lsof -P -n | grep -i listen-P"inhibits the conversion of port numbers to port names for network files"-n"inhibits the conversion of network numbers to host names for network files"grep-ing bylistenlists only those ports that we're serving
lsof -P -n | grep -i listen-P "inhibits the conversion of port numbers to port names for network files"-n "inhibits the conversion of network numbers to host names for network files"grep-ing by listen lists only those ports that we're serving