If there is a program that is not responding, you can manually terminate the program by using the
kill command. This command will send a specific signal to the unresponsive application and instruct the application to terminate itself.
There are forty-six signals in total that you can use, but generally these two signals are used:
SIGTERM (15)— prompts a program to stop running and gives it some time to save its state. If you do not specify the signal when entering the kill command, this will be used.
SIGKILL (9)— forcibly terminates process immediately. You lose the unsaved state.
Apart from knowing the signals, you also need to know the process identification number (
PID) of the program you want to terminate. If you do not know the
PID, run the
ps ux command.
Note: To search directly for a process, you can use grep:
ps ux | grep <process name>
After making sure you know which signal to use and the
PID of the program, enter the following syntax:
kill -<signal> <PID>