Editing Job Control Language (section)

{{Short description|Scripting languages for IBM mainframes}}
{{About|IBM mainframe job control language|open systems|job control (Unix)|general term|job control (computing){{!}}job control}}

'''Job Control Language''' ('''JCL''') is a [[scripting language]] used on [[IBM mainframe]] operating systems to instruct the system on how to run a [[batch processing|batch job]] or start a subsystem.<ref>"Every job submitted for execution ... must include JCL statements" -- ibm.com</ref> The purpose of JCL is to say which programs to run, using which files or devices<ref>and many more [[#Complexity|complex details]], such as whether the file is to be retained or deleted, the maximum disk space to which it can grow, the name of a tape to be pre-mounted</ref> for input or output, and at times to also indicate under what conditions to skip a step. Parameters in the JCL can also provide accounting information for tracking the resources used by a job as well as which machine the job should run on.

There are two distinct IBM Job Control Languages: 
* one for the operating system lineage that begins with [[DOS/360]] and whose latest member is [[z/VSE]]; and 
* the other for the lineage from [[OS/360]] to [[z/OS]], the latter now including [[Job Entry Subsystem 2/3|JES]] extensions, [[#Job Entry Control Language|Job ''Entry'' Control Language (JECL)]].

They share some basic syntax rules and a few basic concepts, but are otherwise very different.<ref>Ashley and Fernandez, ''Job Control Language'', p. 1.</ref> The [[VM (operating system)|VM operating system]] does not have JCL as such; the [[CP/CMS|CP and CMS]] components each have [[command language]]s.  

The term ''job control language'' can also be used in a generic sense, to refer to any dedicated kind of [[programming language]] designed to guide an operating system in how to process batch jobs.<ref name="stallings"/>