Date: Wed, 13 Aug 1997 00:13:36 +0400 (MSD) From: =?KOI8-R?B?4c7E0sXKIP7F0s7P1w==?= <ache@nagual.pp.ru> To: =?KOI8-R?Q?S=F8ren_Schmidt?= <sos@sos.freebsd.dk> Cc: current@FreeBSD.ORG Subject: Re: Error in sleep ! Message-ID: <Pine.BSF.3.96.970812235803.27379A-100000@lsd.relcom.eu.net> In-Reply-To: <199708121948.VAA01292@sos.freebsd.dk>
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On Tue, 12 Aug 1997, Søren Schmidt wrote:
> Well to quote sleep(1):
> The sleep command suspends execution for a minimum of seconds. sleep is
> used to schedule the execution of other commands (see EXAMPLES below).
>
> The sleep utility exits with one of the following values:
>
> 0 On successful completion, or if the signal SIGALRM was received.
>
> >0 An error occurred.
>
> This is not how our sleep(1) functions!, it'll exit on the first signal
> it gets, because of the change in sleep(3)'s behavior....
Your quote says nothing about /bin/sleep signals handling, only about exit
codes. When signal != SIGALRM comes sleep exit with exit code >=0 (An
error occured)
Here is quote from Solaris manpage (their manpages usually better
than ours :-)
SunOS 5.5.1 Last change: 1 Feb 1995 1
NOTES
If the sleep utility receives a SIGALRM signal, one of the
following actions will be taken:
+o Terminate normally with a zero exit status.
+o Effectively ignore the signal.
The sleep utility will take the standard action for all
other signals.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> Now one has to encapsulte sleep(3) in a while loop to get it to
> actually sleep the specified time, thats plain an simple stupid,
> and also poses a risk for busy looping, a complete no-no i an
> *IX system...
You can complain to POSIX commetee. BTW, it is strange for me
1) Why sleep must be different than, say, cat which exits on signal
coming...
2) Why you send signals to sleep, if you want to sleep specified time.
Even if you do such nasty things, use 'trap' to block signals before
sleep.
--
Andrey A. Chernov
<ache@null.net>
http://www.nagual.pp.ru/~ache/
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