NET/MASTER Network Control Language (NCL) Programmer's Guide

System-Defined Error Handlers for Specific Conditions
Run-Time Error Handling
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The following system variables are set specifically for this error handler:
System Variable Setting of System Variable
&SYS.ERROR.NAME Contains the name after all substitution operations have been
performed.
&SYS.ERROR.VALUE Contains the value that had a conversion attempted upon it.
&SYS.ERROR.VALUEOK Contains 1 (TRUE) or 0 (FALSE).
Refer to the discussion on expressions and operators in the NonStop NET/MASTER
NCL Reference Manual for more information on type conversion.
The VARIABLE_ERROR
Error Handler
If present, the VARIABLE_ERROR error handler traps illegal variable names and
variable names used in an illegal context. These errors can occur with substitution or
assignment operations. This error handler also traps the case in which NCL detects an
error while using a mapped data object (MDO) variable. This error handler is set by
the following ON statement:
ON VARIABLE_ERROR statement
The following system variables are set specifically for this error handler:
System Variable Setting of System Variable
&SYS.ERROR.NAME Contains the name specification that caused the error to be raised. If
the error occurred during substitution, this is the name specification
before substitution. If the error occurred during assignment, this is the
name specification after substitution. In a VARS list (or equivalent) in
which the names resulting from an expression are in error, the value is
null.
&SYS.ERROR.VALUEOK Contains 1 (TRUE) or 0 (FALSE).
Refer to the discussion on variables in the NonStop NET/MASTER NCL Reference
Manual for more information on variables.
The VERB_ERROR Error
Handler
If present, the VERB_ERROR error handler is invoked when a verb detects a logical
error condition. Note that this error is not raised as a consequence of performing
expression evaluation or parsing before the verb is called. Examples are: a FILE
CLOSE verb is attempted before a file is opened with FILE OPEN; and a MSGCONT
is attempted before a MSGREAD.
This error handler is set by the following ON statement:
ON VERB_ERROR statement
Refer to the discussion on verb syntax and variable access methods in the NonStop
NET/MASTER NCL Reference Manual for more information on using verbs.