List processes and ports on Mac

• Show listening ports

lsof -i -nP | grep LISTEN

or with all processes

sudo lsof -i -nP | grep LISTEN

• Show ports with any state, e.g. ESTABLISHED, CLOSE_WAIT, CLOSED, LISTEN

sudo lsof -i -nP | grep TCP

or

sudo lsof -i -nP | grep UDP

Switches
-i select IPv[46] files
-n no host names
-P no port names

Refs
http://hints.macworld.com/article.php?story=20070425165628961