quit_flag
quit_flag is a predefined variable set to TRUE when a
quit signal is detected.
Syntax
quit_flagUsage
quit_flag is set to TRUE when a quit signal is detected by the
runtime system. The quit signal is raised when the user presses the quit signal key
([Ctrl]+[Backslash]) in TUI mode, or when another process sends the SIGQUIT signal to the
fglrun process.
quit_flag must be used with the DEFER QUIT configuration instruction.
If the DEFER QUIT instruction is not specified, and quit signal will stop the
program execution.
When the quit signal arrives during a procedural instruction (FOR loop) and
DEFER QUIT is used, the runtime system sets quit_flag to
TRUE and continues the program execution. It is up to the program to check the
quit_flag variable.
When the quit signal arrives during an interactive instruction (INPUT,
CONSTRUCT) and DEFER QUIT is used, the runtime system sets
quit_flag to TRUE and continues with the execution of the
interactive instruction.
Once quit_flag is set to TRUE, it must be reset to
FALSE to detect a new quit event.
Example
MAIN
DEFINE n INTEGER
DEFER QUIT
LET quit_flag = FALSE
FOR n = 1 TO 1000
IF quit_flag THEN EXIT FOR END IF
...
END FOR
END MAIN