I'm writing a script that shows a person a math expression (like "2 + 3")
waits for an answer, then returns if its right or wrong.
What I want though, is for it to wait something like 3 seconds and, if
there is no input, assume the user doesn't know and return "WRONG".
I thought of using 'later, in something like:
(setq A '(NIL))
(later A (timeout 3000) (in NIL (line T)))
(if (car A)
That is, make a child process in parallel, have It die after 3 seconds of
waiting for input, wait for three seconds, and do something depending on
whether the child returned a value (if it didn't, it timed out before the
but I don't know how to connect the new input channel to the current
So the questions are:
1) how to get the child to take over the input channel of the parent,
2) Is this the best way to do it? is there a better way?