From: Andreas Schwarz <f@...>
Date: 2007-03-05T06:33:09+09:00
Subject: Re: Strange interference between LSAPI, popen3 and MySQL

Ara wrote:
> On Mon, 5 Mar 2007, Andreas Schwarz wrote:
> 
>>>      def fork *a, &b
>> executed. Any ideas?
> hmmm. no.  must be related though.  i'm staring to thinks it's lsapi 
> which has
> setup all the funky at_exit handlers, and that this is causing you 
> grief...

I grepped for at_exit in the LSAPI source code, but didn't find 
anything. Maybe it's the stdout/stderr/stdin redirection stuff...

>> Who would have thought that simply calling an external program could be
>> so difficult...
> 
> me ;-)
> 
> ultimately, in ruby queue, i had to setup a drb process before setting 
> up db
> connections.  then i used that drb process to do all forking/waiting for 
> me.
> 
> here's another idea, try systemu, it does not use fork at all
> 
>    gem install systemu
> 
>    http://rubyforge.org/frs/?group_id=1024&release_id=7721
>    http://codeforpeople.com/lib/ruby/systemu/systemu-1.0.0/README

It seems to use popen, isn't this based on fork, too?

The reason I want to use popen3 is not that I need stdin/stderr, but 
that there is a clean way to pass arguments without having to build a 
command line (potential escaping problems etc.).

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