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	Wed, 23 Sep 1998 11:11:19 -0500 (CDT)
Date: Wed, 23 Sep 1998 11:11:19 -0500
From: Dan Nelson <dnelson@emsphone.com>
To: Andre Albsmeier <andre.albsmeier@mchp.siemens.de>,
        Jon Hamilton <hamilton@pobox.com>
Cc: freebsd-questions@FreeBSD.ORG
Subject: Re: How to get the PID before a program is run? (No joke :-)
Message-ID: <19980923111119.A2733@emsphone.com>
References: <199809231352.PAA05460@david.siemens.de> <199809231400.QAA00941@internal>
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In the last episode (Sep 23), Andre Albsmeier said:
> someone wrote:
> > In message <199809230729.JAA12131@internal>, Andre Albsmeier wrote:
> > } I want to start a program but I need its PID before it is run.
> > } One way would be to load the program and send a -STOP signal very
> > } quickly. Then I have got the PID, can do some things and send a
> > } -CONT signal when finished.
> > 
> > It's actually fairly simple, though somewhat off the beaten path. 
> > Something like:
> > 
> > #!/bin/sh
> > echo "PID is $$"
> > exec /your/program/here
> 
> OK, this replaces my shell script. But I have to do some stuff later
> when /your/program/here is finished.

Well, you could call that script from _another_ script :)   You should
be able to do this in one shell script, like this:

#! /bin/sh
(
   echo $$ > /var/run/prog.pid
   echo 'program starting with pid $$'
   exec /bin/prog
)
echo 'program finished'

,but according to the sh manpage, subshells keep $$ at the original
shell's pid, so $$ in the above script has the wrong pid.  You'll have
to split it into two scripts.

	-Dan

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