Linux Command Library


send a signal to a process

- 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 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, it until a SIGCONT ("continue") signal is received:
kill -[17|STOP] [process_id]

kill [options] <pid> [...]

The default signal for kill is TERM. Use -l or -L to list available signals. Particularly useful signals include HUP, INT, KILL, STOP, CONT, and 0. Alternate signals may be specified in three ways: -9, -SIGKILL or -KILL. Negative PID values may be used to choose whole process groups; see the PGID column in ps command output. A PID of -1 is special; it indicates all processes except the kill process itself and init.

<pid> [...]
Send signal to every <pid> listed.
-s <signal> --signal <signal> Specify the signal to be sent. The signal can be specified by using name or number. The behavior of signals is explained in signal(7) manual page.
-l, --list [signal]
List signal names. This option has optional argument, which will convert signal number to signal name, or other way round.
-L, --table
List signal names in a nice table.

Your shell (command line interpreter) may have a built-in kill command. You may need to run the command described here as /bin/kill to solve the conflict.

kill -9 -1
Kill all processes you can kill.
kill -l 11
Translate number 11 into a signal name.
kill -L
List the available signal choices in a nice table.
kill 123 543 2341 3453
Send the default signal, SIGTERM, to all those processes.

kill(2), killall(1), nice(1), pkill(1), renice(1), signal(7), skill(1)

This command meets appropriate standards. The -L flag is Linux-specific.

Albert Cahalan wrote kill in 1999 to replace a bsdutils one that was not standards compliant. The util-linux one might also work correctly.

Please send bug reports to

play store download app store download
Sonnenallee 29, 12047 Berlin, Germany

Privacy policy
Successfully copied