Passing parameters to a c program from JCL using SYSIN DD *

Question

Can anybody show me examples on how to pass to a c program the parameters from SYSIN DD * in JCL.

I used to have my JCL program pass the parameter to a c program using the PARM option, but the PARM option has a 100 character limit, thus, requiring me to use the SYSIN DD * option in JCL instead. However, my old c program uses the argv paramater passing style and I don't know if this would still apply when using SYSIN DD *.

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This is what my old JCL code looks like:

/ SET P1='RBR1 FIRBS.AIC_REHBFG_FDG.BM '                                        
// SET P2='BGM.LOL_FDSG '                                                       
// SET P3='"" '                                                                 
// SET P4='X F GMHKD'                                                           
//ST01    EXEC PGM=VCMBGJF,                                                     
//PARM='&P1.&P2.&P3.&P4' 

This is what my new JCL code looks like:

//ST01    EXEC PGM=VCMBGJF
//SYSIN    DD *    
RBR1 FIRBS.AIC_REHBFG_FDG.BM                                       
BGM.LOL_FDSG                                                      
""                                                               
X F GMHKD
/* 

Answer 1

Have you tried reading STDIN and if so does it return data from SYSIN, or try opening SYSIN, as fp = fopen("SYSIN", "r");

Alternatively, try changing the DD name of SYSIN to STDIN. The DD * says to pull the data from the text lines that follow. It does NOT have to be named SYSIN.

Finally, if all else fails read the C/Mainframe user guide. (I don't have one and it was a long time ago when I wrote on a mainframe, so I forget the particulars.)

Lastly, the first example seems to have a few errors:

// SET P1='RBR1 FIRBS.AIC_REHBFG_FDG.BM '                                        
// SET P2='BGM.LOL_FDSG '                                                       
// SET P3='"" '                                                                 
// SET P4='X F GMHKD'                                                           
//ST01    EXEC PGM=VCMBGJF,PARM='&P1.&P2.&P3.&P4'
//* there should be a space between // and PARM 

I mention this because the parm data you listed is < 100 chars, so fixing the PARM statement might fix the running of your code.

Answer 2

You could use the CEE3PR2 Language Environment callable service. Its purpose is to return parm strings of greater than 80 bytes [sic] to invoking programs. I believe this is new to z/OS 1.13. Note that this is not portable to non-mainframe systems. Of course, neither is JCL.