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.\"     @(#)killpg.2	8.1 (Berkeley) 6/2/93
.\" $FreeBSD: src/lib/libc/compat-43/killpg.2,v 1.14 2007/01/09 00:27:49 imp Exp $
.\"
.Dd October 10, 2006
.Dt KILLPG 2
.Os
.Sh NAME
.Nm killpg
.Nd send signal to a process group
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In signal.h
.Ft int
.Fn killpg "pid_t pgrp" "int sig"
.Sh DESCRIPTION
The
.Fn killpg
function
sends the signal
.Fa sig
to the process group
.Fa pgrp .
See
.Xr sigaction 2
for a list of signals.
If
.Fa pgrp
is 0,
.Fn killpg
sends the signal to the sending process's process group.
.Pp
The sending process and members of the process group must
have the same effective user ID, or
the sender must be the super-user.
As a single special case the continue signal SIGCONT may be sent
to any process with the same session ID as the caller.
.Sh RETURN VALUES
.Rv -std killpg
.Sh ERRORS
The
.Fn killpg
function
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 EPERM
The sending process is not the super-user and one or more
of the target processes has an effective user ID different from that
of the sending process.
.It Bq Er ESRCH
No process can be found in the process group specified by
.Fa pgrp .
.It Bq Er ESRCH
The process group was given as 0
but the sending process does not have a process group.
.El
.Sh LEGACY SYNOPSIS
.Fd #include <sys/types.h>
.Fd #include <signal.h>
.Pp
The include file
.In sys/types.h
is necessary.
.Sh SEE ALSO
.Xr getpgrp 2 ,
.Xr kill 2 ,
.Xr sigaction 2 ,
.Xr compat 5
.Sh HISTORY
The
.Fn killpg
function appeared in
.Bx 4.0 .