lsof
Which programs are using a specific tcp/udp port? lsof -i :portNumber lsof -i tcp:portNumber lsof -i udp:portNumber lsof -i :80 lsof -i :80 | grep LISTEN
Which programs are using a specific tcp/udp port? lsof -i :portNumber lsof -i tcp:portNumber lsof -i udp:portNumber lsof -i :80 lsof -i :80 | grep LISTEN