Job Control Language - OS JCL

OS JCL

Statements those are used in this JCL language are called JCL-Statements. OS JCL consists of three basic statements:

• JOB statement, which identifies the start of the job, and information about the whole job, such as billing, run priority, and time and space limits.
• EXEC statement, which identifies the program to be executed in this step of the job, and information about the step.
• DD (Data Description) statements, which identify a data file to be used in a step, and detailed info about that file. DD statements can be in any order within the step.

Right from the start, JCL for the OS family (up to and including z/OS) was more flexible and easier to use.

The following examples use the old style of syntax which was provided right from the launch of System/360 in 1964. The old syntax is still quite common in jobs that have been running for over 20 years with only minor changes. These old jobs are often complex, and converting them to use the CLIST syntax would be tricky and time-consuming.

Although the CLIST syntax is easier to read, programmers still have to provide the same amount of information as they would using the old syntax.