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

* REXX COMMAND LIST PIPSTEMC */
’PIPE (STAGESEP !) LITERAL %THIS IS MY MESSAGE% ’,
’! DROP 1 ’,
’! STEM C.’
/* */
SAY ’VALUE OF C.0 IS:’ C.0
EXIT
Output from PIPSTEMC follows:
NCCF NETVIEW CNM01 OPER2 12/10/10 12:39:00
* CNM01 PIPSTEMC
C CNM01 VALUE OF C.0 IS: 0
Processing steps:
1. The LITERAL stage inserts the THIS IS MY MESSAGE message to the pipeline,
passing it to the next stage.
2. The DROP stage reads the message and discards it, leaving no messages in the
pipeline.
3. The STEM stage reads its input stream and, because it contains no messages,
cannot create variables C.1 ... C.n. It sets the variable C.0 to zero to indicate that
no messages were written.
Reading from or Writing to a Command Procedure Message:
SAFE
The SAFE stage writes to or reads from a queue of pipeline messages which have
complete message attributes and structure. Messages in a named SAFE can be
processed by a different pipeline as long as the pipeline resides within the same
NetView command list or the same family of nested NetView command lists.
When the NetView command list family is exited, the storage occupied by the
named SAFE is freed.
Messages in an unnamed SAFE cannot be processed by a different NetView
command list. When the current NetView command list is exited, the storage
occupied by the unnamed SAFE is freed.
Example: Reading and Writing a Message Using SAFE
NetView Pipelines Device Drivers
This example shows how to use a REXX command list to process two PIPE
commands using the SAFE stage. The first PIPE command writes messages to a
named SAFE, while the second reads the messages from the same named SAFE,
manipulates and displays them.
/* PIPSAFEA REXX COMMAND LIST */
/* THIS COMMAND LIST USES THE PIPE COMMAND AND THE SAFE STAGE */
/****************************************************************/
/* */
/****************************************************************/
/* PIPE # 1 */
/* DISPLAY REMOTE DOMAIN INFORMATION AND STORE IN SAFE NAMED */
/* HOLDMSG */
/****************************************************************/
’PIPE VTAM D NET,CDRMS’, /* issue command */
’| CORRWAIT 10’, /* wait for messages */
’| CONSOLE’, /* display to terminal */
’| SAFE HOLDMSG’ /* save in SAFE msg queue */
/****************************************************************/
/****************************************************************/
/* PIPE # 2 */
Chapter 3. NetView Pipelines Device Drivers 299