Procedures, symbols and overrides

Two kinds of procedure

• Catalogued — stored as a member of a procedure library. Called by name.
• Instream — written inside the job itself between PROC and PEND, then called. Useful when developing.

* member PAYPROC in PROD.PAY.PROCLIB
//PAYPROC  PROC ENV=PROD,RUNDT=00000000
//CALC     EXEC PGM=PAYCALC,PARM='RUNDATE=&RUNDT'
//STEPLIB  DD DSN=&ENV..PAY.LOADLIB,DISP=SHR
//INFILE   DD DSN=&ENV..PAY.MASTER,DISP=SHR
//OUTFILE  DD DSN=&ENV..PAY.CALC,DISP=(NEW,CATLG,DELETE),
//            SPACE=(CYL,(50,10),RLSE)
//SYSOUT   DD SYSOUT=*

Calling it, and changing it

//PAYRUN01 JOB (ACCT01),'MONTHLY PAY',CLASS=A,MSGCLASS=X
//RUN      EXEC PAYPROC,ENV=TEST,RUNDT=20260930
//* override just the input file inside the CALC step
//RUN.CALC.INFILE DD DSN=TEST.PAY.SMALLSET,DISP=SHR
//* add a DD that the procedure does not have
//RUN.CALC.DEBUG  DD SYSOUT=*

The override rules

1. Overrides are written as stepname.ddname DD … where stepname is the step *inside* the procedure.
2. An override replaces the whole DD statement, not just the parameter you mention. Anything you omit is lost.
3. Overrides must appear in the same order as the steps in the procedure.
4. A DD name that does not exist in the procedure is added to that step.
5. Symbols supplied on the EXEC replace the defaults on the PROC statement.

Seeing what actually ran

Because a procedure hides most of the JCL, the expanded version in JESJCL is the only reliable record of what the system did. Expanded lines are marked so you can tell procedure text from your own. When a job behaves unexpectedly, reading JESJCL is usually faster than reasoning about the override rules.

Symbols the system supplies