeated use of a named function does not suffer much penalty, but PROGRAM-POINTER will be just that little bit faster. To set a PROGRAM-POINTER use SET program-reference TO ENTRY "name" (or get the address from an API, and take part in callback programming).
  15. An extension of CALL allows a call to a Program-Pointer-1 which is preset using SET program-pointer-1 TO ENTRY x. Additional the RETURNING clause may return a data pointer or a PROGRAM-POINTER


7.8.6. CANCEL

CANCEL Syntax
=======================================================================

 CANCEL { literal-1    }...
 ~~~~~~ { identifier-1 }

=======================================================================

The CANCEL statement unloads the dynamically-loadable subprogram module containing the entry-point specified as literal-1 or identifier-1 from memory.

  1. If a dynamically-loadable module unloaded by the CANCEL statement is subsequently re-executed, all data division storage for that module will once again be in its initial state.
  2. Whether the CANCEL statement actually physically unloads a dynamically-loaded module or simply marks it as logically-unloaded depends on the use and value of the COB_PHYSICAL_CANCEL run-time environment variable (see Run Time Environment Variables).


7.8.7. CLOSE

CLOSE Syntax
=======================================================================

 CLOSE { file-name-1 [ { REEL|UNIT [ FOR REMOVAL ] } ] }...
 ~~~~~                 { ~~~~ ~~~~       ~~~~~~~   }
                       { WITH LOCK                 }
                       {      ~~~~                 }
                       { WITH NO REWIND            }
                              ~~ ~~~~~~

The REEL, LOCK and NO REWIND clauses are syntactically recognized but are otherwise non-functional, except for the CLOSE…NO REWIND statement, which will generate a file status of 07 rather than the usual 00 (but take no other action).


=======================================================================

The CLOSE statement terminates the program’s access to the specified file(s).

  1. The reserved words FOR and WITH are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved words REEL and UNIT are interchangeable.
  3. The CLOSE statement may only be executed against files that have been successfully opened.
  4. A successful CLOSE will write any remaining unwritten record buffers to the file (similar to an UNLOCK statement (see UNLOCK)) and release any file locks for the file, regardless of open mode. A closed file will then be no longer available for subsequent I/O statements until it is once again OPENED.
  5. When a ORGANIZATION LINE SEQUENTIAL (see ORGANIZATION LINE SEQUENTIAL) or LINE ADVANCING (see LINE ADVANCING) file is closed, a final delimiter sequence will be written to the file to signal the termination point of the final data record in the file. This will only be necessary if the final record written to the file was written with the AFTER ADVANCING (see WRITE) option.


7.8.8. COMMIT

COMMIT Syntax
=======================================================================

 COMMIT
 ~~~~~~

=======================================================================

The COMMIT statement performs an UNLOCK against every currently-open file, but does not close any of the files. See the UNLOCK statement (see UNLOCK) for additional details.



7.8.9. COMPUTE

COMPUTE Syntax
=======================================================================

   COMPUTE { identifier-1
   ~~~~~~~
       [ ROUNDED [ MODE IS { AWAY-FROM-ZERO         } ] }...
         ~~~~~~~   ~~~~    { ~~~~~~~~~~~~~~         }
                           { NEAREST-AWAY-FROM-ZERO }
                           { ~~~~~~~~~~~~~~~~~~~~~~ }
                           { NEAREST-EVEN           }
                           { ~~~~~~~~~~~~           }
                           { NEAREST-TOWARD-ZERO    }
                           { ~~~~~~~~~~~~~~~~~~~    }
                           { PROHIBITED             }
                           { ~~~~~~~~~~             }
                           { TOWARD-GREATER         }
                           { ~~~~~~~~~~~~~~         }
                           { TOWARD-LESSER          }
                           { ~~~~~~~~~~~~~          }
                           { TRUNCATION             }
                             ~~~~~~~~~~
         =|EQUAL arithmetic-expression-1
           ~~~~~
       [ ON SIZE ERROR imperative-statement-1 ]
            ~~~~ ~~~~~
       [ NOT ON SIZE ERROR imperative-statement-2 ]
         ~~~    ~~~~ ~~~~~
 [ END-COMPUTE ]
   ~~~~~~~~~~~

=======================================================================

The COMPUTE statement provides a means of easily performing complex arithmetic operations with a single statement, instead of using cumbersome and possibly confusing sequences of ADD, SUBTRACT, MULTIPLY and DIVIDE statements. COMPUTE also allows the use of exponentiation — an arithmetic operation for which no other statement exists in COBOL.

  1. The reserved words IS and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved word EQUAL is interchangeable with the use of ‘=’.
  3. Each identifier-1 must be a numeric or numeric-edited data item.
  4. The optional ROUNDED (see ROUNDED) clause available to each identifier-1 will control how non-integer results will be saved.
  5. See Arithmetic Expressions, for more information on arithmetic expressions.
  6. The optional ON SIZE ERROR and NOT ON SIZE ERROR clauses may be used to detect and react to the failure or success, respectively, of an attempt to perform a calculation. In this case, failure is defined either as having an identifier-3 with an insufficient number of digit positions available to the left of any implied decimal point or attempting to divide by zero. See ON SIZE ERROR + NOT ON SIZE ERROR, for additional information.


7.8.10. CONTINUE

CONTINUE Syntax
=======================================================================

 CONTINUE
 ~~~~~~~~

                 { identifier-1            }
 CONTINUE AFTER  { literal-1               }   SECONDS
 ~~~~~~~~ ~~~~~  { arithmetic-expression-1 }   ~~~~~~~


=======================================================================

The CONTINUE statement is a no-operation statement that may be coded anywhere an imperative statement (see Imperative Statement) may be coded.

  1. The CONTINUE statement has no effect on the execution of the program.
  2. This statement (perhaps in combination with an appropriate comment or two) makes a convenient “place holder” — particularly in ELSE (see IF) or WHEN (see EVALUATE) clauses where no code is currently expected to be needed, but a place for code to handle the conditions in question is to be reserved in case it’s ever needed.
  3. The optional extension of (AFTER) when used with the CONTINUE statement pauses execution for a specified length of time.


7.8.11. DELETE

DELETE Syntax
=======================================================================

   DELETE file-name-1 RECORD
   ~~~~~~
     [ INVALID KEY imperative-statement-1 ]
       ~~~~~~~
     [ NOT INVALID KEY imperative-statement-2 ]
       ~~~ ~~~~~~~
 [ END-DELETE ]
   ~~~~~~~~~~

=======================================================================

The DELETE statement logically deletes a record from a COBOL file.

  1. The reserved words KEY and RECORD are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The ORGANIZATION of file-name-1 cannot be ORGANIZATION LINE SEQUENTIAL (see ORGANIZATION LINE SEQUENTIAL).
  3. The file-name-1 file cannot be a sort/merge work file (a file described using a SD (see File/Sort-Description)).
  4. For files in the SEQUENTIAL access mode, the last input-output statement executed against file-name-1 prior to the execution of the DELETE statement must have been a successfully executed sequential-format READ statement (see Sequential READ). That READ will therefore identify the record to be deleted.
  5. If file-name-1 is a RELATIVE file whose ACCESS MODE (see ORGANIZATION RELATIVE) is either RANDOM or DYNAMIC, the record to be deleted is the one whose relative record number is currently the value of the field specified as the files RELATIVE KEY in its SELECT statement.
  6. If file-name-1 is an INDEXED file whose ACCESS MODE (see ORGANIZATION INDEXED) is RANDOM or DYNAMIC, the record to be deleted is the one whose primary key is currently the value of the field specified as the RECORD KEY in the file’s SELECT statement.
  7. The optional INVALID KEY and NOT INVALID KEY clauses may be used to detect and react to the failure or success, respectively, of an attempt to delete a record. See INVALID KEY + NOT INVALID KEY, for additional information.
  8. No INVALID KEY or NOT INVALID KEY clause may be specified for a file who’s ACCESS MODE IS SEQUENTIAL.


7.8.12. DISPLAY



7.8.12.1. DISPLAY UPON device

DISPLAY UPON device Syntax
=======================================================================

   DISPLAY { literal-1    }...
   ~~~~~~~ { identifier-1 }
      [ UPON mnemonic-name-1 ]
        ~~~~
      [ WITH NO ADVANCING ]
             ~~ ~~~~~~~~~
      [ ON EXCEPTION imperative-statement-1 ]
           ~~~~~~~~~
      [ NOT ON EXCEPTION imperative-statement-2 ]
        ~~~    ~~~~~~~~~
 [ END-DISPLAY ]
   ~~~~~~~~~~~

=======================================================================

This format of the DISPLAY statement displays the specified identifier contents and/or literal values on the system output device specified via the UPON clause.

  1. The reserved words ON and WITH are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. If no UPON clause is specified, UPON CONSOLE will be assumed. If the UPON clause is specified, mnemonic-name-1 must be one of the built-in output device names CONSOLE, PRINTER, STDERR, STDOUT, SYSERR, SYSLIST, SYSLST or SYSOUT or a mnemonic name assigned to one of those devices via the SPECIAL-NAMES (see SPECIAL-NAMES) paragraph.

    When displaying upon the STDERR or SYSERR devices or to a mnemonic-name-1 attached to one of those two devices, the output will be written to output pipe #2, which will normally cause the output to appear in the console output window. You may, if desired, redirect that output to a file by appending 2> filename to the end of the command that executes the program. This applies to both Windows (any type) or Unix versions of GnuCOBOL.

    When displaying upon the CONSOLE, PRINTER, STDOUT, SYSLIST, SYSLST or SYSOUT devices or to a mnemonic-name-1 attached to one of them, the output will be written to output pipe #1, which will normally cause the output to appear in the console output window. You may, if desired, redirect that output to a file by appending 1> filename or simply > filename to the end of the command that executes the program. This applies to both Windows (any type) or Unix versions of GnuCOBOL.

  3. The NO ADVANCING clause, if used, will suppress the carriage-return / line-feed sequence that is normally added to the end of any console display.
  4. The optional ON EXCEPTION and NOT ON EXCEPTION clauses may be used to detect and react to the failure or success, respectively, of an attempt to display output to the specified device. See ON EXCEPTION + NOT ON EXCEPTION, for additional information.


7.8.12.2. DISPLAY UPON COMMAND-LINE

DISPLAY UPON COMMAND-LINE Syntax
=======================================================================

   DISPLAY { literal-1    }...
   ~~~~~~~ { identifier-1 }
        UPON { ARGUMENT-NUMBER|COMMAND-LINE }
        ~~~~ { ~~~~~~~~~~~~~~~ ~~~~~~~~~~~~ }
      [ ON EXCEPTION imperative-statement-1 ]
           ~~~~~~~~~
      [ NOT ON EXCEPTION imperative-statement-2 ]
        ~~~    ~~~~~~~~~
 [ END-DISPLAY ]
   ~~~~~~~~~~~

=======================================================================

This form of the DISPLAY statement may be used to specify the command-line argument number to be retrieved by a subsequent ACCEPT FROM ARGUMENT-VALUE statement (see ACCEPT FROM COMMAND-LINE) or to specify a new value for the command-line arguments themselves.

  1. The reserved word ON is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. By displaying a numeric integer value UPON ARGUMENT-NUMBER, you will specify which argument (by its relative number) will be retrieved by a subsequent ACCEPT FROM ARGUMENT-VALUE statement.
  3. Executing a DISPLAY UPON COMMAND-LINE will influence subsequent ACCEPT FROM COMMAND-LINE statements (which will then return the value you displayed), but will not influence subsequent ACCEPT FROM ARGUMENT-VALUE statements — these will continue to return the original program execution parameters.
  4. The optional ON EXCEPTION and NOT ON EXCEPTION clauses may be used to detect and react to the failure or success, respectively, of an attempt to display output to the specified item. See ON EXCEPTION + NOT ON EXCEPTION, for additional information.


7.8.12.3. DISPLAY UPON ENVIRONMENT-NAME

DISPLAY UPON ENVIRONMENT-NAME Syntax
=======================================================================

   DISPLAY { literal-1    }... UPON { ENVIRONMENT-VALUE }
   ~~~~~~~ { identifier-1 }    ~~~~ { ~~~~~~~~~~~~~~~~~ }
                                    { ENVIRONMENT-NAME  }
                                      ~~~~~~~~~~~~~~~~
      [ ON EXCEPTION imperative-statement-1 ]
           ~~~~~~~~~
      [ NOT ON EXCEPTION imperative-statement-2 ]
        ~~~    ~~~~~~~~~
 [ END-DISPLAY ]
   ~~~~~~~~~~~

=======================================================================

This form of the DISPLAY statement can be used to create or modify environment variables.

  1. The reserved word ON is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. To create or change an environment variable will require two DISPLAY statements. The following example sets the environment variable MY_ENV_VAR to a value of ‘Demonstration Value’:
    DISPLAY "MY_ENV_VAR" UPON ENVIRONMENT-NAME
    DISPLAY "Demonstration Value" UPON ENVIRONMENT-VALUE
    
  3. Environment variables created or changed from within GnuCOBOL programs will be available to any sub-shell processes spawned by that program (i.e. CALL 'SYSTEM' (see SYSTEM)) but will not be known to the shell or console window that started the GnuCOBOL program.
  4. Consider using SET ENVIRONMENT (see SET ENVIRONMENT) in lieu of DISPLAY to set environment variables as it is much simpler.
  5. The optional ON EXCEPTION and NOT ON EXCEPTION clauses may be used to detect and react to the failure or success, respectively, of an attempt to display output to the specified item. See ON EXCEPTION + NOT ON EXCEPTION, for additional information.


7.8.12.4. DISPLAY screen-data-item

DISPLAY screen-data-item Syntax
=======================================================================

   DISPLAY identifier-1 [ UPON CRT|CRT-UNDER ]
   ~~~~~~~                ~~~~ ~~~ ~~~~~~~~~
       [ AT { | LINE NUMBER { integer-1    }            | } ]
         ~~ { | ~~~~        { identifier-2 }            | }
            { | COLUMN|COL|POSITION|POS NUMBER { integer-2    }
            { | ~~~~~~ ~~~ ~~~~~~~~ ~~~        { identifier-3 }
            {                                             }
            { { integer-3    }                            }
            { { identifier-4 }                            }

       [ WITH [ Attribute-Specification ]...
         ~~~~
              [ SCROLL { UP   } [ { integer-4    } LINE|LINES ] ]
                ~~~~~~ { ~~   }   { identifier-5 }
                       { DOWN }
                         ~~~~
              [ SIZE { integer-5    }
                ~~~~ { identifier-6 }  ]
       [ ON EXCEPTION imperative-statement-1 ]
            ~~~~~~~~~
       [ NOT ON EXCEPTION imperative-statement-2 ]
         ~~~    ~~~~~~~~~
 [ END-DISPLAY ]
   ~~~~~~~~~~~

The UPON CRT, UPON CRT-UNDER and CONVERSION clauses are syntactically recognized but are otherwise non-functional. They are supported to provide compatibility with COBOL source written for other COBOL implementations.


=======================================================================

This format of the DISPLAY statement presents data onto a formatted screen.

  1. The reserved words AFTER, LINE, LINES, NUMBER and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved words COLUMN and POSITION are interchangeable.
  3. The reserved words LINE and LINES are interchangeable.
  4. If identifier-1 is defined in the SCREEN SECTION (see SCREEN SECTION), any AT, Attribute-Specification and WITH clauses will be ignored. All field definition, cursor positioning and screen control will occur as a result of the screen section definition of identifier-1.
  5. The following points apply if identifier-1 is not defined in the screen section:
    1. The purpose of the AT clause is to define where on the screen identifier-1 should be displayed. See ACCEPT screen-data-item, for additional information.
    2. The purpose of the WITH clause is to define the visual attributes that should be applied to identifier-1 when it is displayed on the screen as well as other presentation-control characteristics.
    3. The following Attribute-Specification clauses are allowed on the DISPLAY statement — these are the same as those allowed for SCREEN SECTION data items. A particular Attribute-Specification may be used only once in any DISPLAY:
    4. See ACCEPT screen-data-item, for additional information on the other WITH clause options.
  6. The optional ON EXCEPTION and NOT ON EXCEPTION clauses may be used to detect and react to the failure or success, respectively, of the screen I/O attempt. See ON EXCEPTION + NOT ON EXCEPTION, for additional information.

When DISPLAY is used with Line and column where multiple variables or literals are used before LINE only the first will be displayed.

If this is needed then the use of CONCATENATE to built more than one element together prior to the display, e.g., DISPLAY FUNCTION CONCATENATE (VARS-1 VARS-2) AT 0201.

When DISPLAY is used without line or column controls only one variable or literal may will appear on a line, so the use of the above example should also be employed.



7.8.13. DIVIDE



7.8.13.1. DIVIDE INTO

DIVIDE INTO Syntax
=======================================================================

 DIVIDE { literal-1    } INTO { identifier-2
 ~~~~~~ { identifier-1 } ~~~~

       [ ROUNDED [ MODE IS { AWAY-FROM-ZERO         } ] ] }...
         ~~~~~~~   ~~~~    { ~~~~~~~~~~~~~~         }
                           { NEAREST-AWAY-FROM-ZERO }
                           { ~~~~~~~~~~~~~~~~~~~~~~ }
                           { NEAREST-EVEN           }
                           { ~~~~~~~~~~~~           }
                           { NEAREST-TOWARD-ZERO    }
                           { ~~~~~~~~~~~~~~~~~~~    }
                           { PROHIBITED             }
                           { ~~~~~~~~~~             }
                           { TOWARD-GREATER         }
                           { ~~~~~~~~~~~~~~         }
                           { TOWARD-LESSER          }
                           { ~~~~~~~~~~~~~          }
                           { TRUNCATION             }
                             ~~~~~~~~~~
    [ ON SIZE ERROR imperative-statement-1 ]
         ~~~~ ~~~~~
    [ NOT ON SIZE ERROR imperative-statement-2 ]
      ~~~    ~~~~ ~~~~~
 [ END-DIVIDE ]
   ~~~~~~~~~~

=======================================================================

This format of the DIVIDE statement will divide a numeric value (specified as a literal or numeric data item) into one or more numeric data items, replacing the value in each of those data items with the result(s).

  1. The reserved words IS and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. Both identifier-1 and identifier-2 must be numeric unedited data items and literal-1 must be a numeric literal.
  3. A division operation will be performed for each identifier-2, in turn. Each of the results of those divisions will be saved to the corresponding identifier-2 data item(s).
  4. Should any identifier-2 be an integer numeric data item, the result computed when that identifier-2 is divided by literal-1 or identifier-1 will also be an integer — any remainder from that division will be discarded.
  5. The optional ROUNDED (see ROUNDED) clause available to each identifier-2 will control how non-integer results will be saved.
  6. The optional ON SIZE ERROR and NOT ON SIZE ERROR clauses may be used to detect and react to the failure or success, respectively, of an attempt to perform a calculation. In this case, failure is defined as being numeric truncation caused by an identifier-2 with an insufficient number of digit positions available to the left of any implied decimal point, or an attempt to divide by zero. See ON SIZE ERROR + NOT ON SIZE ERROR, for additional information.


7.8.13.2. DIVIDE INTO GIVING

DIVIDE INTO GIVING Syntax
=======================================================================

 DIVIDE { literal-1    } INTO { literal-2    } GIVING { identifier-3
 ~~~~~~ { identifier-1 } ~~~~ { identifier-2 } ~~~~~~

            [ ROUNDED [ MODE IS { AWAY-FROM-ZERO         } ] ] }...
              ~~~~~~~   ~~~~    { ~~~~~~~~~~~~~~         }
                                { NEAREST-AWAY-FROM-ZERO }
                                { ~~~~~~~~~~~~~~~~~~~~~~ }
                                { NEAREST-EVEN           }
                                { ~~~~~~~~~~~~           }
                                { NEAREST-TOWARD-ZERO    }
                                { ~~~~~~~~~~~~~~~~~~~    }
                                { PROHIBITED             }
                                { ~~~~~~~~~~             }
                                { TOWARD-GREATER         }
                                { ~~~~~~~~~~~~~~         }
                                { TOWARD-LESSER          }
                                { ~~~~~~~~~~~~~          }
                                { TRUNCATION             }
    [ REMAINDER identifier-4 ]    ~~~~~~~~~~
      ~~~~~~~~~
    [ ON SIZE ERROR imperative-statement-1 ]
         ~~~~ ~~~~~
    [ NOT ON SIZE ERROR imperative-statement-2 ]
      ~~~    ~~~~ ~~~~~
 [ END-DIVIDE ]
   ~~~~~~~~~~

=======================================================================

This format of the DIVIDE statement will divide one numeric value (specified as a literal or numeric data item) into another numeric value (also specified as a literal or numeric data item) and will then replace the contents of one or more receiving data items with the results of that division.

  1. The reserved words IS and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. Both identifier-1 and identifier-2 must be numeric unedited data items while both identifier-3 and identifier-4 must be numeric (edited or unedited) data items.
  3. Both literal-1 and literal-2 must be numeric literals.
  4. If the REMAINDER clause is coded, there may be only one identifier-3 specified.
  5. The result obtained when the value of literal-2 or identifier-2 is divided by the value of literal-1 or identifier-1 is computed; this result is then moved into each identifier-3, in turn, applying the rules defined by the ROUNDED (see ROUNDED) clause (if any) for that identifier-3 to the move.
  6. If a REMAINDER clause is specified, the value of the one and only identifier-3 (as stated earlier, if REMAINDER is specified there may only be a single identifier-3 coded on the statement) after it was assigned a value according to the previous rule will be multiplied by the value of literal-1 or identifier-1; that result is then subtracted from the value of literal-2 or identifier-2 and that result is the value which is moved to identifier-4.
  7. The optional ON SIZE ERROR and NOT ON SIZE ERROR clauses may be used to detect and react to the failure or success, respectively, of an attempt to perform a calculation. In this case, failure is defined as being an identifier-2 with an insufficient number of digit positions available to the left of any implied decimal point, or an attempt to divide by zero. See ON SIZE ERROR + NOT ON SIZE ERROR, for additional information.


7.8.13.3. DIVIDE BY GIVING

DIVIDE BY GIVING Syntax
=======================================================================

 DIVIDE { literal-1    } BY { literal-2    } GIVING { identifier-3
 ~~~~~~ { identifier-1 } ~~ { identifier-2 } ~~~~~~

            [ ROUNDED [ MODE IS { AWAY-FROM-ZERO         } ] ] }...
              ~~~~~~~   ~~~~    { ~~~~~~~~~~~~~~         }
                                { NEAREST-AWAY-FROM-ZERO }
                                { ~~~~~~~~~~~~~~~~~~~~~~ }
                                { NEAREST-EVEN           }
                                { ~~~~~~~~~~~~           }
                                { NEAREST-TOWARD-ZERO    }
                                { ~~~~~~~~~~~~~~~~~~~    }
                                { PROHIBITED             }
                                { ~~~~~~~~~~             }
                                { TOWARD-GREATER         }
                                { ~~~~~~~~~~~~~~         }
                                { TOWARD-LESSER          }
                                { ~~~~~~~~~~~~~          }
                                { TRUNCATION             }
    [ REMAINDER identifier-4 ]    ~~~~~~~~~~
      ~~~~~~~~~
    [ ON SIZE ERROR imperative-statement-1 ]
         ~~~~ ~~~~~
    [ NOT ON SIZE ERROR imperative-statement-2 ]
      ~~~    ~~~~ ~~~~~
 [ END-DIVIDE ]
   ~~~~~~~~~~

=======================================================================

This format of the DIVIDE statement will divide one numeric value (specified as a literal or numeric data item) into another numeric value (also specified as a literal or numeric data item) and will then replace the contents of one or more receiving data items with the results of that division.

  1. The reserved words IS and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. Both identifier-1 and identifier-2 must be numeric unedited data items while both identifier-3 and identifier-4 must be numeric (edited or unedited) data items.
  3. Both literal-1 and literal-2 must be numeric literals.
  4. If the REMAINDER clause is coded, there may be only one identifier-3 specified.
  5. The result obtained when the value of literal-1 or identifier-1 is divided by the value of literal-2 or identifier-2 is computed; this result is then moved into each identifier-3, in turn, applying the rules defined by the ROUNDED (see ROUNDED) clause (if any) for that identifier-3 to the move.
  6. If a REMAINDER clause is specified, the value of the one and only identifier-3 (as stated earlier, if REMAINDER is specified there may only be a single identifier-3 coded on the statement) after it was assigned a value according to the previous rule will be multiplied by the value of literal-2 or identifier-2; that result is then subtracted from the value of literal-1 or identifier-1 and that result is the value which is moved to identifier-4.
  7. The optional ON SIZE ERROR and NOT ON SIZE ERROR clauses may be used to detect and react to the failure or success, respectively, of an attempt to perform a calculation. In this case, failure is defined as being an identifier-2 with an insufficient number of digit positions available to the left of any implied decimal point, or an attempt to divide by zero. See ON SIZE ERROR + NOT ON SIZE ERROR, for additional information.


7.8.14. ENTRY

ENTRY Syntax
=======================================================================

 ENTRY literal-1 [ USING ENTRY-Argument... ]
 ~~~~~             ~~~~~

=======================================================================
ENTRY-Argument Syntax
=======================================================================

 [ BY { REFERENCE } ] identifier-1
      { ~~~~~~~~~ }
      { CONTENT   }
      { ~~~~~~~   }
      { VALUE     }
        ~~~~~

=======================================================================

The ENTRY statement is used to define an alternate entry-point into a subroutine, along with the arguments that subroutine will be expecting.

  1. The reserved word BY is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. You may not use an ENTRY statement in a nested subprogram, nor may you use it in any form of user-defined function.
  3. The USING clause defines the arguments the subroutine entry-point supports. This list of arguments must match up against the USING clause of any CALL statement that will be invoking the subroutine using this entry-point.
  4. Each ENTRY-Argument specified on the ENTRY statement must be defined in the linkage section of the subroutine in which the ENTRY statement exists.
  5. The literal-1 value will specify the entry-point name of the subroutine. It must be specified exactly on CALL statements (with regard to the use of upper- and lower-case letters) as it is specified on the ENTRY statement.
  6. The meaning of REFERENCE, CONTENT and VALUE are the same as the equivalent specifications on the CALL statement (see CALL). Whatever specification will be used for an argument on the CALL to this entry-point should match the specification used in the corresponding ENTRY-Argument. The same rules regarding the presence or absence of a BY clause on a CALL statement apply to the presence or absence of a BY clause on the corresponding argument of the ENTRY statement.


