signal trapping

[Doug Gwyn]

In article <5423 at munnari.oz.au> darrenr at mullauna.cs.mu.OZ.AU (Darren REED) writes:
>Hi, how do I go about detecting when a user quits a program by dropping their
>connection via a network ?

If the networking support is any good, you should get a SIGHUP.

>Also, is it possible to write a signal handler for a SIGKILL which gets
>executed when a SIGKILL is received but doesn't stop the impending death ?

No, SIGKILL cannot be caught or ignored (as the manual says!)
SIGKILL is normally sent only as a last resort; SIGTERM is considered
a better way to try to kill a process.  SIGTERM can be caught.