From: Daniel N <has.sox@...>
Date: 2006-08-03T23:40:39+09:00
Subject: Re: How to tell when IO::popen is finished?

------=_Part_9906_33085174.1154616034660
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
Content-Disposition: inline

On 8/4/06, Christopher Brown <cbrown@atbash.net> wrote:
>
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> If the IO::popen is creating a child process, how about calling
> Process.waitpid?  Once that returns, the subprocess will have
> completed and the file should be complete.
>
> Cheers,
> Chris



How would I get the pid that the child process is on?

On 03 Aug 2006, at 6:29 AM, Daniel N wrote:
>
> > Hi,
> >
> > I've just installed and had some success with the gnuplot library.
> >
> > I'm saving the output to a png file (plot.terminal "png") and this
> > all works
> > well, but when I try to use the file it isn't finished writing it
> > yet and I
> > get an exception.
> >
> > I've used
> >
> > Gnuplot.open(  ) do |gp|
> > ....
> > end
> >
> > while(!File.exists?("/test2.png") || File.zero?("/test2.png") )
> > sleep 0.1
> > end
> >
> > In an attempt to wait until the file is written before I try to do
> > anything
> > with it, but this seems a bit too hackish.
> >
> > Can I capture the Gnuplot.open into a variable and check it?  The last
> > statement in the Gnuplot.open is a call to
> > IO::popen( cmd, "w") { |io| yield io }
> >
> > but if I test the class of what is returned it is
> > Gnuplot::Plot
> >
> > not anything to do with IO
> >
> > Is there a way that I can test the IO::popen to tell when it's
> > finished?
>
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.3 (Darwin)
>
> iD8DBQFE0gh+rOGxDZoCCzURAuTIAKDYiSODiBkrNJRa16V/VzSybhLb/wCgm/7C
> BgaaVLCVUlngxwov8RNO8JY=
> =qb5q
> -----END PGP SIGNATURE-----
>
>

------=_Part_9906_33085174.1154616034660--