7.8.15. EVALUATE

EVALUATE Syntax
=======================================================================

   EVALUATE Selection-Subject-1 [ ALSO Selection-Subject-2 ]...
   ~~~~~~~~                       ~~~~
 { { WHEN Selection-Object-1 [ ALSO Selection-Object-2 ] }...
     ~~~~                      ~~~~
         [ imperative-statement-1 ] }...
   [ WHEN OTHER
     ~~~~ ~~~~~
         imperative-statement-other ]

 [ END-EVALUATE ]
   ~~~~~~~~~~~~

=======================================================================
EVALUATE Selection Subject Syntax
=======================================================================

 { TRUE         }
 { ~~~~         }
 { FALSE        }
 { ~~~~~        }
 { expression-1 }
 { identifier-1 }
 { literal-1    }

=======================================================================
EVALUATE Selection Object Syntax
=======================================================================

 { ANY                                                }
 { ~~~                                                }
 { TRUE                                               }
 { ~~~~                                               }
 { FALSE                                              }
 { ~~~~~                                              }
 { partial-expression-1                               }
 {                                                    }
 { { expression-2 } [ THRU|THROUGH { expression-3 } ] }
 { { identifier-2 }   ~~~~ ~~~~~~~ { identifier-3 }   }
 { { literal-2    }                { literal-3    }   }

=======================================================================

The EVALUATE statement provides a means of defining processing that should take place under any number of mutually-exclusive conditions.

  1. The reserved words THRU and THROUGH are interchangeable.
  2. There must be at least one WHEN clause (in addition to any WHEN OTHER clause) specified on any EVALUATE statement.
  3. There must be at least one Selection-Subject specified on the EVALUATE statement. Any number of additional Selection-Subject clauses may be specified, using the ALSO reserved word to separate each from the prior.
  4. Each WHEN clause (other than the WHEN OTHER clause, if any) must have the same number of Selection-Object clauses as there are Selection-Subject clauses.
  5. When using THRU, the values on both sides of the THRU must be the same class (both numeric, both alphanumeric, etc.).
  6. A partial-expression is one of the following:
    1. A Class Condition without a leading identifier-1 (see Class Conditions).
    2. A Sign Condition without a leading identifier-1 (see Sign Conditions).
    3. A Relation Condition with nothing to the left of the relational operator (see Relation Conditions).
  7. At execution time, each Selection-Subject on the EVALUATE statement will have its value matched against that of the corresponding Selection-Object on a WHEN clause, in turn, until:
    1. A WHEN clause has each of its Selection-Object(s) successfully matched by the corresponding Selection-Subject; this will be referred to as the ’Selected WHEN clause’.
    2. The complete list of WHEN clauses (except for the WHEN OTHER clause, if any) has been exhausted. In this case, there is no ’Selected WHEN Clause’.
  8. If a ’Selected WHEN Clause’ was identified:
    1. The imperative-statement-1 (see Imperative Statement) immediately following the ’Selected WHEN Clause’ will be executed. If the ’Selected WHEN Clause’ is lacking an imperative-statement-1, the first imperative-statement-1 found after any following WHEN clause will be executed.
    2. Once the imperative-statement-1 has been executed, or no imperative-statement-1 was found anywhere after the ’Selected WHEN Clause’, control will proceed to the statement following the END-EVALUATE or, if there is no END-EVALUATE, the first statement that follows the next period. If, however, the imperative-statement-1 included a GO TO statement, and that GO TO was executed, then control will transfer to the procedure named on the GO TO instead.
  9. If no ’Selected WHEN Clause’ was identified:
    1. The WHEN OTHER clause’s imperative-statement-other will be executed, if such a clause was coded.
    2. Control will then proceed to the statement following the END-EVALUATE or the first statement that follows the next period if there is no END-EVALUATE. If,however, the imperative-statement-other included a GO TO statement, and that GO TO was executed, then control will transfer to the procedure named on the GO TO instead.
  10. In order for a Selection-Subject to match the corresponding Selection-Object on a WHEN clause, at least one of the following must be true:
    1. The Selection-Object is ANY
    2. The implied Relation Condition Selection-Subject = Selection Object is TRUE — See Relation Conditions, for the rules on how the comparison will be made.
    3. The value of the Selection-Subject falls within the range of values specified by the THRU clause of the Selection-Object
    4. If the Selection-Object is a partial-expression, then the conditional expression that would be represented by coding Selection-Subject Selection-Object evaluates to TRUE
  11. Here is a sample program that illustrates the EVALUATE statement.
    IDENTIFICATION DIVISION.
    PROGRAM-ID. DEMOEVALUATE.
    DATA DIVISION.
    WORKING-STORAGE SECTION.
    01  Test-Digit                  PIC 9(1).
        88 Digit-Is-Odd VALUE 1, 3, 5, 7, 9.
        88 Digit-Is-Prime VALUE 1, 3, 5, 7.
    PROCEDURE DIVISION.
    P1. PERFORM UNTIL EXIT
        DISPLAY "Enter a digit (0 Quits): "
            WITH NO ADVANCING
        ACCEPT Test-Digit
        IF Test-Digit = 0
            EXIT PERFORM
        END-IF
        EVALUATE Digit-Is-Odd ALSO Digit-Is-Prime
        WHEN TRUE ALSO FALSE
            DISPLAY Test-Digit " is ODD"
                WITH NO ADVANCING
        WHEN TRUE ALSO TRUE
            DISPLAY Test-Digit " is PRIME"
                WITH NO ADVANCING
        WHEN FALSE ALSO ANY
            DISPLAY Test-Digit " is EVEN"
                WITH NO ADVANCING
        END-EVALUATE
        EVALUATE Test-Digit
        WHEN < 5
            DISPLAY " and it's small too"
        WHEN < 8
            DISPLAY " and it's medium too"
        WHEN OTHER
            DISPLAY " and it's large too"
        END-EVALUATE
    END-PERFORM
    DISPLAY "Bye!"
    STOP RUN
    .
    

    Console output when run (user input follows the colons on the prompts for input):

    Enter a digit (0 Quits): 1
    1 is PRIME and it's small too
    Enter a digit (0 Quits): 2
    2 is EVEN and it's small too
    Enter a digit (0 Quits): 3
    3 is PRIME and it's small too
    Enter a digit (0 Quits): 4
    4 is EVEN and it's small too
    Enter a digit (0 Quits): 5
    5 is PRIME and it's medium too
    Enter a digit (0 Quits): 6
    6 is EVEN and it's medium too
    Enter a digit (0 Quits): 7
    7 is PRIME and it's medium too
    Enter a digit (0 Quits): 8
    8 is EVEN and it's large too
    Enter a digit (0 Quits): 9
    9 is ODD and it's large too
    Enter a digit (0 Quits): 0
    Bye!
    


7.8.16. EXIT

EXIT Syntax
=======================================================================

 EXIT [ { PROGRAM           } ]
 ~~~~   { ~~~~~~~           }
        { FUNCTION          }
        { ~~~~~~~~          }
        { PERFORM [ CYCLE ] }
        { ~~~~~~~   ~~~~~   }
        { SECTION           }
        { ~~~~~~~           }
        { PARAGRAPH         }
          ~~~~~~~~~

=======================================================================

The EXIT statement is a multi-purpose statement; it may provide a common end point for a series of procedures, exit an in-line PERFORM, paragraph or section or it may mark the logical end of a subprogram, returning control back to the calling program.

  1. The EXIT PROGRAM statement is not legal anywhere within a user-defined function.
  2. The EXIT FUNCTION statement cannot be used anywhere within a subroutine.
  3. Neither EXIT PROGRAM nor EXIT FUNCTION may be used within a USE GLOBAL routine in DECLARATIVES (see DECLARATIVES).
  4. The following points describe the EXIT statement with none of the optional clauses:
    1. When this form of an EXIT statement is used, it must be the only statement in the procedure (paragraph or section) in which it occurs. This is not enforced in GnuCOBOL.
    2. This usage of the EXIT statement simply provides a common “GO TO” end point for a series of procedures, as may be seen in the following example:
      01  Switches.
          05 Input-File-Switch PIC X(1).
             88 EOF-On-Input-File VALUE ``Y'' FALSE ``N''.
      …
          SET EOF-On-Input-File TO FALSE.
          PERFORM 100-Process-A-Transaction THRU 199-Exit
              UNTIL EOF-On-Input-File.
      …
      100-Process-A-Transaction.
          READ Input-File AT END
              SET EOF-On-Input-File TO TRUE
              GO TO 199-Exit
          END-READ.
          IF Input-Rec of Input-File = SPACES
              GO TO 199-Exit  *> IGNORE BLANK RECORDS!
          END-IF.
          <<process the record just read>>
      199-Exit.
          EXIT.
      
    3. In this case, the EXIT statement takes no other run-time action.
  5. The following points apply to the EXIT PARAGRAPH and EXIT SECTION statements:
    1. If an EXIT PARAGRAPH statement or EXIT SECTION statement resides in a paragraph within the scope of a procedural PERFORM (see Procedural PERFORM), control will be returned back to the PERFORM for evaluation of any TIMES, VARYING and/or UNTIL clauses.
    2. If an EXIT PARAGRAPH statement or EXIT SECTION statement resides outside the scope of a procedural PERFORM, control simply transfers to the first executable statement in the next paragraph (EXIT PARAGRAPH) or section (EXIT SECTION).
    3. The following shows how the previous example could have been coded without a GO TO by utilizing an EXIT PARAGRAPH statement.
      01  Switches.
          05 Input-File-Switch PIC X(1).
             88 EOF-On-Input-File VALUE ``Y'' FALSE ``N''.
      …
          SET EOF-On-Input-File TO FALSE.
          PERFORM 100-Process-A-Transaction
              UNTIL EOF-On-Input-File.
      …
      100-Process-A-Transaction.
          READ Input-File AT END
              SET EOF-On-Input-File TO TRUE
              EXIT PARAGRAPH
          END-READ.
          IF Input-Rec of Input-File = SPACES
              EXIT PARAGRAPH *> IGNORE BLANK RECORDS!
          END-IF.
          <<process the record just read>>
      
  6. The following points apply to the EXIT PERFORM and EXIT PERFORM CYCLE statements:
    1. The EXIT PERFORM and EXIT PERFORM CYCLE statements are intended to be used in conjunction with an in-line PERFORM statement (see Inline PERFORM).
    2. An EXIT PERFORM CYCLE statement will terminate the current iteration of the in-line PERFORM, giving control to any TIMES, VARYING and/or UNTIL clauses for them to determine if another cycle needs to be performed.
    3. An EXIT PERFORM statement will terminate the in-line PERFORM outright, transferring control to the first statement following the END-PERFORM (if there is one) or to the next sentence following the PERFORM if there is no END-PERFORM.
    4. This last example shows the final modification to the previous examples by using an in-line PERFORM along with EXIT PERFORM and EXIT PERFORM CYCLE statements:
      PERFORM FOREVER
          READ Input-File AT END
              EXIT PERFORM
          END-READ
          IF Input-Rec of Input-File = SPACES
              EXIT PERFORM CYCLE *> IGNORE BLANK RECORDS!
          END-IF
          <<process the record just read>>
      END PERFORM
      
  7. The following points apply to the EXIT PROGRAM and EXIT FUNCTION statements:
    1. The EXIT PROGRAM and EXIT FUNCTION statements terminate the execution of a subroutine (i.e. a program that has been CALLed by another) or user-defined function, respectively, returning control back to the calling program.
    2. An EXIT PROGRAM statement returns control back to the statement following the CALL (see CALL) of the subprogram. An EXIT FUNCTION statement returns control back to the processing of the statement in the calling program that invoked the user-defined function.
    3. If executed by a main program, neither the EXIT PROGRAM nor EXIT FUNCTION statements will take any action.
    4. The COBOL2002 standard has made a common extension to the COBOL language — the GOBACK statement (see GOBACK) — a standard language element; the GOBACK statement should be strongly considered as the preferred alternative to both EXIT PROGRAM and EXIT FUNCTION for new subprograms.


7.8.17. FREE

FREE Syntax
=======================================================================

 FREE { [ ADDRESS OF ] identifier-1 }...
 ~~~~     ~~~~~~~

=======================================================================

The FREE statement releases memory previously allocated to the program by the ALLOCATE statement (see ALLOCATE).

  1. The ADDRESS OF clause is optional and may be omitted. The presence or absence of this clause has no effect upon the program.
  2. identifier-1 must have a USAGE (see USAGE) of POINTER, or it must be an 01-level data item with the BASED (see BASED) attribute.
  3. If identifier-1 is a USAGE POINTER data item and it contains a valid address, the FREE statement will release the memory block the pointer references. In addition, any BASED data items that the pointer was used to provide an address for will become un-based and therefore unusable. If identifier-1 did not contain a valid address, no action will be taken.
  4. If identifier-1 is a BASED data item and that data item is currently based (meaning it currently has memory allocated to it), its memory is released and identifier-1 will become un-based and therefore unusable. If identifier-1 was not based, no action will be taken.


7.8.18. GENERATE

GENERATE Syntax
=======================================================================

 GENERATE { report-name-1 }
 ~~~~~~~~ { identifier-1  }

=======================================================================

The GENERATE statement presents data to a report.

  1. The following points apply when identifier-1 is specified:
    1. identifier-1 must be the name of a DETAIL (see RWCS Lexicon) report group.
    2. If necessary, identifier-1 may be qualified with a report name.
    3. The file in whose FD a REPORT clause exists for the report in which identifier-1 is a detail group must be opened for OUTPUT or EXTEND at the time the GENERATE is executed. See OPEN, for information on file open modes.
    4. The report in which identifier-1 is a DETAIL group must have been successfully initiated via the INITIATE statement (see INITIATE) and not yet terminated via the TERMINATE statement (see TERMINATE) at the time the GENERATE is executed.
    5. If at least one GENERATE statement of this form is executed against a report, the report is said to be a detail report. If no GENERATE statements of this form are executed against a report, the report is said to be a summary report.
  2. The following points apply when report-name-1 is specified:
    1. report-name-1 must be the name of a report having an RD defined for it in the report section.
    2. There must be at least one CONTROL (see RWCS Lexicon) group defined for report-name-1.
    3. There cannot be more than one DETAIL group defined for report-name-1.
    4. The file in whose FD a REPORT report-name-1 clause exists must be open for OUTPUT or EXTEND at the time the GENERATE is executed.
    5. report-name-1 must have been successfully initiated (via INITIATE report-name-1) and not yet terminated (via TERMINATE) at the time the GENERATE is executed. See OPEN, for information on file open modes.
    6. The DETAIL group which is defined for report-name-1 will be processed but will not actually be presented to any report page. This will allow summary processing to take place. If all GENERATE statements are of this form, the report is said to be a summary report. If at least one GENERATE identifier-1 is executed, the report is considered to be a detail report.
  3. When the first GENERATE statement for a report is executed, the contents of all control fields are saved so they may be referenced during the processing of subsequent GENERATE statements.
  4. When, during the processing of a subsequent GENERATE, it is determined that a control field has changed value (ie. a control break has occurred), the appropriate control footing and control heading processing will take place and a snapshot of the current values of all control fields will again be saved.


7.8.19. GOBACK

GOBACK Syntax
=======================================================================

 GOBACK [ { RETURNING|GIVING { literal-1    }  ]
 ~~~~~~   { ~~~~~~~~~ ~~~~~~ { identifier-1 }

=======================================================================

The GOBACK statement is used to logically terminate an executing program.

  1. If executed within a subprogram (i.e. a subroutine or user-defined function), GOBACK behaves like an EXIT PROGRAM or EXIT FUNCTION statement, respectively.
  2. If executed within a main program, GOBACK will act as a STOP RUN statement.
  3. The optional RETURNING clause provides the opportunity to return a numeric value to the operating system (technically, an exit status The manner in which the exit status value is interrogated by the operating system varies. Windows can use %ERRORLEVEL% to query the exit status while Unix shells such as sh, bash and ksh can query the exit status as $?. Other Unix shells may have different ways to access the exit status.


7.8.20. GO TO



7.8.20.1. Simple GO TO

Simple GO TO Syntax
=======================================================================

 GO TO procedure-name-1
 ~~

=======================================================================

This form of the GO TO statement unconditionally transfers control in a program to the first executable statement within the specified procedure-name-1.

  1. The reserved word TO is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. If this format of the GO TO statement appears in a consecutive sequence of imperative statements (see Imperative Statement) within a sentence, it must be the final statement in the sentence.
  3. If a GO TO is executed within the scope of…
    1. ...an in-line PERFORM (see PERFORM), the PERFORM is terminated as control of execution transfers to procedure-name-1.
    2. ...a procedural PERFORM (see PERFORM), and procedure-name-1 lies outside the scope of that PERFORM, the PERFORM is terminated as control of execution transfers to procedure-name-1.
    3. ...a MERGE statement (see MERGE) OUTPUT PROCEDURE or within the scope of either an INPUT PROCEDURE or OUTPUT PROCEDURE of a SORT statement (see File-Based SORT), and procedure-name-1 lies outside the scope of that procedure, the SORT or MERGE operation is terminated as control of execution transfers to procedure-name-1. Any sorted or merged data accumulated to that point is lost.


7.8.20.2. GO TO DEPENDING ON

GO TO DEPENDING ON Syntax
=======================================================================

 GO TO procedure-name-1...
 ~~
      DEPENDING ON identifier-1
      ~~~~~~~~~

=======================================================================

This form of the GO TO statement will transfer control to any one of a number of specified procedure names depending on the numeric value of the identifier specified on the statement.

  1. The reserved word TO is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. The PICTURE (see PICTURE) and/or USAGE (see USAGE) of the specified identifier-1 must be such as to define it as a numeric, unedited, preferably unsigned integer data item.
  3. If the value of identifier-1 has the value 1, control will be transferred to the 1st specified procedure name. If the value is 2, control will transfer to the 2nd procedure name, and so on.

    If control of execution is transferred to a procedure named on the statement, and the GO TO is executed within the scope of…

    1. ...an in-line PERFORM (see PERFORM), the PERFORM is terminated as control of execution transfers to the procedure named on the statement.
    2. ...a procedural PERFORM (see PERFORM), and procedure-name-1 lies outside the scope of that PERFORM, the PERFORM is terminated as control of execution transfers to the procedure named on the statement.
    3. ...a MERGE statement (see MERGE) OUTPUT PROCEDURE or within the scope of either an INPUT PROCEDURE or OUTPUT PROCEDURE of a SORT statement (see File-Based SORT), and procedure-name-1 lies outside the scope of that procedure, the SORT or MERGE operation is terminated as control of execution transfers to the procedure named on the statement. Any sorted or merged data accumulated to that point is lost.
  4. If the value of identifier-1 is less than 1 or exceeds the total number of procedure names specified on the statement, control will simply fall through into the next statement following the GO TO.
  5. The following example shows how GO TO ... DEPENDING ON may be used in a real application situation, and compares it against an alternative — EVALUATE (see EVALUATE).
    GO TO DEPENDING ONEVALUATE
        GO TO
          ACCT-TYPE-1
          ACCT-TYPE-2
          ACCT-TYPE-3
        DEPENDING ON Acct-Type.
        <<< Invalid Acct Type >>>
        GO TO All-Done.
    Acct-Type-1.
        <<< Handle Acct Type 1 >>>
        GO TO All-Done.
    Acct-Type-2.
        <<< Handle Acct Type 2 >>>
        GO TO All-Done.
    Acct-Type-3.
        <<< Handle Acct Type 3 >>>
    All-Done.
    
    EVALUATE Acct-Type
    WHEN 1
        <<< Handle Acct Type 1 >>>
    WHEN 2
        <<< Handle Acct Type 2 >>>
    WHEN 3
        <<< Handle Acct Type 3 >>>
    WHEN OTHER
        <<< Invalid Acct Type >>>
    END-EVALUATE.
    
  6. Current programming philosophy would prefer the use of the EVALUATE statement to that of this form of the GO TO statement.


7.8.21. IF

IF Syntax
=======================================================================

   IF conditional-expression
   ~~
   THEN { imperative-statement-1 }
        { NEXT SENTENCE          }
          ~~~~ ~~~~~~~~
 [ ELSE { imperative-statement-2 } ]
   ~~~~ { NEXT SENTENCE          }
          ~~~~ ~~~~~~~~
 [ END-IF ]
   ~~~~~~

=======================================================================

The IF statement is used to conditionally execute an imperative statement (see Imperative Statement) or to select one of two different imperative statements to execute based upon the TRUE/FALSE value of a conditional expression.

  1. The reserved word THEN is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. You cannot use both NEXT SENTENCE and the END-IF scope terminator in the same IF statement.
  3. If conditional-expression evaluates to TRUE, imperative-statement-1 will be executed regardless of whether or not an ELSE clause is present. Once imperative-statement-1 has been executed, control falls into the first statement following the END-IF or to the first statement of the next sentence if there is no END-IF clause.
  4. If the optional ELSE clause is present and conditional-expression evaluates to false, then (and only then) imperative-statement-2 will be executed. Once imperative-statement-2 has been executed, control falls into the first statement following the END-IF or to the first statement of the next sentence if there is no END-IF clause.
  5. The clause NEXT SENTENCE may be substituted for either imperative-statement, but not both. If control reaches a NEXT SENTENCE clause due to the truth or falsehood of conditional-expression, control will be transferred to the first statement of the next sentence found in the program (the first statement after the next period).

    NEXT SENTENCE was needed for COBOL programs that were coded according to pre-1985 standards that wish to nest one IF statement inside another. See Use of VERB/END-VERB Constructs, for an explanation of why NEXT SENTENCE was necessary.

    Programs coded for 1985 (and beyond) standards don’t need it, instead using the explicit scope-terminator END-IF to inform the compiler where imperative-statement-2 (or imperative-statement-1 if there is no ELSE clause coded) ends. New GnuCOBOL programs should be coded to use the END-IF scope terminator for IF statements. See Use of VERB/END-VERB Constructs, for additional information.



7.8.22. INITIALIZE

INITIALIZE Syntax
=======================================================================

  INITIALIZE|INITIALISE identifier-1...
  ~~~~~~~~~~ ~~~~~~~~~~
      [ WITH FILLER ]
             ~~~~~~
      [ { category-name-1 } TO VALUE ]
        { ALL             }    ~~~~~
          ~~~
      [ THEN REPLACING { category-name-2 DATA BY
             ~~~~~~~~~                        ~~
            [ LENGTH OF ] { literal-1    } }... ]
              ~~~~~~      { identifier-1 }

      [ THEN TO DEFAULT ]
                ~~~~~~~

=======================================================================

The INITIALIZE statement initializes each identifier-1 with certain specific values, depending upon the options specified.

  1. The reserved words DATA, OF, THEN, TO and WITH are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved words INITIALIZE and INITIALISE are interchangeable.
  3. The WITH FILLER, REPLACING and DEFAULT clauses are meaningful only if identifier-1 is a group item. They are accepted if it’s an elementary item, but will serve no purpose. The VALUE clause is meaningful in both cases.
  4. A category-name-1 and/or category-name-2 may be any of the following:
    ALPHABETIC

    The PICTURE (see PICTURE) of the data item only contains A symbols.

    ALPHANUMERIC

    The PICTURE of the data item contains only X or a combination of A and 9 symbols.

    ALPHANUMERIC-EDITED

    The PICTURE of the data item contains only X or a combination of A and 9 symbols plus at least one B, 0 (zero) or / symbol.

    NUMERIC

    The data item is one that is described with a picture less USAGE (see USAGE) or has a PICTURE composed of nothing but P, 9, S and V symbols.

    NUMERIC-EDITED

    The PICTURE of the data item contains nothing but the symbol 9 and at least one of the editing symbols $, +, -, CR, DB, ., ,, * or Z.

    NATIONAL

    The data item is one containing nothing but the N symbol.

    NATIONAL-EDITED

    The data item contains nothing but N, B, / and 0 symbols.

  5. From the sequence of identifier-1 data items specified on the INITIALIZE statement, a list of initialized fields referred to as the field list in the remainder of this section, will include:
    1. Every identifier-1 that is an elementary item, including any that may have the REDEFINES (see REDEFINES) clause in their descriptions.
    2. Every non-FILLER 3elementary item subordinate to identifier-1, provided that elementary item neither contains a REDEFINES clause in its definition nor belongs to a group item subordinate to identifier-1 which contains a REDEFINES clause in its definition.
    3. If the optional WITH FILLER clause is included on the INITIALIZE statement, then every FILLER elementary item subordinate to each identifier-1 will be included as well, provided that elementary item neither contains a REDEFINES clause in its definition nor belongs to a group item subordinate to identifier-1 which contains a REDEFINES clause in its definition..
  6. Once a field list has been determined, each item in that field list will be initialized as if an individual MOVE (see MOVE) statement to that effect had been coded. The rules for initialization are as follows:
  7. If no VALUE, REPLACING or DEFAULT clauses are coded, each member of the field list will be initialized as if the figurative constant ZERO (if the field list item is numeric or numeric-edited) or SPACES (otherwise) were being moved to it.
  8. If a VALUE clause is specified on the INITIALIZE statement, each qualifying member of the field list having a compile-time VALUE (see VALUE) specified in its definition will be initialized to that value. Field list members with VALUE clauses will qualify for this treatment as follows:
    1. If the ALL keyword was specified on the VALUE clause, all members of the field list with VALUE clauses will qualify.
    2. If category-name-1 is specified instead of ALL, only those members of the field list with VALUE clauses that also meet the criteria set down for the specified category-name (see the list above) will qualify.
    3. If you need to apply VALUE initialization to multiple category-name-1 values, you will need to use multiple INITIALIZE statements.
  9. If a REPLACING clause is specified on the INITIALIZE statement, each qualifying member of the field list that was not already initialized by a VALUE clause, if any, will be initialized to the specified literal-1 or identifier-1 value.

    Only those as-yet uninitialized list members meeting the criteria set forth for the specified category-name-2 will qualify for this initialization.

    If you need to apply REPLACING initialization to multiple category-name-2 values, you may repeat the syntax after the reserved word REPLACING, as necessary.

  10. If a DEFAULT clause is specified, any remaining uninitialized members of the field list will be initialized according to the default for their class (numeric and numeric-edited are initialized to ZERO, all others are initialized to SPACES).
  11. The following example may help your understanding of how the INITIALIZE statement works. The sample code makes use of the COBDUMP program to dump the storage that is (or is not) being initialized. See COBDUMP in GnuCOBOL Sample Programs, for a source and cross-reference listing of the COBDUMP program.
    IDENTIFICATION DIVISION.
    PROGRAM-ID. DemoInitialize.
    DATA DIVISION.
    WORKING-STORAGE SECTION.
    01  Item-1.
        05 I1-A VALUE ALL '*'.
           10 FILLER                PIC X(1).
           10 I1-A-1                PIC 9(1) VALUE 9.
        05 I1-B                     USAGE BINARY-CHAR.
        05 I1-C                     PIC A(1) VALUE 'C'.
        05 I1-D                     PIC X/X VALUE 'ZZ'.
        05 I1-E                     OCCURS 2 TIMES PIC 9.
    PROCEDURE DIVISION.
    000-Main.
        DISPLAY "MOVE HIGH-VALUES TO Item-1"
            PERFORM 100-Init-Item-1
            CALL "COBDUMP" USING Item-1
            DISPLAY " "
    
        DISPLAY "INITIALIZE Item-1"
            INITIALIZE Item-1
            CALL "COBDUMP" USING Item-1
            PERFORM 100-Init-Item-1
            DISPLAY " "
    
        DISPLAY "INITIALIZE Item-1 WITH FILLER"
            MOVE HIGH-VALUES TO Item-1
            INITIALIZE Item-1 WITH FILLER
            CALL "COBDUMP" USING Item-1
            PERFORM 100-Init-Item-1
            DISPLAY " "
    
        DISPLAY "INITIALIZE Item-1 ALL TO VALUE"
            MOVE HIGH-VALUES TO Item-1
            INITIALIZE Item-1 ALPHANUMERIC TO VALUE
            CALL "COBDUMP" USING Item-1
            PERFORM 100-Init-Item-1
            DISPLAY " "
    
        DISPLAY "INITIALIZE Item-1 REPLACING NUMERIC BY 1"
            MOVE HIGH-VALUES TO Item-1
            INITIALIZE Item-1 REPLACING NUMERIC BY 1
            CALL "COBDUMP" USING Item-1
            PERFORM 100-Init-Item-1
            DISPLAY " "
    
        STOP RUN
        .
    
    100-Init-Item-1.
        MOVE HIGH-VALUES TO Item-1
        .
    

    When executed, this program produces the following output:

    MOVE HIGH-VALUES TO Item-1
    <-Addr-> Byte <---------------- Hexadecimal ----------------> <---- Char ---->
    ======== ==== =============================================== ================
    00404058    1 FF FF FF FF FF FF FF FF FF                      .........
    
    INITIALIZE Item-1
    <-Addr-> Byte <---------------- Hexadecimal ----------------> <---- Char ---->
    ======== ==== =============================================== ================
    00404058    1 FF 30 00 20 20 2F 20 30 30                      .0.  / 00
    
    INITIALIZE Item-1 WITH FILLER
    <-Addr-> Byte <---------------- Hexadecimal ----------------> <---- Char ---->
    ======== ==== =============================================== ================
    00404058    1 20 30 00 20 20 2F 20 30 30                       0.  / 00
    
    INITIALIZE Item-1 ALL TO VALUE
    <-Addr-> Byte <---------------- Hexadecimal ----------------> <---- Char ---->
    ======== ==== =============================================== ================
    00404058    1 2A 2A FF 43 5A 5A 20 FF FF                      **.CZZ ..
    
    INITIALIZE Item-1 REPLACING NUMERIC BY 1
    <-Addr-> Byte <---------------- Hexadecimal ----------------> <---- Char ---->
    ======== ==== =============================================== ================
    00404058    1 FF 31 01 FF FF FF FF 31 31                      .1.....11
    


7.8.23. INITIATE

INITIATE Syntax
=======================================================================

 INITIATE report-name-1
 ~~~~~~~~

=======================================================================

The INITIATE statement starts Report-Writer Control System (RWCS) processing for a report.

