Judge the symbolic value. Perform different steps in jcl Based on the symbolic value.

Identification Division.
Program-id. myprog.

Environment Division.
Input-output section.

Data Division.
FILE Section.

Working-storage section.

Linkage Section.
01 parm.
03 PARM-LENGTH PIC s9 (04) comp sync.
03 THE-PARM.
05 channel pic x (01 ).

Procedure division using parm.
Display THE-PARM.
If channel = 'R' then move 1 to return-code
Else if channel = 'l' then move 2 to return-code
Else move 4 to return-code.
Stop run.

 

 And the jcl:

//*
// Set channel = 'l'
//*
// Step1 exec PGM = myprog, parm = '& channel'
// Steplib dd disp = SHR, DSN =...
// Sysout dd sysout = *
//*
// If (step0001.rc = 1) then
// Step2a exec PGM = process1
// Endif
// If (step0001.rc = 2) then
// Step2b exec PGM = process2
// Endif
//*