User exit coding example

Figure 1 shows how to code a user exit. The exit is called “MYEXIT”. It uses all user exit types and all request types. It uses the field AXPUSER to anchor the storage it has acquired to make it reenterable.

This user exit is not supplied with High Level Assembler. This exit is written for z/OS and CMS only.

The user exit does not show examples of how to open, read, write, or close a data set when it is responsible for opening the data set. Instead, it provides source records from its own storage, and writes output records to the operator using the WTO macro.

The user exit can be invoked as the following exit types.

SOURCE Exit—INEXIT: If you specify EXIT(INEXIT(MYEXIT)), the exit allows the assembler to open the input data set. The exit issues a WTO for each record read from the input data set.

If you specify EXIT(INEXIT(MYEXIT(EXIT))), the exit opens the input data set. It passes the following records to the assembler:

SMALL    TITLE 'Test the assembler exits'
         MACRO
         LITTLE
         BSM   0,14  Return
         MEND
         START
         OUTER
         LITTLE
         REPRO
This is to be written to the punch data set
         COPY  TINY
         END

LIBRARY Exit—LIBEXIT: If you specify EXIT(LIBEXIT(MYEXIT)), the exit allows the assembler to open the library data set. The exit issues a WTO for each record read from the library data set.

If you specify EXIT(LIBEXIT(MYEXIT(EXIT))), the exit opens the library data set. It passes the records for the following macros and COPY members to the assembler:

Macro OUTER
Macro INNER
COPY member TINY
COPY member TINY1

If you specify EXIT(LIBEXIT(MYEXIT(BOTH))), the exit and the assembler opens the library data sets. The exit passes the records for the following macros and COPY members to the assembler:

Macro OUTER
Macro INNER
COPY member TINY
COPY member TINY1

LISTING Exit—PRTEXIT: If you specify EXIT(PRTEXIT(MYEXIT)), the exit allows the assembler to open the listing data set. The exit issues a WTO for the first 80 characters of each listing record.

If you specify EXIT(PRTEXIT(MYEXIT(EXIT))), the exit opens the listing data set. The exit issues a WTO for the first 80 characters of each listing record passed to the exit.