Job Control Language

Why Trust Techopedia

What Does Job Control Language Mean?

Job control language (JCL) is a scripting language executed on an IBM mainframe operating system. It consists of control statements that designate a specific job for the operating system.

Advertisements

JCL provides a means of communication between the application program, operating system and system hardware.

Techopedia Explains Job Control Language

JCL is considered to be one of the rude script languages run on IBM OS/360 batch systems. It can define data set names, parameters and system output devices. One common feature in both DOS and OS JCL is the unit of work, which is called a job. A job consists of several small steps for running a specific program and is identified by cards called job cards, which indicate the beginning of the job and define exactly how the job is to be executed.

Both DOS and OS operating systems use 71 characters per line. However, the maximum length is 80 characters. Characters 73-80 are used for locating the error areas reported by the OS.

When a JCL statement becomes too lengthy and exceeds the 71-character limit, it can be extended using a continuation card. A statement can be continued to as many cards as necessary by ending all the JCL cards excluding the last card at an instance where a comma is used, or by using (//) at the start of the continuation card in column one and using at least a one-space character.

Advertisements

Related Terms

Margaret Rouse
Technology Expert
Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.