To kill a port on Mac and Linux:

Find the process using the port:

lsof -i:<PORT_NUMBER>

Kill the process with its PID:

kill -9 <PID>

The -9 flag forcefully terminates the process, while omitting it allows the process to terminate gracefully. Use -9 only as a last resort if the process is unresponsive.

Example:

Suppose you want to kill the process using port 3001. First, find the process and its PID:

lsof -i :3001

This will be the output:

COMMAND   PID USER   FD   TYPE             DEVICE SIZE/OFF NODE NAME
node    70648 anup   24u  IPv4 0xc0b4578b035212a7      0t0  TCP *:redwood-broker (LISTEN)

To kill the process with PID 70648 forcefully:

kill -9 70648

Please remember to replace <PORT_NUMBER> and <PID> in the commands with the actual port number and process ID you want to work with.