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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook V4.5//EN"
  "http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd" [
<!ENTITY MAX_MEMBERS_PER_GROUP SYSTEM "login.defs.d/MAX_MEMBERS_PER_GROUP.xml">
<!-- SHADOW-CONFIG-HERE -->
]>
<refentry id='groupmod.8'>
  <!-- $Id$ -->
  <refentryinfo>
    <author>
      <firstname>Julianne Frances</firstname>
      <surname>Haugh</surname>
      <contrib>Creation, 1991</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>groupmod</refentrytitle>
    <manvolnum>8</manvolnum>
    <refmiscinfo class="sectdesc">System Management Commands</refmiscinfo>
    <refmiscinfo class="source">shadow-utils</refmiscinfo>
    <refmiscinfo class="version">&SHADOW_UTILS_VERSION;</refmiscinfo>
  </refmeta>
  <refnamediv id='name'>
    <refname>groupmod</refname>
    <refpurpose>modify a group definition on the system</refpurpose>
  </refnamediv>
  <!-- body begins here -->
  <refsynopsisdiv id='synopsis'>
    <cmdsynopsis>
      <command>groupmod</command>
      <arg choice='opt'>
        <replaceable>options</replaceable>
      </arg>
      <arg choice='plain'><replaceable>GROUP</replaceable></arg>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1 id='description'>
    <title>DESCRIPTION</title>
    <para>
      The <command>groupmod</command> command modifies the definition of the
      specified <replaceable>GROUP</replaceable> by modifying the appropriate
      entry in the group database.
    </para>
  </refsect1>

  <refsect1 id='options'>
    <title>OPTIONS</title>
    <para>
      The options which apply to the <command>groupmod</command> command
      are:
    </para>
    <variablelist remap='IP'>
      <varlistentry>
	<term>
	  <option>-g</option>, <option>--gid</option>&nbsp;<replaceable>GID</replaceable>
	</term>
	<listitem>
	  <para>
	    The group ID of the given <replaceable>GROUP</replaceable> will
	    be changed to <replaceable>GID</replaceable>.
	  </para>
	  <para>
	    The value of
	    <replaceable>GID</replaceable> must be a non-negative decimal
	    integer. This value must be unique, unless the
	    <option>-o</option> option is used.
	  </para>
	  <para>
	    Users who use the group as primary group will be updated to
	    keep the group as their primary group.
	  </para>
	  <para>
	    Any files that have the
	    old group ID and must continue to belong to
	    <replaceable>GROUP</replaceable>, must have their group ID
	    changed manually.
	  </para>
	  <para>
	    No checks will be performed with regard to the
	    <option>GID_MIN</option>, <option>GID_MAX</option>,
	    <option>SYS_GID_MIN</option>, or <option>SYS_GID_MAX</option>
	    from <filename>/etc/login.defs</filename>.
	  </para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><option>-h</option>, <option>--help</option></term>
	<listitem>
	  <para>Display help message and exit.</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <option>-n</option>, <option>--new-name</option>&nbsp;<replaceable>NEW_GROUP</replaceable>
	</term>
	<listitem>
	  <para> 
	    The name of the group will be changed from <replaceable>GROUP</replaceable>
	    to <replaceable>NEW_GROUP</replaceable> name.
	  </para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <option>-o</option>, <option>--non-unique</option>
	</term>
	<listitem>
	  <para>
	    When used with the <option>-g</option> option, allow to change the
	    group <replaceable>GID</replaceable> to a non-unique value.
	  </para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <option>-p</option>, <option>--password</option>&nbsp;<replaceable>PASSWORD</replaceable>
	</term>
	<listitem>
	  <para>
	    The encrypted password, as returned by <citerefentry>
	    <refentrytitle>crypt</refentrytitle><manvolnum>3</manvolnum>
	    </citerefentry>.
	  </para>
	  <para>
	    <emphasis role="bold">Note:</emphasis> This option is not
	    recommended because the password (or encrypted password) will
	    be visible by users listing the processes.
	  </para>
	  <para>
	    You should make sure the password respects the system's
	    password policy.
	  </para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <option>-R</option>, <option>--root</option>&nbsp;<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>
  </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>
      &MAX_MEMBERS_PER_GROUP;
    </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>
      <varlistentry>
	<term><filename>/etc/login.defs</filename></term>
	<listitem>
	  <para>Shadow password suite configuration.</para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term><filename>/etc/passwd</filename></term>
	<listitem>
	  <para>User account information.</para>
	</listitem>
      </varlistentry>
    </variablelist>
  </refsect1>

  <refsect1 id='exit_values'>
    <title>EXIT VALUES</title>
    <para>
      The <command>groupmod</command> command exits with the following values:
      <variablelist>
	<varlistentry>
	  <term><replaceable>0</replaceable></term>
	  <listitem>
	    <para>success</para>
	  </listitem>
	</varlistentry>
	<varlistentry>
	  <term><replaceable>2</replaceable></term>
	  <listitem>
	    <para>invalid command syntax</para>
	  </listitem>
	</varlistentry>
	<varlistentry>
	  <term><replaceable>3</replaceable></term>
	  <listitem>
	    <para>invalid argument to option</para>
	  </listitem>
	</varlistentry>
	<varlistentry>
	  <term><replaceable>4</replaceable></term>
	  <listitem>
	    <para>specified group doesn't exist</para>
	  </listitem>
	</varlistentry>
	<varlistentry>
	  <term><replaceable>6</replaceable></term>
	  <listitem>
	    <para>specified group doesn't exist</para>
	  </listitem>
	</varlistentry>
	<varlistentry>
	  <term><replaceable>9</replaceable></term>
	  <listitem>
	    <para>group name already in use</para>
	  </listitem>
	</varlistentry>
	<varlistentry>
	  <term><replaceable>10</replaceable></term>
	  <listitem>
	    <para>can't update group file</para>
	  </listitem>
	</varlistentry>
      </variablelist>
    </para>
  </refsect1>

  <refsect1 id='see_also'>
    <title>SEE ALSO</title>
    <para>
      <citerefentry>
	<refentrytitle>chfn</refentrytitle><manvolnum>1</manvolnum>
      </citerefentry>,
      <citerefentry>
	<refentrytitle>chsh</refentrytitle><manvolnum>1</manvolnum>
      </citerefentry>,
      <citerefentry>
	<refentrytitle>passwd</refentrytitle><manvolnum>1</manvolnum>
      </citerefentry>,
      <citerefentry>
	<refentrytitle>gpasswd</refentrytitle><manvolnum>8</manvolnum>
      </citerefentry>,
      <citerefentry>
	<refentrytitle>groupadd</refentrytitle><manvolnum>8</manvolnum>
      </citerefentry>,
      <citerefentry>
	<refentrytitle>groupdel</refentrytitle><manvolnum>8</manvolnum>
      </citerefentry>,
      <citerefentry>
	<refentrytitle>login.defs</refentrytitle><manvolnum>5</manvolnum>
      </citerefentry>,
      <citerefentry>
	<refentrytitle>useradd</refentrytitle><manvolnum>8</manvolnum>
      </citerefentry>,
      <citerefentry>
	<refentrytitle>userdel</refentrytitle><manvolnum>8</manvolnum>
      </citerefentry>,
      <citerefentry>
	<refentrytitle>usermod</refentrytitle><manvolnum>8</manvolnum>
      </citerefentry>.
    </para>
  </refsect1>
</refentry>