  1. Each report-name-1 must be the name of a report having an RD (see REPORT SECTION) defined for it.
  2. The file in whose FD (see File/Sort-Description) a REPORT report-name-1 clause exists must be open for OUTPUT or EXTEND at the time the INITIATE statement is executed. See OPEN, for more information on file open modes.
  3. The INITIATE statement will initialize all of the following for each report named on the statement:
  4. No report content will actually presented to the report file as a result of a successful INITIATE statement — that will not occur until the first GENERATE statement (see GENERATE) is executed.


7.8.24. INSPECT

INSPECT Syntax
=======================================================================

 INSPECT { literal-1            }
 ~~~~~~~ { identifier-1         }
         { function-reference-1 }

  [ TALLYING { identifier-2 FOR { ALL|LEADING|TRAILING { literal-2    } }
    ~~~~~~~~                ~~~ { ~~~ ~~~~~~~ ~~~~~~~~ { identifier-3 } }
                                { CHARACTERS                            }
                                  ~~~~~~~~~~
               [ | { AFTER|BEFORE } INITIAL { literal-3    } | ] }... ]
                 |   ~~~~~ ~~~~~~           { identifier-4 } |

  [ REPLACING { { { ALL|FIRST|LEADING|TRAILING { literal-4    } }
    ~~~~~~~~~   { { ~~~ ~~~~~ ~~~~~~~ ~~~~~~~~ { identifier-5 } }
                { CHARACTERS                                    }
                { ~~~~~~~~~~                                    }

                 BY { [ ALL ] literal-5 }
                 ~~ {   ~~~             }
                    { identifier-6      }

               [ | { AFTER|BEFORE } INITIAL { literal-6    } | ] }... ]
                 |   ~~~~~ ~~~~~~           { identifier-7 } |

  [ CONVERTING { { literal-7    } TO { literal-8    }
    ~~~~~~~~~~   { identifier-8 } ~~ { identifier-9 }

               [ | { AFTER|BEFORE } INITIAL { literal-9     } | ] ]
                 |   ~~~~~ ~~~~~~           { identifier-10 } |

=======================================================================

The INSPECT statement is used to perform various counting and/or data-alteration operations against strings.

  1. The reserved word INITIAL is optional and may be omitted. The presence or absence of this words has no effect upon the program.
  2. If a CONVERTING clause is specified, neither the TALLYING nor REPLACING clauses may be used.
  3. If either the TALLYING or REPLACING clauses are specified, the CONVERTING clause cannot be used.
  4. If both the TALLYING and REPLACING clauses are specified, they must be specified in the order shown.
  5. All literals and identifiers must be explicitly or implicitly defined as alphanumeric or alphabetic.
  6. If function-reference-1 is specified, it must be an invocation of an intrinsic function that returns a string result. Additionally, only the TALLYING clause may be specified.
  7. If literal-1 is specified, only the TALLYING clause may be specified.
  8. Whichever is specified — literal-1, identifier-1 or function-reference-1 — that item will be referred to in the discussions that follows as the ’inspect subject’.
  9. The three optional clauses control the operation of this statement as follows:
    1. The CONVERTING clause replaces one or more individual characters found in the inspect subject with a different character in much the same manner as is possible with the TRANSFORM statement (see TRANSFORM).
    2. The REPLACING clause replaces one or more sub strings located in the inspect subject with a different, but equally-sized replacement sub string. If you need to replace a sub string with another of a different length, consider using either the SUBSTITUTE intrinsic function (see SUBSTITUTE) or the SUBSTITUTE-CASE intrinsic function (see SUBSTITUTE-CASE).
    3. The TALLYING clause counts the number of occurrences of one or more strings of characters in the inspect subject.
  10. The optional INITIAL clauses may be used to limit the range of characters in the inspect subject that the CONVERTING, REPLACING or TALLYING instruction in which they occur will apply. We call this the ’target range’ of the inspect subject. The target range is defined as follows:
    1. If there is no INITIAL clause specified, the target range is the entire inspect subject.
    2. Either a BEFORE phrase, an AFTER phrase or both may be specified. They may be specified in any order.
    3. The starting point of the target range will be the first character following the sub string identified by the AFTER specification. The ending point will be the last character immediately preceding the sub string identified by the BEFORE specification.
    4. If no AFTER is specified, the first character position of the target range will be character position #1 of the inspect subject.
    5. If no BEFORE is specified, the last character position of the target range will be the last character position of the inspect subject.
  11. The following points apply to the use of the TALLYING clause:
    1. While there will typically be only be a single set of counting instructions on an INSPECT:
      INSPECT Character-String
          TALLYING C-ABC FOR ALL "ABC"
      

      There could be multiple counting instructions specified:

      INSPECT Character-String
          TALLYING C-ABC FOR ALL "ABC"
                   C-BCDE FOR ALL "BCDE"
      

      When there are multiple instructions, the one specified first will take priority over the one specified second, (and so forth) as the INSPECT proceeds forward through the inspect subject, character-by-character.

      With the above example, if the inspect subject were --ABCDEF----BCDEF--, the final result of the counting would be that C-ABC would be incremented by 1 while C-BCDE would be incremented only once; although the human eye clearly sees two ‘BCDE’ sequences, the INSPECT ... TALLYING would only “see” the second — the first would have been processed by the first (higher-priority) counting instruction.

    2. Each set of counting instructions contains the following information:
      1. A target range, specified by the presence of an AFTER INITIAL and/or BEFORE INITIAL clause; the rules for specifying target ranges were covered previously.
      2. A Target Sub string — this is a sequence of characters to be located somewhere in the inspect subject and counted. Target sub strings may be defined as a literal value (figurative constants are allowed) or by the contents of an identifier. If the target sub string is specified as a figurative constant, it will be assumed to have a length of one (‘1’) character. The keywords before the literal or identifier control how many target sub strings could be identified from that replacement instruction, as follows:

        ALL — identifies every possible target sub string that occurs within the target range. There are three occurrences of ALL 'XX' found in aXXabbXXccXXdd.

        LEADING — identifies only an occurrence of the target sub string found either at the first character position of the target range or immediately following a previously-found occurrence. There are no occurrences of LEADING 'XX' found in aXXabbXXccXXdd, but there is one occurrence of LEADING 'a' (the first character).

        TRAILING — identifies only an occurrence of the target sub string found either at the very end of the target range or toward the end, followed by nothing but other occurrences. There are no occurrences of LEADING 'XX' found in aXXabbXXccXXdd, but there are two occurrences of TRAILING 'd'.

        The CHARACTERS option will match any one single character, regardless of what that character is.

    3. identifier-2 will be incremented by 1 each time the target sub string is found within the target range of the inspect subject. The INSPECT statement will not zero-out identifier-2 at the start of execution of the INSPECT — it is the programmer’s responsibility to ensure that all identifier-2 data items are properly initialized to the desired starting values prior to execution of the INSPECT.
  12. The following points apply to the use of the REPLACING clause:
    1. While there will typically be only be a single set of replacement instructions on an INSPECT:
      INSPECT Character-String
          REPLACING ALL "ABC" BY "DEF"
      

      There could be multiple replacement instructions:

      INSPECT Character-String
          REPLACING ALL "ABC" BY "DEF"
                    ALL "BCDE" BY "WXYZ"
      

      When there are multiple replacement instructions, the one specified first will take priority over the one specified second, (and so forth) as the INSPECT proceeds forward through the inspect subject, character-by-character.

      With the above example, if the inspect subject were --ABCDEF----BCDEF--, the final result of the replacement would be --DEFDEF----WXYZF--.

    2. Each set of replacement instructions contains the following information:
      1. A target range, specified by the presence of an AFTER INITIAL and/or BEFORE INITIAL clause; the rules for specifying target ranges were covered previously.
      2. A Target Sub string — this is a sequence of characters to be located somewhere in the inspect subject and subsequently replaced with a new value. Target sub strings, which are specified before the BY keyword, may be defined as a literal value (figurative constants are allowed) or by the contents of an identifier. If the target sub string is specified as a figurative constant, it will be assumed to have a length of one (‘1’) character. The keywords before the literal or identifier control how many target sub strings could be identified from that replacement instruction, as follows:

        ALL — identifies every possible target sub string that occurs within the target range. There are three occurrences of ALL 'XX' found in aXXabbXXccXXdd.

        FIRST — the first occurrence of the target sub string found within the target range. The FIRST 'XX' found in aXXabbXXccXXdd would be the one found between the ‘a’ and ‘b’ characters.

        LEADING — an occurrence of the target sub string found either at the first character position of the target range or immediately following a previously-found occurrence. There are no occurrences of LEADING 'XX' found in aXXabbXXccXXdd, but there is one occurrence of LEADING 'a' (the first character).

        TRAILING — an occurrence of the target sub string found either at the very end of the target range or toward the end, followed by nothing but other occurrences. There are no occurrences of LEADING 'XX' found in aXXabbXXccXXdd, but there are two occurrences of TRAILING 'd'.

        The CHARACTERS option will match any one single character. When you use this option, the replacement sub string (see the next item) must be exactly one character in length.

      3. A Replacement Sub string — this is the sequence of characters that should replace the target sub string. Replacement sub strings are specified after the BY keyword. They too may be specified as a literal, either with or without an ALL prefix (again, figurative constants are allowed) or the value of an identifier. If a figurative constant is coded, the ALL keyword will be assumed, even if it wasn’t specified. Literals without ALL will either be truncated or padded with spaces on the right to match the length of the target sub string. Literals with ALL or figurative constants will be repeated as necessary to match the length of the target sub string. Identifiers specified as replacement sub strings must be defined with a length equal to that of the target sub string.
  13. When both REPLACING and TALLYING are specified:
    1. The INSPECT statement will make a single pass through the sequence of characters comprising the inspect subject. As the pointer to the current inspect target character reaches a point where it falls within the explicit or implicit target ranges specified on the operational instructions of the two clauses, the actions specified by those instructions will become eligible to be taken. As the character pointer reaches a point where it falls past the end of target ranges, the instructions belonging to those target ranges will become disabled.
    2. At any point in time, there may well be multipleREPLACING and/or TALLYING operational instructions active. Only one of the TALLYING and one of the REPLACING instructions (if any) can be executed for any one character pointer position. In each case, it will be the first of the instructions in each category that produces a match with its target string specification.
    3. When both a TALLYING and a REPLACING instruction have been selected for execution, the TALLYING instruction will be executed first. This guarantees that TALLYING will compute occurrences based upon the initial value of the inspect subject before any replacements occur.
  14. The following points apply to the use of the CONVERTING clause:
    1. A CONVERTING clause performs a series of single-character substitutions against a data item in much the same manner as is possible with the TRANSFORM statement (see TRANSFORM).
    2. Unlike the TALLYING and REPLACING clauses, both of which may have multiple operations specified, there may be only one CONVERTING operation per INSPECT.
    3. If the length of literal-7 or identifier-8 (the “from” string) exceeds the length of literal-8 or identifier-9 (the “to” string), then the “to” string will be assumed to be padded to the right with enough spaces to make it the same length as the “from” string.
    4. If the length of the “from” string is less than the length of the “to” string, then the “to” string will be truncated to the length of the “from” string.
    5. Each character, in turn, within the “from” string will be searched for in the target range of the inspect subject. Each located occurrence will be replaced by the corresponding character of the “to” string.


7.8.25. MERGE

MERGE Syntax
=======================================================================

 MERGE sort-file-1
 ~~~~~
    { ON { ASCENDING  } KEY identifier-1... }...
         { ~~~~~~~~~  }
         { DESCENDING }
           ~~~~~~~~~~
    [ WITH DUPLICATES IN ORDER ]
           ~~~~~~~~~~
    [ COLLATING SEQUENCE IS alphabet-name-1 ]
      ~~~~~~~~~
      USING file-name-1 file-name-2...
      ~~~~~
    { OUTPUT PROCEDURE IS procedure-name-1    }
    { ~~~~~~ ~~~~~~~~~                        }
    {       [ THRU|THROUGH procedure-name-2 ] }
    {         ~~~~ ~~~~~~~                    }
    { GIVING file-name-3...                   }
    { ~~~~~~                                  }

The DUPLICATES clause is syntactically recognized but is otherwise non-functional.


=======================================================================

The MERGE statement merges the contents of two or more files that have each been pre-sorted on a set of specified identical keys.

  1. The reserved words IN, IS, KEY, ON, ORDER, SEQUENCE and WITH are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved words THRU and THROUGH are interchangeable.
  3. GnuCOBOL always behaves as if the WITH DUPLICATES IN ORDER clause is specified, even if it isn’t.

    While any COBOL implementation’s sort or merge facilities guarantee that records with duplicate key values will be in proper sequence with regard to other records with different key values, they generally make no promises as to the resulting relative sequence of records having duplicate key values with one another.

    Some COBOL implementations provide this optional clause to force their sort and merge facilities to retain duplicate key-value records in their original input sequence, relative to one another.

  4. The sort-file-1 named on the MERGE statement must be defined using a sort description (SD (see File/Sort-Description)). This file is referred to in the remainder of this discussion as the merge work file.
  5. Each file-name-1, file-name-2 and file-name-3 (if specified) must reference ORGANIZATION LINE SEQUENTIAL (see ORGANIZATION LINE SEQUENTIAL) or ORGANIZATION SEQUENTIAL (see ORGANIZATION SEQUENTIAL) files. These files must be defined using a file description (FD (see File/Sort-Description)).
  6. The identifier-1 … field(s) must be defined as field(s) within a record of sort-file-1.
  7. The record descriptions of file-name-1, file-name-2, file-name-3 (if any) and sort-file-1 are assumed to be identical in layout and size. While the actual data names used for fields in these files’ records may differ, the structure of records, PICTURE (see PICTURE) of fields, USAGE (see USAGE) of fields, size of fields and location of fields within the records should match field-by-field across all files, at least as far as the KEY fields are concerned.
  8. A common programming technique when using the MERGE statement is to define the records of all files involved as simple elementary items of the form 01 record-name PIC X(n). where n is the record size. The only file where records are actually described in detail would then be sort-file-1.
  9. The following rules apply to the files named on the USING clause:
    1. None of them may be open at the time the MERGE is executed.
    2. Each of those files is assumed to be already sorted according to the specifications set forth on the MERGE statement’s KEY clause.
    3. No two of those files may be referenced on a SAME RECORD AREA (see SAME RECORD AREA), SAME SORT AREA or SAME SORT-MERGE AREA statement.
  10. The merging process is as follows:
    1. As the MERGE statement begins execution, the first record in each of the USING files is read automatically.
    2. As the MERGE statement executes, the current record from each of the USING files is examined and compared to each other according to the rules set forth by the KEY clause and the alphabet (see Alphabet-Name-Clause) specified on the COLLATING SEQUENCE clause. The record that should be next in sequence will be written to the merge work file and the USING file from which that record came will be read so that its next record is available. As end-of-file conditions are reached on USING files, those files will be excluded from further processing — processing continues with the remaining files until all the contents of all of them have been exhausted.
    3. After the merge work file has been populated, the merged data will be written to each file-name-3 if the GIVING clause was specified, or will be processed by utilizing an OUTPUT PROCEDURE.
    4. When GIVING is specified, none of the file-name-3 files can be open at the time the MERGE statement is executed.
    5. When an output procedure is used, the procedure(s) specified on the OUTPUT PROCEDURE clause will be invoked as if by a procedural PERFORM (see Procedural PERFORM) statement with no VARYING, TIMES or UNTIL options specified. Merged records may be read from the merge work file — one at a time — within the output procedure using the RETURN (see RETURN) statement.

      A GO TO statement (see GO TO) that transfers control out of the output procedure will terminate the MERGE statement but allows the program to continue executing from the point where the GO TO statement transferred control to. Once an output procedure has been “aborted” using a GO TO it cannot be resumed, and the contents of the merge work file are lost. You may, however, re-execute the MERGE statement itself. Using a GO TO statement to prematurely terminate a merge, or re-starting a previously-cancelled merge is not considered good programming style and should be avoided.

      An output procedure should be terminated in the same way a procedural PERFORM statement would be. Usually, this action will be taken once the RETURN statement indicates that all records in the merge work file have been processed, but termination could occur at any time — via an EXIT statement (see EXIT) — if required.

      Neither a file-based SORT statement (see File-Based SORT) nor another MERGE statement may be executed within the scope of the procedures comprising the output procedure unless those statements utilize a different sort or merge work file.

    6. Once the output procedure terminates, or the last file-name-3 file has been populated with merged data, the output phase — and the MERGE statement itself — is complete.


7.8.26. MOVE



7.8.26.1. Simple MOVE

Simple MOVE Syntax
=======================================================================

 MOVE { literal-1    } TO identifier-2...
 ~~~~ { identifier-1 } ~~

=======================================================================

The Simple MOVE statement moves a specific value to one or more receiving data items.

  1. The MOVE statement will replace the contents of one or more receiving data items (identifier-2) with a new value — the one specified by literal-1 or identifier-1.
  2. Only numeric data can be moved to a numeric or numeric-edited identifier-2. A MOVE involving numeric data will perform any necessary format conversions that might be necessary due to differing USAGE (see USAGE) specifications.
  3. The contents of the identifier-1 data item will not be changed, unless that same data item appears as an identifier-2. Note that such situations will cause a warning message to be issued by the compiler, if warning messages are enabled.


7.8.26.2. MOVE CORRESPONDING

MOVE CORRESPONDING Syntax
=======================================================================

 MOVE CORRESPONDING identifier-1 TO identifier-2...
 ~~~~ ~~~~                       ~~

=======================================================================

The MOVE CORRESPONDING statement similarly-named items from one group item to another.

  1. The reserved word CORRESPONDING may be abbreviated as CORR.
  2. Both identifier-1 and identifier-2 must be group items.
  3. See CORRESPONDING, for a discussion of how corresponding matches between two group items are established.
  4. When corresponding matches are established, the effect of a MOVE CORRESPONDING on those matches will be as if a series of individual MOVEs were done — one for each match.


7.8.27. MULTIPLY



7.8.27.1. MULTIPLY BY

MULTIPLY BY Syntax
=======================================================================

 MULTIPLY { literal-1    } BY { identifier-2
 ~~~~~~~~ { identifier-1 } ~~

      [ ROUNDED [ MODE IS { AWAY-FROM-ZERO         } ] ] }...
        ~~~~~~~   ~~~~    { ~~~~~~~~~~~~~~         }
                          { NEAREST-AWAY-FROM-ZERO }
                          { ~~~~~~~~~~~~~~~~~~~~~~ }
                          { NEAREST-EVEN           }
                          { ~~~~~~~~~~~~           }
                          { NEAREST-TOWARD-ZERO    }
                          { ~~~~~~~~~~~~~~~~~~~    }
                          { PROHIBITED             }
                          { ~~~~~~~~~~             }
                          { TOWARD-GREATER         }
                          { ~~~~~~~~~~~~~~         }
                          { TOWARD-LESSER          }
                          { ~~~~~~~~~~~~~          }
                          { TRUNCATION             }
                            ~~~~~~~~~~
    [ ON SIZE ERROR imperative-statement-1 ]
         ~~~~ ~~~~~
    [ NOT ON SIZE ERROR imperative-statement-2 ]
      ~~~    ~~~~ ~~~~~
 [ END-MULTIPLY ]
   ~~~~~~~~~~~~

=======================================================================

The MULTIPLY BY statement computes the product of one or more data items (identifier-2) and either a numeric literal or another data item.

  1. The reserved words IS and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. Both identifier-1 and identifier-2 must be numeric un-edited data items; literal-1 must be a numeric literal.
  3. The product of identifier-1 or literal-1 and each identifier-2, in turn, will be computed and moved to each of the identifier-2 data items, replacing the prior contents.
  4. The value of identifier-1 is not altered, unless that same data item appears as an identifier-2.
  5. The optional ROUNDED (see ROUNDED) clause available to each identifier-2 will control how non-integer results will be saved.
  6. The optional ON SIZE ERROR and NOT ON SIZE ERROR clauses may be used to detect and react to the failure or success, respectively, of an attempt to perform a calculation. In this case, failure is defined as being an identifier-2 with an insufficient number of digit positions available to the left of any implied decimal point. See ON SIZE ERROR + NOT ON SIZE ERROR, for additional information.


7.8.27.2. MULTIPLY GIVING

MULTIPLY GIVING Syntax
=======================================================================

 MULTIPLY { literal-1    } BY { literal-2    } GIVING { identifier-3
 ~~~~~~~~ { identifier-1 } ~~ { identifier-2 } ~~~~~~

      [ ROUNDED [ MODE IS { AWAY-FROM-ZERO         } ] ] }...
        ~~~~~~~   ~~~~    { ~~~~~~~~~~~~~~         }
                          { NEAREST-AWAY-FROM-ZERO }
                          { ~~~~~~~~~~~~~~~~~~~~~~ }
                          { NEAREST-EVEN           }
                          { ~~~~~~~~~~~~           }
                          { NEAREST-TOWARD-ZERO    }
                          { ~~~~~~~~~~~~~~~~~~~    }
                          { PROHIBITED             }
                          { ~~~~~~~~~~             }
                          { TOWARD-GREATER         }
                          { ~~~~~~~~~~~~~~         }
                          { TOWARD-LESSER          }
                          { ~~~~~~~~~~~~~          }
                          { TRUNCATION             }
                            ~~~~~~~~~~
    [ ON SIZE ERROR imperative-statement-1 ]
         ~~~~ ~~~~~
    [ NOT ON SIZE ERROR imperative-statement-2 ]
      ~~~    ~~~~ ~~~~~
 [ END-MULTIPLY ]
   ~~~~~~~~~~~~

=======================================================================

The MULTIPLY GIVING statement computes the product of two literals and/or data items and saves that result in one or more other data items.

  1. The reserved words IS and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. Both identifier-1 and identifier-2 must be numeric un-edited data items; literal-1 and literal-2 must be numeric literals.
  3. The product of identifier-1 or literal-1 and identifier-2 or literal-2 will be computed and moved to each of the identifier-3 data items, replacing their old contents.
  4. Neither the value of identifier-1 nor identifier-2 will be altered, unless either appears as an identifier-3.
  5. The optional ROUNDED (see ROUNDED) clause available to each identifier-2 will control how non-integer results will be saved.
  6. The optional ON SIZE ERROR and NOT ON SIZE ERROR clauses may be used to detect and react to the failure or success, respectively, of an attempt to perform a calculation. In this case, failure is defined as being an identifier-2 with an insufficient number of digit positions available to the left of any implied decimal point. See ON SIZE ERROR + NOT ON SIZE ERROR, for additional information.


