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Manual Pages  — KILL

NAME

kill – terminate or signal a process

CONTENTS

SYNOPSIS


kill [-s signal_name] pid ...
kill -l [exit_status]
kill signal_name pid ...
kill signal_number pid ...

DESCRIPTION

The kill utility sends a signal to the processes specified by the pid operands.

Only the super-user 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 TERM.
-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 TERM.
signal_number
  A non-negative decimal integer, specifying the signal to be sent instead of the default TERM.

The following PIDs have special meanings:
0 The signal is sent to all processes whose group ID is equal to the process group ID of the sender, and for which the process has permission.
-1 If superuser, broadcast the signal to all processes; otherwise broadcast to all processes belonging to the user.
-PGID The signal is sent to all processes that belong to the specified process group ID (PGID).

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)

Some shells may provide a builtin kill command which is similar or identical to this utility. Consult the builtin(1) manual page.

EXIT STATUS

The utility exits 0 on success, and >0 if an error occurs.

EXAMPLES

Terminate the processes with PIDs 142 and 157:

    kill 142 157

Send the hangup signal ( SIGHUP) to the process with PID 507:

    kill -s HUP 507

Terminate the process group with PGID 117:

    kill -- -117

SEE ALSO

builtin(1), csh(1), killall(1), ps(1), sh(1), kill(2), sigaction(2)

STANDARDS

The kill utility is expected to be IEEE Std 1003.2 ("POSIX.2") compatible.

HISTORY

A kill command appeared in AT&T v3 in section 8 of the manual.

BUGS

A replacement for the command "kill 0" for csh(1) users should be provided.

KILL (1) October 3, 2016

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