netstat, listeners, processes
It’s never too late to learn something that would have saved your hide eons ago:
netstat -lntp
Produces output that looks like:
(Not all processes could be identified, non-owned process info
will not be shown, you would have to be root to see it all.)
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:3000 0.0.0.0:* LISTEN 541328/node