A Simple Restart Script

Let’s say that you have a Python script (or other command), called run.py, that you’d like to run in the background on a Linux OS and then end the session:

import time
while True:
    time.sleep(5)
    print("I'm awake!")

To prevent the session from timing out, one common way to avoid this is to use:

nohup ./run.py &> LOG &

This will execute the command in the background and also write any output to a LOG file. However, if I come back months later and forget that it is still running and I execute this command again then I might end up having multiple processes running the same command. To avoid this, we can do a little better and ensure that we kill the existing process. This typically requires recording the PID of the original process:

cat PID | xargs kill -9 2>/dev/null
nohup ./run.py &> LOG &
echo $! > PID

This simple little trick has come in handy many times and I hope you find it useful too!