Let’s start with JCL
You probably know PHP, Java, C, and lot of other programming languages, but what about JCL ? No, it’s not about Java, it’s about Job Control Language a scripting language used on mainframe to instruct the system on how to run a batch job. It is possible to submit JCL for batch processing or directly by to start a JCL procedure (PROC). JCL is very important to create, check, correct and run the daily batch workload.
It’s easy, you have three basic statements:
- JOB: Provides a name (jobname) for the batch.
- EXEC: Provides the name of a program to execute.
- DD: For Data Definition, provides inputs/outputs to the program.
Let’s see a JCL example:
//MYJOB JOBTES 1 //MYSORT EXEC PGM=SORT //SORTIN DD DISP=SHR,DSN=SUP01.TAB.TEST //SORTOUT DD SYSOUT=* //SYSOUT DD SYSOUT=* //SYSIN DD * SORT FIELDS=(1,4,CH,A) /*
Now, try to understand what’s happen here.
- MYJOB is the jobname associates to the workload, here it’s “JOBTES”.
- MYSORT is the stepname, which ask the system to execute a program called “SORT”.
- SORTIN is the program input, here with the DSN (Data Set Name) SUP01.TAB.TEST, and the dataset can be shared (DISP=SHR).
- SORTOUT is the SORT program output.
- SYSOUT specifies to send system output to JES (Job Entrey Subsystem), but it’s also possible to send the outpu to a dataset.
- SYSIN tell the SORT program which fields of the SORTIN data records are to be sorted.
Enough for the moment, JCL is quite hard at beginning !
Tags: JCL, z/OS