shadow/man/gpasswd.1.xml

<?xml version="1.0" encoding="UTF-8"?>
<refentry id='gpasswd.1'>
  <!-- $Id: gpasswd.1.xml,v 1.21 2006/10/28 12:29:04 kloczek Exp $ -->
  <refmeta>
    <refentrytitle>gpasswd</refentrytitle>
    <manvolnum>1</manvolnum>
    <refmiscinfo class="sectdesc">User Commands</refmiscinfo>
  </refmeta>
  <refnamediv id='name'>
    <refname>gpasswd</refname>
    <refpurpose>administer the <filename>/etc/group</filename> file</refpurpose>
  </refnamediv>
  <!-- body begins here -->
  <refsynopsisdiv id='synopsis'>
    <cmdsynopsis>
      <command>gpasswd</command>
      <arg choice='plain'>
	<replaceable>group</replaceable>
      </arg>
    </cmdsynopsis>
    <cmdsynopsis>
      <command>gpasswd</command>
      <arg choice='plain'>-a <replaceable>user</replaceable></arg>
      <arg choice='plain'><replaceable>group</replaceable></arg>
    </cmdsynopsis>
    <cmdsynopsis>
      <command>gpasswd</command>
      <arg choice='plain'>-d <replaceable>user</replaceable></arg>
      <arg choice='plain'><replaceable>group</replaceable></arg>
    </cmdsynopsis>
    <cmdsynopsis>
      <command>gpasswd</command>
      <arg choice='plain'>-R <replaceable>group</replaceable></arg>
    </cmdsynopsis>
    <cmdsynopsis>
      <command>gpasswd</command>
      <arg choice='plain'>-r <replaceable>group</replaceable></arg>
    </cmdsynopsis>
    <cmdsynopsis>
      <command>gpasswd</command>
      <arg choice='opt' rep='repeat'>-A <replaceable>user,</replaceable></arg>
      <arg choice='opt' rep='repeat'>-M <replaceable>user,</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 the
      <filename>/etc/group</filename> file (and
      <filename>/etc/gshadow</filename> file if compiled with SHADOWGRP
      defined). Every group can have administrators, members and a password. 
      System administrator can use <option>-A</option> option to define
      group administrator(s) and <option>-M</option> option to define
      members and has all rights of group administrators and members.
    </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>
      Group administrator can add and delete users using <option>-a</option>
      and <option>-d</option> options respectively. Administrators can use
      <option>-r</option> option to remove group password. When no password
      is set only group members can use <command>newgrp</command> to join
      the group. Option <option>-R</option> disables access via a password
      to the group through <command>newgrp</command> command (however
      members will still be able to switch to this group).
    </para>

    <para>
      <command>gpasswd</command> called by a group administrator with group
      name only prompts for the group password. If password is set the
      members can still <citerefentry>
      <refentrytitle>newgrp</refentrytitle><manvolnum>1</manvolnum>
      </citerefentry> without a password, non-members must supply the
      password.
    </para>
  </refsect1>

  <refsect1 id='files'>
    <title>FILES</title>
    <variablelist>
      <varlistentry>
	<term><filename>/etc/group</filename></term>
	<listitem>
	  <para>Group account information.</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<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>gshadow</refentrytitle><manvolnum>5</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>.
    </para>
  </refsect1>
</refentry>