The simple learning of JCL

1.JCL Introduction

The language Job control language, which is used primarily to define and control the execution of programs to get the desired output.

The JCL consists of several steps, each with a clear task. JCL can contain multiple steps and up to 255 steps.

The JCL link program and the input and output Files act as bridges between the operating system and the program in a batch environment.

JCL consists of three parts:

JOB Card

Exec

Dd

The JCL must start with the job card and end with '//'.

Use of JCL:

1. Compiling a COBOL program

2. Run a COBOL program.

3. Create a data set. (i.e. PS and PDS)

4. Create a GDG ' s and VSAM file

5. Connect data from multiple files

6. Merge data from multiple files.

7. Execute the utility program.

8. Copy data from one file to another file.

2.JCL Coding Sheet (JCL code table)

Each statement in the JCL can be divided into four types:

1. Name Field Name field

2. Operation Operation

3. Operand operand

4. Comments Notes

3. JCL structure

The JCL structure consists of two parts:

1. Job Card

2. Job Body

The concrete structure is as follows:

4. A simple example

The first line is the job Card, which has the following syntax://job-name job Job-card parameters

A JOB card statement can be divided into three parts:

1. JOB Name

2. JOB operation

3. JOB Card Parameters

JOB Card parameters contains parameters and specific information that applies to all steps.

The second to fifth line statement is a comment

Line Six

Line Seventh

DD represents the data definition, specifies the data that is used in the job step, and provides the technical specifications for how to use the dataset. The DD operator should be encoded between number 12th and 15th. Each EXEC statement will have a corresponding DD statement. The DD statement can be used to specify a data set, and multiple DD statements should be made if more than one dataset needs to be specified. The DD statement contains the actual name of the dataset and his location. The step name should be unique, and the order of execution does not depend on the step name.

Grammar

Ddname DD Positional-parameter[,keyword-parameter][comments]

The DD statement mainly uses the following keyword parameters:

1. DISP

2. DCB

3. SPACE

DISP describes the state of the DataSet, which represents the location of the dataset, and describes whether to delete the dataset after the program terminates.

Sysin statement//sysin DD parameter ... [Comments]

The Sysin card is used to send a large amount of input data to the program using the JCL, the data is accepted by the Accept statement in the program, and each line in the Sysin corresponds to an accept statement in the program.

/* is a delimiter, using it we can terminate the input data stream and must be used with sysin;/* The delimiter always starts at the first column and ends in the second column

If Parm and DD Sysin * In a JCL, the first choice is the Parm parameter, then Sysin *DD

Sysin can handle data from dd* or DD.

Line Eighth

Line Nineth

Reference Source: http://www.mainframestechhelp.com/tutorials/jcl/jcl-introduction.htm

The simple learning of JCL