System Level Procedures: Message Profiles › Message Handling and Processing by System Level Procedures

Message Handling and Processing by System Level Procedures

All system level procedures that have privileged access to a particular message flow have the following capabilities:

• They can read the next message from the traffic flow by using a privileged NCL verb statement which provides access to the queue of messages. The following verbs are used by specific system level procedures:

  &LOGREAD

  Used by the LOGPROC procedure to get a copy of the next message that is to be written to the activity log.

  &PPOREAD

  Used by the PPOPROC procedure to get a copy of the next message received from VTAM.

  &MSGREAD

  Used by a MSGPROC procedure to read the next message queued for display on the OCS window with which the procedure is associated.

  &INTREAD

  Used by any NCL procedure to read the next request or response queued to it via its dependent processing environment.

• They can indicate what is to be done with the message that they have received as a result of executing the 'read' statement. Typically, once a message has been received, the procedure can indicate that the message is to be processed normally (for example, &LOGCONT, &PPOCONT, &MSGCONT), or deleted and not propagated any further (for example, &LOGDEL, &MSGDEL), or replaced with an alternative message (for example, &MSGREPL).