kill

Kill a process by specifying its PID, either via a signal or forced termination.

Syntax
      kill [-s sigspec] [-n signum] [-sigspec] jobspec or pid
      kill -l [exit_status]
      kill -l [sigspec]

Key
   -l   List the signal names
   -s   Send a specific signal
   -n   Send a specific signal number

Send a signal specified by sigspec or signum to the process named by job specification jobspec or process ID pid.

sigspec is either a case-insensitive signal name such as SIGINT (with or without the SIG prefix) or a signal number; signum is a signal number.

If sigspec is not present, SIGTERM is used (Terminate).

If any arguments are supplied when '-l' is given, the names of the signals corresponding to the arguments are listed, and the return status is zero. exit_status is a number specifying a signal number or the exit status of a process terminated by a signal.

The return status is true if at least one signal was successfully sent, or false if an error occurs or an invalid option is encountered.

Common Kill Signals

Signal name	Signal value	Effect
SIGHUP	1	Hangup
SIGINT	2	Interrupt from keyboard
SIGQUIT	3	Quit
SIGABRT	6	Cancel
SIGKILL	9	Kill signal
SIGTERM	15	Termination signal - allow an orderly shutdown
SIGSTOP	17,19,23	Stop the process

This is a BASH shell builtin, to display your local syntax from the bash prompt type: help kill or man kill

Examples

List a running process:

$ ps
PID TTY TIME CMD
1293 pts/5 00:00:00 MyProgram

Then Kill it:

$ kill 1293
[2]+ Terminated MyProgram

To run a command and then kill it after 5 seconds:

$ my_command & sleep 5
$ kill -0 $! && kill $!

“Whom the gods love dies young” ~ Menander 300 BC

Related Linux commands

ctrl+z - Suspend a program.
ctrl+c - Interrupt a program.
bg - Put a process in the background.
jobs - List your own processes (returns Job No.).
killall - kill processes by name.
pkill - Kill processes by a full or partial name.
ps - List running processes (returns PID).
Xkill - Kill a malfunctioning program by clicking on its window.
Windows equivalent command: pskill- Stop a process from running.