Execute Linux Command and Get PID

Question

Normally I use:

os.popen("du folder >> 1.txt ").read()

It was working fine.
But when I wanted to grab the subprocess id, it returns the empty value.

os.popen("du folder >> 1.txt &").read() # Notice the & symbol

Does anyone know why and how to get the PID?

Answer 1

You'll want to use the subprocess module.

# Can't use shell=True if you want the pid of `du`, not the
# shell, so we have to do the redirection to file ourselves
proc = subprocess.Popen("/usr/bin/du folder", stdout=file("1.txt", "ab"))
print "PID:", proc.pid
print "Return code:", proc.wait()