| Introduction to Program Definition | Environment Division | |
The Identification Division identifies the source program and the resultant output listing. The user can include the date the program is written and such other information as desired under the paragraphs in the General Format shown on the next page.
This entire division (including
the division header) is optional.
The AUTHOR, INSTALLATION,
DATE-WRITTEN , DATE-COMPILED, and SECURITY paragraphs are classed as
obsolete elements in the ANSI'85 standard and may be deleted from the next
full revision of the ANSI Standard.
All dialects in this COBOL
implementation fully support this syntax. The FLAGSTD Compiler directive can
be used to detect all occurrences of this syntax.
Although they are a part of the
standard COBOL definition, the obsolete paragraphs are explicitly excluded
from the X/Open COBOL language definitions and should not be used in a
conforming X/Open source program.
Paragraph headers identify the type of information contained in the paragraph. The name of the program must be given in the PROGRAM-ID paragraph. The other paragraphs are optional and can be included in this division at the user's choice, in the order of presentation shown by the general format below.
The General Format of the paragraphs in the Identification Division is given below.
Paragraphs can appear in any
order.
The paragraphs can appear in
any order.
The periods following the
paragraph-names in the Identification Division are optional as is the period
following the program-name.
If the Compiler directive
SOURCEFORMAT is specified as FREE, the comment-entry cannot be continued;
the next line will begin the next non-comment entry.
The comment-entry can contain
the SKIP1, SKIP2, SKIP3, EJECT or TITLE statements anywhere on the line.
These statements will be actioned if they are alone on a line in the
comment-entry, and will not terminate the comment-entry.
The comment-entry can contain
the SKIP1, SKIP2, SKIP3, or EJECT statements anywhere in the B margin.
These statements will be actioned if they are alone on a line in the
comment-entry, and will not terminate the comment-entry.
The comment-entry can be
contained in either area A or area B of the comment-entry lines. However,
the next occurrence in area A of any one of the following COBOL words or
phrases will terminate the comment-entry and begin the next paragraph or
division:
PROGRAM-ID
AUTHOR
INSTALLATION
DATE-WRITTEN
DATE-COMPILED
SECURITY
ENVIRONMENT
DATA
PROCEDURE
When the EXTERNAL clause is
specified in the PROGRAM-ID paragraph, then no other IDENTIFICATION DIVISION
paragraphs should be specified, no ENVIRONMENT DIVISION should be specified,
only the LINKAGE SECTION should be specified in the DATA DIVISION, and only
the PROCEDURE DIVISION header and ENTRY statements should appear in the
PROCEDURE DIVISION. and Nested
Source ProgramsThe PROGRAM-ID paragraph gives the name by which a program is identified, and assigns selected program attributes to that program.
The first 8 characters of
program-name of the outermost program should be unique in the system. The
first character must be alphabetic; otherwise it is converted as follows:
If a hyphen is used in
characters 2 through 8 of the program-name of the outermost program, it is
changed to zero (0).
For programs that are
contained in another program, program-name can be any valid user-defined
COBOL word, up to 30 characters long. The first eight characters need not
be unique, and they will not be converted as described above. Lowercase
letters are valid, but such program-names will be handled in a
case-insensitive manner.
The MAPNAME Compiler directive controls this behavior.
The program-name can be a
nonnumeric literal specified with or without enclosing quotation marks. The
content of the literal must follow the rules for formation of program-names,
but may also contain the characters @, #, and $.
The program-name can be the
same as another user-defined word.
The program-name cannot be the same as another user-defined word.
The program-name of a nested
program must be unique within theseparately compiled program containing it.
The optional COMMON clause can
be used only if the program is contained within another program.
If the IS PROGRAM phrase is
present, either COMMON, INITIAL or both must be specified. When both are
specified, the order is irrelevant. The
COMMON clause specifies that the program is common. A common program is
contained within another program but can be called from programs other than
that containing it.
The
INITIAL clause specifies that the program is initial. When an initial
program is called, it and any programs contained within it are placed in
their initial state. See the section Initial State Of A Program
earlier in this chapter.
A common program is one which, despite being directly contained in another program, can be called by any program directly or indirectly contained in that other progam. The common attribute is attained by specifying the COMMON clause in a program's Identification Division. The COMMON clause facilitates the writing of subprograms which are to be used by all the programs contained in a program.
An initial program is one whose program state is initialized when the program is called. Thus, whenever an initial program is called, its program state is the same as when the program was first called in that run unit. During the process of initializing an initial program, that program's internal Working-Storage data is initialized; thus an item of the program's internal data whose description contains a VALUE clause is initialized to that defined value,
but an item whose description
does not contain a VALUE clause is initialized to a value depending on the
DEFAULTBYTE Compiler
directive.
Files with internal file connectors associated with the program are not in the open mode. The control mechanisms for all PERFORM statements contained in the program are set to their initial state. A GOTO statement referred to by an ALTER statement contained in the same program is set to its initial state. The initial attribute is attained by specifying the INITIAL clause in the program's Identification Division.
Two programs in a run unit can reference common data in the following circumstances:
Two programs in a run unit can reference common file connectors in the following circumstances:
The DATE-COMPILED paragraph provides the date the intermediate code was produced in the Identification Division source program listing.
DATE-COMPILED. current-date-and-time .
where the date and time format is DD-MMM-YY hh:mm.
The DATE Compiler directive can impact the comment-entry replacement string for your COBOL implementation.
The value inserted in the
DATE-COMPILED paragraph will also be the value used in the
When-Compiled intrinsic function. However, the format can differ.
The REMARKS paragraph allows a comment-entry to be specified. (See Syntax Rule 3 under the section Identification Division earlier in this chapter.)
Copyright © 1999 MERANT International Limited. All rights reserved.
This document and the proprietary marks and names
used herein are protected by international law.
| Introduction to Program Definition | Environment Division | |