From: malte@techfak.uni-bielefeld.de
To: rc@hawkwind.utcs.toronto.edu
Subject: Re: rc and signal handlers
Date: Fri, 6 Nov 1992 07:03:35 -0500 [thread overview]
Message-ID: <9211061203.AA01626@dahlie.techfak.uni-bielefeld.de> (raw)
In-Reply-To: Mail from 'Chris Siebenmann <cks@hawkwind.utcs.toronto.edu>' dated: Thu, 5 Nov 1992 18:16:05 -0500
| Also, the man-page is not too clear about signals:
| "Only signals that are being ignored are passed on to programs run by rc"
| The should read "signals that are being caught", I guess.
The manpage is correct as written; caught signals are not passed on to
children, and revert to default behavior. Only ignored signals are passed
on to children.
If one thinks about how catching signals works, it becomes obvious that
this has to be that way.
- cks
This is perfectly true! But also ugly ! This way, one has to redefine signal
handlers for each backquote substitution. On BSD and System V children
inherit signal handlers when forking and one has to change them explicitly.
Could someone explain to me why rc does it automatically ? I'd rather prefer
a simple way to reset signal handlers, something like
fn sigreset {
for( sig in `{ whatis -s | cut -f2 '-d ' } )
eval fn $sig
}
About "return"ing from a signal handler: One really doesn't want to do that.
I just mentioned it to make it clear to beginners. What bothers me most is
that rc doesn't complain about a return when defining the function and that
everything is fine when invoking the function interactively. But, when the
signal is caught, you'll get "return outside of function".
Malte
next prev parent reply other threads:[~1992-11-06 12:03 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cks@hawkwind.utcs.toronto.edu>
1992-11-04 12:45 ` set subtract malte
1992-11-06 12:03 ` malte [this message]
1992-11-05 20:45 rc and signal handlers malte
1992-11-05 23:16 ` Chris Siebenmann
1992-11-05 22:00 Byron Rakitzis
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