INT_FLAG
INT_FLAG
is a predefined variable set
to TRUE
when an interruption event is detected.
Syntax
INT_FLAG
Usage
INT_FLAG
is set to TRUE
by the runtime system when an
interruption event is detected by the runtime system. The interruption event is raised when the user
presses the interruption key, or when the graphical front-end sends an interruption event while the
program is running in a procedure or SQL query.
INT_FLAG
must be used with the DEFER INTERRUPT
configuration instruction. If the DEFER
INTERRUPT
instruction is not specified, and interruption signal will stop the program
execution.
When an interruption event occurs during a procedural instruction (FOR
loop),
the runtime system sets INT_FLAG
to TRUE
. It is up to the program
to check the INT_FLAG
variable.
When an interruption event occurs during an interactive instruction
(INPUT
, CONSTRUCT
), the runtime system sets
INT_FLAG
to TRUE
and exits from the interactive instruction. It is
recommended that you test INT_FLAG
after an interactive instruction to check
whether the input has been canceled.
Once INT_FLAG
is set to TRUE
, it must be reset to
FALSE
in order to detect a new interruption event.
INT_FLAG
will also be used by the runtime system as diagnostic flag for
predefined action block execution such as ON INSERT
in DISPLAY
ARRAY
.
Example
MAIN
DEFER INTERRUPT
LET INT_FLAG = FALSE
INPUT BY NAME ...
AFTER INPUT
IF INT_FLAG THEN
MESSAGE "The input is canceled."
END IF
...
END INPUT
...
END MAIN