Virtual Hometerm Subsystem (VHS) Manual (H06.03+)

Using VHS

Virtual Hometerm Subsystem (VHS) Manual—429311-001

3-10

OPEN Message Processing

When VHS receives an OPEN message, it goes through the following steps:

1. VHS adds an entry into the opener table and executes the NonStop Kernel

procedure PROCESSINFO to determine the name of the object file of the process.

2. If the object file name is equal to Inspect, then VHS sets the opener type as

Inspect.

3. If the state of the program is Debug, then VHS sets the opener type as Debug.

4. For all the other openers, VHS sets the opener type as Unknown.

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 Kernel procedure. This includes DISPLAY messages in COBOL as well as 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 and, at the first Inspect prompt received, VHS sends the

SET PROMPT PID LANGUAGE (SET P P,L) command. When the Inspect prompt

comes back and if the AUTOMATIC-INSPECT-PROCESSING parameter is set to OFF:

•

VHS writes the prompt to its prompt file and the user is able to reply to this Inspect

prompt via the Prompt Browser screen.

Or, if the AUTOMATIC-INSPECT-PROCESSING parameter is set to ON:

Note. VHS cannot be opened by remote processes. VHS can only be opened by local

processes.