Monitoring external processes

[arunasunil at gmail.com]

On Oct 22, 11:33 pm, Graham Dumpleton <Graham.Dumple... at gmail.com>
wrote:
> On Oct 23, 3:09 pm, arunasu... at gmail.com wrote:
>
> > Hi,
>
> > Is there a way to track external processes launched by python on the
> > Mac? I am using subprocess module to launch the process.
>
> > Thanks
> > Sunil
>
> If using Python 2.3/2.4, you can use os.wait().
>
> If using Python 2.5, there is also have os.wait3() and os.wait4().
>
> See the operating system manual pages for the difference. Ie.,
>
>   man wait4
>
> Graham

I'm having a slight problem using wait3 or wait4. I want monitor a
launched process and get its resource usage information. When I call
os.wait4 with the pid the first time the call returns successfully but
the second time around I get a OSError with "No child processes"
error. I have tried using WCONTINUED, WNOHANG and WUNTRACED options.

Sunil.