kill - terminate or signal a process
kill [-s signal_name] pid [...]
kill -l [exit_status]
kill -signal_name pid [...]
kill -signal_number pid [...]
The kill utility sends a signal to the process(es) specified
by the pid
operand(s). If no signal is specified, SIGTERM is used.
Only the superuser may send signals to other users' processes.
The options are as follows:
-s signal_name
A symbolic signal name specifying the signal to be
sent instead
of the default SIGTERM.
-l [exit_status]
If no operand is given, list the signal names; otherwise, write
the signal name corresponding to exit_status.
-signal_name
A symbolic signal name specifying the signal to be
sent instead
of the default SIGTERM.
-signal_number
A non-negative decimal integer specifying the signal
to be sent
instead of the default SIGTERM.
The following PIDs have special meanings:
-1 If superuser, broadcast the signal to all processes; otherwise,
broadcast to all processes belonging to
the user.
-pgid Send the signal to all processes within the
specified process
group.
Some of the more commonly used signals:
1 HUP (hang up)
2 INT (interrupt)
3 QUIT (quit)
6 ABRT (abort)
9 KILL (non-catchable, non-ignorable kill)
14 ALRM (alarm clock)
15 TERM (software termination signal)
For a more complete list, consult the sigaction(2) manual
page.
A signal number of 0 (kill -0 pid) checks the validity of a
certain PID,
to see if it exists. An exit code of 0 means that the specified process
exists.
The kill utility exists as a built-in to most shells; they
allow job
specifiers of the form ``%...'' as arguments, so process IDs
are not as
often used as kill arguments.
Forcibly terminate process ID 1234:
$ kill -9 1234
Send the inetd(8) daemon the hangup signal, instructing it
to re-read its
configuration from /etc/inetd.conf:
# kill -HUP `cat /var/run/inetd.pid`
csh(1), pkill(1), ps(1), sh(1), kill(2), sigaction(2)
The kill utility is expected to be IEEE Std 1003.2
(``POSIX.2'') compatible.
A kill command appeared in Version 3 AT&T UNIX.
OpenBSD 3.6 April 28, 1995
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