Killing processes with psutil

Question

I'm looking to write some code that will kill off a process based on it's name and who owns it. This works fine on Windows XP but when I come to run the same code on Windows 7 I get Access Denied errors when trying to get the username of the process.

Is there an easier way to kill a process that will work on XP and Win7?

The check to see if the process is owned by the 'SYSTEM' is actually needed so I can check when the process has user processes are finished, as the SYSTEM process remains, and I'm not concerned with this one.

PROCNAME = 'python.exe'
for proc in psutil.process_iter():
  if proc.name == PROCNAME:
    p = psutil.Process(proc.pid)
  
    if not 'SYSTEM' in p.username:
      proc.kill()

Solution 1

If you don't have the privilege to kill a process with PSUTIL, you're not going to have it with anything else. The first thing that comes to mind is, obviously, UAC, which appeared exactly between XP and Windows 7. Which implies that your PSUTIL must run from an elevated prompt, not surprising. Add a manifest to request elevation.

Solution 2

Starting october 2010 (see issue 114), username is obtained using a C function call (see get_process_username in the source)

This means it suffers from the problem described in this previous stackoverflow question

Basically you can catch the AccessDenied exception and assume the user is either 'SYSTEM' or 'LOCAL SERVICE'

Edit: From what I see there is also a bug in Python that causes many more AccessDenied errors than there should have been. The SetSeDebug function from psutil calls RevertToSelf at the end, practically reverting all the changes it has done.

Solution 3

the problem is some of the processes does not have names, and therefor you get the error.

If you put that in a try block it will work:

PROCNAME = 'python.exe'
for proc in psutil.process_iter():
  try:
      if proc.name == PROCNAME:
      p = psutil.Process(proc.pid)

      etc..
  except:
    pass