156 lines
4.7 KiB
Groff
156 lines
4.7 KiB
Groff
.\" Copyright (c) 1980, 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)kill.2 8.3 (Berkeley) 4/19/94
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd April 19, 1994
|
|
.Dt KILL 2
|
|
.Os
|
|
.Sh NAME
|
|
.Nm kill
|
|
.Nd send signal to a process
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In sys/types.h
|
|
.In signal.h
|
|
.Ft int
|
|
.Fn kill "pid_t pid" "int sig"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn kill
|
|
system call sends the signal given by
|
|
.Fa sig
|
|
to
|
|
.Fa pid ,
|
|
a
|
|
process or a group of processes.
|
|
The
|
|
.Fa sig
|
|
argument
|
|
may be one of the signals specified in
|
|
.Xr sigaction 2
|
|
or it may be 0, in which case
|
|
error checking is performed but no
|
|
signal is actually sent.
|
|
This can be used to check the validity of
|
|
.Fa pid .
|
|
.Pp
|
|
For a process to have permission to send a signal to a process designated
|
|
by
|
|
.Fa pid ,
|
|
the real or effective user ID of the receiving process must match
|
|
that of the sending process or the user must have appropriate privileges
|
|
(such as given by a set-user-ID program or the user is the super-user).
|
|
A single exception is the signal SIGCONT, which may always be sent
|
|
to any descendant of the current process.
|
|
.Bl -tag -width Ds
|
|
.It \&If Fa pid No \&is greater than zero :
|
|
The
|
|
.Fa sig
|
|
signal
|
|
is sent to the process whose ID is equal to
|
|
.Fa pid .
|
|
.It \&If Fa pid No \&is zero :
|
|
The
|
|
.Fa sig
|
|
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;
|
|
this is a variant of
|
|
.Xr killpg 2 .
|
|
.It \&If Fa pid No \&is -1 :
|
|
If the user has super-user privileges,
|
|
the signal is sent to all processes excluding
|
|
system processes
|
|
(with
|
|
.Dv P_SYSTEM
|
|
flag set),
|
|
process with ID 1
|
|
(usually
|
|
.Xr init 8 ) ,
|
|
and the process sending the signal.
|
|
If the user is not the super user, the signal is sent to all processes
|
|
with the same uid as the user excluding the process sending the signal.
|
|
No error is returned if any process could be signaled.
|
|
.El
|
|
.Pp
|
|
For compatibility with System V,
|
|
if the process number is negative but not -1,
|
|
the signal is sent to all processes whose process group ID
|
|
is equal to the absolute value of the process number.
|
|
This is a variant of
|
|
.Xr killpg 2 .
|
|
.Sh RETURN VALUES
|
|
.Rv -std kill
|
|
.Sh ERRORS
|
|
The
|
|
.Fn kill
|
|
system call
|
|
will fail and no signal will be sent if:
|
|
.Bl -tag -width Er
|
|
.It Bq Er EINVAL
|
|
The
|
|
.Fa sig
|
|
argument
|
|
is not a valid signal number.
|
|
.It Bq Er ESRCH
|
|
No process can be found corresponding to that specified by
|
|
.Fa pid .
|
|
.It Bq Er ESRCH
|
|
The process id was given as 0
|
|
but the sending process does not have a process group.
|
|
.It Bq Er EPERM
|
|
The sending process is not the super-user and its effective
|
|
user id does not match the effective user-id of the receiving process.
|
|
When signaling a process group, this error is returned if any members
|
|
of the group could not be signaled.
|
|
.El
|
|
.Sh SEE ALSO
|
|
.Xr getpgrp 2 ,
|
|
.Xr getpid 2 ,
|
|
.Xr killpg 2 ,
|
|
.Xr sigaction 2 ,
|
|
.Xr raise 3 ,
|
|
.Xr init 8
|
|
.Sh STANDARDS
|
|
The
|
|
.Fn kill
|
|
system call is expected to conform to
|
|
.St -p1003.1-90 .
|
|
.Sh HISTORY
|
|
The
|
|
.Fn kill
|
|
function appeared in
|
|
.At v7 .
|