2008-03-26, 14:26(+00), Ron Eggler:
[...]
> Well for X11, not sure what would be about the others without X11... :?

Then that would be system dependant. On Linux, you could watch
/proc/interrupts for instance, there might be more specific
APIs.

On a terminal, you can look at the modification time of $(tty).

--
Stéphane