Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

.\" Copyright (c) 1983, 1990, 1993, 1994, 2003
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" the Institute of Electrical and Electronics Engineers, Inc.
.\"
.\" 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.
.\"
.\"     from: @(#)chgrp.1	8.3 (Berkeley) 3/31/94
.\"	$NetBSD: chgrp.1,v 1.8 2017/07/04 06:52:20 wiz Exp $
.\"
.Dd October 22, 2012
.Dt CHGRP 1
.Os
.Sh NAME
.Nm chgrp
.Nd change group
.Sh SYNOPSIS
.Nm
.Oo
.Fl R
.Op Fl H | Fl L | Fl P
.Oc
.Op Fl fhv
.Ar group
.Ar
.Nm
.Oo
.Fl R
.Op Fl H | Fl L | Fl P
.Oc
.Op Fl fhv
.Fl Fl reference=rfile
.Ar
.Sh DESCRIPTION
The
.Nm
utility sets the group ID of the file named by each
.Ar file
operand to the
.Ar group
ID specified by the group operand,
or to the group of the given
.Ar rfile ,
specified by the
.Fl Fl reference
argument.
.Pp
Options:
.Bl -tag -width Ds
.It Fl H
If the
.Fl R
option is specified, symbolic links on the command line are followed.
(Symbolic links encountered in the tree traversal are not followed.)
.It Fl L
If the
.Fl R
option is specified, all symbolic links are followed.
.It Fl P
If the
.Fl R
option is specified, no symbolic links are followed.
.It Fl R
Change the group ID for the file hierarchies rooted
in the files instead of just the files themselves.
.It Fl f
The force option ignores errors, except for usage errors and doesn't
query about strange modes (unless the user does not have proper permissions).
.It Fl h
If
.Ar file
is a symbolic link, the group of the link is changed.
.It Fl v
Cause
.Nm
to be verbose, showing files as they are processed.
.El
.Pp
If
.Fl h
is not given, unless the
.Fl H
or
.Fl L
option is set,
.Nm
on a symbolic link always succeeds and has no effect.
The
.Fl H ,
.Fl L
and
.Fl P
options are ignored unless the
.Fl R
option is specified.
In addition, these options override each other and the
command's actions are determined by the last one specified.
The default is as if the
.Fl P
option had been specified.
.Pp
The
.Ar group
operand can be either a group name from the group database,
or a numeric group ID.
Since it is valid to have a group name that is numeric (and
doesn't have the numeric ID that matches its name) the name lookup
is always done first.
Preceding the ID with a ``#'' character will force it to be taken
as a number.
.Pp
The user invoking
.Nm
must belong to the specified group and be the owner of the file,
or be the super-user.
.Pp
Unless invoked by the super-user,
.Nm
clears the set-user-id and set-group-id bits on a file to prevent
accidental or mischievous creation of set-user-id or set-group-id
programs.
.Sh FILES
.Bl -tag -width /etc/group -compact
.It Pa /etc/group
Group ID file
.El
.Sh EXIT STATUS
.Ex -std chgrp
.Sh SEE ALSO
.Xr chown 2 ,
.Xr lchown 2 ,
.Xr fts 3 ,
.Xr group 5 ,
.Xr passwd 5 ,
.Xr symlink 7 ,
.Xr chown 8
.Sh STANDARDS
The
.Nm
utility is expected to be POSIX 1003.2 compatible.
.Pp
The
.Fl v
option and the use of ``#'' to force a numeric group ID
are extensions to
.St -p1003.2 .