Recently I was trying to use bash/terminal to kill a running process on my local machine. I’d been running a Python service that was hanging and wouldn’t stop so I knew it was going to take something a little more to free-up the port it was hogging. Like with most terminal commands, my memory drew a blank and I had to do a quick Google search to find the exact command I was looking for. There’s a few ways of doing this but here’s the usual way of killing a running process.

Using Bash/Terminal

Get the process attached to the port you need to free-up (e.g. port 4000)

lsof -i :4000

Kill the process using the process ID retrieved from the above command

kill -9 <process ID>

The above will kill a process immediately and should make the desired port available.

Using NodeJS

After doing a bit more searching, I came across a new way of killing processes that I’ve since started using. There is one prerequisite - it requires NodeJS and NPM to be installed. If you have NodeJS and NPM installed, you can run the following command and it will kill any running process on the port specified.

npx kill-port 3000

Installing NodeJS and NPM purely for killing running processes seems a bit excessive, but if you already have them installed, this feels like a great alternative compared to the original commands I’ve listed above using bash/terminal. It’s much more concise and reduces the need to lookup process IDs before you can kill a running process.

-Andrew