This tutorial will quickly show you how to to find and kill processes on Linux, Mac and other Unix based systems such as CentOS based on the port number.
Finding a process on Unix
Let’s say I would like to kill a database process such as Postgres, which in turn, usually runs on the standard port 5432. First, let’s list the processes attached to port 5432:
lsof -i :5432
Which prints a list of processes connected to port 5432:
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME pgAdmin4 31159 bgasparotto 21u IPv6 0xabf485c509f250b7 0t0 TCP localhost:61843->localhost:postgresql (CLOSE_WAIT) pgAdmin4 31159 bgasparotto 22u IPv6 0xabf485c4f2d26737 0t0 TCP localhost:62091->localhost:postgresql (CLOSE_WAIT) java 42403 bgasparotto 126u IPv6 0xabf485c50bdb0737 0t0 TCP localhost:57785->localhost:postgresql (ESTABLISHED) java 42403 bgasparotto 134u IPv6 0xabf485c50bdb12b7 0t0 TCP localhost:57786->localhost:postgresql (ESTABLISHED)
Often you will find that it prints more processes than you were expecting. However, in our example, I know that pgAdmin4 is a strong candidate to be running our Postgres since it is the admin application, hence, let’s copy its process id (PID) 31159.
Killing a process on Unix
With the PID in hands, let’s kill it:
kill 31159
If you get an error saying you don’t have permission to kill this process as it might not have been started by your user, try adding sudo before the command (assuming you have admin privileges).
Now, if you list the processes connected to port 5432 again, you will notice that pgAdmin4 is no longer there:
lsof -i :5432 COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME java 42403 bgasparotto 126u IPv6 0xabf485c50bdb0737 0t0 TCP localhost:57785->localhost:postgresql (ESTABLISHED) java 42403 bgasparotto 134u IPv6 0xabf485c50bdb12b7 0t0 TCP localhost:57786->localhost:postgresql (ESTABLISHED)
Hope this helped you to kill processes on Linux and Mac.
Cya!