Issue listen request with QUAL=ENF37Q00

The following code segment sets up and loads into common storage the SMFLST00 listener user exit routine, which gains control only if the qualifier equals ENF37Q00.

Note that the qualifiers are declared in the IFAENF37 mapping macro. The ENFREQ macro specifies QMASK=ALL, which specifies that all four bytes of the qualifier mask are to be used in the qualifier comparison.

See SMFLST00 - Sample ENF listener user exit routine for a description of this listener user exit routine.

* Load ENF Listen Exit (SMFLST00) into common storage and save address
* SMFL00@ contains the address of the listener user exit routine
         .
         .
         ST    R00,SMFL00@
*
* Issue LISTEN Request for SMF Event Code (Qualifier ENF37Q00)
         L     R02,SMFL00@
         ENFREQ ACTION=LISTEN,    -- Function                          +
               CODE=ENFC37,       -- Event Code                        +
               EXIT=(R02),        -- Exit Address                      +
               QUAL=ENF37Q00,     -- Qualifier Value                   +
               QMASK=ALL,         -- Qualifier Mask (Full Word)        +
               ESTBNME=THISMOD,   -- Establisher Name                  +
               EXITNME=SMFLST00,  -- Exit Name                         +
               DTOKEN=SMFL00T     -- Returned Token Field
*
* Check the return code from ENFREQ - if not zero issue message
*