Trying to kill a daemon at logout time

[Chip Salzenberg]

According to madd at world.std.com (jim frost):
>peter at ficc.uu.net (Peter da Silva) writes:
>>	signal(SIGHUP, exit);
>
>Doesn't happen under csh background processes.  (I call that a
>"feature" :-).

It *does* happen -- under V7, SysVr0, SysVr1, SysVr2 and their
derivatives, such as Xenix.

Without a signal mask, the only protection a background task has
against SIGHUP is the signal(SIGHUP, SIG_IGN) call done in csh.  Once
you've overridden the SIG_IGN, you'll get the SIGHUP.  Of course,
there's no guarantee that you'll call signal() in time.  :-(

Of course, BSD and SysVr4 have signal masks, so for those
environments, Jim is right.  SysVr3?  Who knows?  :-)
-- 
Chip Salzenberg at ComDev/TCT   <chip%tct at ateng.com>, <uunet!ateng!tct!chip>