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<?xml version="1.0" encoding="UTF-8"?>
<!--
Copyright (c) 1996 , Rafal Maszkowski
Copyright (c) 2007 - 2011, Nicolas François
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. The name of the copyright holders or contributors may not be used to
endorse or promote products derived from this software without
specific prior written permission.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT
HOLDERS 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.
-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
<!ENTITY ENCRYPT_METHOD SYSTEM "login.defs.d/ENCRYPT_METHOD.xml">
<!ENTITY MAX_MEMBERS_PER_GROUP SYSTEM "login.defs.d/MAX_MEMBERS_PER_GROUP.xml">
<!ENTITY MD5_CRYPT_ENAB SYSTEM "login.defs.d/MD5_CRYPT_ENAB.xml">
<!ENTITY SHA_CRYPT_MIN_ROUNDS SYSTEM "login.defs.d/SHA_CRYPT_MIN_ROUNDS.xml">
<!-- SHADOW-CONFIG-HERE -->
]>
<refentry id='gpasswd.1'>
<!-- $Id$ -->
<refentryinfo>
<author>
<firstname>Rafal</firstname>
<surname>Maszkowski</surname>
<contrib>Creation, 1996</contrib>
</author>
<author>
<firstname>Thomas</firstname>
<surname>Kłoczko</surname>
<email>kloczek@pld.org.pl</email>
<contrib>shadow-utils maintainer, 2000 - 2007</contrib>
</author>
<author>
<firstname>Nicolas</firstname>
<surname>François</surname>
<email>nicolas.francois@centraliens.net</email>
<contrib>shadow-utils maintainer, 2007 - now</contrib>
</author>
</refentryinfo>
<refmeta>
<refentrytitle>gpasswd</refentrytitle>
<manvolnum>1</manvolnum>
<refmiscinfo class="sectdesc">User Commands</refmiscinfo>
<refmiscinfo class="source">shadow-utils</refmiscinfo>
<refmiscinfo class="version">&SHADOW_UTILS_VERSION;</refmiscinfo>
</refmeta>
<refnamediv id='name'>
<refname>gpasswd</refname>
<refpurpose>
<phrase condition="no_gshadow">
administer <filename>/etc/group</filename>
</phrase>
<phrase condition="gshadow">
administer <filename>/etc/group</filename> and
<filename>/etc/gshadow</filename>
</phrase>
</refpurpose>
</refnamediv>
<!-- body begins here -->
<refsynopsisdiv id='synopsis'>
<cmdsynopsis>
<command>gpasswd</command>
<arg choice='opt'>
<replaceable>option</replaceable>
</arg>
<arg choice='plain'>
<replaceable>group</replaceable>
</arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1 id='description'>
<title>DESCRIPTION</title>
<para>
The <command>gpasswd</command> command is used to administer
<filename>/etc/group</filename><phrase condition="gshadow">,
and <filename>/etc/gshadow</filename></phrase>.
Every group can have
<phrase condition="gshadow">administrators,</phrase>
members and a password.
</para>
<para condition="gshadow">
System administrators can use the <option>-A</option> option to define
group administrator(s) and the <option>-M</option> option to define
members. They have all rights of group administrators and members.
</para>
<para>
<command>gpasswd</command> called by
<phrase condition="gshadow">a group administrator</phrase>
<phrase condition="no_gshadow">a system administrator</phrase>
with a group name only prompts for the new password of the
<replaceable>group</replaceable>.
</para>
<para>
If a password is set the members can still use <citerefentry>
<refentrytitle>newgrp</refentrytitle><manvolnum>1</manvolnum>
</citerefentry> without a password, and non-members must supply the
password.
</para>
<refsect2 id='notes_about_group_passwords'>
<title>Notes about group passwords</title>
<para>
Group passwords are an inherent security problem since more than one
person is permitted to know the password. However, groups are a
useful tool for permitting co-operation between different users.
</para>
</refsect2>
</refsect1>
<refsect1 id='options'>
<title>OPTIONS</title>
<para condition="gshadow">
Except for the <option>-A</option> and <option>-M</option> options,
the options cannot be combined.
</para>
<para condition="no_gshadow">
The options cannot be combined.
