shadow/man/groupadd.8.xml

<?xml version="1.0" encoding="UTF-8"?>
<!--
   SPDX-FileCopyrightText: 1991       , Julianne Frances Haugh
   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 GID_MAX               SYSTEM "login.defs.d/GID_MAX.xml">
<!ENTITY MAX_MEMBERS_PER_GROUP SYSTEM "login.defs.d/MAX_MEMBERS_PER_GROUP.xml">
<!ENTITY SYS_GID_MAX           SYSTEM "login.defs.d/SYS_GID_MAX.xml">
<!-- SHADOW-CONFIG-HERE -->
]>
<refentry id='groupadd.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>groupadd</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>groupadd</refname>
    <refpurpose>create a new group</refpurpose>
  </refnamediv>
  <!-- body begins here -->
  <refsynopsisdiv id='synopsis'>
    <cmdsynopsis>
      <command>groupadd</command>
      <arg choice='opt'>
	<replaceable>OPTIONS</replaceable>
      </arg>
      <arg choice='plain'>
	<replaceable>NEWGROUP</replaceable>
      </arg>
    </cmdsynopsis>
  </refsynopsisdiv>

  <refsect1 id='description'>
    <title>DESCRIPTION</title>
    <para>The <command>groupadd</command> command creates a new group
      account using the values specified on the command line plus the default
      values from the system. The new group will be entered into the system
      files as needed.
    </para>
     <para>
       Groupnames must start with a lower case letter or an underscore,
       followed by lower case letters, digits, underscores, or dashes.
       They can end with a dollar sign.
       In regular expression terms: [a-z_][a-z0-9_-]*[$]?
     </para>
     <para>
       Groupnames may only be up to &GROUP_NAME_MAX_LENGTH; characters long.
     </para>
  </refsect1>

  <refsect1 id='options'>
    <title>OPTIONS</title>
    <para>
      The options which apply to the <command>groupadd</command> command
      are:
    </para>
    <variablelist remap='IP'>
      <varlistentry>
	<term>
	  <option>-f</option>, <option>--force</option>
	</term>
	<listitem>
	  <para>
	    This option causes the command to simply exit with success
	    status if the specified group already exists. When used with
	    <option>-g</option>, and the specified GID already exists,
	    another (unique) GID is chosen (i.e. <option>-g</option> is
	    turned off).
	  </para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <option>-g</option>, <option>--gid</option>&nbsp;<replaceable>GID</replaceable>
	</term>
	<listitem>
	  <para>The numerical value of the group's ID. <replaceable>GID</replaceable> 
	    must be unique, unless the <option>-o</option> option is used. The value
	    must be non-negative. The default is to use the smallest ID
	    value greater than or equal to <option>GID_MIN</option> and
	    greater than every other group.
	  </para>
	  <para>
	    See also the <option>-r</option> option and the
	    <option>GID_MAX</option> description.
	  </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>-K</option>, <option>--key</option>&nbsp;<replaceable>KEY</replaceable>=<replaceable>VALUE</replaceable>
	</term>
	<listitem>
	  <para>
	    Overrides <filename>/etc/login.defs</filename> defaults 
	    (GID_MIN, GID_MAX and others). Multiple
	    <option>-K</option> options can be specified.
	  </para>
	  <para>
	     Example: <option>-K</option>&nbsp;<replaceable>GID_MIN</replaceable>=<replaceable>100</replaceable>&nbsp;
	    <option>-K</option>&nbsp;<replaceable>GID_MAX</replaceable>=<replaceable>499</replaceable>
	  </para>
	  <para>
	    Note: <option>-K</option>&nbsp;<replaceable>GID_MIN</replaceable>=<replaceable>10</replaceable>,<replaceable>GID_MAX</replaceable>=<replaceable>499</replaceable>
	    doesn't work yet.
	  </para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <option>-o</option>, <option>--non-unique</option>
	</term>
	<listitem>
	  <para>
	    permits the creation of a group with an already used
	    numerical ID. As a result, for this
	    <replaceable>GID</replaceable>, the mapping towards group
	    <replaceable>NEWGROUP</replaceable> may not be unique.
	  </para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <option>-p</option>, <option>--password</option>&nbsp;<replaceable>PASSWORD</replaceable>
	</term>
	<listitem>
	  <para>
	    defines an initial password for the group account. PASSWORD is expected to
            be encrypted, as returned by <citerefentry><refentrytitle>crypt
            </refentrytitle><manvolnum>3</manvolnum></citerefentry>. 
	  </para>
	  <para>
            Without this option, the group account will be locked and
            with no password defined, i.e. a single exclamation mark
            in the respective field of ths system account file 
            <filename>/etc/group</filename> or <filename>/etc/gshadow</filename>.
          </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>--system</option>
	</term>
	<listitem>
	  <para>
	    Create a system group.
	  </para>
	  <para>
	    The numeric identifiers of new system groups are chosen in
	    the <option>SYS_GID_MIN</option>-<option>SYS_GID_MAX</option>
	    range, defined in <filename>login.defs</filename>, instead of
	    <option>GID_MIN</option>-<option>GID_MAX</option>.
	  </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.
	    Only absolute paths are supported.
	  </para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <option>-P</option>, <option>--prefix</option>&nbsp;<replaceable>PREFIX_DIR</replaceable>
	</term>
	<listitem>
	  <para>
	    Apply changes to configuration files under the root filesystem
	    found under the directory <replaceable>PREFIX_DIR</replaceable>.
	    This option does not chroot and is intended for preparing a cross-compilation
	    target.  Some limitations: NIS and LDAP users/groups are
	    not verified.  PAM authentication is using the host files.
	    No SELINUX support.
	  </para>
	</listitem>
      </varlistentry>
      <varlistentry>
	<term>
	  <option>-U</option>, <option>--users</option>
	</term>
	<listitem>
	  <para>
	    A list of usernames to add as members of the group.
	  </para>
	  <para>
	    The default behavior (if the <option>-g</option>,
	    <option>-N</option>, and <option>-U</option> options are not
	    specified) is defined by the <option>USERGROUPS_ENAB</option>
	    variable in <filename>/etc/login.defs</filename>.
	  </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>
      &GID_MAX; <!-- documents also GID_MIN -->
      &MAX_MEMBERS_PER_GROUP;
      &SYS_GID_MAX; <!-- documents also SYS_GID_MIN -->
    </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>
    </variablelist>
  </refsect1>

   <refsect1 id='caveats'>
     <title>CAVEATS</title>
     <para>
       You may not add a NIS or LDAP group. This must be performed on the
       corresponding server.
     </para>
     <para>
       If the groupname already exists in an external group database such
       as NIS or LDAP, <command>groupadd</command> will deny the group
       creation request.
     </para>
   </refsect1>

  <refsect1 id='exit_values'>
    <title>EXIT VALUES</title>
    <para>
      The <command>groupadd</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>GID is already used (when called without <option>-o</option>)</para>
	  </listitem>
	</varlistentry>
	<varlistentry>
	  <term><replaceable>9</replaceable></term>
	  <listitem>
	    <para>group name is already used</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>groupdel</refentrytitle><manvolnum>8</manvolnum>
      </citerefentry>,
      <citerefentry>
	<refentrytitle>groupmod</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>