NET/MASTER Network Control Language (NCL) Reference Manual

&SYS.DOM.ID
System Variables
106126 Tandem Computers Incorporated 5–17
&SYS.DOM.ID The &SYS.DOM.ID system variable contains the message identifier (DOM ID) of a
non-roll-delete (NRD) message. The NRDDEL verb enables an NCL procedure to
delete a NRD message it has created before the procedure terminates. &SYS.DOM.ID
contains the DOM ID identifier that must be used with the NRDDEL verb to indicate
which NRD message is to be deleted.
NRD messages are used to communicate important information to the operator. When
displayed, they remain visible until explicitly deleted by the operator or the system.
NRD messages are generated by NCL procedures, and &SYS.DOM.ID is set by using
the WRITE verb with the NRD=YES option.
&SYS.DOM.ID
Considerations
The WRITE verb supports the NRD=OPER operand. NRD=OPER requests that a
NRD message be generated and that it should not be deleted when the procedure
terminates. &SYS.DOM.ID is not set for messages written using NRD=OPER, as
there is no deletion identifier for this type of message. Messages generated in this
manner must be deleted manually by the operator.
Only the last &SYS.DOM.ID value is kept. If you want to write multiple NRD
messages, write the procedure so that the value of each &SYS.DOM.ID is
preserved in user variables.
For more information on deleting messages, refer to the PURGE command in the
NonStop NET/MASTER MS Command Reference Manual.
See also the NRDDEL and WRITE verbs in Section 3, “Verbs.”
Example
The following example creates a NRD (non-roll-delete) message using the WRITE verb
and then marks the message for deletion:
APROC: PROCEDURE
WRITE NRD=YES DATA="A NRD MESSAGE"
/* Delete NRD message */
NRDDEL &SYS.DOM.ID
SAY "MESSAGE DELETED WITH DOM-ID = "&SYS.DOM.ID
END APROC
In the previous example, &SYS.DOM.ID is required to identify the message to be
deleted with the NRDDEL verb. The content of &SYS.DOM.ID is displayed before the
procedure terminates. The message remains marked for deletion until the space it
occupies on the terminal screen is required. At this point the NRD message
disappears.