IBM Tivoli NetView for z/OS Programming: Pipes - IBM notice

PIPE PERSIST
Usage Notes
180 Programming: Pipes
commands, the tText parameter is only written to the queue when the specified
timeout occurs. After receiving the message containing this text, the procedure
does not issue another WAIT FOR MESSAGES request or use the VIEW option
EXTEND with respect to the completed persist.
v Issue NCCF LIST PERSIST to get information about outstanding PERSIST
elements.
v The PERSIST stage defines the action to be taken for messages that arrive after
termination of the correlation represented by a CORRWAIT stage. The conditions
defined by PERSIST are enabled following termination of the preceding
CORRWAIT stage (WAIT) when one of the following statements is true:
– WAIT times out
– WAIT responds to GO or RESET
– WAIT end prematurely because of a PIPEND (non-zero return code)
– DEBUG option is in effect for the PERSIST stage
The PERSIST stage can be used after a NETV stage without any WAIT stage. In
this case, the PERSIST stage is always enabled and absorbs all messages from
the preceding command, even synchronous messages.
v The command, routing, or display specified on your PERSIST stages is activated
by the arrival of a message that was to be correlated to the CORRWAIT
preceding your PERSIST, had that wait not ended prematurely.
v Unless DEBUG is in effect, the PERSIST condition is disabled when an
affirmative end of processing is detected by PERSIST. All native NetView
commands provide this affirmative end signal when complete. For VTAM in
MVS release 10 and later, VTAM commands DISPLAY, MODIFY, and a few
VARY commands also provide it. MVS commands and most VTAM VARY
commands do not have an affirmative end.
v If you specify more than one PERSIST stage for a given command correlation
environment, only the last specified PERSIST stage takes effect.
v Messages subject to DISPLAY action are exposed to user exits, trapping,
automation, and logging just as for uncorrelated messages.
v Messages subject to ROUTE action are routed first, then are exposed as for other
messages.
v A message subject to COMMAND action is provided as the current message
when the indicated command runs. Any output from the command, including
the original message, is subject to exposure in the same way as the output of a
command issued from the command facility command line.
v When PERSIST invokes a command, it does so with the same authority as was
in effect for the pipeline which established the PERSIST action.
v When PERSIST TRAP is active, the invoking procedure can issue a WAIT FOR
MESSAGES command or use the EXTEND option on a VIEW command to wait
for additional data. When the persist completes, the REXX function EVENT()
returns a value of X.
v Do not use the TRAP option when including the PERSIST stage in sample
DSICCDEF.