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Diffstat (limited to 'static/openbsd/man2/kill.2')
| -rw-r--r-- | static/openbsd/man2/kill.2 | 168 |
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diff --git a/static/openbsd/man2/kill.2 b/static/openbsd/man2/kill.2 new file mode 100644 index 00000000..f12cc4b0 --- /dev/null +++ b/static/openbsd/man2/kill.2 @@ -0,0 +1,168 @@ +.\" $OpenBSD: kill.2,v 1.26 2020/02/08 01:09:57 jsg Exp $ +.\" $NetBSD: kill.2,v 1.7 1995/02/27 12:33:53 cgd Exp $ +.\" +.\" 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. 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 +.\" +.Dd $Mdocdate: February 8 2020 $ +.Dt KILL 2 +.Os +.Sh NAME +.Nm kill +.Nd send signal to a process +.Sh SYNOPSIS +.In signal.h +.Ft int +.Fn kill "pid_t pid" "int sig" +.Sh DESCRIPTION +The +.Fn kill +function sends the signal given by +.Fa sig +to +.Fa pid , +a +process or a group of processes. +.Fa sig +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 superuser). +A single exception is the signal +.Dv SIGCONT , +which may always be sent +to any process with the same session ID as the caller. +.Bl -tag -width Ds +.It \&If Fa pid No \&is greater than zero : +.Fa sig +is sent to the process whose ID is equal to +.Fa pid . +.It \&If Fa pid No \&is zero : +.Fa sig +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 3 . +.It \&If Fa pid No \&is -1 : +If the user has superuser privileges, +the signal is sent to all processes excluding +system processes and the process sending the signal. +If the user is not the superuser, 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. +.It \&If Fa pid No \&is negative but not -1 : +.Fa sig +is sent to all processes whose process group ID +is equal to the absolute value of +.Fa pid ; +this is a variant of +.Xr killpg 3 . +.El +.Pp +If the value of +.Fa pid +causes +.Fa sig +to be sent to the calling process, either +.Fa sig +or at least one pending unblocked signal will be delivered before +.Fn kill +returns unless +.Fa sig +is blocked in the calling thread, +.Fa sig +is unblocked in another thread, or another thread is waiting for +.Fa sig +in +.Fn sigwait . +.Pp +Setuid and setgid processes are dealt with slightly differently. +For the non-root user, to prevent attacks against such processes, some signal +deliveries are not permitted and return the error +.Er EPERM . +The following signals are allowed through to this class of processes: +.Dv SIGKILL , +.Dv SIGINT , +.Dv SIGTERM , +.Dv SIGSTOP , +.Dv SIGTTIN , +.Dv SIGTTOU , +.Dv SIGTSTP , +.Dv SIGHUP , +.Dv SIGUSR1 , +.Dv SIGUSR2 . +.Sh RETURN VALUES +.Rv -std +.Sh ERRORS +.Fn kill +will fail and no signal will be sent if: +.Bl -tag -width Er +.It Bq Er EINVAL +.Fa sig +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 EPERM +The sending process is not the superuser 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 none of the members +of the group could be signaled. +.El +.Sh SEE ALSO +.Xr getpgrp 2 , +.Xr getpid 2 , +.Xr sigaction 2 , +.Xr killpg 3 , +.Xr raise 3 +.Sh STANDARDS +The +.Fn kill +function conforms to +.St -p1003.1-2008 . +.Sh HISTORY +The +.Fn kill +system call first appeared in +.At v2 . +The +.Fa sig +argument was introduced in +.At v4 . |