I’m running lots of Angular 2 using the CLI on OSX (and loving it).

I have one small issue…

Often after stopping the app, when re-running it I get

‘Port 4200 is already in use.’

Here is a little linux magic for you:

lsof -t -i tcp:4200 | xargs kill -9 | ng serve

This will find the process using port 4200, kill it, then re-serve your application.

(Posted for my FireBootCamp students that are having this issue.)