Input phase

DFSORT runs the two exit routines, EFS01 and EFS02, during the input phase. The EFS01 routine supports sorting or merging user-defined data types with user-defined collating sequences and is called once for each record. The EFS02 routine provides logic to include or omit records on user-defined data types and is called one or more times for each record, according to the logic.

Information is passed in both directions between DFSORT and the exit routines across the EFS01 and EFS02 parameter lists.

DFSORT supplies the EFS01 routine with fields in the parameter list containing:

An Extract Buffer Area to which the EFS01 routine must move all EFS control fields. See EFS01 user exit routine for more information.
The input data record.
An EFS Program Context Area (a private communication area for the EFS program).

When the EFS01 routine returns control to DFSORT, it must return a return code in general register 15.

DFSORT supplies the EFS02 routine with fields in the parameter list containing:

A Correlator Identifier, which identifies a relational condition containing EFS fields. See EFS02 user exit routine for more information.
The input data record.

When the EFS02 routine returns control to DFSORT, it must return a return code in general register 15.