Kill process using a specific port...

I've been debugging an app that will sometimes get into an unresponsive state. The app is using the play framework, and I've been starting activator with the -jvm-debug option (and using port 9999). Sometimes when I try to terminate the activator terminal the CTRL+C will be ignored. I used lsof -i :9999 to find the pid to kill so that I can make changes and restart activator.

A quick search led me to this posting on askubuntu.com, and it shows that you can kill a list of pids returned by lsof by using this form:

kill -9 $(lsof -ti :9999)

The "t" tells lsof to print terse info, and the info that is printed is just the pid.