7.8.28. OPEN

OPEN Syntax
=======================================================================

 OPEN { { INPUT  } [ SHARING WITH { ALL OTHER } ] file-name-1
 ~~~~   { ~~~~~  }   ~~~~~~~      { ~~~       }
        { OUTPUT }                { NO OTHER  }
        { ~~~~~~ }                { ~~        }
        { I-O    }                { READ ONLY }
        { ~~~    }                  ~~~~ ~~~~
        { EXTEND }
          ~~~~~~
      [ { REVERSED           } ] }...
        { ~~~~~~~~           }
        { WITH { NO REWIND } }
        {      { ~~ ~~~~~~ } }
        {      { LOCK      } }
                 ~~~~

The NO REWIND, and REVERSED clauses are syntactically recognized but are otherwise non-functional.


=======================================================================

The OPEN statement makes one or more files described in your program available for use.

  1. The reserved words OTHER and WITH are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The SHARING and WITH LOCK clauses may not both be specified in the same OPEN statement.
  3. Any file defined in a GnuCOBOL program must be successfully opened before it or any of its record descriptions may be referenced on:

    A CLOSE statement (see CLOSE)

    A DELETE statement (see DELETE)

    A READ statement (see READ)

    A REWRITE statement (see REWRITE)

    A START statement (see START)

    An UNLOCK statement (see UNLOCK)

    A WRITE statement (see WRITE)

  4. Any attempt to open a file that is already open will fail with a file status of 41 (see File Status Codes).
  5. Any open failure (including status 41) may be trapped using DECLARATIVES (see DECLARATIVES) or an error procedure established using the CBL_ERROR_PROC built-in system subroutine (see CBL_ERROR_PROC) built-in subroutine or even just checking the status field defined. It is up to the programmer to check for bad statuses and respond accordingly such as issue a CLOSE before dealing with the problem.
  6. The INPUT, OUTPUT, I-O and EXTEND open modes inform GnuCOBOL of the manner in which you wish to use the file, as follows:
    INPUT

    You may only read the existing contents of the file — only the CLOSE, READ, START and UNLOCK statements will be allowed. This enforcement takes place at execution time, not compilation time.

    OUTPUT

    You may only write new content (which will completely replace any previous file contents) to the file — only the CLOSE, UNLOCK and WRITE statements will be allowed. This enforcement takes place at execution time, not compilation time.

    I-O

    You may perform any operation you wish against the file — all file I/O statements will be allowed.

    EXTEND

    You may only write new content (which will be appended after the previously existing file contents) to the file — only the CLOSE, UNLOCK and WRITE statements will be allowed. This enforcement takes place at execution time, not compilation time. You cannot extend an empty file; this will not generate a runtime error, but no output will appear in the file.

  7. The SHARING clause informs the GnuCOBOL file runtime modules how you are willing to co-exist with any other GnuCOBOL programs that may attempt to open the same file after your program does. See File Sharing, for an explanation of the SHARING clause.
  8. The WITH LOCK option will be functional only if your GnuCOBOL build can support it. GnuCOBOL built for MinGW or native Windows will not, because the Unix fcntl primitive doesn’t exist in those environments. GnuCOBOL built for Cygwin or Unix will.


7.8.29. PERFORM



7.8.29.1. Procedural PERFORM

Procedural PERFORM Syntax
=======================================================================

 PERFORM procedure-name-1 [ THRU|THROUGH procedure-name-2 ]
 ~~~~~~~                    ~~~~ ~~~~~~~
    [ { [ WITH TEST { BEFORE } ] { VARYING-Clause                 } } ]
      {        ~~~~ { ~~~~~~ }   { UNTIL conditional-expression-1 } }
      {             { AFTER  }     ~~~~~                            }
      {               ~~~~~                                         }
      { UNTIL EXIT|FOREVER                                          }
      { ~~~~~ ~~~~ ~~~~~~~                                          }
      { { literal-1    } TIMES                                      }
      { { identifier-1 } ~~~~~                                      }

=======================================================================

This format of the PERFORM statement is used to transfer control to one or more procedures, which will return control back when complete. Execution of the procedure(s) can be done a single time, multiple times, repeatedly until a condition becomes TRUE or forever (with some way of breaking out of the control of the PERFORM or of halting program execution within the procedure(s)).

  1. The reserved word WITH is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. The reserved words THRU and THROUGH are interchangeable.
  3. The reserved word and phrase FOREVER and UNTIL EXIT are interchangeable.
  4. Both procedure-name-1 and procedure-name-2 must be procedure division sections or paragraphs defined in the same program as the PERFORM statement. If procedure-name-2 is specified, it must follow procedure-name-1 in the program’s source code.
  5. The perform scope is defined as being the statements within procedure-name-1, the statements within procedure-name-2 and all statements in all procedures defined between them.
  6. literal-1 must be a numeric literal or a reference to a function that returns a numeric value. The value must be an integer greater than zero.
  7. identifier-1 must be an elementary un-edited numeric data item with an integer value greater than zero.
  8. Without the UNTIL, UNTIL EXIT, TIMES, VARYING-Clause (see VARYING) or FOREVER clauses, the code within the perform scope will be executed once, after which control will return to the statement following the PERFORM.
  9. The FOREVER option will repeatedly execute the code within the perform scope with no conditions defined for termination of the repetition — it will be up to the programmer to include an EXIT SECTION statement (see EXIT) or EXIT PARAGRAPH statement within the procedure(s) being performed that will break out of the loop.
  10. The TIMES option will repeat the execution of the code within the perform scope a fixed number of times. When the PERFORM statement begins execution, an internal repeat counter (not accessible to the programmer) will be set to the value of literal-1 or the value within identifier-1.

    If the counter has a value greater than zero, the statement(s) within the PERFORM scope will be executed, after which the counter will be decremented by 1 with each repetition. Once that counter reaches zero, repetition will cease and control will fall into the next statement following the PERFORM.

    If the identifier-1 option was used, altering the value of that data item within the perform scope will not affect the repetition count.

  11. The UNTIL conditional-expression-1 option will repeat the code within the perform scope until the specified conditional expression evaluates to a TRUE value.
  12. The optional WITH TEST clause will control whether UNTIL testing occurs BEFORE the statements within the perform scope are executed on each iteration (creating the possibility — if conditional-expression-1 is initially TRUE — that the statements within the perform scope will never be executed) or AFTER (guaranteeing the statements within the perform scope will be executed at least once).

    The default, if this clause is absent, is WITH TEST BEFORE.

    This clause may not be coded when the TIMES clause is used.

  13. The optional VARYING-Clause is a mechanism that creates an advanced loop-management mechanism complete with one or more numeric data items being automatically incremented (or decremented) on each loop iteration as well as the termination control of an UNTIL clause. See VARYING, for the details.


7.8.29.2. Inline PERFORM

Inline PERFORM Syntax
=======================================================================

   PERFORM
   ~~~~~~~
    [ { [ WITH TEST { BEFORE } ] { VARYING-Clause                 } } ]
      {        ~~~~ { ~~~~~~ }   { UNTIL conditional-expression-1 } }
      {             { AFTER  }     ~~~~~                            }
      {               ~~~~~                                         }
      { UNTIL EXIT|FOREVER                                          }
      { ~~~~~ ~~~~ ~~~~~~~                                          }
      { { literal-1    } TIMES                                      }
      { { identifier-1 } ~~~~~                                      }

      imperative-statement-1

 [ END-PERFORM ]
   ~~~~~~~~~~~

=======================================================================

This format of the PERFORM statement is identical in operation to the procedural PERFORM, except for the fact that the statement(s) comprising the perform scope (imperative-statement-1) (see Imperative Statement) are now specified in-line with the PERFORM code rather than in procedures located elsewhere within the program.



7.8.29.3. VARYING

VARYING Syntax
=======================================================================

 VARYING identifier-2 FROM { literal-2    } [ BY { literal-3    } ]
 ~~~~~~~              ~~~~ { identifier-3 }   ~~ { identifier-4 }
         [ UNTIL conditional-expression-1 ]
           ~~~~~
 [ AFTER identifier-5 FROM { literal-4    } [ BY { literal-5    } ]
   ~~~~~              ~~~~ { identifier-6 }   ~~ { identifier-7 }
         [ UNTIL conditional-expression-2 ] ]...
           ~~~~~

=======================================================================

The VARYING clause, available on both formats of the PERFORM statement, is a looping mechanism that allows for the specification of one or more numeric data items that will be initialized to a programmer-specified value and automatically incremented by another programmer-specified value after each loop iteration.

  1. All identifiers used in a VARYING-Clause must be elementary, un-edited numeric data items. All literals must be numeric literals.
  2. The following points describe the sequence of events that take place as a result of the VARYING portion of the clause:
    1. When the PERFORM begins execution, the FROM value will be moved to identifier.
    2. If the PERFORM specifies or implies WITH TEST BEFORE, conditional-expression-1 will be evaluated and processing of the PERFORM will halt if the expression evaluates to TRUE. If WITH TEST BEFORE was not specified or implied, or if the conditional expression evaluated to FALSE, processing proceeds with step C.
    3. The statements within the perform scope will be executed. If a GO TO executed within the perform scope transfers control to a point outside the perform scope, processing of the PERFORM will halt.
    4. When the statements within the perform scope terminate the loop iteration, by one of:
      • allowing the flow of execution to attempt to fall past the last statement in the perform scope
      • executing an EXIT PERFORM CYCLE statement (see EXIT)
      • executing an EXIT PARAGRAPH statement or EXIT SECTION statement when there is only one paragraph (or section) in the perform scope ( this option only applies to a procedural PERFORM)

      If WITH TEST AFTER was specified, control will return back to the PERFORM, where conditional-expression-1 will be evaluated, and processing of the PERFORM will halt if the expression evaluates to TRUE. If WITH TEST AFTER was not specified, or if the conditional expression evaluated to FALSE, processing continues with the next step.

    5. The BY value, if any, will be added to identifier-2. If no BY is specified, it will be treated as if BY 1 had been specified.
    6. Return to step C.
  3. Most VARYING-Clauses have no AFTER specified. Those that do, however, are establishing a loop-within-a-loop situation where the process described above in steps (‘A’) through (‘F’) will take place from the AFTER, and those six processing steps actually replace step C of the VARYING. This “nesting” process can continue indefinitely, with each additional AFTER.

An example should really help you see this at work. Observe the following code which defines a two-dimensional (3 row by 4 column) table and a pair of numeric data items to be used to subscript references to each element of the table:

01  PERFORM-DEMO.
    05 PD-ROW             OCCURS 3 TIMES.
       10 PD-COL          OCCURS 4 TIMES
          15 PD           PIC X(1).
01  PD-Col-No             PIC 9 COMP.
01  PD-Row-No             PIC 9 COMP.

Let’s say the 3x4 “grid” defined by the above structure has these values:

A B C D
E F G H
I J K L

This code will display ABCDEFGHIJKL on the console output window:

PERFORM WITH TEST AFTER
        VARYING PD-Row-No FROM 1 BY 1 UNTIL PD-Row-No = 3
          AFTER PD-Col-No FROM 1 BY 1 UNTIL PD-Col-No = 4
    DISPLAY PD (PD-Row-No, PD-Col-No) WITH NO ADVANCING
END-PERFORM

While this code will display AEIBFJCGKDHL on the console output window:

PERFORM WITH TEST AFTER
        VARYING PD-Col-No FROM 1 BY 1 UNTIL PD-Col-No = 4
          AFTER PD-Row-No FROM 1 BY 1 UNTIL PD-Row-No = 3
    DISPLAY PD (PD-Row-No, PD-Col-No) WITH NO ADVANCING
END-PERFORM

While we’re looking at sample code, this code displays ABCEFG:

PERFORM
        VARYING PD-Row-No FROM 1 BY 1 UNTIL PD-Row-No = 3
          AFTER PD-Col-No FROM 1 BY 1 UNTIL PD-Col-No = 4
    DISPLAY PD (PD-Row-No, PD-Col-No) WITH NO ADVANCING
END-PERFORM

By removing the WITH TEST clause, the statement is now assuming WITH TEST BEFORE. Since testing now happens before the DISPLAY statement gets executed, when PD-Row-No is 3 and PD-Col-No is 4 the DISPLAY statement won’t be executed.

Most COBOL programmers, when using WITH TEST BEFORE explicitly or implicitly have developed the habit of using ‘>’ rather than ‘=’ on UNTIL clauses. This would make the sample code:

PERFORM
        VARYING PD-Row-No FROM 1 BY 1 UNTIL PD-Row-No > 3
          AFTER PD-Col-No FROM 1 BY 1 UNTIL PD-Col-No > 4
    DISPLAY PD (PD-Row-No, PD-Col-No) WITH NO ADVANCING
END-PERFORM

With this change, ABCDEFGHIJKL is once again displayed.



7.8.30. READ



7.8.30.1. Sequential READ

Sequential READ Syntax
=======================================================================

   READ file-name-1 [ { NEXT|PREVIOUS } ] RECORD [ INTO identifier-1 ]
   ~~~~               { ~~~~ ~~~~~~~~ }            ~~~~
    [ { IGNORING LOCK    } ]
      { ~~~~~~~~ ~~~~    }
      { WITH [ NO ] LOCK }
      {        ~~   ~~~~ }
      { WITH KEPT LOCK   }
      {      ~~~~ ~~~~   }
      { WITH IGNORE LOCK }
      {      ~~~~~~ ~~~~ }
      { WITH WAIT        }
             ~~~~
    [ AT END imperative-statement-1 ]
         ~~~
    [ NOT AT END imperative-statement-2 ]
      ~~~    ~~~
 [ END-READ ]
   ~~~~~~~~

=======================================================================

This form of the READ statement retrieves the next (or previous) record from a file.

  1. The reserved words AT, RECORD and WITH are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The file-name-1 file must have been defined via an FD (see File/Sort-Description), not an SD.
  3. The file-name-1 file must currently be open for INPUT (see File OPEN Modes) or I-O.
  4. If file-name-1 is an ORGANIZATION RELATIVE (see ORGANIZATION RELATIVE) or ORGANIZATION INDEXED (see ORGANIZATION INDEXED) file with an ACCESS MODE RANDOM, this statement cannot be used.
  5. If file-name-1 was specified as ACCESS MODE SEQUENTIAL, this is the only format of the READ statement that is available.
  6. If file-name-1 is an ORGANIZATION RELATIVE (see ORGANIZATION RELATIVE) or ORGANIZATION INDEXED (see ORGANIZATION INDEXED) file with ACCESS MODE DYNAMIC, this statement as well as a random READ (see Random READ) may be used.
  7. The keywords NEXT and PREVIOUS specify what “direction of travel” the reading process will take through the file. If neither is specified, NEXT is assumed.
  8. The PREVIOUS option is available only for ORGANIZATION INDEXED files.
  9. When reading any sequential (any organization) or relative file, the “next” direction refers to the physical sequence of records in the file. When reading an indexed file, the “next” and “previous” directions refer to the sequence of primary or alternate record key values in the file’s records, regardless of where the records physically occur within the file.
  10. The minimal statement READ file-name-1 is perfectly legal according to both READ formats. For that reason, when ACCESS MODE DYNAMIC has been specified and you want to tell the GnuCOBOL compiler that this minimal statement should be treated as a sequential READ, you must add either NEXT or PREVIOUS to the statement (otherwise it will be treated as a random READ).
  11. A successful sequential READ will retrieve the next available record from file-name-1, in either a “next” or “previous” direction from the most-recently-read record, depending upon the use of the NEXT or PREVIOUS option. The newly-retrieved record data will be saved into the 01-level record structure(s) that immediately follow the file’s FD. If the optional INTO clause is present, a copy of the just-retrieved record will be automatically moved to identifier-1.
  12. When an ORGANIZATION RELATIVE file has been successfully read, the file’s RELATIVE KEY (see ORGANIZATION RELATIVE) field will be automatically populated with the relative record number (ordinal occurrence number) of the record in the file.
  13. The optional LOCK options may be used to manually control access to the retrieved record by other programs while this program is running. See Record Locking, to review the various record locking behaviours.
  14. The optional AT END clause, if coded, is used to detect and react to the failure of an attempt to retrieve another record from the file due to an end-of-file (i.e. no more records) condition.
  15. The optional NOT AT END clause, if coded, will check for a file status value of 00. See File Status Codes, for additional information.


7.8.30.2. Random READ

Random READ Syntax
=======================================================================

   READ file-name-1 RECORD [ INTO identifier-1 ]
   ~~~~                      ~~~~
    [ { IGNORING LOCK    } ]
      { ~~~~~~~~ ~~~~    }
      { WITH [ NO ] LOCK }
      {        ~~   ~~~~ }
      { WITH KEPT LOCK   }
      {      ~~~~ ~~~~   }
      { WITH IGNORE LOCK }
      {      ~~~~~~ ~~~~ }
      { WITH WAIT        }
             ~~~~
    [ KEY IS identifier-2 ]
      ~~~
    [ INVALID KEY imperative-statement-1 ]
      ~~~~~~~
    [ NOT INVALID KEY imperative-statement-2 ]
      ~~~ ~~~~~~~
 [ END-READ ]
   ~~~~~~~~

=======================================================================

This form of the READ statement retrieves an arbitrary record from an ORGANIZATION RELATIVE (see ORGANIZATION RELATIVE) or ORGANIZATION INDEXED (see ORGANIZATION INDEXED) file.

  1. The reserved words IS, KEY (on the INVALID and NOT INVALID clauses), RECORD and WITH are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The file-name-1 file must have been defined via an FD (see File/Sort-Description), not an SD.
  3. The file-name-1 file must currently be open for INPUT (see File OPEN Modes) or I-O.
  4. If the ACCESS MODE of file-name-1 is SEQUENTIAL, or the ORGANIZATION of the file is any form of sequential, this format of the READ statement cannot be used.
  5. If the ACCESS MODE of file-name-1 is RANDOM, this is the only format of the READ statement that is available.
  6. If file-name-1 is an ORGANIZATION RELATIVE (see ORGANIZATION RELATIVE) or ORGANIZATION INDEXED (see ORGANIZATION INDEXED) file with ACCESS MODE DYNAMIC, this statement as well as a sequential READ (see Sequential READ) may be used.
  7. The minimal statement READ file-name-1 is perfectly legal according to both READ formats. For that reason, when ACCESS MODE DYNAMIC has been specified and you want to tell the GnuCOBOL compiler that this minimal statement should be treated as a random READ, you must omit the NEXT or PREVIOUS available to the sequential format of the READ statement to ensure the statement will be treated as a random READ.
  8. The optional KEY clause tells the compiler how a record is to be located in the file.

    If the KEY clause is absent, and the file is

    ORGANIZATION RELATIVE

    the contents of the field declared as the file’s RELATIVE KEY will be used to identify a record

    ORGANIZATION INDEXED

    the contents of the field declared as the file’s RECORD KEY will be used to identify a record.

    If the KEY clause is specified, and the file is

    ORGANIZATION RELATIVE

    the contents of identifier-2 will be used as the relative record number of the record to be accessed. identifier-2 need not be the RELATIVE KEY (see ORGANIZATION RELATIVE) field of the file (although it could be if you wish).

    ORGANIZATION INDEXED

    identifier-2 must be the RECORD KEY (see ORGANIZATION INDEXED) or one of the file’s ALTERNATE RECORD KEY fields (if any). The current contents of that field will identify the record to be accessed. If an alternate record key is used, and that key allows duplicate values, the record accessed will be the first one having that key value.

  9. Once read from the file, the newly-retrieved record data will be saved into the 01-level record structure(s) that immediately follow the file’s FD. If the optional INTO clause is present, a copy of the just-retrieved record will be automatically moved to identifier-1.
  10. When an ORGANIZATION RELATIVE file has been successfully read, the file’s RELATIVE KEY (see ORGANIZATION RELATIVE) field will be automatically populated with the relative record number (ordinal occurrence number) of the record in the file.
  11. The optional LOCK options may be used to manually control access to the retrieved record by other programs while this program is running. See Record Locking, to review the various record locking behaviours.
  12. The optional INVALID KEY and NOT INVALID KEY clauses may be used to detect and react to the failure or success, respectively, by detecting non-zero (typically 23 = key not found = record not found) and 00 file status codes, respectively. See File Status Codes, for additional information.


7.8.31. READY TRACE

READY TRACE Syntax
=======================================================================

 READY TRACE
 ~~~~~ ~~~~~

=======================================================================

The READY TRACE statement turns procedure or procedure-and-statement tracing on.

  1. In order for this statement to be functional, tracing code must have been generated into the compiled program using either the -ftrace switch (procedures only) or -ftraceall switch (procedures and statements).
  2. Tracing may be turned off at any point by executing the RESET TRACE statement (see RESET TRACE).
  3. The COB_SET_TRACE run-time environment variable (see Run Time Environment Variables) provides another way to control tracing. If this environment variable is set to a value of ‘Y’ prior to the start of program execution, tracing starts at the point the program begins execution, as if READY TRACE were the first executed statement.


7.8.32. RELEASE

RELEASE Syntax
=======================================================================

 RELEASE record-name-1 [ FROM { literal-1    } ]
 ~~~~~~~                 ~~~~ { identifier-1 }

=======================================================================

The RELEASE statement adds a new record to a sort work file.

  1. This statement is valid only within the INPUT PROCEDURE of a file-based SORT statement (see File-Based SORT).
  2. The specified record-name-1 must be a record defined to the sort description (SD (see File/Sort-Description)) of the sort work file being processed by the current sort.
  3. The optional FROM clause will cause literal-1 or identifier-1 to be automatically moved into record-name-1 prior to writing record-name-1’s contents to the file-name-1. If this clause is not specified, it is the programmer’s responsibility to populate record-name-1 with the desired data prior to executing the RELEASE.


7.8.33. RESET TRACE

RESET TRACE Syntax
=======================================================================

 RESET TRACE
 ~~~~~ ~~~~~

=======================================================================

The RESET TRACE statement turns procedure or procedure-and-statement tracing off.

  1. By default, procedure and procedure-and-statement tracing is off as programs begin execution. The READY TRACE statement (see READY TRACE) can be used to turn tracing on.
  2. In order for this statement to be functional, tracing code must have been generated into the compiled program using either the -ftrace switch (procedures only) or -ftraceall switch (procedures and statements).
  3. The COB_SET_TRACE run-time environment variable (see Run Time Environment Variables) provides another way to control tracing. If this environment variable is set to a value of ‘Y’ prior to the start of program execution, tracing started at the point the program begins execution, as if READY TRACE were the first executed statement. The RESET TRACE statement, if executed, will then turn off tracing.


7.8.34. RETURN

RETURN Syntax
=======================================================================

   RETURN sort-file-name-1 RECORD
   ~~~~~~
    [ INTO identifier-1 ]
      ~~~~
      AT END imperative-statement-1
         ~~~
    [ NOT AT END imperative-statement-2 ]
      ~~~    ~~~
 [ END-RETURN ]
   ~~~~~~~~~~

=======================================================================

The RETURN statement reads a record from a sort or merge work file.

  1. The reserved words AT and RECORD are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The RETURN statement is valid only within the OUTPUT PROCEDURE of a file-based SORT (see File-Based SORT) or a MERGE statement (see MERGE) statement.
  3. The sort-file-name-1 file must be a sort- or merge work file defined with a SD (see File/Sort-Description), not an FD.
  4. A successful RETURN will retrieve the next available record from sort-file-name-1. The newly-retrieved record data will be saved into the 01-level record structure(s) that immediately follow the file’s SD. If the optional INTO clause is present, a copy of the just-retrieved record will be automatically moved to identifier-1.
  5. The mandatory AT END clause is used to detect and react to the failure of an attempt to retrieve another record from the file due to an end-of-file (i.e. no more records) condition.
  6. The optional NOT AT END clause, if coded, will check checking for a file status value of 00. See File Status Codes, for additional information.


7.8.35. REWRITE

REWRITE Syntax
=======================================================================

   REWRITE record-name-1
   ~~~~~~~
      [ FROM { literal-1    } ]
        ~~~~ { identifier-1 }

      [ WITH [ NO ] LOCK ]
               ~~   ~~~~
      [ INVALID KEY imperative-statement-1 ]
        ~~~~~~~
      [ NOT INVALID KEY imperative-statement-2 ]
        ~~~ ~~~~~~~
 [ END-REWRITE ]
   ~~~~~~~~~~~

=======================================================================

The REWRITE statement replaces a logical record on a disk file.

  1. The reserved words KEY and WITH are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The record-name-1 specified on the statement must be defined as an 01-level record subordinate to the File Description (FD (see File/Sort-Description)) of a file that is currently open for I-O (see File OPEN Modes).
  3. The optional FROM clause will cause literal-1 or identifier-1 to be automatically moved into record-name-1 prior to writing record-name-1’s contents to the file-name-1. If this clause is not specified, it is the programmer’s responsibility to populate record-name-1 with the desired data prior to executing the REWRITE.
  4. This statement may not be used with ORGANIZATION LINE SEQUENTIAL (see ORGANIZATION LINE SEQUENTIAL) files.
  5. Rewriting a record does not cause the contents of the file to be physically updated until the next block of the file is read, a COMMIT (see COMMIT) or UNLOCK statement (see UNLOCK) is issued or that file is closed.
  6. If the file has ORGANIZATION SEQUENTIAL (see ORGANIZATION SEQUENTIAL):
    1. The record to be rewritten will be the one retrieved by the most-recently executed READ (see READ) of the file.
    2. If the FD of the file contains the RECORD CONTAINS or RECORD IS VARYING clause, and that clause allows the record size to vary, the size of record-name-1 cannot be altered.
  7. If the file has ORGANIZATION RELATIVE (see ORGANIZATION RELATIVE) or ORGANIZATION INDEXED (see ORGANIZATION INDEXED):
    1. If the file has ACCESS MODE SEQUENTIAL, the record to be rewritten will be the one retrieved by the most-recently executed READ of the file. If the file has ACCESS MODE RANDOM or ACCESS MODE DYNAMIC, no READ is required before a record may be rewritten — the RELATIVE KEY or RECORD KEY definition for the file, respectively, will specify the record to be updated.
    2. If the FD of the file contains the RECORD CONTAINS or RECORD IS VARYING clause, and that clause allows the record size to vary, the size can be altered.
  8. The optional LOCK options may be used to manually control access to the re-written record by other programs while this program is running. See Record Locking, to review the various record locking behaviours.
  9. The optional INVALID KEY and NOT INVALID KEY clauses may be used to detect and react to the failure or success, respectively, by detecting non-zero (typically 23 = key not found = record not found) and 00 file status codes, respectively. See File Status Codes, for additional information.


7.8.36. ROLLBACK

ROLLBACK Syntax
=======================================================================

 ROLLBACK
 ~~~~~~~~

=======================================================================

The ROLLBACK statement has the same effect as if an UNLOCK statement (see UNLOCK) were executed against every open file in the program.

