Module 4: JCL DD Statement
REFERBACK
The backward reference or refer back is used to reference information from previous JCL statements in the job stream. Asterisk is used as refer-back operator. This help in reducing and simplifying JCL code.
Using this feature, we can refer-back parameters: DSN, DCB, VOL, OUTPUT and PGM. We can make use of refer back using following ways
- *.DDNAME :- This way we can refer another DD in the same step
- *.STEPNAME.DDNAME :- This way we can refer another DD in another step
- *.STEP-INVOKING-PROC.PROC-STEP.DDNAME :- This way we can refer another DD in step that is in proc
- Note:- Asterisk in SYSOUT parameter refers back to MSGCLASS of JOB CARD
Example :-
//JOB1 JOB A123,’STEVE’
//STEP1 EXEC PGM=PROGRAM1
//DDNM1 DD DSN=DEPT1.EMP1.DATA1,
// DISP=(NEW,CATLG,DELETE),
// UNIT=SYSDA
//DDNM2 DD DSN=DEPT1.EMP1.DATA2,
// DISP=(NEW,CATLG,DELETE),
// UNIT=3380
//DDNM3 DD DSN=*.DDNM1,
// DISP=(NEW,CATLG,DELETE),
// UNIT=3380
//STEP2 EXEC PGM=PROGRAM2
//DDNM12 DD DSN=*.STEP1.DDNM1