Examples of using the RDR procedure

The operator can invoke the RDR procedure to read:

A job stream from the second file of a tape named JOBTAP on device 180:
```
S  RDR,180,JOBTAP,LABEL=2,DSN=JOBS
```
A job stream from a cataloged library of jobs:
```
S  RDR,3330,DSN=PRODUCTN(PAYROLL)
```

A job stream starting with a specific job on a tape named JOBTAP, the operator must submit a job to JES2 similar to:

//READJOBx    JOB    ...
//            EXEC   RDR
//IEFRDER     DD     DSN=JOBS,VOL=SER=JOBTAP,
//                   UNIT=3400,DISP=OLD
//SYSIN       DD     *
              EDIT   START=JOBx
/*

By using conditional JCL, you can cause internal readers to start only under specific conditions. You can then form a dependent job or set of jobs that execute (without operator intervention) only when a master job executes in a manner you want.

For example, to submit BADNEWS only if GOODNEWS does not complete successfully, specify the following:

//STEPTHEN IF (RC = 0)THEN
//*
//GOODNEWS EXEC PGM=IEBGENER
//SYSPRINT DD DUMMY
//SYSIN  DD DUMMY
//SYSUT1  DD JOBS(JOBA)
//SYSUT2  DD SYSOUT=(A,INTRDR)
//*
//STEPELSE ELSE
//BADNEWS EXEC PGM=IEBGENER
//SYSPRINT DD DUMMY
//SYSIN  DD DUMMY
//SYSUT1  DD JOBS(JOBB)
//SYSUT2  DD SYSOUT=(A,INTRDR)
//*
//STEPEND ENDIF

User-written procedures and programs can further exploit the internal reader facility to select particular jobs, to generate special job streams, and to allow operator submission of production job streams.