How to kill a process running a particular port in Linux.

How To

Sometimes when stopping some applications the process will not kill itself correctly. This can lead to rogue processes consuming a port resource which will prevent your application stopping/starting/re-running. This can sometimes occur with some server applications like Tomcat, Python Flask, Python FastAPI or any scripts that do not exit gracefully.

Example with port 5000:

# will show the list of processes using port 8080
sudo lsof -t -i:5000

# see the PID and pass the PID to the following command
sudo kill -9 PID

Explained:

lsof stands for LiSt Open Files which is a Linux command to find out which files are open in which processes.

-t shows only the process IDs.

-i limit the processes to internet specific processes.

:5000 the port number.

kill kills a specific process.

-9 nuke it!

PID is the process ID that you want to kill.