Appendix D: JCL Quick Reference

Overview

Job Control Language (JCL) is the command language used on IBM mainframes to communicate with the operating system (z/OS). JCL tells the system which programs to execute, which files to use, and how to handle output. Every COBOL batch program on a mainframe is executed through JCL.

JCL Statement Format

All JCL statements begin in column 1 with a double slash (//). The general format is:

//name     operation    operand(s)    comments

• Columns 1-2: Must contain // (or /* for delimiter statements)
• Name field: 1-8 alphanumeric characters starting with a letter or national character
• Operation field: JOB, EXEC, DD, or other JCL statement keyword
• Operand field: Parameters separated by commas (no embedded spaces)
• Continuation: Code a comma after the last parameter on the line, then continue in columns 4-16 of the next line

1. JOB Statement

The JOB statement marks the beginning of a job and specifies accounting and scheduling information.

//jobname  JOB  (accounting-info),programmer-name,parameters

JOB Statement Parameters

Example JOB Statement

//PAYROLL  JOB (ACCT01,DEPT55),'J SMITH',
//         CLASS=A,MSGCLASS=X,MSGLEVEL=(1,1),
//         NOTIFY=&SYSUID,REGION=0M,TIME=30

2. EXEC Statement

The EXEC statement identifies the program or procedure to execute within a job step.

//stepname EXEC PGM=program-name,parameters
//stepname EXEC PROC=procedure-name,parameters

EXEC Statement Parameters

COND Parameter Logic

The COND parameter tests the return code from previous steps. The step is bypassed (not executed) when the condition is true.

Important: COND parameter logic is inverted from what many programmers expect. COND=(4,LT) means "skip this step if 4 is less than any previous return code" (i.e., if any prior step returned greater than 4).

Example EXEC Statement

//STEP01   EXEC PGM=COBPROG1,PARM='PROD',
//         REGION=64M,TIME=(5,0),
//         COND=(4,LT)

3. DD Statement

The DD (Data Definition) statement defines datasets (files) used by a program step.

//ddname   DD   parameters

DD Statement Parameters

DISP Parameter Values

Common DISP combinations:

SPACE Parameter

SPACE=(unit,(primary,secondary,directory),RLSE,CONTIG,ROUND)

Examples:

SPACE=(CYL,(10,5),RLSE)             Sequential file: 10 primary, 5 secondary cylinders
SPACE=(TRK,(100,50,10))             PDS: 100 tracks primary, 50 secondary, 10 dir blocks
SPACE=(27920,(500,100),RLSE,ROUND)  Block allocation rounded to cylinder boundary

DCB Parameter

DCB=(RECFM=xx,LRECL=nnnn,BLKSIZE=nnnnn)

Common DCB examples:

DCB=(RECFM=FB,LRECL=80,BLKSIZE=27920)     Standard 80-byte card-image file
DCB=(RECFM=FB,LRECL=133,BLKSIZE=27930)     Print file with 133-byte records
DCB=(RECFM=VB,LRECL=32756,BLKSIZE=32760)   Variable-length blocked file

4. IF/THEN/ELSE/ENDIF

The IF/THEN/ELSE construct provides a clearer alternative to the COND parameter for conditional step execution.

//name     IF (condition) THEN
//stepname EXEC ...
//         ...
//name     ELSE
//stepname EXEC ...
//         ...
//name     ENDIF

Condition Syntax

stepname.RC  operator  value

Logical Operators

Examples

//CHK1     IF (STEP01.RC = 0) THEN
//STEP02   EXEC PGM=NEXTPROG
//         ...
//CHK1     ELSE
//ERRSTEP  EXEC PGM=ERRHANDL
//         ...
//CHK1     ENDIF

//CHK2     IF (STEP01.RC <= 4 AND STEP02.RC = 0) THEN
//STEP03   EXEC PGM=FINALPGM
//CHK2     ENDIF

5. PROC and PEND

Procedures (PROCs) are reusable sets of JCL statements that can be parameterized and invoked from multiple jobs.

Cataloged Procedure

//procname PROC parameter=default,...
//STEP01   EXEC PGM=&PROGRAM
//INPUT    DD   DSN=&INFILE,DISP=SHR
//OUTPUT   DD   DSN=&OUTFILE,
//              DISP=(NEW,CATLG,DELETE),
//              SPACE=(CYL,(10,5),RLSE)
//         PEND

Invoking a Procedure

//STEP01   EXEC PROC=procname,PROGRAM=MYPROG,
//              INFILE=MY.INPUT.FILE,
//              OUTFILE=MY.OUTPUT.FILE

Overriding DD Statements in a PROC

//STEP01   EXEC PROC=MYPROC
//STEP01.INPUT DD DSN=OVERRIDE.INPUT.FILE,DISP=SHR

The format for overrides is stepname.ddname where stepname is the step within the PROC.

Symbolic Parameters

6. Common Utility Programs

IEBGENER — Sequential File Copy

//COPY     EXEC PGM=IEBGENER
//SYSUT1   DD   DSN=input.file,DISP=SHR
//SYSUT2   DD   DSN=output.file,DISP=(NEW,CATLG,DELETE),
//              SPACE=(CYL,(10,5),RLSE),
//              DCB=(RECFM=FB,LRECL=80,BLKSIZE=27920)
//SYSPRINT DD   SYSOUT=*
//SYSIN    DD   DUMMY

Use SYSIN DD DUMMY for a straight copy. Provide SYSIN control statements for record selection and reformatting.

