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

Answer 1

On Windows another option is to use tasklist.exe:

Syntax: tasklist.exe /NH /FI "PID eq processID"

def IsProcessRunning( processId ):
    ps= subprocess.Popen(r'tasklist.exe /NH /FI "PID eq %d"' % (processId), shell=True, stdout=subprocess.PIPE)
    output = ps.stdout.read()
    ps.stdout.close()
    ps.wait()
    if processId in output:
       return True
    return False

Answer 2

You have to find it twice..

Like this :

ps -ef | grep 71676 | sed 's/71676//' | grep 71676

If this returns True then this is actually running !!

Answer 3

If that process belongs to the same user the checking process, you can just try to kill it. If you use signal 0, kill will not send anything but still allow you to tell if the process is available.

From kill(2):

If sig is 0, then no signal is sent, but error checking is still performed; this can be used to check for the existence of a process ID or process group ID.

This should propagate appropriately to python's methods.

Answer 4

The simplest answer in my opinion (albiet maybe not ideal), would be to change your

ps -ef | grep <pid>

To:

ps -ef | grep <pid> | grep -v grep

This will ignore the process listing for the grep search containing the PID of the process you are trying to find.

It seems user9876's answer is far more "pythonic" however.

Answer 5

You could check if the folder /proc/[process_id] exists.

 >>> import os.path
 >>> os.path.exists("/proc/0")
 False
 >>> os.path.exists("/proc/12")
 True

See this SO: How do you check in Linux with Python if a process is still running?

Answer 6

If you don't mind using external module I'd suggest psutil. It is cross-platform and easier to use than spawning subshell only for purpose of finding a running process.