Find The Process Using A Specific Port On Mac
netstat utility is often recommended for finding the PID (process ID)
bound to a specific port. Unfortunately, Mac's version of netstat does not
-p (process) flag. Instead, you'll want to use the
$ sudo lsof -i tcp:4567
Running this will produce a nicely formatted response that tells you several
pieces of information about the process bound to
:4567 including the PID.