Kill Process On Port Ubuntu

You want to use backtick, not regular tick:

sudo kill -9 `sudo lsof -t -i:9001`

If that doesn’t work, you could also use $() for command interpolation:

sudo kill -9 $(sudo lsof -t -i:9001)

To list any process listening to the port 8080:

lsof -i:8080

To kill any process listening to the port 8080:

kill $(lsof -t -i:8080)

or more violently:

kill -9 $(lsof -t -i:8080)