JCL

Entering commands from TSO is one way to accomplish tasks in z/OS, but many other ways exist. 

-   One of the most popular and powerful ways is to create files that contain lists of things to do. These lists are called          batch jobs and are written in z/OS Job Control Language (JCL).

-  It fulfills roughly the same role as shell scripting languages in UNIX.

Introduction to JCL

JCL is a language with its own unique vocabulary and syntax.

JCL to create batch jobs. A batch job is a request that z/OS will execute later.

 z/OS will choose when to execute the job and how much z/OS resources the job can have based upon the policies that the system administrator has set up. 

z/OS can manage multiple diverse workloads (jobs) based upon the service level that the installation wants. 

For example, online financial applications will be given higher priority and, therefore, more z/OS resources, and noncritical work will be given a lower priority and, therefore, fewer z/OS resources

In your batch job, you will tell z/OS this information:

• You'll give the name of your job, with a //JOB statement
• You'll specify the program you want to execute, with a //EXEC PGM=<program name>statement
• If your program uses or creates any data, you'll point to the data using a //DDstatement.

Example Job:

This job executes an IBM-provided z/OS program called IEFBR14. This is a dummy program that tells z/OS "I'm done and all is well." It requires no input and produces no output other than an indication to the operating system that it completed successfully.

//Arunams JOB CLASS=A, NOTIFY=&SYSUID,MSGGLASS=H

//                    EXEC PGM=IEFBR14

You can also run TSO as a batch job by using JCL to tell z/OS this information:

• The name of the job
• The program to run, which is the TSO interpreter IKJEFT01
• Where to get the input for IKJEFT01 and the commands that you want to execute
• Where to put the output from IKJEFT01, the output from TSO, and the commands that you execute

//TSOJOB  JOB CLASS=A,NOTIFY=&SYSUID,MSGCLASS=H
//        EXEC PGM=IKJEFT01
//SYSTSPRT DD SYSOUT=*
//SYSTSIN  DD *
SEND 'Hello, World' U(ORIPOME)
/*