Virtual Hometerm Subsystem (VHS) Manual (G06.24+, H06.04+, J06.03+)

Using VHS
Virtual Hometerm Subsystem (VHS) Manual—429311-002
3-9
Display Message Processing
Display Message Processing
When VHS receives a DISPLAY message (a WRITE), it updates its opener table to
reflect that the last message received was a DISPLAY and validates the text message
to ensure that no unprintable characters are present.
If the parameter ACCEPT-EXT-ASCII-CHARACTER (default is OFF) is set to ON, VHS
accepts these characters (for example, Kanji characters); if not, VHS converts these
characters into question marks (?).
If the parameter REMOVE-EXTRA-SPACES is set to ON, VHS replaces an occurrence
of multiple spaces by only one space in the DISPLAY message. It then adds a
timestamp to the message and writes the message to its current primary log file.
If the parameter GENERATE-DISPLAY-EVENT is set to ON, VHS generates an EMS
message with the ZEMS-TKN-TEXT token containing the text message received from
the application.
Note that DISPLAY type messages include all messages written using the WRITE
NonStop procedure. This includes DISPLAY messages in COBOL in addition to all
messages from the COBOL 74 and COBOL85 run-time libraries.
Inspect Prompt Processing
When VHS receives an Inspect message, it logs all display messages received from
Inspect in its Primary log file. At the first Inspect prompt received, VHS sends the SET
PROMPT PID LANGUAGE (SET P P,L) command. When the Inspect prompt returns, if
the AUTOMATIC-INSPECT-PROCESSING parameter is set to OFF:
•
VHS writes the prompt to its prompt file and the user can reply to this Inspect
prompt via the Prompt Browser screen.
Or, if the AUTOMATIC-INSPECT-PROCESSING parameter is set to ON:
•
VHS extracts the name and the PID of the application from the result of the
SET P P,L command.
•
VHS extracts the language of the application trapped into Inspect from the ENV
Inspect command.
•
When Inspect prompts VHS back, VHS tries to find a match between the
application information and one of the sections from the VHS Inspect file. The VHS
Inspect file format is described later in this section.
•
When a section matched the application information, VHS sends the commands of
this particular section to Inspect. If, after executing the Inspect commands, Inspect
prompts VHS again, VHS creates a saveabend file and stops the application.
•
When none of the VHS Inspect file sections matched the application information
trapped into Inspect, VHS creates a saveabend file and stops the application.