Check if a process is running using Python on Linux [duplicate]

Answer 1

On Windows, you can use WMI.

from win32com.client import GetObject
GetObject('winmgmts:').ExecQuery("Select * from Win32_Process where ProcessId = " + str(pid)).count

You can also use other filters. For example, I'm much more likely to just want to tell if a process is running by name and take action. For example, if DbgView isn't running, then start it.

if not GetObject('winmgmts:').ExecQuery("Select * from Win32_Process where Name = 'dbgview.exe'").count:
    subprocess.Popen(r"C:\U\dbgview.exe", shell=False)

You can also iterate and do other interesting things. Complete list of fields is here.

Answer 2

Try:

os.kill(pid, 0)

Should succeed (and do nothing) if the process exists, or throw an exception (that you can catch) if the process doesn't exist.

Answer 3

I know this is old, but I've used this and it seems to work; you can do a quick adaptation to convert from process name to process id:

 try:
    if len( os.popen( "ps -aef | grep -i 'myprocess' | grep -v 'grep' | awk '{ print $3 }'" ).read().strip().split( '\n' ) ) > 1:
        raise SystemExit(0)
 except Exception, e:
        raise e

Answer 4

This is a bit of a kludge, but on *nix you can use os.getpgid(pid) or os.kill(pid, sig) to test the existence of the process ID.

import os

def is_process_running(process_id):
    try:
        os.kill(process_id, 0)
        return True
    except OSError:
        return False

EDIT: Note that os.kill works on Windows (as of Python 2.7), while os.getpgid won't. But the Windows version calls TerminateProcess(), which will "unconditionally cause a process to exit", so I predict that it won't safely return the information you want without actually killing the process if it does exist.

If you're using Windows, please let us know, because none of these solutions are acceptable in that scenario.

Answer 5

Recently I had to list the running processes and did so:

def check_process(process):
  import re
  import subprocess

  returnprocess = False
  s = subprocess.Popen(["ps", "ax"],stdout=subprocess.PIPE)
  for x in s.stdout:
      if re.search(process, x):
          returnprocess = True

  if returnprocess == False:        
      print 'no process executing'
  if returnprocess == True:
      print 'process executing'