Global user exit programs

You can use the CICS® global user exit points with programs of a special type that you write yourself called global user exit programs to customize your CICS regions.

A global user exit point or global user exit is a place in a CICS module or domain at which CICS can transfer control to a global user exit program that you have written. CICS can resume control when your exit program has finished its work.

Each global user exit point has a unique identifier, and is located at a point in the module or domain at which it might be useful to do some extra processing. For example, at exit point XSTOUT in the statistics domain, an exit program can be given control before each statistics record is written to the SMF data set, and can access the relevant statistics record. You might want to use an exit program at this exit point to examine the statistics record and suppress the writing of unwanted records.

Global user exit support is provided automatically by CICS. However, there are several conventions that govern how you write your exit program. These conventions are described in Writing global user exit programs. Because global user exit programs work as if they were part of the CICS module or domain, there are limits on the use you can make of CICS services. Most global user exit programs cannot use EXEC CICS commands, but can call some CICS services with the exit programming interface (XPI). For more information, see Using CICS services.

CICS provides two sets of sample and example global user exit programs. For more information, see Samples.