CALL statement USING logical-file-name

[kiranp78]

In few of our COBOL programs I see that they are CALLing another program with a logical file name in the USING clause. And the called program has defined the Procedure division USING linkage-storage-variable defined as X(133). refer the sample code provided below.

-----------------------------------------------------------------------------
ProgramA
...
ENVIRONMENT DIVISION.
INPUT-OUTPUT SECTION.
FILE-CONTROL.
SELECT INP-FILE ASSIGNED TO INPFILE.
...
DATA DIVISION.
FILE SECTION.
FD INP-FILE.
01 INP-REC PIC X(236).
...
PROCEDURE DIVISION.
...
CALL 'SOMEPGM' USING INP-FILE.

-----------------------------------------------------------------------------
ProgramB
...
DATA DIVISION.
LINKAGE SECTION.
01 WS-LEN PIC S9(04) COMP.
01 WS-INP-FILE PIC X(133).
01 WS-CODE PIC X(01).
...
PROCEDURE DIVISION.
...
ENTRY 'SOMEPGM' USING WS-INP-FILE
WS-CODE.
-----------------------------------------------------------------------------
The variable WS-INP-FILE is never used in the ProgramB after the ENTRY USING statement.

I have never used such CALLs with logical file name and I tried to look at IBM manuals and it just says that the data control block will be passed to the called program. I am trying to understand what exactly is being passed to the "Called" program and how it works? Can anybody who have used such technique can explain, please?

[William Collins]

As the documentation has told you, it is the Data Control Block (DCB).

The two programs you show do not match up. You would get a S0C4 in the CALLed program.

The PIC X(133) is garbage, indicating that whoever coded and used it didn't really know what they were doing.

I'd advise against attempting to use it for anything. It is not portable to other COBOL compilers (it is an IBM Extension to the language) and an absolute need for it for a business purpose would be incredibly rate.

If you are just interested, do some search-engineing for IBM Data Control Block layout, there are different ones depending on access method - QSAM for a plain sequential file.

[kiranp78]

[quote="William Collins"] The two programs you show do not match up. You would get a S0C4 in the CALLed program. [/quote]

Sorry I did not get exactly why do you say they do not match up. I can not paste the exact code snippet from the programs, so I have extracted lines from the programs pasted here.

[quote="William Collins"] The PIC X(133) is garbage, indicating that whoever coded and used it didn't really know what they were doing.

I'd advise against attempting to use it for anything. It is not portable to other COBOL compilers (it is an IBM Extension to the language) and an absolute need for it for a business purpose would be incredibly rate.[/quote]

Exactly, I am planning to use a different COBOL compiler (migrating from IBM COBOL to Unix based COBOL compilers, which does not support it).

[quote="William Collins"] If you are just interested, do some search-engineing for IBM Datac Control Block layout, there are different ones depending on access method - QSAM for a plain sequential file.[/quote]

Thanks for the pointer.[/quote]

[William Collins]

Code: Select all

CALL 'SOMEPGM' USING INP-FILE. 

Code: Select all

ENTRY 'SOMEPGM' USING WS-INP-FILE
WS-CODE.

The parameters don't match in number, and they should.

[kiranp78]

[quote="William Collins"][code]CALL 'SOMEPGM' USING INP-FILE. [/code]

[code]ENTRY 'SOMEPGM' USING WS-INP-FILE
WS-CODE.[/code]

The parameters don't match in number, and they should.[/quote]

Oops.. Did not notice that, yes. They are actually matching in the Called and Caller programs.