.\" Copyright (c) 1980, 1991 Regents of the University of California.
.\" All rights reserved.
.\"
.\" %%%LICENSE_START(BSD_4_CLAUSE_UCB)
.\" 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.
.\" %%%LICENSE_END
.\"
.\"     @(#)killpg.2	6.5 (Berkeley) 3/10/91
.\"
.\" Modified Fri Jul 23 21:55:01 1993 by Rik Faith <faith@cs.unc.edu>
.\" Modified Tue Oct 22 08:11:14 EDT 1996 by Eric S. Raymond <esr@thyrsus.com>
.\" Modified 2004-06-16 by Michael Kerrisk <mtk.manpages@gmail.com>
.\"     Added notes on CAP_KILL
.\" Modified 2004-06-21 by aeb
.\"
.TH KILLPG 3 2017-09-15 "Linux" "Linux Programmer's Manual"
.SH NAME
killpg \- send signal to a process group
.SH SYNOPSIS
.B #include <signal.h>
.PP
.BI "int killpg(int " pgrp ", int " sig );
.PP
.in -4n
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.in
.ad l
.TP 4
.BR killpg ():
_XOPEN_SOURCE\ >=\ 500
.\"    || _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED
    || /* Since glibc 2.19: */ _DEFAULT_SOURCE
    || /* Glibc versions <= 2.19: */ _BSD_SOURCE
.ad
.SH DESCRIPTION
.BR killpg ()
sends the signal
.I sig
to the process group
.IR pgrp .
See
.BR signal (7)
for a list of signals.
.PP
If
.I pgrp
is 0,
.BR killpg ()
sends the signal to the calling process's process group.
(POSIX says: if
.I pgrp
is less than or equal to 1, the behavior is undefined.)
.PP
For the permissions required to send a signal to another process, see
.BR kill (2).
.SH RETURN VALUE
On success, zero is returned.
On error, \-1 is returned, and
.I errno
is set appropriately.
.SH ERRORS
.TP
.B EINVAL
.I sig
is not a valid signal number.
.TP
.B EPERM
The process does not have permission to send the signal
to any of the target processes.
For the required permissions, see
.BR kill (2).
.TP
.B ESRCH
No process can be found in the process group specified by
.IR pgrp .
.TP
.B ESRCH
The process group was given as 0 but the sending process does not
have a process group.
.SH CONFORMING TO
POSIX.1-2001, POSIX.1-2008, SVr4, 4.4BSD
.RB ( killpg ()
first appeared in 4BSD).
.SH NOTES
There are various differences between the permission checking
in BSD-type systems and System\ V-type systems.
See the POSIX rationale for
.BR kill ().
A difference not mentioned by POSIX concerns the return
value
.BR EPERM :
BSD documents that no signal is sent and
.B EPERM
returned when the permission check failed for at least one target process,
while POSIX documents
.B EPERM
only when the permission check failed for all target processes.
.SS C library/kernel differences
On Linux,
.BR killpg ()
is implemented as a library function that makes the call
.IR "kill(-pgrp,\ sig)" .
.SH SEE ALSO
.BR getpgrp (2),
.BR kill (2),
.BR signal (2),
.BR capabilities (7),
.BR credentials (7)
.SH COLOPHON
This page is part of release 4.16 of the Linux
.I man-pages
project.
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
\%https://www.kernel.org/doc/man\-pages/.