  1. All locks currently being held for all open files will be released.
  2. See Record Locking, to review the various record locking behaviours.


7.8.37. SEARCH

SEARCH Syntax
=======================================================================

   SEARCH table-name-1
   ~~~~~~
      [ VARYING index-name-1 ]
        ~~~~~~~
      [ AT END imperative-statement-1 ]
           ~~~
      { WHEN conditional-expression-1 imperative-statement-2 }...
        ~~~~
 [ END-SEARCH ]
   ~~~~~~~~~~

=======================================================================

The SEARCH statement is used to sequentially search a table, stopping either once a specific value is located within the table or when the table has been completely searched.

  1. The reserved word AT is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. The searching process will be controlled through a Search Index — a data item with a USAGE (see USAGE) of INDEX. The search index is either the index-name-1 identifier specified on the VARYING clause or — if no VARYING is specified — the USAGE INDEX data item implicitly created by an INDEXED BY (see OCCURS) clause in the table’s definition.
  3. At the time the SEARCH statement is executed, the current value of the search index data item will define the starting position in the table where the searching process will begin. Typically, one initializes that index to a value of 1 before starting the SEARCH via SET search-index TO 1.
  4. Each of the conditional-expression-ns on the WHEN clause(s) should involve a data element within the table, subscripted using the search index.
  5. The searching process is as follows:
    1. Each conditional-expression-n will be evaluated, in turn, until either one evaluates to a value of TRUE or all have evaluated to FALSE.
    2. The imperative-statement-n (see Imperative Statement) specified on the WHEN clause whose conditional-expression-n evaluated to TRUE will be executed; after that, the search will be considered complete and control will fall into the first executable statement following the SEARCH.
    3. If all conditional-expression-ns evaluated to FALSE:
      • The search index will be incremented by 1
      • If the search index now has a value greater than the number of entries in the table, the search is considered to have failed and the imperative-statement-1 on the optional AT END clause, if any, will be executed. After that, control will fall into the first executable statement following the SEARCH.
      • If the search index now has a value less than or equal to the number of entries in the table, search processing returns back to step A.


7.8.38. SEARCH ALL

SEARCH ALL Syntax
=======================================================================

   SEARCH ALL table-name-1
   ~~~~~~ ~~~
      [ AT END imperative-statement-1 ]
           ~~~
        WHEN conditional-expression-1 imperative-statement-2
        ~~~~
 [ END-SEARCH ]
   ~~~~~~~~~~

=======================================================================

The SEARCH ALL statement performs a binary, or half-interval, search against a sorted table. This is generally significantly faster than performing a sequential SEARCH of a table, especially if the table contains a large number of entries.

  1. The reserved word AT is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. To be eligible for searching via SEARCH ALL:
    1. The OCCURS clause of table-name-1 must contain the following elements:
      • An INDEXED BY entry to define an implicit search index data item with a USAGE (see USAGE) of INDEX.
      • An ASCENDING KEY or DESCENDING KEY clause to specify the field within the table by which all entries in the table are sorted.
    2. Just because the table has one or more KEY clauses doesn’t mean the data is actually in that sequence in the table — the actual sequence of the data must agree with the KEY clause(s)! A table-based SORT (see Table SORT) can prove very useful in this regard.
    3. No two records in the table may have the same KEY field values. If the table has multiple KEY definitions, then no two records in the table may have the same combination of KEY field values.
  3. If rule A is violated, the compiler will reject the SEARCH ALL. If rules B and/or C are violated, there will be no message issued by the compiler, but the run-time results of a SEARCH ALL against the table will probably be incorrect.
  4. The conditional-expression-1 should involve the KEY field(s), using the search index (the table’s INDEXED BY index name) as a subscript.
  5. The function of the single, mandatory, WHEN clause is to compare the key field(s) of the table, as indexed by the search index data item, against whatever literal and/or identifier values you are comparing the key field(s) to in the conditional-expression-1 in order to locate the desired entry in the table. The search index will be automatically varied in a manner designed to require the minimum number of tests.
  6. The internal processing of the SEARCH ALL statement begins by setting internal “first” and “last” pointers to the 1st and last entry locations of the table. Processing then proceeds as follows:
    1. The entry half-way between “first” and “last” is identified. We’ll call this the “current” entry, and will set its table entry location into index-name-1.
    2. The conditional-expression-1 is evaluated. This comparison of the key(s) against the target literal/identifier values will have one of three possible outcomes:
      • If the key(s) and value(s) match, imperative-statement-2 (see Imperative Statement) is executed, after which control falls through into the next statement following the SEARCH ALL.
      • If the key(s) are LESS THAN the value(s), then the table entry being searched for can only occur in the “current” to “last” range of the table, so a new “first” pointer value is set (it will be set to the “current” pointer).
      • If the key(s) are GREATER THAN the value(s), then the table entry being searched for can only occur in the “first” to “current” range of the table, so a new “last” pointer value is set (it will be set to the “current” pointer).
    3. If the new “first” and “last” pointers are different than the old “first” and “last” pointers, there’s more left to be searched, so return to step A and continue.
    4. If the new “first” and “last” pointers are the same as the old “first” and “last” pointers, the table has been exhausted and the entry being searched for cannot be found; imperative-statement-1 is executed, after which control falls through into the next statement following the SEARCH ALL. If there is no AT END clause coded, control simply falls into the next statement following the SEARCH ALL.
  7. The net effect of the above algorithm is that only a fraction of the number of elements in the table need ever be tested in order to decide whether or not a particular entry exists. This is because the half the remaining entries in the table are discarded each time an entry is checked.
  8. Computer scientists will compare the two techniques implemented by the SEARCH and SEARCH ALL statements as follows:
  9. When searching a table with N entries, a sequential search will need an average of N/2 tests and a worst case of N tests in order to find an entry and N tests to identify that an entry doesn’t exist.
  10. When searching a table with N entries, a binary search will need a worst-case of log2(N) tests in order to find an entry and log2(N) tests to identify that an entry doesn’t exist (N = the number of entries in the table), where log2 is the base-2 logarithm function.

Here’s a more practical view of the difference. Let’s say that a table has 1,000 entries in it. With a sequential search, on average, you’ll have to check 500 of them to find an entry and you’ll have to look at all 1,000 of them to find that an entry doesn’t exist.

With a binary search, express the number of entries as a binary number (1,000 = 1111101000), count the number of digits in the result (which is, essentially, what a logarithm is, when rounded up to the next integer — the number of digits a decimal number would have if expressed in the logarithm’s number base). In this case, we end up with 10 — that is the worst-case number of tests required to find an entry or to identify that it doesn’t exist. That’s quite an improvement!



7.8.39. SET



7.8.39.1. SET ENVIRONMENT

SET ENVIRONMENT Syntax
=======================================================================

 SET ENVIRONMENT { literal-1    } TO { literal-2    }
 ~~~ ~~~~~~~~~~~ { identifier-1 } ~~ { identifier-2 }

=======================================================================

The SET ENVIRONMENT statement provides a straight-forward means of setting environment values from within a program.

  1. The value of literal-1 or identifier-1 specifies the name of the environment variable to set.
  2. The value of literal-2 or identifier-2 specifies the value to be assigned to the environment variable.
  3. Environment variables created or changed from within GnuCOBOL programs will be available to any sub-shell processes spawned by that program (i.e. CALL "SYSTEM") but will not be known to the shell or console window that started the GnuCOBOL program.

This is a much simpler and more readable means of setting environment variables than by using the DISPLAY UPON ENVIRONMENT-NAME statement (see DISPLAY UPON ENVIRONMENT-NAME). For example, these two code sequences produce identical results:

DISPLAY "VARNAME" UPON ENVIRONMENT-NAME
DISPLAY "VALUE" UPON ENVIRONMENT-VALUE

SET ENVIRONMENT "VARNAME" TO "VALUE"


7.8.39.2. SET Program-Pointer

SET Program-Pointer Syntax
=======================================================================

 SET program-pointer-1 TO ENTRY { literal-1    }
 ~~~                   ~~ ~~~~~ { identifier-1 }

=======================================================================

The SET Program-Pointer statement allows you to retrieve the address of a procedure division code module — specifically the PROGRAM-ID, FUNCTION-ID or an entry-point established via the ENTRY statement (see ENTRY).

  1. The USAGE (see USAGE) of program-pointer-1 must be PROGRAM-POINTER.
  2. The literal-1 or identifier-1 value specified must name a primary entry-point name (PROGRAM-ID of a subroutine or FUNCTION-ID of a user-defined function) or an alternate entry-point defined via an ENTRY statement within a subprogram.
  3. Once the address of a procedure division code area has been acquired in this way, the address could be passed to a subroutine (usually written in C) for whatever use it needs it for. For examples of PROGRAM-POINTERs at work, see the discussions of the CBL_ERROR_PROC built-in system subroutine (see CBL_ERROR_PROC) and CBL_EXIT_PROC built-in system subroutine (see CBL_EXIT_PROC).


7.8.39.3. SET ADDRESS

SET ADDRESS Syntax
=======================================================================

 SET [ ADDRESS OF ] { pointer-name-1 }...
 ~~~   ~~~~~~~ ~~   { identifier-1   }

     TO [ ADDRESS OF ]  { pointer-name-2 }
     ~~   ~~~~~~~ ~~    { identifier-2   }

=======================================================================

The SET ADDRESS statement can be used to work with the addresses of data items rather than their contents.

  1. When the ADDRESS OF clause is used before the TO you will be using this statement to alter the address of a linkage section or BASED (see BASED) data item. Without that clause you will be assigning an address to one or more data items whose USAGE (see USAGE) is POINTER.
  2. When the ADDRESS OF clause is used after the TO, this statement will be identifying the address of identifier-2 as the address to be assigned to identifier-1 or stored in pointer-name-1.
  3. If the ADDRESS OF clause is absent after the TO, the contents of pointer-name-2 will serve as the address to be assigned.


7.8.39.4. SET Index

SET Index Syntax
=======================================================================

 SET index-name-1 TO { literal-1    }
 ~~~              ~~ { identifier-2 }

=======================================================================

This statement assigns a value to a USAGE INDEX data item.

  1. Either the USAGE (see USAGE) of index-name-1 should be INDEX, or index-name-1 must be identified in a table INDEXED BY clause.


7.8.39.5. SET UP/DOWN

SET UP/DOWN Syntax
=======================================================================

 SET identifier-1 { UP   } BY [ LENGTH OF ] { literal-1    }
 ~~~              { ~~   } ~~   ~~~~~~ ~~   { identifier-2 }
                  { DOWN }
                    ~~~~

=======================================================================

Use this statement to increment or decrement the value of an index or pointer by a specified amount.

  1. The USAGE (see USAGE) of identifier-1 must be INDEX, POINTER or PROGRAM-POINTER.
  2. The typical usage when identifier-1 is a USAGE INDEX data item is to increment its value UP or DOWN by 1, since an index is usually being used to sequentially walk through the elements of a table.


7.8.39.6. SET Condition Name

SET Condition Name Syntax
=======================================================================

 SET condition-name-1... TO { TRUE  }
 ~~~                     ~~ { ~~~~  }
                            { FALSE }
                              ~~~~~

=======================================================================

The SET Condition Name statement provides one method of specifying the TRUE / FALSE value of a level-88 condition name.

  1. By setting the specified condition-name-1(s) to a TRUE or FALSE value, you will actually be assigning a value to the parent data item(s) to which the condition name data item(s) is(are) subordinate to.
  2. When specifying TRUE, the value assigned to each parent data item will be the first value specified on the condition name’s VALUE clause.
  3. When specifying FALSE, the value assigned to each parent data item will be the value specified for the FALSE clause of the condition name’s definition; if any condition-name-1 occurrence lacks a FALSE clause, the SET statement will be rejected by the compiler.


7.8.39.7. SET Switch

SET Switch Syntax
=======================================================================

 SET mnemonic-name-1... TO { ON  }
 ~~~                    ~~ { ~~  }
                           { OFF }
                             ~~~

=======================================================================

This form of the SET statement is used to turn switches on or off.

  1. Switches are defined using the SPECIAL-NAMES (see SPECIAL-NAMES) paragraph.
  2. Switches may be tested via the IF statement (see IF) and a Switch-Status Condition. See Switch-Status Conditions, for more information.


7.8.39.8. SET ATTRIBUTE

SET ATTRIBUTE Syntax
=======================================================================

 SET identifier-1 ATTRIBUTE { { BELL          } { ON  }...
 ~~~              ~~~~~~~~~   { ~~~~          } { ~~  }
                              { BLINK         } { OFF }
                              { ~~~~~         }   ~~~
                              { HIGHLIGHT     }
                              { ~~~~~~~~~     }
                              { LEFTLINE      }
                              { ~~~~~~~~      }
                              { LOWLIGHT      }
                              { ~~~~~~~~      }
                              { OVERLINE      }
                              { ~~~~~~~~      }
                              { REVERSE-VIDEO }
                              { ~~~~~~~~~~~~~ }
                              { UNDERLINE     }
                                ~~~~~~~~~

=======================================================================

The SET ATTRIBUTE statement may be used to modify one or more attributes of a screen section data item at run-time.

  1. When making an attribute change to identifier-1, the change will not become visible on the screen until the screen section data item containing identifier-1 is next accepted (if identifier-1 is an input field) or is next displayed (if identifier-1 is not an input field).
  2. The attributes shown in the syntax diagram are the only ones that may be altered by this statement. See Data Description Clauses, for information on their usage.


7.8.39.9. SET LAST EXCEPTION

SET ATTRIBUTE Syntax
=======================================================================

 SET LAST EXCEPTION TO { OFF }
 ~~~ ~~~~ ~~~~~~~~~ ~~   ~~~

=======================================================================

The SET LAST EXCEPTION statement will set the last program exception status to indicate no exception.

  1. The predefined object reference EXCEPTION-OBJECT is set to null, and the last exception status is set to indicate no exception.
  2. This action resets the global exception object completely (FUNCTION EXCEPTION-{FILE, LOCATION, STATEMENT, STATUS } ), and will not show anything afterwards), no matter what the last exception was (such as a divide by zero). Use with care.


7.8.40. SORT



7.8.40.1. File-Based SORT

File-Based SORT Syntax
=======================================================================

 SORT sort-file-1
 ~~~~
    { ON { ASCENDING  } KEY identifier-1... }...
         { ~~~~~~~~~  }
         { DESCENDING }
           ~~~~~~~~~~
    [ WITH DUPLICATES IN ORDER ]
           ~~~~~~~~~~
    [ COLLATING SEQUENCE IS alphabet-name-1 ]
      ~~~~~~~~~

    { INPUT PROCEDURE IS procedure-name-1      }
    { ~~~~~~ ~~~~~~~~~                         }
    {       [ THRU|THROUGH procedure-name-2 ]  }
    {         ~~~~ ~~~~~~~                     }
    { USING file-name-1...                     }
      ~~~~~
    { OUTPUT PROCEDURE IS procedure-name-3     }
    { ~~~~~~ ~~~~~~~~~                         }
    {       [ THRU|THROUGH procedure-name-4 ]  }
    {         ~~~~ ~~~~~~~                     }
    { GIVING file-name-2...                    }
      ~~~~~~

The DUPLICATES clause is syntactically recognized but is otherwise non-functional.


=======================================================================

This format of the SORT statement is designed to sort large volumes of data according to one or more key fields.

  1. The reserved words IN, IS, KEY, ON, ORDER, SEQUENCE and WITH are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved words THRU and THROUGH are interchangeable.
  3. GnuCOBOL always behaves as if the WITH DUPLICATES IN ORDER clause is specified, even if it isn’t.

    While any COBOL implementation’s sort or merge facilities guarantee that records with duplicate key values will be in proper sequence with regard to other records with different key values, they generally make no promises as to the resulting relative sequence of records having duplicate key values with one another.

    Some COBOL implementations provide this optional clause to force their sort and merge facilities to retain duplicate key-value records in their original input sequence, relative to one another.

  4. The sort-file-1 named on the SORT statement must be defined using a sort description (SD (see File/Sort-Description)). This file is referred to in the remainder of this discussion as the sort work file.
  5. If specified, file-name-1 and file-name-2 must reference ORGANIZATION LINE SEQUENTIAL (see ORGANIZATION LINE SEQUENTIAL) or ORGANIZATION SEQUENTIAL (see ORGANIZATION SEQUENTIAL) files. These files must be defined using a file description (FD (see File/Sort-Description)). The same file(s) may be used for file-name-1 and file-name-2.
  6. The identifier-1 … field(s) must be defined as field(s) within a record of sort-file-1.
  7. A sort work file is never opened or closed.
  8. The sorting process works in three stages — the Input Stage, the Sort Stage and the Output Stage.
  9. The following points pertain to the Input Stage:
    1. The data to be sorted is loaded into the sort work file either by copying the entire contents of the file(s) named on the USING clause (done automatically by the sort) or by utilizing an input procedure.
    2. When USING is specified, none of the file-name-1 files may be open at the time the SORT statement is executed.
    3. When an input procedure is used, the procedure(s) specified on the INPUT PROCEDURE clause will be invoked as if by a procedural PERFORM statement (see Procedural PERFORM) with no VARYING, TIMES or UNTIL options specified. Records will be loaded into the sort work file — one at a time — within the input procedure using the RELEASE statement (see RELEASE). This, by the way, is how you could sort the contents of relative or indexed files.

      A GO TO statement (see GO TO) that transfers control out of the input procedure will terminate the SORT statement but allows the program to continue executing from the point where the GO TO statement transferred control to. Once an input procedure has been “aborted” using a GO TO it cannot be resumed, and the contents of the sort work file are lost. You may, however, re-execute the SORT statement itself.3

      An input procedure should be terminated in the same way a procedural PERFORM statement would be.

      Neither a another file-based SORT statement nor a MERGE statement may be executed within the input procedure unless those statements utilize a different sort or merge work file.

    4. Once the input procedure terminates, the input phase is complete.
    5. As data is loaded into the sort work file, it is actually being buffered in dynamically-allocated memory. Only if the amount of data to be sorted exceeds the amount of available sort memory (128 MB) will actual disk files be allocated and utilized. There is a COB_SORT_MEMORY run-time environment variable (see Run Time Environment Variables) that you may use to allocate more or less memory to the sorting process.
  10. The following points pertain to the Sort Stage:
    1. The sort will take place by arranging the data records in the sequence defined by the KEY specification(s) on the SORT statement according to the COLLATING SEQUENCE specified on the SORT (if any) or — if none was defined — the PROGRAM COLLATING SEQUENCE (see OBJECT-COMPUTER). Keys may be any supported data type and USAGE (see USAGE) except for level-78 or level-88 data items.
    2. For example, let’s assume we’re sorting a series of financial transactions. The SORT statement might look like this:
      SORT Sort-File
          ASCENDING  KEY Transaction-Date
          ASCENDING  KEY Account-Number
          DESCENDING KEY Transaction-Amount
      

      The effect of this statement will be to sort all transactions into ascending order of the date the transaction took place (oldest first, newest last). Unless the business running this program is going out of business, there are most-likely many transactions for any given date. Therefore, within each grouping of transactions all with the same date, transactions will be sub-sorted into ascending sequence of the account number the transactions apply to. Since it’s quite possible there might be multiple transactions for an account on any given date, a third level sub-sort will arrange all transactions for the same account on the same date into descending sequence of the actual amount of the transaction (largest first, smallest last). If two or more transactions of $100.00 were recorded for account #12345 on the 31st of August 2009, those transactions will be retained in the order in which they were loaded into the sort work file.

    3. Should disk work files be necessary due to the amount of data being sorted, they will be automatically allocated to disk in a folder defined by the TMPDIR run-time environment variable, TMP run-time environment variable or TEMP run-time environment variable run-time environment variables (see Run Time Environment Variables) (checked for existence in that sequence). These disk files will be automatically purged upon SORT termination or program execution termination (normal or otherwise).
  11. The following points pertain to the Output Stage:
    1. Once the sort stage is complete, a copy of the sorted data will be written to each file-name-2 if the GIVING clause was specified. None of the file-name-2 files can be open at the time the sort is executed.
    2. When an output procedure is used, the procedure(s) specified on the OUTPUT PROCEDURE clause will be invoked as if by a procedural PERFORM statement (see Procedural PERFORM) with no VARYING, TIMES or UNTIL options specified. Records will be retrieved from the sort work file — one at a time — within the output procedure using the RETURN statement (see RETURN).

      A GO TO statement (see GO TO) that transfers control out of the output procedure will terminate the SORT statement but allows the program to continue executing from the point where the GO TO statement transferred control to. Once an output procedure has been “aborted” using a GO TO it cannot be resumed, and the contents of the sort work file are lost. You may, however, re-execute the SORT statement itself. USING A GO TO statement4

      An output procedure should be terminated in the same way a procedural PERFORM statement would be.

      Neither a another file-based SORT statement nor a MERGE statement may be executed within the output procedure unless those statements utilize a different sort or merge work file.

    3. Once the output procedure terminates, the sort is complete.


7.8.40.2. Table SORT

Table SORT Syntax
=======================================================================

 SORT table-name-1
 ~~~~
    { ON { ASCENDING  } KEY identifier-1... }...
         { ~~~~~~~~~  }
         { DESCENDING }
           ~~~~~~~~~~
    [ WITH DUPLICATES IN ORDER ]
           ~~~~~~~~~~
    [ COLLATING SEQUENCE IS alphabet-name-1 ]
      ~~~~~~~~~

The DUPLICATES clause is syntactically recognized but is otherwise non-functional.


=======================================================================

This format of the SORT statement sorts relatively small quantities of data — namely data contained in a data division table — according to one or more key fields.

  1. The reserved words IN, IS, KEY, ON, ORDER, SEQUENCE and WITH are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. GnuCOBOL always behaves as if the WITH DUPLICATES IN ORDER clause is specified, even if it isn’t.

    While any COBOL implementation’s sort or merge facilities guarantee that records with duplicate key values will be in proper sequence with regard to other records with different key values, they generally make no promises as to the resulting relative sequence of records having duplicate key values with one another.

    Some COBOL implementations provide this optional clause to force their sort and merge facilities to retain duplicate key-value records in their original input sequence, relative to one another.

  3. The table-name-1 data item must be a table defined in any data division section except the report or screen sections.
  4. The data within table-name-1 will be sorted in-place (i.e. no sort file is required).
  5. The sort will take place by rearranging the data in table-name-1 into the sequence defined by the KEY specification(s) on the SORT statement, according to the COLLATING SEQUENCE specified on the SORT (if any) or — if none was defined — the PROGRAM COLLATING SEQUENCE (see OBJECT-COMPUTER). Keys may be any supported data type and USAGE (see USAGE) except for level-78 or level-88 data items.
  6. If you are sorting table-name-1 for the purpose of preparing the table for use with a SEARCH ALL statement (see SEARCH ALL), care must be taken that the KEY specifications on the SORT agree with those in the table’s definition.
  7. Although the specification of one or more KEY clauses is optional, currently, a table sort with no KEY specification(s) made on the SORT statement is unsupported by GnuCOBOL and will be rejected by the compiler.


7.8.41. START

START Syntax
=======================================================================

   START file-name-1
   ~~~~~
     [ { FIRST                                                    } ]
       { ~~~~~                                                    }
       { LAST                                                     }
       { ~~~~                                                     }
       { KEY { IS EQUAL TO | IS = | EQUALS         } identifier-1 }
             {    ~~~~~             ~~~~~~         }
             { IS GREATER THAN | IS >              }
             {    ~~~~~~~                          }
             { IS GREATER THAN OR EQUAL TO | IS >= }
             {    ~~~~~~~      ~~ ~~~~~            }
             { IS NOT LESS THAN                    }
             {    ~~~ ~~~~                         }
             { IS LESS THAN | IS <                 }
             {    ~~~~                             }
             { IS LESS THAN OR EQUAL TO | IS <=    }
             {    ~~~~      ~~ ~~~~~               }
             { IS NOT GREATER THAN                 }
                  ~~~ ~~~~~~~
    [ INVALID KEY imperative-statement-1 ]
      ~~~~~~~
    [ NOT INVALID KEY imperative-statement-2 ]
      ~~~ ~~~~~~~
 [ END-START ]
   ~~~~~~~~~

=======================================================================

The START statement defines the logical starting point within a relative or indexed file for subsequent sequential read operations. It positions an internal logical record pointer to a particular record in the file, but does not actually transfer any of that record’s data into the record buffer.

  1. The reserved words IS, KEY, THAN and TO are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. To use this statement, file-name-1 must be an ORGANIZATION RELATIVE (see ORGANIZATION RELATIVE) or ORGANIZATION INDEXED (see ORGANIZATION INDEXED) file that must have been defined with an ACCESS MODE DYNAMIC or ACCESS MODE SEQUENTIAL in its SELECT statement (see SELECT).
  3. At the time this statement is executed, file-name-1 must be open in either INPUT or I-O (see File OPEN Modes) mode.
  4. If file-name-1 is a relative file, identifier-1 must be the defined RELATIVE KEY of the file.
  5. If file-name-1 is an indexed file, identifier-1 must be the defined RECORD KEY of the file or any of the ALTERNATE RECORD KEY fields for the file.
  6. If no FIRST, LAST or KEY clause is specified, KEY IS EQUAL TO xxx will be assumed, where xxx is the defined RELATIVE KEY of (if file-name-1 is a relative file) or the defined RECORD KEY (if file-name-1 is an indexed file).
  7. After successful execution of a START statement, the internal logical record pointer into the file-name-1 data will be positioned to the record which satisfied the actual or implied FIRST, LAST or KEY clause specification, as follows:
    FIRST

    the logical record pointer will point to the first record in the file.

    LAST

    the logical record pointer will point to the last record in the file.

    KEY

    (specified or implied), and the relation used is

    EQUAL TO, GREATER THAN or GREATER THAN OR EQUAL TO (or equivalent)

    the logical record pointer will be specified to the first record satisfying the relation condition; to identify this record. The file’s contents are searched in a first-to-last (in sequence of the key implied by the KEY clause), provided the relation is

    LESS THAN, LESS THAN OR EQUAL TO or NOT GREATER THAN (or equivalent)

    the logical record pointer will be specified to the last record satisfying the relation condition; to identify this record. The file’s contents are searched in a last-to-first (in sequence of the key implied by the KEY clause)

    The next sequential READ statement will read the record that is pointed to by the logical record pointer.

  8. The optional INVALID KEY and NOT INVALID KEY clauses may be used to detect and react to the failure or success, respectively, by detecting non-zero (typically 23 = key not found = record not found) and 00 file status codes, respectively. See File Status Codes, for additional information.


7.8.42. STOP

STOP Syntax
=======================================================================

 STOP { RUN [ { RETURNING|GIVING { literal-1    }           } ] }
 ~~~~ { ~~~   { ~~~~~~~~~ ~~~~~~ { identifier-1 }           }   }
      {       {                                             }   }
      {       { WITH { ERROR  } STATUS [ { literal-2    } ] }   }
      {       {      { ~~~~~  }          { identifier-2 }   }   }
      {       {      { NORMAL }                             }   }
      {                ~~~~~~                                   }
      { literal-3                                               }

=======================================================================

The STOP statement suspends program execution. Some options will allow program execution to resume while others return control to the operating system.

