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<?xml version="1.0" encoding="UTF-8"?>
<!--
SPDX-FileCopyrightText: 1996 , Rafal Maszkowski
SPDX-FileCopyrightText: 2007 - 2011, Nicolas François
SPDX-License-Identifier: BSD-3-Clause
-->
<!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.
Only absolute paths are supported.
</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>
|
