Table 59lists the language elements that are different between COBOL for OS/390 & VM and the IBM Workstation COBOL compilers (COBOL Set for AIX and VisualAge COBOL). Many COBOL for OS/390 & VM clauses and phrases are treated as comments under AIX, OS/2, and Windows. However, this will have minimal effect on existing applications that you download to the workstation. The Workstation compilers recognize and process most COBOL for OS/390 & VM language syntax, even if the language element has no functional effect.
Table 59. Language Difference Between Mainframe and Workstation IBM COBOL | |
Language Element | Implementation |
---|---|
ACCEPT statement |
Under AIX, OS/2, and Windows, environment-name determines file identification. |
APPLY WRITE-ONLY clause |
Treated as a comment under AIX, OS/2, and Windows. |
ASSIGN clause |
Different syntax for the ASSIGNment name. ASSIGN...USING data-name is not supported on OS/390 and VM. |
BLOCK CONTAINS clause |
Treated as a comment under AIX, OS/2, and Windows. |
CALL statement |
A file-name as a CALL argument is not supported under AIX, OS/2, and Windows. |
CLOSE statement |
The following phrases are treated as comments under AIX, OS/2, and Windows: FOR REMOVAL, WITH NO REWIND, and UNIT/REEL. |
CODE-SET clause |
Treated as a comment under AIX, OS/2, and Windows. |
DISPLAY statement |
Under AIX, OS/2, and Windows, environment-name determines file identification. |
File Status data-name-1 |
Some values and meanings for file status 9x are different under OS/390 and VM than under AIX, OS/2, and Windows. |
File Status data-name-8 |
The format and values are different depending on the platform and the file system. |
LABEL RECORD clause |
LABEL RECORD IS data-name, USE...AFTER...LABEL PROCEDURE, and GO TO MORE-LABELS are treated as comments under AIX, OS/2, and Windows. These language elements are processed by the compiler; however, the user label declaratives are not invoked at run time. |
Line Sequential files |
Line sequential I-O is not supported on OS/390 and VM. |
LOCK MODE clause |
For OS/2 VSAM files, you can use this clause to specify the locking technique used for files. |
MULTIPLE FILE TAPE |
Treated as a comment under AIX, OS/2, and Windows. On the workstation, all files are treated as single volume files. |
OPEN statement |
The following phrases are treated as comments under AIX, OS/2, and Windows: REVERSED and WITH NO REWIND. |
PASSWORD clause |
Treated as a comment under AIX, OS/2, and Windows. |
POINTER and PROCEDURE-POINTER data items |
Under COBOL for OS/390 & VM, a POINTER data item is defined as 4 bytes; a PROCEDURE-POINTER data item is defined as 8 bytes. Under AIX, OS/2, and Windows, the size of these data items are consistent with the native pointer definition of the platform (4 bytes for 32-bit machines and 8 bytes for 64-bit machines). |
READ...PREVIOUS |
Under AIX, OS/2, and Windows only, allows you to read the previous record for relative or index files with DYNAMIC access mode. |
RECORD CONTAINS clause |
The RECORD CONTAINS n CHARACTERS clause is accepted with one exception: RECORD CONTAINS 0 CHARACTERS is treated as a comment under AIX, OS/2, and Windows. |
RECORDING MODE clause |
Treated as a comment under AIX, OS/2, and Windows for relative, indexed, and line sequential files. |
RERUN clause |
Treated as a comment under AIX, OS/2, and Windows. |
RESERVE clause |
Treated as a comment under AIX, OS/2, and Windows. |
SAME AREA clause |
Treated as a comment under AIX, OS/2, and Windows. |
SAME SORT clause |
Treated as a comment under AIX, OS/2, and Windows. |
SET statement |
Under AIX, OS/2, and Windows, format 5, rules for identifier-7 have extensions. |
SORT-CONTROL special register |
The contents of this special register differ between host and workstation COBOL. |
SORT-CORE-SIZE special register |
The contents of this special register differ between host and workstation COBOL. |
SORT-FILE-SIZE special register |
Treated as a comment under AIX, OS/2, and Windows. Values in this special register are not used. |
SORT-MESSAGE special register |
Treated as a comment under AIX, OS/2, and Windows. |
SORT-MODE-SIZE special register |
Treated as a comment under AIX, OS/2, and Windows. Values in this special register are not used. |
SORT MERGE AREA clause |
Treated as a comment under AIX, OS/2, and Windows. |
START...< |
Under AIX, OS/2, and Windows, the following relational operators are allowed: IS LESS THAN, IS <, IS NOT GREATER THAN, IS NOT >, IS LESS THAN OR EQUAL TO, IS <= |
USAGE clause |
Under AIX, OS/2, and Windows, addition of COMP-5 (new data type, native binary data format). |
WRITE statement |
Under AIX, OS/2, and Windows, if you specify the WRITE...ADVANCING with environment names: C01 - C12 or S01 - S05, one line is advanced. |
Names known to the platform environment |
The following names are identified differently: program-name, text-name, library-name, assignment-name, SORT-CONTROL special register, basis-name, DISPLAY/ACCEPT target identification, and system-dependent names. |
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