The kill command takes the process ID as the argument. The killall command terminates the process by name:

    $ killall process_name

The -s option specifies the signal to send. By default, killall sends a SIGTERM signal:

    $ killall -s SIGNAL process_name

The -9 option forcibly kills a process by name:

    $ killall -9 process_name

Here's an example of the preceding:

    $ killall -9 gedit

The -u owner specifies the process's user:

    $ killall -u USERNAME process_name

The -I option makes killall run in interactive mode:

The pkill command is similar to the kill command, but by default it accepts a process name instead of a process ID:

    $ pkill process_name
    $ pkill -s SIGNAL process_name

SIGNAL is the signal number. The SIGNAL name is not supported with pkill. The pkill command provides many of the same options as the kill command. Check the pkill man pages for more details.