</para>
<para>
The options which apply to the <command>gpasswd</command> command are:
</para>
<variablelist remap='IP'>
<varlistentry>
<term>
<option>-a</option>, <option>--add</option> <replaceable>user</replaceable>
</term>
<listitem>
<para>
Add the <replaceable>user</replaceable> to the named
<replaceable>group</replaceable>.
</para>
</listitem>
</varlistentry>
</variablelist>
<variablelist remap='IP'>
<varlistentry>
<term>
<option>-d</option>, <option>--delete</option> <replaceable>user</replaceable>
</term>
<listitem>
<para>
Remove the <replaceable>user</replaceable> from the named
<replaceable>group</replaceable>.
</para>
</listitem>
</varlistentry>
</variablelist>
<variablelist remap='IP'>
<varlistentry>
<term><option>-h</option>, <option>--help</option></term>
<listitem>
<para>Display help message and exit.</para>
</listitem>
</varlistentry>
</variablelist>
<variablelist remap='IP'>
<varlistentry>
<term>
<option>-Q</option>, <option>--root</option> <replaceable>CHROOT_DIR</replaceable>
</term>
<listitem>
<para>
Apply changes in the <replaceable>CHROOT_DIR</replaceable>
directory and use the configuration files from the
<replaceable>CHROOT_DIR</replaceable> directory.
</para>
</listitem>
</varlistentry>
</variablelist>
<variablelist remap='IP'>
<varlistentry>
<term>
<option>-r</option>, <option>--remove-password</option>
</term>
<listitem>
<para>
Remove the password from the named <replaceable>group</replaceable>.
The group password will be empty.
Only group members will be allowed to use
<command>newgrp</command> to join the named
<replaceable>group</replaceable>.
</para>
</listitem>
</varlistentry>
</variablelist>
<variablelist remap='IP'>
<varlistentry>
<term>
<option>-R</option>, <option>--restrict</option>
</term>
<listitem>
<para>
Restrict the access to the named <replaceable>group</replaceable>.
The group password is set to "!".
Only group members with a password will be allowed to use
<command>newgrp</command> to join the named
<replaceable>group</replaceable>.
</para>
</listitem>
</varlistentry>
</variablelist>
<variablelist remap='IP' condition="gshadow">
<varlistentry>
<term>
<option>-A</option>, <option>--administrators</option> <replaceable>user</replaceable>,...
</term>
<listitem>
<para>
Set the list of administrative users.
</para>
</listitem>
</varlistentry>
</variablelist>
<variablelist remap='IP'>
<varlistentry>
<term>
<option>-M</option>, <option>--members</option> <replaceable>user</replaceable>,...
</term>
<listitem>
<para>
Set the list of group members.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 id='caveats'>
<title>CAVEATS</title>
<para>
This tool only operates on the <filename>/etc/group</filename>
<phrase condition="gshadow"> and <filename>/etc/gshadow</filename>
files.</phrase>
<phrase condition="no_gshadow">file.</phrase>
Thus you cannot change any NIS or LDAP group. This must be performed
on the corresponding server.
</para>
</refsect1>
<refsect1 id='configuration'>
<title>CONFIGURATION</title>
<para>
The following configuration variables in
<filename>/etc/login.defs</filename> change the behavior of this
tool:
</para>
<variablelist>
&ENCRYPT_METHOD;
&MAX_MEMBERS_PER_GROUP;
&MD5_CRYPT_ENAB;
&SHA_CRYPT_MIN_ROUNDS; <!--This also document SHA_CRYPT_MAX_ROUNDS-->
</variablelist>
</refsect1>
<refsect1 id='files'>
<title>FILES</title>
<variablelist>
<varlistentry>
<term><filename>/etc/group</filename></term>
<listitem>
<para>Group account information.</para>
</listitem>
</varlistentry>
<varlistentry condition="gshadow">
<term><filename>/etc/gshadow</filename></term>
<listitem>
<para>Secure group account information.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 id='see_also'>
<title>SEE ALSO</title>
<para>
<citerefentry>
<refentrytitle>newgrp</refentrytitle><manvolnum>1</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>groupadd</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>groupdel</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>groupmod</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>grpck</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>group</refentrytitle><manvolnum>5</manvolnum>
</citerefentry><phrase condition="gshadow">,
<citerefentry>
<refentrytitle>gshadow</refentrytitle><manvolnum>5</manvolnum>
</citerefentry></phrase>.
</para>
</refsect1>
</refentry>
|