  1. The reserved words STATUS and WITH are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved words RETURNING and GIVING are interchangeable.
  3. The RUN clause halts the program without displaying any special message to that effect.
  4. The literal-3 clause displays the specified text on the SYSOUT/STDOUT device, waits for the user to press the Enter key and then — once the key has been pressed — allows the program to continue execution.
  5. The optional RETURNING clause provides the opportunity to return a numeric value to the operating system (an exit status). The manner in which the exit status may be interrogated by the operating system varies, but Windows can use %ERRORLEVEL% to query the exit status while Unix shells such as sh, bash and ksh can query the exit status as $?. Other Unix shells may have different ways to access return code values.
  6. The STATUS clause provides another means of returning an exit status. Using the STATUS clause is functionally equivalent to using the RETURNING clause.
  7. Using the STATUS clause without a literal-2 or identifier-2 will return an exit status of 0 if the NORMAL keyword is used or a 1 if ERROR was specified.
  8. Your program will always return an exit status, even if no RETURNING or STATUS clause is specified. In the absence of the use of these clauses, the value in the RETURN-CODE special register (see Special Registers) at the time the STOP statement is executed will be used as the exit status.
  9. Any programmer-defined exit procedure (established via the CBL_EXIT_PROC built-in system subroutine (see CBL_EXIT_PROC)) will be executed by STOP RUN, but not by STOP literal-3.
  10. Valid return code values can be in the range -2147483648 to +2147483647.
  11. The three code snippets below are all equivalent. They show different ways in which a GnuCOBOL program may be coded to pass an exit status value of 16 back to the operating system and then halt.
    1. STOP RUN RETURNING 16
      
    2. MOVE 16 TO RETURN-CODE
      STOP RUN
      
    3. STOP RUN WITH ERROR STATUS 16
      


7.8.43. STRING

STRING Syntax
=======================================================================

   STRING
   ~~~~~~
      { { literal-1    } [ DELIMITED BY { SIZE         } ] }...
        { identifier-1 }   ~~~~~~~~~    { ~~~~         }
                                        { literal-2    }
                                        { identifier-2 }
        INTO identifier-3
        ~~~~
      [ WITH POINTER identifier-4 ]
             ~~~~~~~
      [ ON OVERFLOW imperative-statement-1 ]
           ~~~~~~~~
      [ NOT ON OVERFLOW imperative-statement-2 ]
        ~~~    ~~~~~~~~
 [ END-STRING ]
   ~~~~~~~~~~

=======================================================================

The STRING statement is used to concatenate all or a part of one or more strings together, forming a new string.

  1. The reserved words BY, ON and WITH are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. All literals and identifiers (except for identifier-4) must be explicitly or implicitly defined with a USAGE (see USAGE) of DISPLAY. Any of the identifiers may be group items.
  3. The POINTER data item — identifier-4 — must be a non-edited elementary integer numeric data item with a value greater than zero.
  4. Each literal-1 / identifier-1 will be referred to as a source item. The receiving data item is identifier-3.
  5. The STRING statement’s processing is based upon a current character pointer. The initial value of the current character pointer will be the value of identifier-4 at the time the STRING statement began execution. If no POINTER clause is coded, a value of 1 (meaning “the 1st character position”) will be assumed for the current character pointer’s initial value.
  6. For each source item, the contents of the sending item will be copied — character-by-character — into identifier-3 at the character position specified by the current character pointer. After each character is copied, the current character pointer will be incremented by 1 so that it points to the position within identifier-3 where the next character should be copied.
  7. The DELIMITED BY clause specifies how much of each source item will be copied into identifier-3. DELIMITED BY SIZE (the default if no DELIMITED BY clause is specified) causes the entire contents of the source item to be copied into identifier-3.
  8. Using DELIMITED BY literal-2 or DELIMITED BY identifier-2 causes only the contents of the source item up to but not including the character sequence specified by the literal or identifier to be copied.
  9. STRING processing will cease when one of the following occurs:
    1. The initial value of the current character pointer is less than 1 or greater than the number of characters in identifier-3, or…
    2. The value of the current character pointer exceeds the size of identifier-3 at the point the STRING statement wants to copy a character into identifier-3, or…
    3. All sending items have been fully processed
  10. If event A occurs, identifier-3 will remain unchanged.
  11. The occurrence of either event A or B triggers what is referred to as an overflow condition.
  12. The identifier-3) is neither automatically initialized (to spaces or any other value) at the start of a STRING statement nor will it be space-filled should the total number of sending item characters copied into it be less than its size. You may explicitly initialize identifier-3 yourself via the INITIALIZE (see INITIALIZE) or MOVE (see MOVE) statements before executing the STRING if you wish.
  13. The optional ON OVERFLOW and NOT ON OVERFLOW clauses may be used to detect and react to the occurrence or not, respectively, of an overflow condition. See ON OVERFLOW + NOT ON OVERFLOW, for additional information.


7.8.44. SUBTRACT



7.8.44.1. SUBTRACT FROM

SUBTRACT FROM Syntax
=======================================================================

   SUBTRACT { literal-1    }... FROM { identifier-2
   ~~~~~~~~ { identifier-1 }    ~~~~

          [ ROUNDED [ MODE IS { AWAY-FROM-ZERO         } ] ] }...
            ~~~~~~~   ~~~~    { ~~~~~~~~~~~~~~         }
                              { NEAREST-AWAY-FROM-ZERO }
                              { ~~~~~~~~~~~~~~~~~~~~~~ }
                              { NEAREST-EVEN           }
                              { ~~~~~~~~~~~~           }
                              { NEAREST-TOWARD-ZERO    }
                              { ~~~~~~~~~~~~~~~~~~~    }
                              { PROHIBITED             }
                              { ~~~~~~~~~~             }
                              { TOWARD-GREATER         }
                              { ~~~~~~~~~~~~~~         }
                              { TOWARD-LESSER          }
                              { ~~~~~~~~~~~~~          }
                              { TRUNCATION             }
                                ~~~~~~~~~~
     [ ON SIZE ERROR imperative-statement-1 ]
          ~~~~ ~~~~~
     [ NOT ON SIZE ERROR imperative-statement-2 ]
       ~~~    ~~~~ ~~~~~
 [ END-SUBTRACT ]
   ~~~~~~~~~~~~

=======================================================================

This format of the SUBTRACT statement generates the arithmetic sum of all arguments that appear before the FROM (identifier-1 or literal-1) and subtracts that sum from each identifier-2.

  1. The reserved words IS and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. Both identifier-1 and identifier-2 must be numeric unedited data items.
  3. literal-1 must be a numeric literal.
  4. The optional ROUNDED (see ROUNDED) clause available to each identifier-2 will control how non-integer results will be saved.
  5. The optional ON SIZE ERROR and NOT ON SIZE ERROR clauses may be used to detect and react to the failure or success, respectively, of an attempt to perform a calculation. In this case, failure is defined as being an identifier-2 with an insufficient number of digit positions available to the left of any implied decimal point. See ON SIZE ERROR + NOT ON SIZE ERROR, for additional information.


7.8.44.2. SUBTRACT GIVING

SUBTRACT GIVING Syntax
=======================================================================

   SUBTRACT { literal-1    }... FROM identifier-2
   ~~~~~~~~ { identifier-1 }    ~~~~

       GIVING { identifier-3
       ~~~~~~
          [ ROUNDED [ MODE IS { AWAY-FROM-ZERO         } ] ] }...
            ~~~~~~~   ~~~~    { ~~~~~~~~~~~~~~         }
                              { NEAREST-AWAY-FROM-ZERO }
                              { ~~~~~~~~~~~~~~~~~~~~~~ }
                              { NEAREST-EVEN           }
                              { ~~~~~~~~~~~~           }
                              { NEAREST-TOWARD-ZERO    }
                              { ~~~~~~~~~~~~~~~~~~~    }
                              { PROHIBITED             }
                              { ~~~~~~~~~~             }
                              { TOWARD-GREATER         }
                              { ~~~~~~~~~~~~~~         }
                              { TOWARD-LESSER          }
                              { ~~~~~~~~~~~~~          }
                              { TRUNCATION             }
                                ~~~~~~~~~~
     [ ON SIZE ERROR imperative-statement-1 ]
          ~~~~ ~~~~~
     [ NOT ON SIZE ERROR imperative-statement-2 ]
       ~~~    ~~~~ ~~~~~
 [ END-SUBTRACT ]
   ~~~~~~~~~~~~

=======================================================================

The SUBTRACT GIVING statement generates the arithmetic sum of all arguments that appear before the FROM (identifier-1 or literal-1), subtracts that sum from the contents of identifier-2 and then replaces the contents of the identifiers listed after the GIVING (identifier-3) with that result.

  1. The reserved words IS and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. Both identifier-1 and identifier-2 must be numeric unedited data items.
  3. literal-1 must be a numeric literal.
  4. identifier-3 must be a numeric (edited or unedited) data item.
  5. The optional ROUNDED (see ROUNDED) clause available to each identifier-2 will control how non-integer results will be saved.
  6. The optional ON SIZE ERROR and NOT ON SIZE ERROR clauses may be used to detect and react to the failure or success, respectively, of an attempt to perform a calculation. In this case, failure is defined as being an identifier-2 with an insufficient number of digit positions available to the left of any implied decimal point. See ON SIZE ERROR + NOT ON SIZE ERROR, for additional information.


7.8.44.3. SUBTRACT CORRESPONDING

SUBTRACT CORRESPONDING Syntax
=======================================================================

   SUBTRACT CORRESPONDING identifier-1 FROM identifier-2
   ~~~~~~~~                            ~~~~
     [ ROUNDED [ MODE IS { AWAY-FROM-ZERO         } ] ]
       ~~~~~~~   ~~~~    { ~~~~~~~~~~~~~~         }
                         { NEAREST-AWAY-FROM-ZERO }
                         { ~~~~~~~~~~~~~~~~~~~~~~ }
                         { NEAREST-EVEN           }
                         { ~~~~~~~~~~~~           }
                         { NEAREST-TOWARD-ZERO    }
                         { ~~~~~~~~~~~~~~~~~~~    }
                         { PROHIBITED             }
                         { ~~~~~~~~~~             }
                         { TOWARD-GREATER         }
                         { ~~~~~~~~~~~~~~         }
                         { TOWARD-LESSER          }
                         { ~~~~~~~~~~~~~          }
                         { TRUNCATION             }
                           ~~~~~~~~~~
     [ ON SIZE ERROR imperative-statement-1 ]
          ~~~~ ~~~~~
     [ NOT ON SIZE ERROR imperative-statement-2 ]
       ~~~    ~~~~ ~~~~~
 [ END-SUBTRACT ]
   ~~~~~~~~~~~~

=======================================================================

The SUBTRACT CORRESPONDING statement generates code equivalent to individual SUBTRACT FROM statements for corresponding matches of data items found subordinate to the two identifiers.

  1. The reserved words IS and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. Both identifier-1 and identifier-2 must be group items.
  3. See CORRESPONDING, for information on how corresponding matches will be found between identifier-1 and identifier-2.
  4. The optional ROUNDED (see ROUNDED) clause available to each identifier-2 will control how non-integer results will be saved.
  5. The optional ON SIZE ERROR and NOT ON SIZE ERROR clauses may be used to detect and react to the failure or success, respectively, of an attempt to perform a calculation. In this case, failure is defined as being an identifier-2 with an insufficient number of digit positions available to the left of any implied decimal point. See ON SIZE ERROR + NOT ON SIZE ERROR, for additional information.


7.8.45. SUPPRESS

SUPPRESS Syntax
=======================================================================

 SUPPRESS PRINTING
 ~~~~~~~~

=======================================================================

The SUPPRESS statement causes the presentation of a report group to be suppressed.

  1. The reserved word PRINTING is optional and may be omitted. The presence or absence of this word has no effect upon the program.
  2. This statement may only appear within a USE BEFORE REPORTING procedure (in DECLARATIVES (see DECLARATIVES)).
  3. SUPPRESS only prevents the presentation of the report group within whose USE BEFORE REPORTING procedure the statement occurs.
  4. This statement must be executed each time presentation of the report group is to be suppressed.
  5. When a report group’s presentation is suppressed, none of the following operations for the report will take place:
    1. Actual presentation of the report group in question.
    2. Processing of any LINE (see LINE) clauses within the report group in question.
    3. Processing of the NEXT GROUP (see NEXT GROUP) clause (if any) within the report group in question.
    4. Any modification to the LINE-COUNTER special register (see Special Registers).
    5. Any modification to the PAGE-COUNTER special register.


7.8.46. TERMINATE

TERMINATE Syntax
=======================================================================

 TERMINATE report-name-1...
 ~~~~~~~~~

=======================================================================

The TERMINATE statement causes the processing of the specified report(s) to be completed.

  1. Each report-name-1 must be the name of a report having an RD (see REPORT SECTION) defined for it.
  2. The specified report name(s) must be currently initiated (via INITIATE (see INITIATE)) and cannot yet have been terminated.
  3. The TERMINATE statement will present each CONTROL FOOTING (if any), in reverse sequence of the control hierarchy, starting with the most minor up to FINAL (if any). During the presentation of these groups and the processing of any USE BEFORE REPORTING procedures for those groups, the prior set of control data item values will be available, as though a control break had been detected at the most major control data name.
  4. During the presentation of the CONTROL FOOTING groups, any necessary PAGE FOOTING and PAGE HEADING groups will be presented as well.
  5. Finally,the REPORT FOOTING group, if any, will be presented.
  6. If an INITIATE is followed by a TERMINATE with no intervening GENERATE (see GENERATE) statements (all pertaining to the same report, of course), no report groups will be presented to the output file.


7.8.47. TRANSFORM

TRANSFORM Syntax
=======================================================================

 TRANSFORM identifier-1 FROM { literal-1    } TO { literal-2    }
 ~~~~~~~~~              ~~~~ { identifier-2 } ~~ { identifier-3 }

=======================================================================

The TRANSFORM statement scans a data item performing a series of mono-alphabetic substitutions, defined by the arguments before and after the TO clause.

  1. Both literal-1 and/or literal-2 must be alphanumeric literals.
  2. All of identifier-1, identifier-2 and identifier-3 must either be group items or alphanumeric data items. Numeric data items with a USAGE (see USAGE) of DISPLAY are accepted, but will generate warning messages from the compiler.
  3. The TRANSFORM statement will replace characters within identifier-1 that are found in the string specified before the TO keyword with the corresponding characters from the string specified after the TO keyword.
  4. This statement exists within GnuCOBOL to provide compatibility with COBOL programs written to pre-1985 standards. The TRANSFORM statement was made obsolete in the 1985 standard of COBOL, having been replaced by the CONVERTING clause of the INSPECT statement (see INSPECT). New programs should be coded to use INSPECT CONVERTING rather than TRANSFORM.


7.8.48. UNLOCK

UNLOCK Syntax
=======================================================================

 UNLOCK filename-1 RECORD|RECORDS
 ~~~~~~

=======================================================================

This statement synchronizes any as-yet unwritten file I/O buffers to the specified file (if any) and releases any record locks held for records belonging to file-name-1.

  1. The reserved words RECORD and RECORDS are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. If file-name-1 is a Sort/Merge work file, no action will be taken.
  3. Not all GnuCOBOL implementations support locking. Whether they do or not depends upon the operating system they were built for and the build options that were used when GnuCOBOL was generated. When a program using one of those GnuCOBOL implementations issues an UNLOCK, it will ignored. There will be no compiler message issued. Buffer syncing, if needed, will still occur.
  4. See Record Locking, for additional information on record locking.


7.8.49. UNSTRING

UNSTRING Syntax
=======================================================================

   UNSTRING identifier-1
   ~~~~~~~~
        DELIMITED BY { [ ALL ] literal-1 } [ OR { [ ALL ] literal-2 } ]...
        ~~~~~~~~~    {   ~~~             }   ~~ {   ~~~             }
                     { identifier-2      }      { identifier-3      }

        INTO { identifier-4
        ~~~~ [ DELIMITER IN identifier-5 ] [ COUNT IN identifier-6 ] }...
               ~~~~~~~~~                     ~~~~~
      [ WITH POINTER identifier-7 ]
             ~~~~~~~
      [ TALLYING IN identifier-8 ]
        ~~~~~~~~
      [ ON OVERFLOW imperative-statement-1 ]
           ~~~~~~~~
      [ NOT ON OVERFLOW imperative-statement-2 ]
        ~~~    ~~~~~~~~
 [ END-UNSTRING ]
   ~~~~~~~~~~~~

=======================================================================

The UNSTRING statement parses a string, extracting any number of sub strings from it.

  1. The reserved words BY, IN and ON are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. identifier-1 through identifier-5 must be explicitly or implicitly defined with a USAGE (see USAGE) of DISPLAY. Any of those identifiers may be group items.
  3. Both literal-1 and literal-2 must be alphanumeric literals.
  4. Each of identifier-6, identifier-7 and identifier-8 must be elementary non-edited integer numeric items.
  5. At the time the UNSTRING statement begins execution, identifier-7 must have a value greater than 0.
  6. identifier-1 will be referred to as the source string and each identifier-4 will be referred to as a destination field in the following discussions.
  7. The UNSTRING statement’s processing is based upon a current character pointer, the initial value of which will be the value of identifier-7 at the time the UNSTRING statement began execution. If no POINTER clause is coded, a value of 1 (meaning “the 1st character position”) will be assumed for the current character pointer’s initial value.
  8. The source string will be parsed into sub strings starting from the current character pointer position. Sub strings are identified by using the various delimiter strings specified on the DELIMITED BY clause as inter-sub string separators.
  9. Using the ALL option allows a delimiter sequence to be an arbitrarily long sequence of occurrences of the delimiter literal whereas its absence treats each occurrence as a separate delimiter. When multiple delimiters are specified, they will be looked for in the source string in the sequence in which they are coded.
  10. Two consecutive delimiter sequences will identify a null sub string.
  11. Identified sub strings will be moved into each destination field in the sequence they are identified; values moved into a destination field will be truncated if the sub string length exceeds the destination field length, or padded with spaces if the destination field length exceeds the sub string length. Both truncation and padding will be controlled by the presence or absence of a JUSTIFIED (see JUSTIFIED) clause on the destination field.
  12. Each destination field may have an optional DELIMITER clause. If a DELIMITER clause is specified, identifier-5 will have the delimiter character string used to identify the sub string for the destination field moved into it. If a destination field was not altered (because an insufficient number of sub strings were identified), identifier-5 for that destination field will also be unchanged.
  13. Each destination field may have an optional COUNT clause. If a COUNT clause is specified, identifier-6 will have the size of the sub string (in characters) for the destination field moved into it. If a destination field was not altered (because an insufficient number of sub strings were identified), identifier-6 for that destination field will also be unchanged.
  14. If a TALLYING clause is coded, identifier-8 will be incremented by 1 each time a destination field is populated.
  15. None of identifier-4, identifier-5, identifier-6, identifier-7 or identifier-8 are initialized by the UNSTRING statement. You need to do that yourself via a MOVE (see MOVE) or INITIALIZE statement (see INITIALIZE).
  16. UNSTRING processing will cease when one of the following occurs:
    1. The initial value of the current character pointer is less than 1 or greater than the number of character positions in identifier-1, or…
    2. All destination fields have been fully processed
  17. If event A occurs, none of the destination field contents (or the contents of their DELIMITER or COUNT identifiers) will be changed.
  18. An overflow condition exists if either event A occurs, or if event B occurs with at least one character position in identifier-1 not having been processed.
  19. The optional ON OVERFLOW and NOT ON OVERFLOW clauses may be used to detect and react to the occurrence or not, respectively, of an overflow condition. See ON OVERFLOW + NOT ON OVERFLOW, for additional information.

The following sample program illustrates the UNSTRING statement statement.

IDENTIFICATION DIVISION.
PROGRAM-ID. DEMOUNSTRING.
DATA DIVISION.
WORKING-STORAGE SECTION.
01  Full-Name                   PIC X(40).
01  Parsed-Info.
    05 Last-Name                PIC X(15).
    05 First-Name               PIC X(15).
    05 MI                       PIC X(1).
    05 Delim-LN                 PIC X(1).
    05 Delim-FN                 PIC X(1).
    05 Delim-MI                 PIC X(1).
    05 Count-LN                 BINARY-CHAR.
    05 Count-FN                 BINARY-CHAR.
    05 Count-MI                 BINARY-CHAR.
    05 Tallying-Ctr             BINARY-CHAR.
PROCEDURE DIVISION.
P1. PERFORM UNTIL EXIT
      DISPLAY "Enter Full Name (null quits):"
          WITH NO ADVANCING
      ACCEPT Full-Name
      IF Full-Name = SPACES
        EXIT PERFORM
      END-IF
      INITIALIZE Parsed-Info
      UNSTRING Full-Name
        DELIMITED BY ", "
                  OR ","
                  OR ALL SPACES
        INTO Last-Name
                 DELIMITER IN Delim-LN
                 COUNT IN Count-LN
             First-Name
                 DELIMITER IN Delim-FN
                 COUNT IN Count-FN
             MI
                 DELIMITER IN Delim-MI
                 COUNT IN Count-MI
        TALLYING Tallying-Ctr
    DISPLAY "First-Name=" First-Name
            " Delim='"    Delim-FN
            "' Count="    Count-FN
    DISPLAY "MI        =" MI "              "
            " Delim='"    Delim-MI
            "' Count="    Count-MI
    DISPLAY "Last-Name =" Last-Name
            " Delim='"    Delim-LN
            "' Count="    Count-LN
    DISPLAY "Tally=     " Tallying-Ctr
  END-PERFORM
  DISPLAY "Bye!"
  STOP RUN   .

The following is sample output from the program:

Enter Full Name (null quits):Cutler, Gary L
First-Name=Gary            Delim=' ' Count=+004
MI        =L               Delim=' ' Count=+001
Last-Name =Cutler          Delim=',' Count=+006
Tally=     +003
Enter Full Name (null quits):Snoddgrass,Throckmorton,P
First-Name=Throckmorton    Delim=',' Count=+012
MI        =P               Delim=' ' Count=+001
Last-Name =Snoddgrass      Delim=',' Count=+010
Tally=     +003
Enter Full Name (null quits):Munster   Herman
First-Name=Herman          Delim=' ' Count=+006
MI        =                Delim=' ' Count=+000
Last-Name =Munster         Delim=' ' Count=+007
Tally=     +002
Enter Full Name (null quits):
Bye!


7.8.50. WRITE

WRITE Syntax
=======================================================================

   WRITE record-name-1
   ~~~~~
      [ FROM { literal-1    } ]
        ~~~~ { identifier-1 }

      [ WITH [ NO ] LOCK ]
               ~~   ~~~~
      [ { BEFORE } ADVANCING { { literal-2    } LINE|LINES } ]
        { ~~~~~~ }           { { identifier-2              }
        { AFTER  }           { PAGE                        }
          ~~~~~              { ~~~~                        }
                             { mnemonic-name-1             }

      [ AT END-OF-PAGE|EOP imperative-statement-1 ]
           ~~~~~~~~~~~ ~~~
      [ NOT AT END-OF-PAGE|EOP imperative-statement-2 ]
        ~~~    ~~~~~~~~~~~ ~~~
      [ INVALID KEY imperative-statement-3 ]
        ~~~~~~~
      [ NOT INVALID KEY imperative-statement-4 ]
        ~~~ ~~~~~~~
 [ END-WRITE ]
   ~~~~~~~~~

=======================================================================

The WRITE statement writes a new record to an open file.

