is_interrupted

is_interrupted
{-check | -start | -stop} 

Description

Controls the interrupt checker. You use the interrupt checker in Tcl scripts to break out of sequences and loops.

Arguments

-check	Checks for a user interrupt. If the ESC key has been pressed, the command returns true.
-start	Starts the interrupt checker.
-stop	Stops the interrupt checker.

Value Returned

true | false

For is_interrupted -check, specifies whether the ESC key has been pressed when the interrupt checker is active.

Examples

The following example illustrates how to start, check, and stop the interrupt checker in a script.

# start the interrupt checker
is_interrupt -start

while {<condition is true>} {
   # has the ESC key been pressed? 
   if {[is_interrupted -check]} {
      # user interrupted loop. Stop the interrupt checker and break out.
      is_interrupted -stop
      return;

   }
   # No interrupt, continue with normal loop processing here
}

# stop the interrupt checker
is_interrupted -stop

Related Topics

System Commands

pause

Return to top