Address already in use: bind code example

Example 1: address already in use :::3001

lsof -i tcp:3001
kill -9 {PID}

Example 2: address already in use

# To see ports in use
sudo lsof -i -P -n | grep LISTEN 
sudo netstat -tulpn | grep LISTEN

Example 3: address already in use :::8081 windows

netstat -a -n -o 
//then find the pid which is running in this port and run 
taskkill /F /PID [pidnumber]

Example 4: address already in use

comSocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)