Run a process and prepare it to terminate when it becomes orphan

RunMe.py

# -*- coding: utf-8 -*-

# RunMe.Py
# 2018 - Diego Queiroz
#
# Usage:
#    Linux  : python /path/to/RunMe.py /path/to/your/your_script.sh
#    Windows: C:\path\to\python.exe C:\path\to\RunMe.py C:\path\to\your_script.bat
#
import atexit
import subprocess
import os
import sys
import psutil

# It has only one parameter, that is the file to be called
# Be warned: it does NOT support complex scripts
# Each line of the script will be called until it find one that spawn a process
filename = ' '.join(sys.argv[1:])

def parent_running():
    return psutil.pid_exists(os.getppid())

with open(filename, 'r') as f:
    for line in f:
        # for each line of the script
        try:
            # spawn a new process and keep track of the PID
            process = subprocess.Popen(line[:-1], cwd=os.path.dirname(sys.argv[1]))

            # log process name
            print(os.linesep + os.path.dirname(filename)+ '>' + line + os.linesep)
            sys.stdout.flush()

            # mark the PID to terminate when this process terminate
            atexit.register(process.terminate)

            # wait 1 second for the process to run
            # this first check exists because sometimes
            # the process terminate very fast
            try:
                exitcode = process.wait(1)
            except subprocess.TimeoutExpired:
                exitcode = None

            # loop while process is still running
            while exitcode is None:
                # check if parent is running
                # if not, break loop
                if not parent_running():
                    exitcode = 255 # inform error
                    break

                # wait 1 second for the process to finish
                # then check again if the parent is running
                try:
                    exitcode = process.wait(1)
                except subprocess.TimeoutExpired:
                    exitcode = None

            # if the process terminated, break loop
            # if you want the script to check other lines
            # you may try to change this to "continue" instead of "break"
            if exitcode != 0:
                break

        except FileNotFoundError:
            # ignore if the process can't run (comments, etc)
            pass

    # propagate last exitcode
    sys.exit(exitcode)