Writing exit routines to tailor the Network Print Facility

Installations can create exit routines to preclude the use of the Network Print Facility's own mechanism for routing by:

Creating the routing data area (RDA)
Modifying the key (for JES, DEST and CLASS, for example) and access the routing and options files
Modifying the RDA after it has been created
Modifying print data

Such exit routines must supply all the information the Network Print Facility requires involving routing and options. These optional exit routines can route output dynamically by modifying the routing data area (RDA), a critical data area described in more detail in The Routing Data Area (RDA).

See Table 1 for a short description of the Network Print Facility exits.

Table 1. Network Print Facility user exits
Exit	Description
*Routing Exits* - alter the routing of printed output Used to determine where output is printed. (Substitute for the routing file or options file, or both.) Used to modify routing file information. Used to modify options file information.	Two types: *General routing exit* - changes JES and VTAM® input parameters *before* the routing or options data is read. It can replace the functions of the routing or options files or change the key used to access the routing or options files. *Specific routing exit* - invoked after the routing or options data is read or *after* the general routing exit completes. It can change or augment the routing and options data obtained from those sources.
*Input record exit* - alters the content of the data to be printed. Invoked each time data is received by the Network Print Facility. Used to insert, modify, or delete application data. Used to modify routing or options data based on contents of application data.	Allows specification of reformatting, translation, encryption, or other installation-defined functions needed to accommodate output to destined printers.

The exits are entered through an MVS™ link and follow normal MVS register conventions.

This chapter presents the following information:

General routing exit information
Specific routing exit information
Input record exit information
The routing data area
Using the EZAPPFCD macro to generate the data areas you need