Run Process and Don't Wait

This call doesn't wait for the child process to terminate (on Linux). Don't ask me what close_fds does; I wrote the code some years ago. (BTW: The documentation of subprocess.Popen is confusing, IMHO.)

proc = Popen([cmd_str], shell=True,             stdin=None, stdout=None, stderr=None, close_fds=True)

Edit:

I looked at the the documentation of subprocess, and I believe the important aspect for you is stdin=None, stdout=None, stderr=None,. Otherwise Popen captures the program's output, and you are expected to look at it. close_fds makes the parent process' file handles inaccessible for the child.

I finally got this to work. I'm running "Python 2.6.6 (r266:84297, Aug 24 2010, 18:13:38) [MSC v.1500 64 bit (AMD64)] win32". Here's how I had to code it:

from subprocess import PopenDETACHED_PROCESS = 0x00000008cmd = [    sys.executable,    'c:\somepath\someprogram.exe',    parm1,    parm2,    parm3,]p = Popen(    cmd, shell=False, stdin=None, stdout=None, stderr=None,    close_fds=True, creationflags=DETACHED_PROCESS,)

This turns off all piping of standard input/output and does NOT execute the called program in the shell. Setting 'creationflags' to DETACHED_PROCESS seemed to do the trick for me. I forget where I found out about it, but an example is used here.

I think the simples way to implement this is using the os.spawn* family of functions passing the P_NOWAIT flag.

This for example will spawn a cp process to copy a large file to a new directory and not bother to wait for it.

import osos.spawnlp(os.P_NOWAIT, 'cp', 'cp', '/path/large-file.db', '/path/dest')