Mainframe, MVS and zOS Discussion

Hi,

Following questions I'dlike to verify:

1. In a JCL, if COND=(0,LE) is specified on the first step of JCL, what will happen?

My answer was, "For first step if COND is specified, it will always be false and first step executes unless there is a restart istruction" .

2. In a JCL we have 6 steps: S1, S2, S3, S4, S5 and S6 in the order mentioned. How or can we change the execution order of the steps, like excute S4 after S5?

My answer was to run two seperate jobs.

Can you please help if the answers are correct? And if they are not correct, what is the right answer.

For Q1:

what is the right answer.

Why not read up in the JCL manual (and post the result of your research)?
For Q2:
Yes, you cannot hop backwards and forwards in a job so you have to edit the JCL - copy it and cut out the unwanted stuff and re-arrange the steps and do an initial run with TYPRUN=SCAN or an initial step with PGM=NOTFOUND. Note that you can only reverse the steps if they are independent of each other i.e step 5 does not require data from step 4.

Vivek Soni wrote:2. In a JCL we have 6 steps: S1, S2, S3, S4, S5 and S6 in the order mentioned. How or can we change the execution order of the steps, like excute S4 after S5?

My answer was to run two seperate jobs.

You answer is one of the possible answers. You can also use IEBEDIT or open the job in VIEW mode, do your edits and SUBmit it.

Vivek Soni wrote:1. In a JCL, if COND=(0,LE) is specified on the first step of JCL, what will happen?

My answer was, "For first step if COND is specified, it will always be false and first step executes unless there is a restart istruction" .

By rule, COND skips a step when the condition specified in the COND becomes true. As this is the first step, COND will have no effect as there is no previous step to check the return code with and the step gets executed; tough it'll be checked for the syntax. So your answer is correct.

Anuj Dhawan wrote:

Vivek Soni wrote:1. In a JCL, if COND=(0,LE) is specified on the first step of JCL, what will happen?

My answer was, "For first step if COND is specified, it will always be false and first step executes unless there is a restart istruction" .

By rule, COND skips a step when the condition specified in the COND becomes true. As this is the first step, COND will have no effect as there is no previous step to check the return code with and the step gets executed; tough it'll be checked for the syntax. So your answer is correct.

Thanks, nicely explained.

You're welcome!

By Any chance if interviewer asks how to bypass very first step in JCL using COND parameter , answer is use COND=ONLY

Thanks,
Chandan

Don't make use of that. The behaviour is not documented, and could change at any future release of z/OS. That's a more important part of the answer than anything else. Yes, for winning bets. No for anything "useful".

Totally agree with you William