JCL Interview Questions and Answers - DoAnswers.com

JCL (job control language) is a language for describing jobs (units of work) to the MVS, OS/390, and VSE operating systems, which run on IBM's S/390 large server (mainframe) computers. These operating systems allocate their time and space resources among the total number of jobs that have been started in the computer. Jobs in turn break down into job steps. All the statements required to run a particular program constitute a job step. Jobs are background (sometimes called batch) units of work that run without requiring user interaction (for example, print jobs). In addition, the operating system manages interactive (foreground) user requests that initiate units of work. In general, foreground work is given priority over background work.

JCL Interviews are getting tough these days as the technology grows faster. To get through the JCL interview one needs to update him/herself in a regular manner. Having said that, just before the interview, it is very important to have a quick glance of the reputed JCL questions and answers to make yourself comfortable during the interview process. This is where DoAnswers.com helps you in renewing yourself on JCL and various other technologies interview preparation.

21. A PROC has five steps. Step 3 has a condition code. How can you override/nullify this condition code?

Provide the override on the EXEC stmt in the JCL as follows: //STEP001 EXEC procname, COND.stepname=value All parameters on an EXEC stmt in the proc such as COND, PARM have to be overridden like this.

22. Can an individual step be restricted from using all the job?s allowed CPU time ?

I did not know the answer and my interviewer said NO. Later I tried and executed PROC from a PROC, three levels deep. Manuals do not state any limit on PROC calling PROC, or nesting.

COND is a condition parameter, consists of 2 sub parameters, 1st - return code from the previous step, 2nd - condition. If COND is true, the step on which COND is coded will be BYPASSED.

the dd statement links the external dataset name (dsn) to the ddname coded within the executing program. it links the file names within the program code to the file names know to the mvs operating system. the syntax is // ddname dd dsn=dataset name. other keywords after dsn are disp, dcb, space, etc.

The DD statement links the external dataset name (DSN) to the DDNAME coded within the executing program. It links the file names within the program code to the file names know to the MVS operating system. The syntax is // ddname DD DSN=dataset name. Other keywords after DSN are DISP, DCB, SPACE, etc.

the exec statement identifies the program to be executed via a pgm=program name keyword. its format is //jobname exec pgm=program name. the parm= keyword can be used to pass external values to the executing program.

The EXEC statement identifies the program to be executed via a PGM= program name keyword. Its format is //jobname EXEC PGM= program name. The PARM= keyword can be used to pass external values to the executing program.

30. describe the job statement, its meaning, syntax and significant keywords.

the job statement is the first in a jcl stream. its format is // jobname, keyword job, accounting information in brackets and keywords, msgclass, msglevel, notify, class, etc.