Programming considerations

The exit must follow standard linkage conventions. It must save the registers on entry and restore the registers when it returns. The exit must be reusable and reentrant.

If you use the sample exit (IKJEFF53) in SYS1.SAMPLIB or write an exit that contains the same checking of the RACF® resource classes (JESJOBS and/or JESSPOOL), the exit will return without doing any jobname checking for the:

CANCEL command, if the RACF JESJOBS class is active
OUTPUT command, if the RACF JESSPOOL class is active

Note: If the RACF JESJOBS and JESSPOOL classes are inactive, jobname checking will be done.

The exit can check the command code in word 7 of the parameter list to determine which command processor invoked the exit. It can check the user ID, job name, and jobid to determine whether the command should execute based on your installation's processing requirements. Word 10 of the parameter list contains the address of a list of pointers and bits that reflect the syntax the user entered on the OUTPUT command. The exit can check word 10 to tailor processing of the OUTPUT command.

The exit can also return a message to the command processor, which the command processor displays to the user. The exit can return an informational message (return code of 8) or a message that requires a response (return code of 4). The exit must obtain the message text area and should free it.

The address of the user response is passed in word 6 of the parameter list. The command processor that invokes the exit obtains and frees the reply text area for the user response.

The exit can set different return codes to handle different types of processing. Before using return code 12, you should consider using return code 8 first to display a message to the user. You can also use return code 4 to display a message and prompt the user for a response. When the exit receives control again (with the same job name), it can then set a return code of 12. The exit itself must keep track of the processing it is performing and the return codes it sets.

The exit can use any of the TSO/E service routines in its processing. For a description of the service routines, see .

You can use the IKJEFFIE mapping macro instruction to format the parameter list. For CANCEL or STATUS, IKJEFFIE creates an assembler DSECT named IEDSECTD. For OUTPUT, IKJEFFIE creates two assembler DSECTs, IEDSECTD and IEOUTPLD. For the format of each DSECT, see .

For the CANCEL or STATUS command, issue:

IKJEFFIE IETYPE=CANST

For the OUTPUT command, or if the exit gets control for all three commands, issue:

IKJEFFIE IETYPE=OUTPUT

After you establish addressability with each DSECT, you can refer to the DSECT fields by name.