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

Notice that the vertical bar (|) has replaced the first characters of each line,
indicating that the message is no longer held. When the user presses ENTER
the message disappears.
Example 3: Multiple CONSOLE Stages
This example shows how the insertion of multiple CONSOLE stages into the
pipeline affects output. It illustrates how the CONSOLE stages handle their input
streams, processing messages as they receive them. If single-line messages are
processed by multiple CONSOLE stages there is no way to predict in what order
the messages by one CONSOLE stage interfaces with messages written by other
CONSOLE stages. Study this example in conjunction with Example 4, which
demonstrates how adding the COLLECT stage to gather the pipeline messages into
a multiline message prior to a CONSOLE stage modifies the screen output.
This example shows how the insertion of the CONSOLE stage between other
stages affects output from the pipeline.
PIPE LITERAL ? This is the CCC message ?
| CONSOLE
| LITERAL / This is the BBB message /
| CONSOLE
| LITERAL ! This is the AAA message !
| CONSOLE
Output from the pipeline looks like this:
NetView Pipelines Device Drivers
NCCF NETVIEW CNM01 OPER5 02/01/10 10:40:10
* CNM01 PIPE LITERAL ? THIS IS THE CCC MESSAGE ? | CONSOLE | LITERAL / THIS
IS THE BBB MESSAGE / | CONSOLE | LITERAL ! THIS IS THE AAA MESSAGE
! | CONSOLE
| CNM01 THIS IS THE CCC MESSAGE (written by console stage # 1)
| CNM01 THIS IS THE BBB MESSAGE (written by console stage # 2)
| CNM01 THIS IS THE AAA MESSAGE (written by console stage # 3)
| CNM01 THIS IS THE CCC MESSAGE (written by console stage # 2)
| CNM01 THIS IS THE BBB MESSAGE (written by console stage # 3)
| CNM01 THIS IS THE CCC MESSAGE (written by console stage # 3)
Processing steps:
1. The first LITERAL stage writes the CCC message to the pipeline.
2. The first CONSOLE stage reads the CCC message and displays it on the screen.
The message remains in the pipeline.
3. The second LITERAL stage writes the BBB message to the output stream in
front of the CCC message in the stream.
4. The second CONSOLE stage reads the BBB message in its input stream and
writes it on the screen. The message also remains in the pipeline.
5. The third LITERAL stage writes the AAA message to the output stream in front
of the BBB and CCC messages in the stream.
6. The third CONSOLE stage reads the AAA message and writes it on the screen. It
also remains in the pipeline, although there are no additional stages to process
it.
7. The second CONSOLE stage reads the CCC message in its input stream and
writes it on the screen. The message also remains in the pipeline.
8. The third CONSOLE stage reads the BBB message in its input stream and writes
it on the screen. The message also remains in the pipeline, although there are
no additional stages to process it.
Chapter 3. NetView Pipelines Device Drivers 285