Kill

kill command is used to terminate a process manually. It sends a signal which ultimately terminates or kills a particular process or group of processes.

Usage¶

Syntax

kill [OPTION] [PID]

Terminate a program using the default SIGTERM (terminate) signal:

      kill process_id

  List available signal names (to be used without the `SIG` prefix):

      kill -l

  Terminate a background job:

      kill %job_id

  Terminate a program using the SIGHUP (hang up) signal. Many daemons will reload instead of terminating:

      kill -1|HUP process_id

  Terminate a program using the SIGINT (interrupt) signal. This is typically initiated by the user pressing `Ctrl + C`:

      kill -2|INT process_id

  Signal the operating system to immediately terminate a program (which gets no chance to capture the signal):

      kill -9|KILL process_id

  Signal the operating system to pause a program until a SIGCONT ("continue") signal is received:

      kill -17|STOP process_id

  Send a `SIGUSR1` signal to all processes with the given GID (group id):

      kill -SIGUSR1 -group_id

Most used signals¶

To get list of all signal names or signal number, use the command kill -l.

kill PID : Kill a process with a default signal
kill -1 : Restart
kill -2 : Interrupt from keyboard (like Ctrl C)
kill -9 : Forcefully kill the process
kill -15 : Kill a process gracefully.

Other similar kill commands¶

killall : kills the processes and its child processes as well.
pkill