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Date:	Fri, 6 Nov 1992 07:03:35 -0500
From:	malte@techfak.uni-bielefeld.de
Message-Id: <9211061203.AA01626@dahlie.techfak.uni-bielefeld.de>
To:	rc@hawkwind.utcs.toronto.edu
Subject: Re: rc and signal handlers 
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