  1. The reserved words ADVANCING, AT, KEY, LINE, LINES and WITH are optional and may be omitted. The presence or absence of these words has no effect upon the program.
  2. The reserved words END-OF-PAGE and EOP are interchangeable.
  3. The record-name-1 specified on the statement must be defined as an 01-level record subordinate to the File Description (FD (see File/Sort-Description)) of a file that is currently open for OUTPUT (see File OPEN Modes), EXTEND or I-O.
  4. The optional FROM clause will cause literal-1 or identifier-1 to be automatically moved into record-name-1 prior to writing record-name-1’s contents to the appropriate file. If this clause is not specified, it is the programmer’s responsibility to populate record-name-1 with the desired data prior to executing the WRITE.
  5. The optional LOCK options may be used to manually control access to the just-written record by other programs while this program is running. See Record Locking, to review the various record locking behaviour.
  6. The optional INVALID KEY and NOT INVALID KEY clauses may be used when writing to relative or indexed files to detect and react to the failure (non-zero file status code) or success (00 file status code), respectively, of the statement. See File Status Codes, for additional information.
  7. When WRITE is used against an ORGANIZATION LINE SEQUENTIAL (see ORGANIZATION LINE SEQUENTIAL) file, with or without the LINE ADVANCING (see LINE ADVANCING) option, an end-of-record delimiter character sequence will be written to the file to signify where one record ends and the next record begins. This delimiter sequence will be either of the following:
  8. The following points pertain to the use (or not) of the ADVANCING clause:
    1. Using this clause with any organization other than ORGANIZATION LINE SEQUENTIAL will either be rejected outright by the compiler (relative or indexed files) or may introduce unwanted characters into the file (ORGANIZATION SEQUENTIAL (see ORGANIZATION SEQUENTIAL)).
    2. If no ADVANCING clause is specified on a WRITE to a line-advancing file, AFTER ADVANCING 1 LINE will be assumed; on other than line-advancing files, BEFORE ADVANCING 1 LINE will be assumed.
    3. When BEFORE ADVANCING is used (or implied), the record is written to the file before the ADVANCING action writes line-terminator characters to the file.
    4. If AFTER ADVANCING is used (or implied), the ADVANCING action writes line-terminator characters to the file and then the record data is written to the file.
    5. The ADVANCING n LINES clause will introduce the specified number of line-terminator character sequences into the file either before the written record (AFTER ADVANCING) or after the written record (BEFORE ADVANCING).
    6. If the LINAGE (see File/Sort-Description) clause is absent from the file’s FD:
      1. The ADVANCING PAGE clause will introduce an ASCII formfeed character into the file either before the written record (AFTER PAGE) or after the written record (BEFORE PAGE).
      2. Management of areas on the printed page such as top-of page headers, bottom-of-page footers, dealing with “full page” situations and the like are the complete responsibility of the programmer.
    7. If the LINAGE clause is present in the file’s FD:
      1. The ADVANCING PAGE clause will introduce the appropriate number of line-terminator character sequences into the file either before the written record (AFTER ADVANCING) or after the written record (BEFORE ADVANCING) so as to force the printer to automatically advance to a new sheet of paper when the file prints. No formfeed characters will be generated when LINAGE is specified — instead, it is assumed that the printer to which the report will be printed will be loaded with special forms that conform to the specifications defined by the LINAGE clause.
      2. Management of areas on the printed page such as top-of page headers, bottom-of-page footers, dealing with “full page” situations and the like are now the joint responsibility of the programmer and the GnuCOBOL run-time library, which provides tools such as the LINAGE-COUNTER special register (see Special Registers) and the END-OF-PAGE clause to deal with page formatting issues.
      3. The AT END-OF-PAGE clause will be triggered, thus executing imperative-statement-1 (see Imperative Statement), if the WRITE statement introduces a data line or line-feed character into the file at a line position within the Page Footer area defined by the LINAGE clause. The NOT AT END-OF-PAGE clause will be triggered (thus executing imperative-statement-2) if no end-of-page condition occurred during the WRITE.


8. Functions



8.1. Intrinsic Functions

GnuCOBOL supports a wide variety of “intrinsic functions” that may be used anywhere in the PROCEDURE DIVISION where a literal is allowed. For example:

MOVE FUNCTION LENGTH(Employee-Last-Name) TO Employee-LN-Len

Note how the word FUNCTION is part of the syntax when you use an intrinsic function. You can use intrinsic functions without having to include the reserved word FUNCTION via settings in the REPOSITORY (see REPOSITORY) paragraph. You may accomplish the same thing by specifying the -fintrinsics switch to the GnuCOBOL compiler when you compile your programs.

User-written functions (see Subprogram Types) never require the FUNCTION keyword when they are executed, because each user-written function a program uses must be included in that program’s REPOSITORY paragraph, which therefore makes the FUNCTION keyword optional.

The following intrinsic functions, known to other “dialects” of COBOL, are defined to GnuCOBOL as reserved words but are not otherwise implemented currently. Any attempts to use these functions will result in a compile-time error message. However they are described at the end of this chapter.

BOOLEAN-OF-INTEGER
CHAR-NATIONAL
DISPLAY-OF
EXCEPTION-FILE-N
EXCEPTION-LOCATION-N
INTEGER-OF-BOOLEAN
NATIONAL-OF
STANDARD-COMPARE

The supported intrinsic functions are listed in the following sections, along with their syntax and usage notes.



8.1.1. ABS

ABS Function Syntax
=======================================================================

 ABS(number)
 ~~~

=======================================================================

This function determines and returns the absolute value of number (a numeric literal or data item) supplied as an argument.

Note that ABSOLUTE-VALUE has an alias for this function.



8.1.2. ACOS

ACOS Function Syntax
=======================================================================

 ACOS(cosine)
 ~~~~

=======================================================================

The ACOS function determines and returns the trigonometric arc-cosine, or inverse cosine, of cosine value (a numeric literal or data item) supplied as an argument.

The result will be an angle, expressed in radians. You may convert this to an angle measured in degrees, as follows:

COMPUTE degrees = ( radians * 180 ) / FUNCTION PI


8.1.3. ANNUITY

ANNUITY Function Syntax
=======================================================================

 ANNUITY(interest-rate, number-of-periods)
 ~~~~~~~

=======================================================================

This function returns a numeric value approximating the ratio of an annuity paid at interest-rate (numeric data item or literal) for each of number-of-periods (numeric data items or literals).

interest-rate is the rate of interest paid at each payment. If you only have an annual interest rate and you wish to compute monthly annuity payments, divide the annual interest rate by 12 and use that value for interest-rate.

Multiply the result of this function times the desired principal amount to determine the amount of each period’s payment.

A note for the financially challenged: an annuity is basically a reverse loan; an accountant would take the result of this function multiplied by -1 times the principal amount to compute a loan payment you are making.



8.1.4. ASIN

ASIN Function Syntax
=======================================================================

 ASIN(sine)
 ~~~~

=======================================================================

The ASIN function determines and returns the trigonometric arc-sine, or inverse sine, of sine value (a numeric literal or data item) supplied as an argument.

The result will be an angle, expressed in radians. You may convert this to an angle measured in degrees, as follows:

COMPUTE degrees = ( radians * 180 ) / FUNCTION PI


8.1.5. ATAN

ATAN Function Syntax
=======================================================================

 ATAN(tangent)
 ~~~~

=======================================================================

Use this function to determine and return the trigonometric arc-tangent, or inverse tangent, of tangent value (a numeric literal or data item) supplied as an argument.

The result will be an angle, expressed in radians. You may convert this to an angle measured in degrees, as follows:

COMPUTE degrees = ( radians * 180 ) / FUNCTION PI


8.1.6. BYTE-LENGTH

BYTE-LENGTH Function Syntax
=======================================================================

 BYTE-LENGTH(string)
 ~~~~~~~~~~~

=======================================================================

BYTE-LENGTH returns the length — in bytes — of string (a group item, USAGE DISPLAY elementary item or alphanumeric literal). This intrinsic function is identical to the LENGTH-AN (see LENGTH-AN) function. Note that the value returned by this function is not necessarily the number of characters comprising string, but rather the number of actual bytes required to store it.

For example, if string is encoded using a double-byte character set such as Unicode UTF-16 (where each character is represented by 16 bits of storage, not the 8-bits inherent to character sets like ASCII or EBCDIC), then calling this function with a string argument whose PICTURE (see PICTURE) is X(4) would return a value of 8 rather than the value 4.

Contrast this with the LENGTH (see LENGTH) function.



8.1.7. CHAR

CHAR Function Syntax
=======================================================================

 CHAR(integer)
 ~~~~

=======================================================================

This function returns the character in the ordinal position specified by integer (a numeric integer literal or data item with a value of 1 or greater) from the COLLATING SEQUENCE (see OBJECT-COMPUTER) being used by the program.

For example, if the program is using the (default) ASCII character set, CHAR(34) returns the 34th character in the ASCII character set — an exclamation-point (‘!’). If you are using this function to convert a numeric value to its corresponding ASCII character, you must use an argument value one greater than the numeric value.

If an argument whose value is less than 1 or greater than 256 is specified, the character in the program collating sequence corresponding to a value of all zero bits is returned.

The following code is an alternative approach when you just wish to convert a number to its ASCII equivalent:

01  Char-Value.
    05 Numeric-Value        USAGE BINARY-CHAR.
…
    MOVE numeric-character-value TO Numeric-Value

The Char-Value item now has the corresponding ASCII character value.



8.1.8. COMBINED-DATETIME

COMBINED-DATETIME Function Syntax
=======================================================================

 COMBINED-DATETIME(days, seconds)
 ~~~~~~~~~~~~~~~~~

=======================================================================

This function returns a 12-digit numeric result, the first seven digits of which are the integer value of days argument (a numeric data item or literal) and the last five of which are the integer value of seconds argument (also a numeric data item or literal).

If days is less than 1 or greater than 3,067,671, or if seconds is less than 1 or greater than 86,400, a value of 0 is returned and a runtime error will result.



8.1.9. CONCATENATE

CONCATENATE Function Syntax
=======================================================================

 CONCATENATE(string-1 [, string-2 ]...)
 ~~~~~~~~~~~

=======================================================================

This function concatenates the string-1, string-2, … (group items, USAGE DISPLAY elementary items and/or alphanumeric literals) together into a single string result.

If a numeric literal or PIC 9 identifier is specified as an argument, decimal points, if any, will be removed and negative signs in PIC S9 fields or numeric literals will be inserted as defined by the SIGN IS (see SIGN IS) clause (or absence thereof) of the field. Numeric literals are processed as if SIGN IS TRAILING SEPARATE were in effect.



8.1.10. COS

COS Function Syntax
=======================================================================

 COS(angle)
 ~~~

=======================================================================

The COS function determines and returns the trigonometric cosine of angle (a numeric literal or data item) supplied as an argument.

angle is assumed to be a value expressed in radians. If you need to determine the cosine of an angle measured in degrees, you first need to convert that angle to radians as follows:

COMPUTE radians = ( degrees * FUNCTION PI) / 180


8.1.11. CURRENCY-SYMBOL

CURRENCY-SYMBOL Function Syntax
=======================================================================

 CURRENCY-SYMBOL
 ~~~~~~~~~~~~~~~

=======================================================================

The CURRENCY-SYMBOL function returns the currency symbol character currently in effect for the locale under which your program is running. On UNIX systems, your locale is established via the LANG run-time environment variable (see Run Time Environment Variables) environment variable. On Windows, the Control Panel’s "Regional and Language Options" define the locale.

Changing the currency symbol via the SPECIAL-NAMES (see SPECIAL-NAMES) paragraph’s CURRENCY SYMBOL setting will not affect the value returned by this function.



8.1.12. CURRENT-DATE

CURRENT-DATE Function Syntax
=======================================================================

 CURRENT-DATE
 ~~~~~~~~~~~~

=======================================================================

Returns the current date and time as the following 21-character structure:

01  CURRENT-DATE-AND-TIME.
    05 CDT-Year                PIC 9(4).
    05 CDT-Month               PIC 9(2). *> 01-12
    05 CDT-Day                 PIC 9(2). *> 01-31
    05 CDT-Hour                PIC 9(2). *> 00-23
    05 CDT-Minutes             PIC 9(2). *> 00-59
    05 CDT-Seconds             PIC 9(2). *> 00-59
    05 CDT-Hundredths-Of-Secs  PIC 9(2). *> 00-99
    05 CDT-GMT-Diff-Hours      PIC S9(2)
                               SIGN LEADING SEPARATE.
    05 CDT-GMT-Diff-Minutes    PIC 9(2). *> 00 or 30

Since this function has no arguments, no parenthesis should be specified.



8.1.13. DATE-OF-INTEGER

DATE-OF-INTEGER Function Syntax
=======================================================================

 DATE-OF-INTEGER(integer)
 ~~~~~~~~~~~~~~~

=======================================================================

This function returns a numeric calendar date in yyyymmdd (i.e. Gregorian) format. The date is determined by adding the number of days specified as integer (a numeric integer data item or literal) to the date December 31, 1600. For example, DATE-OF-INTEGER(1) returns 16010101 while DATE-OF-INTEGER(150000) returns 20110908.

A value less than 1 or greater than 3067671 (9999/12/31) will return a result of 0.



8.1.14. DATE-TO-YYYYMMDD

DATE-TO-YYYYMMDD Function Syntax
=======================================================================

 DATE-TO-YYYYMMDD(yymmdd [, yy-cutoff [, yy-execution-time ]])
 ~~~~~~~~~~~~~~~~

=======================================================================

You can use this function to convert the six-digit Gregorian date specified as yymmdd (a numeric integer data item or literal) to an eight-digit format (yyyymmdd).

The optional yy-cutoff (a numeric integer data item or literal) argument is the year cutoff used to delineate centuries; if the year component of the date meets or exceeds this cutoff value, the result will be 19yymmdd; if the year component of the date is less than the cutoff value, the result will be 20yymmdd. The default cutoff value if no second argument is given will be 50.

The optional yy-execution-time argument (a numeric integer data item or literal) The default execution time value if no third argument is given will be now equivalent to specifying (FUNCTION NUMVAL (FUNCTION CURRENT-DATE (1:4))).



8.1.15. DAY-OF-INTEGER

DAY-OF-INTEGER Function Syntax
=======================================================================

 DAY-OF-INTEGER(integer)
 ~~~~~~~~~~~~~~

=======================================================================

This function returns a calendar date in yyyyddd (i.e. Julian) format. The date is determined by adding the number of days specified as integer (a numeric integer data item or literal) to December 31, 1600. For example, DAY-OF-INTEGER(1) returns 1601001 while DAY-OF-INTEGER(250000) returns 2011251.

A value less than 1 or greater than 3067671 (9999/12/31) will return a result of 0.



8.1.16. DAY-TO-YYYYDDD

DAY-TO-YYYYDDD Function Syntax
=======================================================================

 DAY-TO-YYYYDDD(yyddd [, yy-cutoff [, yy-execution-time ]])
 ~~~~~~~~~~~~~~

=======================================================================

You can use this function to convert the five-digit Julian date specified as yyddd (a numeric integer data item or literal) to a seven-digit numeric Julian format (yyyyddd).

The optional yy-cutoff argument (a numeric integer data item or literal) is the year cutoff used to delineate centuries; if the year component of the date meets or exceeds this cutoff value, the result will be 19yyddd; if the year component of the date is less than the cutoff, the result will be 20yyddd. The default cutoff value if no second argument is given will be 50.

The optional yy-execution-time argument (a numeric integer data item or literal) The default execution time value if no third argument is given will be now equivalent to specifying (FUNCTION NUMVAL (FUNCTION CURRENT-DATE (1:4))).



8.1.17. E

E Function Syntax
=======================================================================

 E
 ~

=======================================================================

This function returns the mathematical constant E (the base of natural logarithms). The maximum precision with which this value may be returned is 2.7182818284590452353602874713526625.

Since this function has no arguments, no parenthesis should be specified.



8.1.18. EXCEPTION-FILE

EXCEPTION-FILE Function Syntax
=======================================================================

 EXCEPTION-FILE
 ~~~~~~~~~~~~~~

=======================================================================

This function returns I/O exception information from the most-recently executed input or output statement. The information is returned as a 34-character string, where the first two characters are the two-digit file status value (see File Status Codes) and the remaining 32 are the file-name-1 specification from the file’s SELECT (see SELECT) statement.

The name returned after the file status information will be returned only if the returned file status value is not 00.

Since this function has no arguments, no parenthesis should be specified.

The documentation of the CBL_ERROR_PROC built-in system subroutine (see CBL_ERROR_PROC) built-in subroutine illustrates the use of this function.



8.1.19. EXCEPTION-LOCATION

EXCEPTION-LOCATION Function Syntax
=======================================================================

 EXCEPTION-LOCATION
 ~~~~~~~~~~~~~~~~~~

=======================================================================

This function returns exception information from the most-recently failing statement. The information is returned to a 1023 character string in one of the following formats, depending on the nature of the failure:

Since this function has no arguments, no parenthesis should be specified.

The program must be compiled with the -debug switch, -ftraceall switch or -g switch for this function to return any meaningful information.

The documentation of the CBL_ERROR_PROC built-in system subroutine (see CBL_ERROR_PROC) built-in subroutine illustrates the use of this function.



8.1.20. EXCEPTION-STATEMENT

EXCEPTION-STATEMENT Function Syntax
=======================================================================

 EXCEPTION-STATEMENT
 ~~~~~~~~~~~~~~~~~~~

=======================================================================

This function returns the most-recent COBOL statement that generated an exception condition.

Since this function has no arguments, no parenthesis should be specified.

The program must be compiled with the -debug switch, -ftraceall switch or -g switch for this function to return any meaningful information.

The documentation of the CBL_ERROR_PROC built-in system subroutine (see CBL_ERROR_PROC) built-in subroutine illustrates the use of this function.



8.1.21. EXCEPTION-STATUS

EXCEPTION-STATUS Function Syntax
=======================================================================

 EXCEPTION-STATUS
 ~~~~~~~~~~~~~~~~

=======================================================================

This function returns the error type (a text string — see column 2 of the upcoming table for the possible values) from the most-recent COBOL statement that generated an exception condition.

Since this function has no arguments, no parenthesis should be specified.

The documentation of the CBL_ERROR_PROC built-in system subroutine (see CBL_ERROR_PROC) built-in subroutine illustrates the use of this function.

The following are the error type strings, and their corresponding exception codes and descriptions.

CodeError TypeDescription
0101EC-ARGUMENT-FUNCTIONFunction argument error
0202EC-BOUND-ODOOCCURS … DEPENDING ON data item out of bounds
0204EC-BOUND-PTRData-pointer contains an address that is out of bounds
0205EC-BOUND-REF-MODReference modifier out of bounds
0207EC-BOUND-SUBSCRIPTSubscript out of bounds
0303EC-DATA-INCOMPATIBLEIncompatible data exception
0500EC-I-Oinput-output exception
0501EC-I-O-AT-ENDI-O status 1x
0502EC-I-O-EOPAn end of page condition occurred
0504EC-I-O-FILE-SHARINGI-O status 6x
0505EC-I-O-IMPI-O status 9x
0506EC-I-O-INVALID-KEYI-O status 2x
0508EC-I-O-LOGIC-ERRORI-O status 4x
0509EC-I-O-PERMANENT-ERRORI-O status 3x
050AEC-I-O-RECORD-OPERATIONI-O status 5x
0601EC-IMP-ACCEPTImplementation-defined accept condition
0602EC-IMP-DISPLAYImplementation-defined display condition
0A00EC-OVERFLOWOverflow condition
0A02EC-OVERFLOW-STRINGSTRING overflow condition
0A03EC-OVERFLOW-UNSTRINGUNSTRING overflow condition
0B05EC-PROGRAM-NOT-FOUNDCalled program not found
0D03EC-RANGE-INSPECT-SIZESize of replace item in inspect differs
1000EC-SIZESize error exception
1004EC-SIZE-OVERFLOWArithmetic overflow in calculation
1005EC-SIZE-TRUNCATIONSignificant digits truncated in store
1007EC-SIZE-ZERO-DIVIDEDivision by zero
1202EC-STORAGE-NOT-ALLOCThe data-pointer specified in a FREE statement does not identify currently allocated storage
1203EC-STORAGE-NOT-AVAILThe amount of storage requested by an
ALLOCATE statement is not available


8.1.22. EXP

EXP Function Syntax
=======================================================================

 EXP(number)
 ~~~

=======================================================================

Computes and returns the value of the mathematical constant e raised to the power specified by number (a numeric literal or data item).



8.1.23. EXP10

EXP10 Function Syntax
=======================================================================

 EXP10(number)
 ~~~~~

=======================================================================

Computes and returns the value of 10 raised to the power specified by number (a numeric literal or data item).



8.1.24. FACTORIAL

FACTORIAL Function Syntax
=======================================================================

 FACTORIAL(number)
 ~~~~~~~~~

=======================================================================

This function computes and returns the factorial value of number (a numeric literal or data item).



8.1.25. FORMATTED-CURRENT-DATE

FORMATTED-CURRENT-DATE Function Syntax
=======================================================================

 FORMATTED-CURRENT-DATE ( argument-1 )
 ~~~~~~~~~~~~~~~~~~~~~~

=======================================================================

FORMATTED-CURRENT-DATE returns the current date and time provided by the system at run-time, formatted according to date-and-time-format according to the argument type.

The function argument must be a national or alphanumeric literal and the content, a combined date and time format.

The returned value is formatted to the same form as argument-1.



8.1.26. FORMATTED-DATE

FORMATTED-DATE Function Syntax
=======================================================================

 FORMATTED-DATE ( argument-1, argument-2 )
 ~~~~~~~~~~~~~~

=======================================================================

FORMATTED-DATE uses a format to convert a date in integer date form to a date in the requested format. The returned value will be in date format.

argument-1 shall be a national or alphanumeric literal.

argument-2 shall be a value in integer date form.



8.1.27. FORMATTED-DATETIME

FORMATTED-DATETIME Function Syntax
=======================================================================

 FORMATTED-DATETIME ( argument-1, argument-2, argument-3, argument-4 )
 ~~~~~~~~~~~~~~~~~~

=======================================================================

FORMATTED-DATETIME uses a combined time and date form to convert and combine a date in integer form and a numeric time expressed as seconds past midnight in UTC.

argument-1 shall be a national or alphanumeric literal.

argument-2 shall be a value in integer date form.

argument-3 shall be a value in standard numeric time form.

argument-4 is an integer specifying the offset from UTC expressed in minutes. If specified but have a value equal or less than 1439.

Note: The offset value 1439 represents 23 hours 59 minutes which is one minutes less than a day.

argument-4 must not be specified if the time portion in argument-1 is neither a UTC nor an offset format.

The returned value is a representation of the date contained in argument-2 combined with the time contained in argument-3 according to the format in argument-1.

If the format in argument-1 indicates that the returned value is to be expressed in UTC, the time portion of the returned value reflects the adjustment of the value in argument-3 by the offset in argument-4.

If the format in argument-1 indicates that the time is to be returned as an offset from UTC, the value in argument-3 is reflected directly in the time portion of the returned value and the offset in argument-4 is reflected directly in the offset portion of the returned value.



8.1.28. FORMATTED-TIME

FORMATTED-TIME Function Syntax
=======================================================================

 FORMATTED-TIME ( argument-1, argument-2, argument-3 )
 ~~~~~~~~~~~~~~

=======================================================================

FORMATTED-TIME converts a value representing seconds past midnight formatted time of day with optional offset.

argument-1 shall be a national or alphanumeric literal.

argument-2 shall be a value in integer time form.

argument-3 is an integer specifying the offset from UTC expressed in minutes. If specified but have a value equal or less than 1439.

Note: The offset value 1439 represents 23 hours 59 minutes which is one minutes less than a day.

argument-3 must not be specified if the time portion in argument-1 is neither a UTC nor an offset format.

Returned value :

Is a representation of the standard numeric time contained in argument-2 according to the format in argument-1.

If the format in argument-1 indicates that the returned value is to be expressed in UTC, the time portion of the returned value reflects the adjustment of the value in argument-2 by the offset in argument-3.

If the format in argument-1 indicates that the time is to be returned as an offset from UTC, the value in argument-2 is reflected directly in the time portion of the returned value and the offset in argument-3 is reflected directly in the offset portion of the returned value.



8.1.29. FRACTION-PART

FRACTION-PART Function Syntax
=======================================================================

 FRACTION-PART(number)
 ~~~~~~~~~~~~~

=======================================================================

This function returns that portion of number (a numeric data item or a numeric literal) that occurs to the right of the decimal point. FRACTION-PART(3.1415), for example, returns a value of 0.1415. This function is equivalent to the expression:

number -- FUNCTION INTEGER-PART(number)


8.1.30. HIGHEST-ALGEBRAIC

HIGHEST-ALGEBRAIC Function Syntax
=======================================================================

 HIGHEST-ALGEBRAIC(numeric-identifier)
 ~~~~~~~~~~~~~~~~~

=======================================================================

This function returns the highest (i.e. largest or farthest away from 0 in a positive direction if numeric-identifier is signed) value that could possibly be stored in numeric-identifier.



8.1.31. INTEGER

INTEGER Function Syntax
=======================================================================

 INTEGER(number)
 ~~~~~~~

=======================================================================

The INTEGER function returns the greatest integer value that is less than or equal to number (a numeric literal or data item).



8.1.32. INTEGER-OF-DATE

INTEGER-OF-DATE Function Syntax
=======================================================================

 INTEGER-OF-DATE(date)
 ~~~~~~~~~~~~~~~

=======================================================================

This function converts date (a numeric integer data item or literal) — presumed to be a Gregorian calendar form standard date (YYYYMMDD) — to internal date form (the number of days that have transpired since 1600/12/31).

Once in that form, mathematical operations may be performed against the internal date before it is transformed back into a date using the DATE-OF-INTEGER (see DATE-OF-INTEGER) or DAY-OF-INTEGER (see DAY-OF-INTEGER) function.



8.1.33. INTEGER-OF-DAY

INTEGER-OF-DAY Function Syntax
=======================================================================

 INTEGER-OF-DAY(date)
 ~~~~~~~~~~~~~~

=======================================================================

This function converts date (a numeric integer data item or literal) — presumed to be a Julian calendar form standard date (YYYYDDD) — to internal date form (the number of days that have transpired since 1600/12/31).

Once in that form, mathematical operations may be performed against the internal date before it is transformed back into a date using the DATE-OF-INTEGER (see DATE-OF-INTEGER) or DAY-OF-INTEGER (see DAY-OF-INTEGER) function.



8.1.34. INTEGER-OF-FORMATTED-DATE

INTEGER-OF-FORMATTED-DATE Function Syntax
=======================================================================

 INTEGER-OF-FORMATTED-DATE ( argument-1, argument-2 )
 ~~~~~~~~~~~~~~~~~~~~~~~~~

=======================================================================

INTEGER-OF-FORMATTED-DATE converts a date that is in specified format to integer date form.

argument-1 shall be a national or alphanumeric literal. The content must be either a date format or a combined date and time format.

argument-2 shall be a data item of the same type as argument-1.

If argument-1 is a date format the content of argument-2 shall be a valid date in that format.

If argument-1 is a combined date and time format, the content of argument-2 shall be a valid combined date and time in same format.



8.1.35. INTEGER-PART

INTEGER-PART Function Syntax
=======================================================================

 INTEGER-PART(number)
 ~~~~~~~~~~~~

=======================================================================

Returns the integer portion of number (a numeric literal or data item).



