June 2018 Update

Lang/JCL/00DESCRIPTION

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+[[Category:JCL]]
+IBM Job Control Language
+
+Job Control Language, commonly named JCL, refers to certain scripting languages, particularly IBM mainframe operating systems, whose role is to run a batch job.
+
+There are two distinct IBM Job Control languages:
+* DOS JCL for system DOS/360, VSE, z/VSE
+*  OS JCL for system  OS/360, MVS, z/OS
+<br>
+Although they have syntax and design rules in common, they are quite different languages.
+
+In the JCL, the unit is the job, which consists of one or more steps. Each step consists of the execution of a specific program.
+
+It is possible to create JCL scripts that can be called in other JCL scripts by passing parameters if necessary. Such scripts are called procedures.
+
+==DOS JCL==
+DOS JCL parameters are positional, which makes them harder to read and write, but easier for the system to parse.
+
+==OS JCL==
+In general, the OS JCL is more flexible and easier to use than the DOS JCL.
+
+===Basic cards===
+The JCL statements are called cards because the  method of providing new input to a computer system was 80-column punched cards. 
+The OS JCL has only three basic cards:
+* the JOB card, which identifies the job and provides information related to it;
+* the EXEC card, which allows each step to identify which program to call;
+* the DD card that identifies the datasets (files) to use during a step.
+<br>
+In the following examples JCL refers only to IBM OS JCL.
+
+==Wikipedia article==
+https://en.wikipedia.org/wiki/Job_Control_Language
+
+==See also==
+https://www.ibm.com/support/knowledgecenter/zosbasics/com.ibm.zos.zjcl/zjclc_basicjclconcepts.htm

Lang/JCL/Conditional-structures

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