Functions of the Output Writer Routine

When you specify IEFSD087 as the output writer on the SYSOUT= parameter of the DD statement, or when you leave this parameter blank, control will pass to the IBM-supplied output writing routine in module IEFSD087, and it:

Issues an OPEN (J type) for the input data set previously taken from the JES spool.
Provides its own SYNAD error-handling routine on behalf of both the input and output data sets. See z/OS DFSMSdfp Advanced Services for more information about OPEN-J and SYNAD.
Reads the input data set, using the locate mode of the GET macro.
Calls a subroutine to handle ANSI and machine control character differences and to handle conversions between the input records and the output data set.
Calls a routine to write records to the output data set, using the locate mode of the PUT macro.
Closes the input data set after it has been read.
Provides accounting support by updating fields in the SMF type 6 record for the input data set.
Frees the buffer associated with the input data set (by issuing the FREEPOOL macro).
Returns control to the main logic control module of the external writer, IASXWR00, using the RETURN macro and setting a return code.

Note: When writing multiple data sets to a PDS/PDSE member, if the ‘end-of-output-data-set’ condition arises, the output external writer cannot guarantee (even if you set CERTIFY=Y as a startup parameter) that all records will be saved. The current data set is saved, but all records written up to that point cannot be recovered in the case of writing to a PDS/PDSE member.

The following diagram shows the general flow of the IBM-supplied output writing routine:

Figure 1. General Flow of IBM's Output Writing Routine The diagram shows the general flow of the output writing routine.