Date: Wed, 17 May 2000 10:18:27 -0700 From: Doug Barton <DougB@gorean.org> To: Ben Smithurst <ben@scientia.demon.co.uk> Cc: Marc Silver <marcs@draenor.org>, freebsd-questions@freebsd.org Subject: Re: "Hangup" in mail from cron Message-ID: <3922D463.C2B7E366@gorean.org> References: <Pine.BSF.4.21.0005161231480.53178-100000@dt051n0b.san.rr.com> <20000517074925.F58332@draenor.org> <39223554.E45081A@gorean.org> <20000517141912.I10128@strontium.scientia.demon.co.uk>
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Ben Smithurst wrote:
>
> Doug Barton wrote:
>
> > if [ -n "${PID}" ]; then
> > kill -HUP $PID
> > else
>
> How is $PID obtained?
PID=`ps -auxww | grep httpd | grep root | grep -v grep | awk '{ print $2
}'`
> It looks to me like the HUP is being sent to the
> shell script somehow, that would explain why the shell prints "Hangup"
> and cron mails that to you. But I can't see how that would happen
> unless the code to get $PID is badly broken.
I see what you're saying, and it does sound like a valid option. I'm
concerned about this though, because that's the whole point of the -n
test.
> On further investigation it seems that the shell prints Hangup when one of
> its children sets SIGHUP, not when it itself gets SIGHUP. Anyway, knowing
> how PID is determined might be useful.
>
> > ps -auxww | grep httpd | grep -v grep
>
> ps -auxww | grep '[h]ttpd'
>
> ok, so I'm very fussy about using too many processes when one fewer
> would do. :-)
I certainly agree that reducing subshells is a worthy goal. However
that trick works with our (GNU) grep (although I've never seen a
satisfactory explanation of why) but it doesn't work with Sun's, and I
need my scripts to be portable.
Thanks,
Doug
--
"Live free or die"
- State motto of my ancestral homeland, New Hampshire
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