It'd be nice if you could create a command using 'define' and then use 'handle' to specify that when a signal is given you want execution to pause *and* execute your command. This can be useful for diagnosing time sensitive bugs (my command might include some 'shell sleep' calls) or GUIs where you don't want to move your mouse back to the terminal window because it'll trigger more X events.
I'm closing this as a dup; I think it is a restatement of the "catch signal" idea. *** This bug has been marked as a duplicate of 7221 ***