A way to intervene "after" in tcl

Question

I have written a tcl script where there is wait for 20 seconds in between. Sometimes I have to come out of the waiting (or rather stop ) in between. I have used: after 20000

Is there a way to stop the waiting?

Answer 1

If you just use:

after 20000

Then no, there's no way (other than killing the process with Ctrl+C or kill, of course).

If you want an interruptable wait in Tcl, use this:

after 20000 set done 1
vwait done

That will continue to service events and so can be interrupted. Save the token returned by after 20000 set done 1 and you can cancel the timer (e.g., if you want to reschedule it). Set the (global done) variable yourself otherwise and you'll finish waiting sooner.