I have written a process-control program (in gforth) for use on
an eeePC-901 netbook. It all works very well. But there is a
practical problem:

Non-technical users will be using the keyboard on the netbook. It is
important that they not be able to accidentally kick the focus away
from the gforth program by hitting a key combination that takes the
focus to some other task. I fear, among MANY others, key strokes like Ctrl-D or
Ctrl-C, or a function key, etc. etc. It should only be possible to kick the
focus away from the gforth program by typing one arcane key combination
(specified by me, the programmer) that terminates the program, and takes the
focus back to the shell.

So, the question is, how do I protect the gforth program from the careless
operator?