1. Find out what is running on a given port
$sudo lsof -i :4567
Password:
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
ruby 86461 zepho 9u IPv6 0xffffff803ac28f80 0t0 TCP localhost:tram (LISTEN)
ruby 86461 zepho 10u IPv4 0xffffff8022e51c00 0t0 TCP localhost:tram (LISTEN)
ruby 86461 zepho 11u IPv6 0xffffff802197bac0 0t0 TCP localhost:tram (LISTEN)
2. Check what process is running with that process id.
$ ps aux | grep 86461
zepho 86461 0.0 0.1 2492352 18280 s005 T 4:59PM 0:00.31 ruby hello.rb
zepho 91001 0.0 0.0 2434892 460 s005 R+ 8:37PM 0:00.00 grep 86461
3. Kill that mother fucker like this:
$ kill -9 86461
