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Wednesday, April 1, 2009

COND Statement – How does it work?


Q. How does the COND statement work?
The COND statement is used to bypass Job-step. 

Example 1

Consider the statement

//STEP02  EXEC  PGM=IEFBR14,COND=(4,GT,STEP01)
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In this example, if condition-code of STEP1 is between 0 to 3, the COND condition is satisfied. Thus, STEP02 is bypassed.

Example 2

Consider the statement,

//STEP02  EXEC  PGM=IEFBR14,COND=((16,GE),(90,LE,STEP1),ONLY)

In the above example, the system executes this step if all of the three conditions are met,
1. Return codes of Any of the previous job-steps is 17 or greater.
2. Return code of STEP1 is 89 or less.
3. Any of the previous step abnormally terminates.

Example 3

Consider the series of statements :

//STEP01 EXEC PGM=IEFBR14
//STEP02 EXEC PGM=IEFBR14,COND=(0,EQ,STEP01)
//STEP03 EXEC PGM=IEFBR14,COND=((8,LT,STEP01),(8,GT,STEP02))

In the above scenario, assume the system successfully executes STEP01 with Return Code=0. The system finds that 0 is equal to return code of STEP01 i.e. 0. So, STEP02 is bypassed. When the system evaluates condition on STEP03, it finds that  8 is greater than return code of STEP01(we don’t consider the other part of the condition, since STEP02 was bypassed). Since, 8 > 0, the system executes STEP03.
Rule : Bypassing a job-step because of a return code test, is not the same as abnormally terminating the job-step.

You can now try and predict in this JCL, which job-steps the system executes, and which job-steps are bypassed...



Answer :
System executes STEP01. Return Code = 0.
(4,LT,0) false. System executes STEP02. Return Code = 0.
(16,GE,return code of any preceding step) true. System bypasses STEP03.  

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