Kill any process that is running on port 3000. Particularly useful for an HTTP server running an React application with NPM on Debian Linux.

kill-port.sh

#! /bin/sh

# Author: Jesse Wood
# Date: 2021-09-25
# 
# This script kills processes on the 3000 port.
# The default port for running react applications.

# Get the pid for processes running on port 3000.
id=`lsof -i tcp:3000 | grep '*:3000' | cut -d " " -f 5`

# Check if process exists?
if [ -z "${id}" ]; then
	# No pid on port 3000 exists.
	echo "Port 3000 is not in use.";
else 	
	# Kill the process.
	kill -9 "${id}";
fi