how can i get the name of a mainprogram from a subprogram

ajaehnert · New User Joined: 05 Dec 2007 Posts: 13 Location: Germany

I want the name of a main program from a subprogram( all in cobol)

The subprogram is linked to with the main program.

Can i use a function in cobol ???

thanks

dick scherrer · Posted: Tue Mar 16, 2010 9:29 pm

Hello,

No.

Suggeest you search in the forum (SEARCH in the blue bar above) as this has been discussed fairly recently. . .

agkshirsagar · Posted: Tue Mar 16, 2010 11:03 pm

If you pass the calling program name as a part of linkage section/commarea this can be achieved. From what I understand, your requirement is-
If calling prog = proga
do something
else
do something else.
Please elaborate if you wanted something else so that we can come up with better suggestions.

dick scherrer · Posted: Tue Mar 16, 2010 11:06 pm

Hello,

ajaehnert · New User Joined: 05 Dec 2007 Posts: 13 Location: Germany

i cant pass the program name as part of the linkage section, because this is a migration an the old linkage section is to small and i do not want to change the calling programs.

it was a ASM program, which ask the name of the maim program via a macro.

Andreas

dick scherrer · Posted: Tue Mar 16, 2010 11:37 pm

Hello,

How did the assembler code accomplish this (what did the macro do)?

If you understand how the assembler works, you could possibly do something like this in the called replacement code.

Akatsukami · Posted: Tue Mar 16, 2010 11:37 pm

I am not a COBOL programmer; I believe that recent versions of COBOL can handle pointers/addresses, but I don't know if they can be manipulated. It may be necessary to write the external sub-routine/function in PL/I, C/370, HLASM, or smilar language.

Get the TCB (always at address 540 decimal, IIRC). The address of the last LLE is at offset 36 decimal from the TCB; the address of the CDE is at offset 4 from the LLE. The program name is the 8-byte string beginning at offset 8 from the CDE.

dick scherrer · Posted: Tue Mar 16, 2010 11:50 pm

Hello,

ajaehnert · New User Joined: 05 Dec 2007 Posts: 13 Location: Germany

hi,

an this program name ist the name of the maim program?

Andreas

Akatsukami · Posted: Wed Mar 17, 2010 12:35 am

Yes; note, however, if the "main" program is really a dynamically-linked (or attached, fetched, etc.) subroutine of a genuine main program as IJKEFTxx, DFSRRC00, etc., that the latter will be returned.

ajaehnert · New User Joined: 05 Dec 2007 Posts: 13 Location: Germany

hi

i want to know the name of the main program when i executing the sub programm( not dynamily linked)

Thanke

Robert Sample · Posted: Wed Mar 24, 2010 4:49 pm

You have three choices:

1. Pass the calling program name as a parameter to the subprogram.
2. Chase z/OS control blocks to get this data -- search the forum for exactly what you have to in this case.
3. Accept that what you want is not otherwise possible. There is no COBOL way to get this data, for example -- you have to directly read memory areas for the control blocks.

Anuj Dhawan · Posted: Wed Mar 24, 2010 6:48 pm

MBabu · Posted: Wed Mar 24, 2010 11:56 pm

Chasing control blocks isn't necessarily good though. If load module A has routines M1 and M2 and they call S1, then finding the CDE will show A but you still don't know if M1 or M2 made the call. If you Really want to do this accurately, you might be able to find the CDE, run AMBLIST to get the offsets for the various CSECTs in the load module and do the math. But that sort of thing is still probably imperfect and would be a *real* pain in the *** and implies that you know the address of the subroutine and have access to the save areas and that the compiler is using standard linkage or some other chaining mechanism you can trace. In assembler programs this isn't as bad because most programs use a standard base register, and often have an eyecatcher at at the module, so all you need to do is find the previous save area, grab its 1st base register and use that to find the eye catcher. COBOL though? I wouldn't go there.

dick scherrer · Posted: Thu Mar 25, 2010 12:01 am