Riccardo Coppola

OS X/Linux: Check who is listening on a port

September 18, 2014

If you ever experienced errors like Fatal error: Port xxxxx is already in use by another process you may be interested in finding out who is actually using that port.

A simple one-liner that works on Mac OSX and Linux will tell you what you need: lsof -n -i4TCP:$PORT | grep LISTEN $PORT is the port you are trying to use.

Notes on web development, life, learning and the world.