IKJEFT01, IKJEFT1A, and IKJEFT1B

Category: JCL and z/OS Utilities

Overview

Three IBM mainframe terminal emulator programs that handle command execution and return code processing differently.

IKJEFT01

When a command completes with a non-zero return code, the program simply goes to the next command. If a command fails with an abend, the step terminates with condition code 12 (hex C). This program essentially masks or suppresses failure indicators.

IKJEFT1A

System abends cause the job step to terminate with completion code X'04C'
The completion code is returned to the caller via register 15
User abends also trigger termination with the code saved in register 15
Non-zero return codes from commands and programs are captured in register 15
However, non-zero codes from CLISTs do not affect register 15

IKJEFT1B

Both system and user abends result in job step termination with X'04C'
Non-zero returns from commands, programs, CLISTs, and REXX execs all trigger register 15 assignment and termination
Indirect failures don't interrupt processing

Key Distinction

IKJEFT1B handles CLIST and REXX return codes more comprehensively than IKJEFT1A, making it more suitable for error-sensitive batch jobs.