Learn JCL-SCRIPTING with Real Code Examples

JCL specifies what programs to run, input/output resources, and job execution parameters on IBM mainframes.

It is not a programming language but a scripting/command language for job automation.

Enables conditional processing, job dependencies, and error handling.

Works closely with datasets, files, and mainframe subsystems.

Widely used in enterprise batch processing, financial services, and legacy systems.

JOB statement - defines the job name, accounting, and priority

EXEC statement - executes a program or procedure

DD (Data Definition) statement - defines datasets and file resources

IF/THEN/ELSE constructs for conditional execution

Symbolic parameters and PROC procedures for reusable logic

JOB statement - starts a job and sets attributes

EXEC statement - runs a program or procedure

DD statement - defines datasets, files, or devices

Procedures (PROC) - reusable job steps

Conditional execution using IF/THEN/ELSE constructs

JOB statement for each batch job

Multiple EXEC steps per job

DD statements for dataset allocation

PROCs for reusable steps

Optional SYSIN for program input control

Identify the batch process requirement

Determine programs and datasets involved

Write JCL with JOB, EXEC, and DD statements

Include conditional logic if needed

Submit job to mainframe and monitor execution

Beginner: Run a single COBOL program with input/output datasets

Intermediate: Use symbolic parameters and PROCs

Advanced: Conditional steps, IF/ELSE logic

Expert: Multi-job dependencies and scheduling integration

Architect: Design enterprise batch workflows with error handling and reporting

JCL vs Shell scripts: JCL is mainframe-specific, shell scripts are general-purpose

JCL vs Python scripts: Python handles data and logic, JCL handles job control

JCL vs SQL scripts: SQL queries data, JCL runs batch jobs

JCL vs PowerShell: PowerShell automates Windows tasks, JCL automates mainframe batch jobs

JCL vs COBOL: COBOL is programming, JCL is job control

1964 - JCL introduced for IBM OS/360

1970s - Standardized across OS/VS and MVS

1980s - Enhanced features for dataset management and utilities

1990s - Integration with JES2/JES3 subsystems

2000s - Conditional processing and symbolic parameters matured

2010s - z/OS improvements and security enhancements

2025 - Continued usage in enterprise batch and legacy mainframe systems

JCL - Job Control Language for mainframes

JOB statement - Defines a batch job and its attributes

EXEC statement - Executes a program or PROC

DD statement - Defines datasets or files used in a job

PROC - Procedure, a reusable set of JCL steps