IEBCOPY — PDS Copy/Compress

//* COPY MEMBERS FROM ONE PDS TO ANOTHER
//COPYSTEP EXEC PGM=IEBCOPY
//SYSUT3   DD   UNIT=SYSDA,SPACE=(CYL,(5,1))
//SYSUT4   DD   UNIT=SYSDA,SPACE=(CYL,(5,1))
//SYSPRINT DD   SYSOUT=*
//INDD     DD   DSN=source.pds,DISP=SHR
//OUTDD    DD   DSN=target.pds,DISP=SHR
//SYSIN    DD   *
  COPY OUTDD=OUTDD,INDD=INDD
  SELECT MEMBER=(MEMBER1,MEMBER2,MEMBER3)
/*

//* COMPRESS A PDS IN PLACE
//COMPRESS EXEC PGM=IEBCOPY
//SYSUT3   DD   UNIT=SYSDA,SPACE=(CYL,(5,1))
//SYSUT4   DD   UNIT=SYSDA,SPACE=(CYL,(5,1))
//SYSPRINT DD   SYSOUT=*
//MYPDS    DD   DSN=my.pds.library,DISP=OLD
//SYSIN    DD   *
  COPY OUTDD=MYPDS,INDD=MYPDS
/*

IDCAMS — Access Method Services (VSAM)

//* DEFINE A VSAM KSDS CLUSTER
//DEFVSAM  EXEC PGM=IDCAMS
//SYSPRINT DD   SYSOUT=*
//SYSIN    DD   *
  DEFINE CLUSTER (                          -
           NAME(MY.VSAM.CLUSTER)            -
           INDEXED                          -
           RECORDSIZE(200 200)              -
           KEYS(10 0)                       -
           SHAREOPTIONS(2 3)                -
           FREESPACE(20 10)                 -
         )                                  -
         DATA (                             -
           NAME(MY.VSAM.CLUSTER.DATA)       -
           CYLINDERS(10 5)                  -
           CONTROLINTERVALSIZE(4096)        -
         )                                  -
         INDEX (                            -
           NAME(MY.VSAM.CLUSTER.INDEX)      -
           CYLINDERS(2 1)                   -
         )
/*

//* DELETE A VSAM CLUSTER
//DELVSAM  EXEC PGM=IDCAMS
//SYSPRINT DD   SYSOUT=*
//SYSIN    DD   *
  DELETE MY.VSAM.CLUSTER CLUSTER PURGE
  SET MAXCC = 0
/*

//* REPRO (COPY DATA INTO VSAM)
//LOADVSAM EXEC PGM=IDCAMS
//INFILE   DD   DSN=my.sequential.file,DISP=SHR
//OUTFILE  DD   DSN=my.vsam.cluster,DISP=SHR
//SYSPRINT DD   SYSOUT=*
//SYSIN    DD   *
  REPRO INFILE(INFILE) OUTFILE(OUTFILE)
/*

//* LISTCAT (LIST CATALOG INFORMATION)
//LISTCAT  EXEC PGM=IDCAMS
//SYSPRINT DD   SYSOUT=*
//SYSIN    DD   *
  LISTCAT ENTRIES(MY.VSAM.CLUSTER) ALL
/*

//* VERIFY (FIX IMPROPERLY CLOSED VSAM FILE)
//VERIFY   EXEC PGM=IDCAMS
//SYSPRINT DD   SYSOUT=*
//MYCLUST  DD   DSN=MY.VSAM.CLUSTER,DISP=SHR
//SYSIN    DD   *
  VERIFY FILE(MYCLUST)
/*

DFSORT (ICEMAN) — Sort/Merge Utility

//SORT     EXEC PGM=SORT
//SORTIN   DD   DSN=input.file,DISP=SHR
//SORTOUT  DD   DSN=output.file,DISP=(NEW,CATLG,DELETE),
//              SPACE=(CYL,(10,5),RLSE),
//              DCB=(RECFM=FB,LRECL=80)
//SYSOUT   DD   SYSOUT=*
//SYSIN    DD   *
  SORT FIELDS=(1,10,CH,A,11,5,ZD,D)
  INCLUDE COND=(15,2,CH,EQ,C'NY')
  OUTREC FIELDS=(1,20,30,10,50,5)
/*

DFSORT Control Statements

Sort Field Data Types

7. Common JCL Error Messages

8. Dataset Naming Rules

1. Maximum total length: 44 characters
2. Composed of qualifiers separated by periods
3. Each qualifier: 1-8 characters
4. First character of each qualifier: A-Z, @, #, or $
5. Remaining characters: A-Z, 0-9, @, #, $, or hyphen
6. No embedded blanks
7. High-level qualifier (HLQ) typically corresponds to the owner's user ID or a system-defined prefix
8. Common conventions: - HLQ.PROJECT.TYPE.name (e.g., PROD.PAYROLL.DATA.MASTER) - GDG format: DSN.NAME(+1) for next generation, (0) for current, (-1) for previous

9. DD Name Conventions

JCL is essential for running COBOL programs in a mainframe batch environment. Mastering JCL is as important as mastering COBOL itself for productive mainframe development.