Best way to determine if a certain PID is still running

[Thomas Guettler]

Am Thu, 02 Feb 2006 17:10:24 -0800 schrieb David Hirschfield:

> I'm launching a process via an os.spawnvp(os.P_NOWAIT,...) call.
> So now I have the pid of the process, and I want a way to see if that 
> process is complete.
> 
> I don't want to block on os.waitpid(), I just want a quick way to see if 
> the process I started is finished. I could popen("ps -p %d" % pid) and 
> see whether it's there anymore...but since pids get reused, there's the 
> chance (however remote) that I'd get a false positive, plus I don't 
> really like the idea of calling something non-pure-python to find out.

Hi,

at least on linux you can test this:
os.path.exists("/proc/%d" % mypid)

If you want to be sure that the pid is not reused, you
can look at: /proc/PID/cmdline

Maybe you can read the parent-pid in the proc directory. This should be
the pid if your script.

HTH,
 Thomas

-- 
Thomas Güttler, http://www.thomas-guettler.de/
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