shadow/man/useradd.8.xml

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<?xml version="1.0" encoding="UTF-8"?>
<refentry id='useradd.8'>
<!-- $Id$ -->
<refmeta>
<refentrytitle>useradd</refentrytitle>
<manvolnum>8</manvolnum>
<refmiscinfo class="sectdesc">System Management Commands</refmiscinfo>
</refmeta>
<refnamediv id='name'>
<refname>useradd</refname>
<refpurpose>create a new user or update default new user information</refpurpose>
</refnamediv>
<refsynopsisdiv id='synopsis'>
<cmdsynopsis>
<command>useradd</command>
<arg choice='opt'>
<replaceable>options</replaceable>
</arg>
<arg choice='plain'><replaceable>LOGIN</replaceable></arg>
</cmdsynopsis>
<cmdsynopsis>
<command>useradd</command>
<arg choice='plain'>-D </arg>
</cmdsynopsis>
<cmdsynopsis>
<command>useradd</command>
<arg choice='plain'>-D </arg>
<arg choice='opt'>
<replaceable>options</replaceable>
</arg>
</cmdsynopsis>
</refsynopsisdiv>
<refsect1 id='description'>
<title>DESCRIPTION</title>
<para>
When invoked without the <option>-D</option> option, the
<command>useradd</command> command creates a new user account using
the values specified on the command line plus the default values from
the system. Depending on command line options, the
<command>useradd</command> command
will update system files and may also create the new user's home
directory and copy initial files.
</para>
</refsect1>
<refsect1 id='options'>
<title>OPTIONS</title>
<para>The options which apply to the <command>useradd</command> command are:
</para>
<variablelist remap='IP'>
<varlistentry>
<term>
<option>-c</option>, <option>--comment</option>
<replaceable>COMMENT</replaceable>
</term>
<listitem>
<para>
Any text string. It is generally a short description of the
login, and is currently used as the field for the user's full
name.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-b</option>, <option>--base-dir</option>
<replaceable>BASE_DIR</replaceable>
</term>
<listitem>
<para>
The default base directory for the system if <option>-d</option>
dir is not specified. <replaceable>BASE_DIR</replaceable> is
concatenated with the account name to define the home directory.
If the <option>-m</option> option is not used,
<replaceable>BASE_DIR</replaceable> must exist.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-D</option>
</term>
<listitem>
<para>
See below, the subsection "Changing the default values".
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-d</option>, <option>--home</option>
<replaceable>HOME_DIR</replaceable>
</term>
<listitem>
<para>
The new user will be created using
<replaceable>HOME_DIR</replaceable> as the value for the user's
login directory. The default is to append the
<replaceable>LOGIN</replaceable> name to
<replaceable>BASE_DIR</replaceable> and use that as the login
directory name. The directory <replaceable>HOME_DIR</replaceable>
does not have to exist but will not be created if it is missing.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-e</option>, <option>--expiredate</option>
<replaceable>EXPIRE_DATE</replaceable>
</term>
<listitem>
<para>
The date on which the user account will be disabled. The date is
specified in the format <emphasis remap='I'>YYYY-MM-DD</emphasis>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-f</option>, <option>--inactive</option>
<replaceable>INACTIVE</replaceable>
</term>
<listitem>
<para>
The number of days after a password expires until the account is
permanently disabled. A value of 0 disables the account as soon
as the password has expired, and a value of -1 disables the
feature. The default value is -1.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-g</option>, <option>--gid</option>
<replaceable>GROUP</replaceable>
</term>
<listitem>
<para>
The group name or number of the user's initial login group. The
group name must exist. A group number must refer to an already
existing group. The default group number is 1 or whatever is
specified in <filename>/etc/default/useradd</filename>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-G</option>, <option>--groups</option>
<replaceable>GROUP1</replaceable>[<emphasis remap='I'>,GROUP2,...</emphasis>[<emphasis remap='I'>,GROUPN</emphasis>]]]
</term>
<listitem>
<para>
A list of supplementary groups which the user is also a member
of. Each group is separated from the next by a comma, with no
intervening whitespace. The groups are subject to the same
restrictions as the group given with the <option>-g</option>
option. The default is for the user to belong only to the
initial group.
</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>-m</option>, <option>--create-home</option>
</term>
<listitem>
<para>
The user's home directory will be created if it does not exist.
The files contained in <replaceable>SKEL_DIR</replaceable> will
be copied to the home directory if the <option>-k</option>
option is used, otherwise the files contained in
<filename>/etc/skel</filename> will be used instead. Any
directories contained in <replaceable>SKEL_DIR</replaceable> or
<filename>/etc/skel</filename> will be created in the user's
home directory as well. The <option>-k</option> option is only
valid in conjunction with the <option>-m</option> option. The
default is to not create the directory and to not copy any
files.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-K</option>, <option>--key</option>
<replaceable>KEY</replaceable>=<replaceable>VALUE</replaceable>
</term>
<listitem>
<para>
Overrides /etc/login.defs defaults (UID_MIN, UID_MAX, UMASK,
PASS_MAX_DAYS and others).
<para>
</para>
Example: <option>-K </option><replaceable>PASS_MAX_DAYS</replaceable>=<replaceable>-1</replaceable>
can be used when creating system account to turn off password
ageing, even though system account has no password at all.
