Ndtyjky

So I have a completely independent process, with a known PID.

I want to send it some kind of interrupt from another unrelated process that will cause it to 'gracefully' exit.

In linux it would look something like this :

first_script:

def signal_handler(signum, stack):

    print("SIGNAL RECIEVED")

    sys.exit()



signal.signal(signal.SIGUSR1, handle_signal)

while True:

    print("Im working")

Second script:

known_pid = input("Enter pid")

os.kill(int(known_pid), signal.SIGUSR1)

Since, Windows doesn't support signaling in this way, it obviously won't work but I couldn't find any other simple solution (After quite extensive research).

You can use the Windows API as provided by pywin32 or hack it with a socket.

The socket solution is quick and dirty:

# waiting process



import socket

import select

import time



server = socket.socket()

server.bind(('localhost', 1337))

server.listen(5)



# this select() call returns ([server], , )

# if server is readable, else (, , ), and waits 0 seconds

while not select.select([server], , , 0)[0]:

    print('working')

    time.sleep(0.5)





# parent process



import socket    

socket.create_connection(('localhost', 1337))

The windows solution is longer but more accurately represents the problem:

# waiting process



import time

import win32event



# open an existing event by name with the required access

# (didn't work for me with EVENT_MODIFY_STATE, got "Access denied" error)

event = win32event.OpenEvent(win32event.EVENT_ALL_ACCESS, 0, "MY_NAME")



# Wait 0 seconds on the event. If event has been set, WAIT_OBJECT_0 is returned

while win32event.WaitForSingleObject(event, 0) != win32event.WAIT_OBJECT_0:

    print('working')

    time.sleep(0.5)





# parent process

# note that it should be run first



import win32event

import time



# create event by name

event = win32event.CreateEvent(

    None,       # not inherited by child processes

    False,      # auto-reset the event after it is set

    False,      # created unset

    "MY_NAME",  # event name

)

time.sleep(5)  # wait for waiting process to start

win32event.SetEvent(event)

This is only a minimal POC. It is recommended that you read about event objects to find the exact solution that suits you.

How about consider using psutil, I think it is quite suitable for your case.

As stated in document, following code can do what you want. Though you may not need the part of find_procs_by_name.

import os

import signal

import psutil



def find_procs_by_name(name):

    "Return a list of processes matching 'name'."

    ls = 

    for p in psutil.process_iter(attrs=["name", "exe", "cmdline"]):

        if name == p.info['name'] or 

                p.info['exe'] and os.path.basename(p.info['exe']) == name or 

                p.info['cmdline'] and p.info['cmdline'][0] == name:

            ls.append(p)

    return ls



def kill_proc_tree(pid, sig=signal.SIGTERM, include_parent=True,

                   timeout=None, on_terminate=None):

    """Kill a process tree (including grandchildren) with signal

    "sig" and return a (gone, still_alive) tuple.

    "on_terminate", if specified, is a callabck function which is

    called as soon as a child terminates.

    """

    if pid == os.getpid():

        raise RuntimeError("I refuse to kill myself")

    parent = psutil.Process(pid)

    children = parent.children(recursive=True)

    if include_parent:

        children.append(parent)

    for p in children:

        p.send_signal(sig)

    gone, alive = psutil.wait_procs(children, timeout=timeout,

                                    callback=on_terminate)

    return (gone, alive)



pid = find_procs_by_name('POWERPNT.EXE')[0].pid

print(find_procs_by_name('POWERPNT.EXE')[0].pid)

kill_proc_tree(pid)