The EFS interface consists of a variable-length parameter list used to communicate between DFSORT and your EFS program. DFSORT activates the EFS program you write at specific points during run-time, and communicates information back and forth across the interface as your EFS program runs.

You can activate your EFS program with the installation or run-time option EFS=name (name is the name of your EFS program):

See Specification/override of DFSORT options for override information. Figure 1 illustrates the role of the EFS interface in linking DFSORT's processing capabilities to the EFS program you write.

Figure 1. Relationship Between DFSORT and an EFS Program