stdout redirect : Howto with popen2.popen3

[Eric Brunel]

Fabien Henon wrote:
[snip]
>   2. How can I tell when the raytrace is over ? The poll() gets out of
> the loop.
> What is command to listen to a program to tell if it's running or not?
[snip]
> while run.poll() <>-1:
>      print "attente"   # // I never got to here and goes straight to
> fd=open.....

Errr, maybe you just inverted the condition? The library reference says for 
the poll method on the Popen3 class: "poll() Returns -1 if child process 
hasn't completed yet, or its return code otherwise.". So, if I understand 
correctly, that means that while the child is running, poll() returns -1, 
and when the child has exited, poll() returns its exit code. So your loop 
should be:

while run.poll() == -1:
  # etc...

Didn't try it though. HTH however...
 - eric -