Finding the PID listening to a port-CodePudding

I use a bash script to run both the frontend and the backend of my full-stack application on macOS:

#!/usr/bin/env bash

export PORT="3001"
export API_PORT="5001"
export MAIN_URL="http://localhost:"

cd Client
npm run dev &
cd ..
nodemon index.js &

The issue is that I want to kill the PID listening to the port before I execute the npm and nodemon commands. Is there a way I can get the specific PID? Can I write the listening PID to a .pid file and then read from it when I want to kill?

CodePudding user response：

Try this:

pid=$(sudo lsof -i :3001 -F | grep '^p' | sed 's/^.//')
kill $pid

CodePudding user response：

I would rewrite that into

pid=$(lsof -i :$PORT -F pid | sed 's/^.//')

pid=$(lsof -i :$PORT -F pid)
pid=${pid:1}

depending on taste - if the lsof of Mac knows these options

sudo if needed - depends on the way it is installed