From help-octave-request at bevo dot che dot wisc dot edu Fri Feb 14 12:11:54 2003
Subject: Blocking I/O to gnuplot pipe
From: "John W. Eaton" <jwe at bevo dot che dot wisc dot edu>
To: David Bateman<David dot Bateman at motorola dot com>
Cc: <help-octave at bevo dot che dot wisc dot edu>
Date: Fri, 14 Feb 2003 12:11:46 -0600

On 14-Feb-2003, David Bateman <David dot Bateman at motorola dot com> wrote:

| So, what I wanted to know. Is there a file descriptor for the gnuplot
| pipe in a script file?  Can I use "fcntl" on it to clear the
| O_NONBLOCK flag?

I don't think there is really a solution for this problem (other than
fixing gnuplot, or perhaps giving up on it entirely for Octave).  Even
if you delete the file as soon as gnuplot has opened it the first time,
then replot will fail.  And how do you know that gnuplot will have it
opened immediately after you send the command, even with blocking I/O?
Isn't there still a race condition?

BTW, you might also think that it would be better to use gnuplot's
ability to read data in the command stream, but that has other
problems that are just about as bad.

jwe



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