8.1.36. LENGTH

LENGTH Function Syntax
=======================================================================

 LENGTH(string)
 ~~~~~~

=======================================================================

Returns the length — in characters — of string (a group item, USAGE DISPLAY elementary item or alphanumeric literal).

The value returned by this function is not the number of bytes of storage occupied by string, but rather the number of actual characters making up the string. For example, if string is encoded using a double-byte character set such as Unicode UTF-16 (where each character is represented by 16 bits of storage, not the 8-bits inherent to character sets like ASCII or EBCDIC), then calling this function with a string argument whose PICTURE is X(4) would return a value of 4 rather than the value 8 (the actual number of bytes of storage occupied by that item).

Contrast this function with the BYTE-LENGTH (see BYTE-LENGTH) and LENGTH-AN (see LENGTH-AN) functions.



8.1.37. LENGTH-AN

LENGTH-AN Function Syntax
=======================================================================

 LENGTH-AN(string)
 ~~~~~~~~~

=======================================================================

This function returns the length — in bytes of storage — of string (a group item, USAGE DISPLAY elementary item or alphanumeric literal).

This intrinsic function is identical to the BYTE-LENGTH (see BYTE-LENGTH) function.

Note that the value returned by this function is not the number of characters making up the string, but rather the number of actual bytes of storage required to store string. For example, if string is encoded using a double-byte character set such as Unicode UTF-16 (where each character is represented by 16 bits of storage, not the 8-bits inherent to character sets like ASCII or EBCDIC), then calling this function with a string argument whose PICTURE is X(4) would return a value of 8 rather than the value 4.

Contrast this with the LENGTH (see LENGTH) function.



8.1.38. LOCALE-COMPARE

LOCALE-COMPARE Function Syntax
=======================================================================

 LOCALE-COMPARE(argument-1, argument-2 [ , locale ])
 ~~~~~~~~~~~~~~

=======================================================================

The LOCALE-COMPARE function returns a character indicating the result of comparing argument-1 and argument-2 using a culturally-preferred ordering defined by a locale.

Either or both of the 1st two arguments may be an alphanumeric literal, a group item or an elementary item appropriate to storing alphabetic or alphanumeric data. If the lengths of the two arguments are unequal, the shorter will be assumed to be padded to the right with spaces.

The two arguments will be compared, character by character, against each other until their relationship to each other can be determined. The comparison is made according to the cultural rules in effect for locale name or for the current locale if no locale argument is specified. Once that relationship is determined, a one-character alphanumeric value will be returned as follows:

See LOCALE Names, for a list of typically-available locale names.



8.1.39. LOCALE-DATE

LOCALE-DATE Function Syntax
=======================================================================

 LOCALE-DATE(date [, locale ])
 ~~~~~~~~~~~

=======================================================================

Converts the eight-digit Gregorian date (a numeric integer data item or literal) from yyyymmdd format to the format appropriate to the current locale. On a Windows system, this will be the “short date” format as set using Control Panel.

You may include an optional second argument to specify the locale name (group item or PIC X identifier) you’d like to use for date formatting. If used, this second argument must be an identifier. Locale names are specified using UNIX-standard names.



8.1.40. LOCALE-TIME

LOCALE-TIME Function Syntax
=======================================================================

 LOCALE-TIME(time [, locale ])
 ~~~~~~~~~~~

=======================================================================

Converts the four- (hhmm) or six-digit (hhmmss) time (a numeric integer data item or literal) to a format appropriate to the current locale. On a Windows system, this will be the “time” format as set using Control Panel.

You may include an optional locale name (a group item or PIC X identifier) you’d like to use for time formatting. If used, this second argument must be an identifier. Locale names are specified using UNIX-standard names.



8.1.41. LOCALE-TIME-FROM-SECONDS

LOCALE-TIME-FROM-SECONDS Function Syntax
=======================================================================

 LOCALE-TIME-FROM-SECONDS(seconds [, locale ])
 ~~~~~~~~~~~~~~~~~~~~~~~~

=======================================================================

Converts the number of seconds since midnight (a numeric integer data item or literal) to a format appropriate to the current locale. On a Windows system, this will be the “time” format as set using Control Panel.

You may include an optional locale name (a group item or PIC X identifier) you’d like to use for time formatting. If used, this second argument must be an identifier. Locale names are specified using UNIX-standard names.

See LOCALE Names, for a list of typically-available locale names.



8.1.42. LOG

LOG Function Syntax
=======================================================================

 LOG(number)
 ~~~

=======================================================================

Computes and returns the natural logarithm (base e) of number (a numeric literal or data item).



8.1.43. LOG10

LOG10 Function Syntax
=======================================================================

 LOG10(number)
 ~~~~~

=======================================================================

Computes and returns the base 10 logarithm of number (a numeric literal or data item).



8.1.44. LOWER-CASE

LOWER-CASE Function Syntax
=======================================================================

 LOWER-CASE(string)
 ~~~~~~~~~~

=======================================================================

This function returns the value of string (a group item, USAGE DISPLAY elementary item or alphanumeric literal), converted entirely to lower case.

What constitutes a “letter” (or upper/lower case too, for that manner) may be influenced through the use of a CHARACTER CLASSIFICATION (see OBJECT-COMPUTER).



8.1.45. LOWEST-ALGEBRAIC

LOWEST-ALGEBRAIC Function Syntax
=======================================================================

 LOWEST-ALGEBRAIC(numeric-identifier)
 ~~~~~~~~~~~~~~~~

=======================================================================

This function returns the lowest (i.e. smallest or farthest away from 0 in a negative direction if numeric-identifier is signed) value that could possibly be stored in numeric-identifier.



8.1.46. MAX

MAX Function Syntax
=======================================================================

 MAX(number-1 [, number-2 ]...)
 ~~~

=======================================================================

This function returns the maximum value from the specified list of numbers (each number-n may be a numeric data item or a numeric literal).



8.1.47. MEAN

MEAN Function Syntax
=======================================================================

 MEAN(number-1 [, number-2 ]...)
 ~~~~

=======================================================================

This function returns the statistical mean value of the specified list of numbers (each number-n may be a numeric data item or a numeric literal).



8.1.48. MEDIAN

MEDIAN Function Syntax
=======================================================================

 MEDIAN(number-1 [, number-2 ]...)
 ~~~~~~

=======================================================================

This function returns the statistical median value of the specified list of numbers (each number-n may be a numeric data item or a numeric literal).



8.1.49. MIDRANGE

MIDRANGE Function Syntax
=======================================================================

 MIDRANGE(number-1 [, number-2 ]...)
 ~~~~~~~~

=======================================================================

The MIDRANGE (middle range) function returns a numeric value that is the arithmetic mean (average) of the values of the minimum and maximum numbers from the supplied list. Each number-n may be a numeric data items or a numeric literal.



8.1.50. MIN

MIN Function Syntax
=======================================================================

 MIN(number-1 [, number-2 ]...)
 ~~~

=======================================================================

This function returns the minimum value from the specified list of numbers (each number-n may be a numeric data item or a numeric literal).



8.1.51. MOD

MOD Function Syntax
=======================================================================

 MOD(value, modulus)
 ~~~

=======================================================================

This function returns the value of value modulo modulus (essentially the remainder from the division of value by modulus). Both arguments may be numeric data items or numeric literals. Either (or both) may have a non-integer value.



8.1.52. MODULE-CALLER-ID

MODULE-CALLER-ID Function Syntax
=======================================================================

 MODULE-CALLER-ID
 ~~~~~~~~~~~~~~~~

=======================================================================

This function returns the null string if it is executed within a main program. When executed with a subprogram, it returns the entry-point name of the program that called the subprogram.

The discussion of the MODULE-TIME (see MODULE-TIME) function includes a sample program that uses this function.

Since this function has no arguments, no parenthesis should be specified.



8.1.53. MODULE-DATE

MODULE-DATE Function Syntax
=======================================================================

 MODULE-DATE
 ~~~~~~~~~~~

=======================================================================

This function Returns the date the GnuCOBOL program that is executing the function was compiled, in the form yyyymmdd.

The discussion of the MODULE-TIME (see MODULE-TIME) function includes a sample program that uses this function.

Since this function has no arguments, no parenthesis should be specified.



8.1.54. MODULE-FORMATTED-DATE

MODULE-FORMATTED-DATE Function Syntax
=======================================================================

 MODULE-FORMATTED-DATE
 ~~~~~~~~~~~~~~~~~~~~~

=======================================================================

This function returns the fully-formatted date and time when the program executing the function was compiled. The exact format of this returned string value may vary depending on the operating system and GnuCOBOL build type.

The discussion of the MODULE-TIME (see MODULE-TIME) function includes a sample program that uses this function.

Since this function has no arguments, no parenthesis should be specified.



8.1.55. MODULE-ID

MODULE-ID Function Syntax
=======================================================================

 MODULE-ID
 ~~~~~~~~~

=======================================================================

This function returns the primary entry-point name (i.e. the PROGRAM-ID or FUNCTION-ID of the program. See IDENTIFICATION DIVISION, for information on those clauses.

The discussion of the MODULE-TIME (see MODULE-TIME) function includes a sample program that uses this function.

Since this function has no arguments, no parenthesis should be specified.



8.1.56. MODULE-PATH

MODULE-PATH Function Syntax
=======================================================================

 MODULE-PATH
 ~~~~~~~~~~~

=======================================================================

This function returns the full path to the executable version of this GnuCOBOL program. The filename component of this value will be exactly as typed on the command line, down to the use of upper- and lower-case letters and presence (or absence) of any extension.

The discussion of the MODULE-TIME (see MODULE-TIME) function includes a sample program that uses this function.

Since this function has no arguments, no parenthesis should be specified.



8.1.57. MODULE-SOURCE

MODULE-SOURCE Function Syntax
=======================================================================

 MODULE-SOURCE
 ~~~~~~~~~~~~~

=======================================================================

The filename of the source code of the program (as specified on the cobc command when the program was compiled) is returned by this function.

The discussion of the MODULE-TIME (see MODULE-TIME) function includes a sample program that uses this function.

Since this function has no arguments, no parenthesis should be specified.



8.1.58. MODULE-TIME

MODULE-TIME Function Syntax
=======================================================================

 MODULE-TIME
 ~~~~~~~~~~~

=======================================================================

This function returns the time the GnuCOBOL program was compiled, in the form hhmmss.

Since this function has no arguments, no parenthesis should be specified.

The following sample program uses all the MODULE- Functions:

IDENTIFICATION DIVISION.
PROGRAM-ID. DEMOMODULE.
ENVIRONMENT DIVISION.
CONFIGURATION SECTION.
REPOSITORY.
    FUNCTION ALL INTRINSIC.
PROCEDURE DIVISION.
000-Main.
    DISPLAY "MODULE-CALLER-ID      = [" MODULE-CALLER-ID ‘]’
    DISPLAY "MODULE-DATE           = [" MODULE-DATE ‘]’
    DISPLAY "MODULE-FORMATTED-DATE = [" MODULE-FORMATTED-DATE ‘]’
    DISPLAY "MODULE-ID             = [" MODULE-ID ‘]’
    DISPLAY "MODULE-PATH           = [" MODULE-PATH ‘]’
    DISPLAY "MODULE-SOURCE         = [" MODULE-SOURCE ‘]’
    DISPLAY "MODULE-TIME           = [" MODULE-TIME ‘]’
    STOP RUN
    .

The program produces this output when executed:

MODULE-CALLER-ID = []
MODULE-DATE = [20180522]
MODULE-FORMATTED-DATE = [May 22 2018 12:43:14]
MODULE-ID = [DEMOMODULE]
MODULE-PATH = [/home/vince/cobolsrc/ACAS/demomodule]
MODULE-SOURCE = [demomodule.cbl]
MODULE-TIME = [124314]


8.1.59. MONETARY-DECIMAL-POINT

MONETARY-DECIMAL-POINT Function Syntax
=======================================================================

 MONETARY-DECIMAL-POINT
 ~~~~~~~~~~~~~~~~~~~~~~

=======================================================================

MONETARY-DECIMAL-POINT returns the character used to separate the integer portion from the fractional part of a monetary currency value according to the rules currently in effect for the locale under which your program is running.

On UNIX (including OSX, Windows/Cygwin and Windows/MinGW) systems, your locale is established via the LANG run-time environment variable (see Run Time Environment Variables) environment variable. On Windows, the Control Panel’s Regional and Language Options define the locale.

Using the DECIMAL-POINT IS COMMA (see SPECIAL-NAMES) clause in your program will not affect the value returned by this function.

Since this function has no arguments, no parenthesis should be specified.



8.1.60. MONETARY-THOUSANDS-SEPARATOR

MONETARY-THOUSANDS-SEPARATOR Function Syntax
=======================================================================

 MONETARY-THOUSANDS-SEPARATOR
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~

=======================================================================

This function returns the character used to separate the thousands digit groupings of monetary currency values according to the rules currently in effect for the locale under which your program is running.

On UNIX (including OSX, Windows/Cygwin and Windows/MinGW) systems, your locale is established via the LANG run-time environment variable (see Run Time Environment Variables) environment variable. On Windows, the Control Panel’s Regional and Language Options define the locale.

Using the DECIMAL-POINT IS COMMA (see SPECIAL-NAMES) clause in your program will not affect the value returned by this function.

Since this function has no arguments, no parenthesis should be specified.



8.1.61. NUMERIC-DECIMAL-POINT

NUMERIC-DECIMAL-POINT Function Syntax
=======================================================================

 NUMERIC-DECIMAL-POINT
 ~~~~~~~~~~~~~~~~~~~~~

=======================================================================

This function returns the character used to separate the integer portion of a non-integer numeric item from the fractional part according to the rules currently in effect for the locale under which your program is running.

On UNIX (including OSX, Windows/Cygwin and Windows/MinGW) systems, your locale is established via the LANG run-time environment variable (see Run Time Environment Variables) environment variable. On Windows, the Control Panel’s Regional and Language Options define the locale.

Using the DECIMAL-POINT IS COMMA (see SPECIAL-NAMES) clause in your program will not affect the value returned by this function.

Since this function has no arguments, no parenthesis should be specified.



8.1.62. NUMERIC-THOUSANDS-SEPARATOR

NUMERIC-THOUSANDS-SEPARATOR Function Syntax
=======================================================================

 NUMERIC-THOUSANDS-SEPARATOR
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~

=======================================================================

This function returns the character used to separate the thousands digit groupings of numeric values according to the rules currently in effect for the locale under which your program is running.

On UNIX (including OSX, Windows/Cygwin and Windows/MinGW) systems, your locale is established via the LANG run-time environment variable (see Run Time Environment Variables) environment variable. On Windows, the Control Panel’s Regional and Language Options define the locale.

Using the DECIMAL-POINT IS COMMA (see SPECIAL-NAMES) clause in your program will not affect the value returned by this function.

Since this function has no arguments, no parenthesis should be specified.



8.1.63. NUMVAL

NUMVAL Function Syntax
=======================================================================

 NUMVAL(string)
 ~~~~~~

=======================================================================

The NUMVAL function converts a string (a group item, USAGE DISPLAY elementary item or alphanumeric literal) to its corresponding numeric value.

The string must have any of the following formats, where ’#’ represents a sequence of one or more decimal digits:

#   -#   +#   #-   #+   #CR   #DB
#.#   -#.#   +#.#   #.#-   #.#+   #.#CR   #.#DB

There must be at least one digit character in the string.

Leading and/or trailing spaces are allowed, as are spaces before the first digit.

The character period in argument-1 string, represents the decimal separator. The character comma in argument-1 represents the grouping separator. When the DECIMAL-POINT IS COMMA clause is specified, the character comma shall be used in argument-1 to represent the decimal separator and the character period shall be used to represent the grouping separator.

Note: Locale-based functionality equivalent to NUMVAL can be obtained by using the NUMVAL-C function with the LOCALE keyword. A currency sign is optional in NUMVAL-C. The locale category LC_MONETARY will be used because there is no sign convention specified in locale category LC_NUMERIC.

Returned values:

The returned value is the numeric value represented by string.

If it contains a CR, DB, or the minus sign (‘-’), the returned value is negative.



8.1.64. NUMVAL-C

NUMVAL-C Function Syntax
=======================================================================

 NUMVAL-C (string [, symbol               ]
 ~~~~~~~~
                  [, LOCALE locale-name-1 ] [, ANYCASE ])

=======================================================================

This function converts a string (a group item, USAGE DISPLAY elementary item or alphanumeric literal) representing a currency value to its corresponding numeric value.

The currency string if any, and any grouping separators preceding the decimal separator are ignored. Optionally, the currency string, sign convention, grouping separator and the decimal separator permitted in the character string may be specified by locale category LC-MONETARY, or the currency string may be specified by symbol.

The optional symbol character represents the currency symbol (a non-space single-character group item, USAGE DISPLAY elementary item or alphanumeric literal) that may be used as the currency character in string. Any spaces including leading or trailing are ignored. If no symbol is specified, the value that would be returned by the CURRENCY-SYMBOL intrinsic function (see CURRENCY-SYMBOL) will be used.

If this references the LOCALE :

Changing the currency symbol via the SPECIAL-NAMES paragraph’s CURRENCY SYMBOL setting will not affect the value returned by this function.

While NUMVAL-C will always use the currency symbol that is specified via the SPECIAL-NAMES paragraph’s CURRENCY SYMBOL (or the system default which is currently always ‘$’).

string may have any of the following formats, where ’#’ represents a sequence of one or more decimal digits and ’$’ represents the symbol character:

#   -#   +#   #-   #+   #CR   #DB
#.#   -#.#   +#.#   #.#-   #.#+   #.#CR   #.#DB
$#   -$#   +$#   $#-   $#+   $#CR   $#DB
$#.#   -$#.#   +$#.#   $#.#-   $#.#+   $#.#CR   $#.#DB

There must be at least one digit character in the string.

Leading and/or trailing spaces are allowed, as are spaces before and/or after the currency symbol, sign, CR and DB characters.

If the ANYCASE keyword is used the matching rules for detecting a currency string in argument-1 are case-insensitive. If the ANYCASE keyword is not specified, the matching rules are case-sensitive.

If neither symbol nor the LOCALE keyword is specified, there shall be only one currency string used, either the default currency sign or a currency string specified in the SPECIAL-NAMES paragraph.

The returned value is the numeric value represented by string.

When the LOCALE keyword is specified, the returned value is negative if string contains a negative sign.

When the LOCALE keyword is not specified, the returning value is negative if string contains CR, DB, or a minus sign.



8.1.64B. NUMVAL-C-2

NUMVAL-C Function Syntax
=======================================================================

 NUMVAL-C (argument-1 [, argument-2           ]
 ~~~~~~~~
                      [, LOCALE locale-name-1 ] [, ANYCASE ])

=======================================================================

This function returns the numeric value represented by the character string specified by argument-1 and defined as alphanumeric.

argument-2, the currency string if any, and any grouping separators preceding the decimal separator are ignored. Optionally, the currency string, sign convention, grouping separator and the decimal separator permitted in the character string may be specified by locale category LC-MONETARY, or the currency string may be specified by argument-2.

The optional alphanumeric argument-2 character represents the currency symbol (a non-space and at least one single-character item, that may be used as the currency character in argument-1. Any spaces including leading or trailing are ignored. If no argument-2 is specified, the value that would be returned by the CURRENCY-SYMBOL intrinsic function (see CURRENCY-SYMBOL) will be used. argument-2 must not contain any of the digits - through 9, characters ‘*’, ‘+’, ‘-’, ‘,’ or ‘.’; or the two consecutive letters CR or DB, whether upper or lower case or a combination of both.

argument-2 specifies a currency string that may appear in argument-1.

If the ANYCASE keyword is specified, the matching rules for detecting a currency string in argument-1 are case-insensitive. If not specified, the matching rules are case-sensitive.

If neither argument-2 nor the LOCALE keyword is specified, there shall be only one currency string used, either the default currency sign or a currency string specified in the SPECIAL-NAMES paragraph.

While NUMVAL-C will always use the currency symbol that is specified via the SPECIAL-NAMES paragraph’s CURRENCY SYMBOL (or the system default which is currently always ’$’) argument-1 shall have any of the following formats, where ’#’ represents a sequence of one or more decimal digits and ’$’ represents the symbol character:

#   -#   +#   #-   #+   #CR   #DB
#.#   -#.#   +#.#   #.#-   #.#+   #.#CR   #.#DB
$#   -$#   +$#   $#-   $#+   $#CR   $#DB
$#.#   -$#.#   +$#.#   $#.#-   $#.#+   $#.#CR   $#.#DB

There must be at least one digit character in the string.

Leading and/or trailing spaces are allowed, as are spaces before and/or after the currency symbol, sign, CR and DB characters.

The returned value is the numeric value represented by argument-1.

When the LOCALE keyword is specified, the returned value is negative if string contains a negative sign and when not specified, the returning value is negative if string contains CR, DB, or a minus sign.



8.1.65. NUMVAL-F

NUMVAL-F Function Syntax
=======================================================================

 NUMVAL-F(char)
 ~~~~~~~~

=======================================================================

This function converts a string (a group item, USAGE DISPLAY elementary item or alphanumeric literal) representing a floating-point value to its corresponding numeric value.

#   -#   +#   #E#   -#E#   +#E#
#E+#   -#E+#   +#E+#   #E-#   -#E-#   +#E-#
#.#   -#.#   +#.#   #.#E#   -#.#E#   +#.#E#
#.#E+#   -#.#E+#   +#.#E+#   #.#E-#   -#.#E-#   +#.#E-#

There must be at least one digit character both before and after the E in the string.

Leading and/or trailing spaces are allowed, as are spaces before and/or after any sign characters.



8.1.66. ORD

ORD Function Syntax
=======================================================================

 ORD(char)
 ~~~

=======================================================================

This function returns the ordinal position in the program character set (usually ASCII) corresponding to the 1st character of char argument (a group item, USAGE DISPLAY elementary item or alphanumeric literal).

For example, assuming the program is using the standard ASCII collating sequence, ORD('!') returns 34 because ‘!’ is the 34th ASCII character. If you are using this function to convert an ASCII character to its numeric value, you must subtract one from the result.

The following code is an alternative approach when you just wish to convert an ASCII character to its numeric equivalent:

01  Char-Value.
    05 Numeric-Value        USAGE BINARY-CHAR.
…
    MOVE "character" TO Char-Value

Numeric-Value now has the numeric value of character.



8.1.67. ORD-MAX

ORD-MAX Function Syntax
=======================================================================

 ORD-MAX(char-1 [, char-2 ]...)
 ~~~~~~~

=======================================================================

This function returns the ordinal position in the argument list corresponding to the char-n whose 1st character has the highest position in the program collating sequence (usually ASCII).

For example, assuming the program is using the standard ASCII collating sequence, ORD-MAX('Z', 'z', '!') returns 2 because the 2nd character in the argument list (the ASCII character ‘z’) occurs after ‘Z’ and ‘!’ in the program collating sequence. Each char-n argument may be a group item, USAGE DISPLAY elementary item or alphanumeric literal.



8.1.68. ORD-MIN

ORD-MIN Function Syntax
=======================================================================

 ORD-MIN(char-1 [, char-2 ]...)
 ~~~~~~~

=======================================================================

This function returns the ordinal position in the argument list corresponding to the char-n whose 1st character has the lowest position in the program collating sequence (usually ASCII).

For example, assuming the program is using the standard ASCII collating sequence, ORD-MIN('Z', 'z', '!') returns 3 because the 3rd character in the argument list (the ASCII character ‘!’) occurs before ‘Z’ and ‘z’ in the program collating sequence. Each char-n argument may be a group item, USAGE DISPLAY elementary item or alphanumeric literal.



8.1.69. PI

PI Function Syntax
=======================================================================

 PI
 ~~

=======================================================================

This function returns the mathematical constant PI. The maximum precision with which this value may be returned is 3.1415926535897932384626433832795029.

Since this function has no arguments, no parenthesis should be specified.



8.1.70. PRESENT-VALUE

PRESENT-VALUE Function Syntax
=======================================================================

 PRESENT-VALUE(rate, value-1 [, value-2 ])
 ~~~~~~~~~~~~~

=======================================================================

The PRESENT-VALUE function returns a value that approximates the present value of a series of future period-end amounts specified by the various value-n arguments at a discount rate specified by the rate argument.

All arguments are numeric data items and/or numeric literals.



8.1.71. RANDOM

RANDOM Function Syntax
=======================================================================

 RANDOM[(seed)]
 ~~~~~~

=======================================================================

This function returns a pseudo-random non-integer value in the range 0 to 1 (for example, 0.123456789).

The purpose of the optional seed argument, is to initialize the chain of pseudo-random numbers that will be returned by the function. Not only will calls to this function using the same seed value return the same pseudo-random number, but so will all subsequent executions of the function without a seed. This is actually a good thing when you are testing your program because you can rely on always receiving the same sequence of “random” numbers if you always start using the same seed.

The seed may be any form of literal or data item. If seed is numeric, its numeric value will serve as the seed value. If seed is alphanumeric, a value for it will be determined as if it were used as an argument to NUMVAL (see NUMVAL).

Take, for example, the following sample program:

    IDENTIFICATION DIVISION.
    PROGRAM-ID. DEMORANDOM.
    DATA DIVISION.
    WORKING-STORAGE SECTION.
    01  Pseudo-Random-Number        USAGE COMP-1.
    PROCEDURE DIVISION.
    000-Main.
        MOVE FUNCTION RANDOM(1) TO Pseudo-Random-Number
        DISPLAY Pseudo-Random-Number
        PERFORM 4 TIMES
            MOVE FUNCTION RANDOM    TO Pseudo-Random-Number
            DISPLAY Pseudo-Random-Number
        END-PERFORM
        STOP RUN
        .

Every time this program is executed, it will produce the same output, because the same sequence of pseudo-random numbers will be generated:

    0.41
    0.18467
    0.63340002
    0.26499999
    0.19169

It is worth mentioning that if the first execution of RANDOM in your program lacks a seed argument, the result will be exactly as if that execution were coded with a seed argument value of 1.

Once your program has been thoroughly tested, you’ll want different sequences to be generated each time the program runs. One possible way to accomplish this is to use a seed that is likely to be different every time the program is executed, as is likely to be the case if the first MOVE statement in the previous example were replaced by this:

    MOVE RANDOM(FUNCTION CURRENT-DATE(1:16))
      TO Pseudo-Random-Number

The first 16 characters returned by the CURRENT-DATE (see CURRENT-DATE) function will be a number in the format YYYYMMDDhhmmssnn, where YYYYMMDD is the current calendar date and hhmmssnn is the current time of day to the one one-hundredth of a second. Since two different executions of the program will never get identical CURRENT-DATE values (unless they are executed in extremely close time frames to one another), using those first sixteen characters as the RANDOM seed will guarantee that receiving a duplicate sequence of pseudo-random numbers in two different executions of the program will be highly unlikely.



8.1.72. RANGE

RANGE Function Syn