Multiple <option>-K</option> options can be specified, e.g.:
<option>-K </option>
<replaceable>UID_MIN</replaceable>=<replaceable>100</replaceable>
<option> -K </option>
<replaceable>UID_MAX</replaceable>=<replaceable>499</replaceable>
</para>
<para>
Note: <option>-K </option>
<replaceable>UID_MIN</replaceable>=<replaceable>10</replaceable>,<replaceable>UID_MAX</replaceable>=<replaceable>499</replaceable>
doesn't work yet.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-o</option>, <option>--non-unique</option>
</term>
<listitem>
<para>Allow the creation of a user account with a duplicate (non-unique) UID.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-p</option>, <option>--password</option>
<replaceable>PASSWORD</replaceable>
</term>
<listitem>
<para>
The encrypted password, as returned by <citerefentry>
<refentrytitle>crypt</refentrytitle><manvolnum>3</manvolnum>
</citerefentry>. The default is to disable the account.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-s</option>, <option>--shell</option>
<replaceable>SHELL</replaceable>
</term>
<listitem>
<para>
The name of the user's login shell. The default is to leave this
field blank, which causes the system to select the default login
shell.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-u</option>, <option>--uid</option>
<replaceable>UID</replaceable>
</term>
<listitem>
<para>
The numerical value of the user's ID. This value 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 999 and greater than every other user. Values
between 0 and 999 are typically reserved for system accounts.
</para>
</listitem>
</varlistentry>
</variablelist>
<refsect2 id='changing_the_default_values'>
<title>Changing the default values</title>
<para>
When invoked with only the <option>-D</option> option,
<command>useradd</command> will display the current default values.
When invoked with <option>-D</option> plus other options,
<command>useradd</command> will update the default values for the
specified options. Valid default-changing options are:
</para>
<variablelist remap='IP'>
<varlistentry>
<term>
<option>-b</option>, <option>--base-dir</option>
<replaceable>BASE_DIR</replaceable>
</term>
<listitem>
<para>
The path prefix for a new user's home directory. The
user's name will be affixed to the end of
<replaceable>BASE_DIR</replaceable> to form the new user's
home directory name, if the <option>-d</option> option is not used
when creating a new account.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-e</option>, <option>--expiredate</option>
<replaceable>EXPIRE_DATE</replaceable>
</term>
<listitem>
<para>The date on which the user account is disabled.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-f</option>, <option>--inactive</option>
<replaceable>INACTIVE</replaceable>
</term>
<listitem>
<para>
The number of days after a password has expired before the
account will be disabled.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-g</option>, <option>--gid</option>
<replaceable>GROUP</replaceable>
</term>
<listitem>
<para>
The group name or ID for a new user's initial group. The named
group must exist, and a numerical group ID must have an
existing entry.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>
<option>-s</option>, <option>--shell</option>
<replaceable>SHELL</replaceable>
</term>
<listitem>
<para>
The name of a new user's login shell.
</para>
</listitem>
</varlistentry>
</variablelist>
</refsect2>
</refsect1>
<refsect1 id='notes'>
<title>NOTES</title>
<para>The system administrator is responsible for placing the default
user files in the <filename>/etc/skel/</filename> directory.
</para>
</refsect1>
<refsect1 id='caveats'>
<title>CAVEATS</title>
<para>
You may not add a user to a NIS group. This must be performed on the
NIS server.
</para>
<para>
Similarly, if the username already exists in an external user
database such as NIS, <command>useradd</command> will deny
the user account creation request.
</para>
<para>
Usernames must begin with a lower case letter or an underscore, and
only lower case letters, underscores, dashes, and dollar signs may
follow. In regular expression terms: [a-z_][a-z0-9_-]*[$]
</para>
</refsect1>
<refsect1 id='files'>
<title>FILES</title>
<variablelist>
<varlistentry>
<term><filename>/etc/passwd</filename></term>
<listitem>
<para>User account information.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><filename>/etc/shadow</filename></term>
<listitem>
<para>Secure user account information.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><filename>/etc/group</filename></term>
<listitem>
<para>Group account information.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><filename>/etc/default/useradd</filename></term>
<listitem>
<para>Default values for account creation.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><filename>/etc/skel/</filename></term>
<listitem>
<para>Directory containing default files.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><filename>/etc/login.defs</filename></term>
<listitem>
<para>Shadow password suite configuration.</para>
</listitem>
</varlistentry>
</variablelist>
</refsect1>
<refsect1 id='exit_values'>
<title>EXIT VALUES</title>
<para>
The <command>useradd</command> command exits with the following values:
<variablelist>
<varlistentry>
<term><replaceable>0</replaceable></term>
<listitem>
<para>success</para>
</listitem>
</varlistentry>
<varlistentry>
<term><replaceable>1</replaceable></term>
<listitem>
<para>can't update password file</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>UID already in use (and no <option>-o</option>)</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>username already in use</para>
</listitem>
</varlistentry>
<varlistentry>
<term><replaceable>10</replaceable></term>
<listitem>
<para>can't update group file</para>
</listitem>
</varlistentry>
<varlistentry>
<term><replaceable>12</replaceable></term>
<listitem>
<para>can't create home directory</para>
</listitem>
</varlistentry>
<varlistentry>
<term><replaceable>13</replaceable></term>
<listitem>
<para>can't create mail spool</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>crypt</refentrytitle><manvolnum>3</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>login.defs</refentrytitle><manvolnum>5</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>newusers</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>userdel</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
<refentrytitle>usermod</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>.
</para>
</refsect1>
</refentry>