At Major Call 1, your EFS program can send a control statement request list to indicate the control statements and EXEC PARM options you want DFSORT to send to your EFS program at Major Call 2. OUTFIL statements cannot be requested by an EFS program.

At Major Call 2, your EFS program can examine, alter, or ignore control statements and EXEC PARM options that DFSORT reads from the EXEC statement, SYSIN, SORTCNTL, DFSPARM, or a parameter list passed from an invoking program. OUTFIL statements cannot be passed to an EFS program or returned from an EFS program to be parsed.

Refer to Figure 1 for an illustration of the control statement processing sequence used when an EFS program is activated.

The same override rules apply to control statements and parameters returned from an EFS program as apply to the original control statements and parameters.

For example, a STOPAFT parameter added to the SORT statement by an EFS program is overridden by a STOPAFT parameter in an OPTION statement in the same way as if the SORT statement originally contained the STOPAFT parameter.

See Specification/override of DFSORT options for full override details.

Figure 1. Control Statement Processing Sequence