Qualifying events

For certain types of events, you can use the QUAL and the QMASK parameters on the ENFREQ macro to more specifically define the event for which you would like to listen. For example, if you were listening for event code 37 without using the QUAL and QMASK parameters, you would receive notification when any SMF accounting-related event occurred. By using the QUAL and QMASK parameters, however, you can specify that you want to receive notification only when certain SMF accounting-related events occur. For instance, you can request notification only when SMF is initialized.

The QMASK parameter, in combination with the QUAL parameter, specifies the bytes of the four-byte qualifier that ENF uses to further define the event. The listener user exit routine receives control only when a system event occurs that matches the characteristics specified by the QMASK bytes of the QUAL field. The default for QMASK is QMASK=NONE.

For example, if QMASK=BYTE1, the listener user exit routine receives control when an event with characteristics described by the first byte in the qualifier occurs. Because QMASK=BYTE1, ENF ignores information in bytes 2 through 4.

If you specify ALL or NONE, do not code any other QMASK values. If you do not specify any QMASK values, the default is NONE.

The qualifiers that are valid depend on the system event for which you are listening. For a list of QUAL values see ENF event codes and meanings.