Previous Topic: Using the User Exit

Next Topic: The Parameter List

User Exits › Transparency User Exit › Coding the User Exit

Coding the User Exit

The first 4 words of the user exit define the routines that are to get control at each of the 4 phases of the user exit - PRECMP, POSTCMP, PREXPD, and POSTXPD. If any of these addresses is zero, that phase does not get control. The routines follow the 4 word prolog.

To simplify coding, CA Compress supplies a prolog macro, ZXITPLOG, in the installation library. ZXITPLOG builds the following prolog logic:

  1. The 4 word entry point list, addressing the routines you specify for each phase, or zero for those you do not specify.
  2. Register equates, with comments.
  3. A dsect and a USING statement for the parameter list.
  4. Dsects for the RPL and ACB to permit you to address their fields symbolically.
  5. The module name, date, time, and user-specified identification field.