Provided by: passwd_4.1.1-6ubuntu6_i386 bug

NAME

       useradd - create a new user or update default new user information

SYNOPSIS

       useradd [options] LOGIN

       useradd -D

       useradd -D [options]

DESCRIPTION

       useradd is a low level utility for adding users. On Debian,
       administrators should usually use adduser(8) instead.

       When invoked without the -D option, the useradd 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
       useradd command will update system files and may also create the new
       user´s home directory and copy initial files.

OPTIONS

       The options which apply to the useradd command are:

       -c, --comment COMMENT
           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.

       -b, --base-dir BASE_DIR
           The default base directory for the system if -d HOME_DIR is not
           specified.  BASE_DIR is concatenated with the account name to
           define the home directory. If the -m option is not used, BASE_DIR
           must exist.

       -D, --defaults
           See below, the subsection "Changing the default values".

       -d, --home HOME_DIR
           The new user will be created using HOME_DIR as the value for the
           user´s login directory. The default is to append the LOGIN name to
           BASE_DIR and use that as the login directory name. The directory
           HOME_DIR does not have to exist but will not be created if it is
           missing.

       -e, --expiredate EXPIRE_DATE
           The date on which the user account will be disabled. The date is
           specified in the format YYYY-MM-DD.

       -f, --inactive INACTIVE
           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.

       -g, --gid GROUP
           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 /etc/default/useradd.

       -G, --groups GROUP1[,GROUP2,...[,GROUPN]]]
           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 -g option. The default is
           for the user to belong only to the initial group.

       -h, --help
           Display help message and exit.

       -k, --skel SKEL_DIR
           The skeleton directory, which contains files and directories to be
           copied in the user´s home directory, when the home directory is
           created by useradd.

           This option is only valid if the -m (or --create-home) option is
           specified.

           If this option is not set, the skeleton directory is defined in
           /etc/default/useradd or, by default, /etc/skel.

           This option may not function correctly if the username has a / in
           it.

       -K, --key KEY=VALUE
           Overrides /etc/login.defs defaults (UID_MIN, UID_MAX, UMASK,
           PASS_MAX_DAYS and others).

           Example: -K PASS_MAX_DAYS=-1 can be used when creating system
           account to turn off password ageing, even though system account has
           no password at all. Multiple -K options can be specified, e.g.: -K
           UID_MIN=100
            -K UID_MAX=499

           Note: -K UID_MIN=10,UID_MAX=499 doesn´t work yet.

           For the compatibility with previous Debian´s useradd, the -O option
           is also supported.

       -l
           Do not add the user to the lastlog and faillog databases.

           By default, the user´s entries in the lastlog and faillog databases
           are resetted to avoid reusing the entry from a previously deleted
           user.

       -m, --create-home
           Create the user´s home directory if it does not exist. The files
           and directories contained in the skeleton directory (which can be
           defined with the -k option) will be copied to the home directory.

           By default, no home directories are created.

       -N, --no-user-group
           Do not create a group with the same name as the user, but add the
           user to the group specified by the -g option or by the GROUP
           variable in /etc/default/useradd.

           The default behavior (if the -g, -N, and -U options are not
           specified) is defined by the USERGROUPS_ENAB variable in
           login.defs.

       -o, --non-unique
           Allow the creation of a user account with a duplicate (non-unique)
           UID.

       -p, --password PASSWORD
           The encrypted password, as returned by crypt(3). The default is to
           disable the account.

       -r, --system
           Create a system account.

           System users will be created with no aging information in
           /etc/shadow, and their numeric identifiers are choosen in the
           SYS_UID_MIN-SYS_UID_MAX range, defined in login.defs, instead of
           UID_MIN-UID_MAX (and their GID counterparts for the creation of
           groups).

       -s, --shell SHELL
           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.

       -u, --uid UID
           The numerical value of the user´s ID. This value must be unique,
           unless the -o 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.

       -U, --user-group
           Create a group with the same name as the user, and add the user to
           this group.

           The default behavior (if the -g, -N, and -U options are not
           specified) is defined by the USERGROUPS_ENAB variable in
           login.defs.

   Changing the default values
       When invoked with only the -D option, useradd will display the current
       default values. When invoked with -D plus other options, useradd will
       update the default values for the specified options. Valid
       default-changing options are:

       -b, --base-dir BASE_DIR
           The path prefix for a new user´s home directory. The user´s name
           will be affixed to the end of BASE_DIR to form the new user´s home
           directory name, if the -d option is not used when creating a new
           account.

       -e, --expiredate EXPIRE_DATE
           The date on which the user account is disabled.

       -f, --inactive INACTIVE
           The number of days after a password has expired before the account
           will be disabled.

       -g, --gid GROUP
           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.

       -s, --shell SHELL
           The name of a new user´s login shell.

NOTES

       The system administrator is responsible for placing the default user
       files in the /etc/skel/ directory.

CAVEATS

       You may not add a user to a NIS or LDAP group. This must be performed
       on the corresponding server.

       Similarly, if the username already exists in an external user database
       such as NIS or LDAP, useradd will deny the user account creation
       request.

       It is usually recommended to only use usernames that begin with a lower
       case letter or an underscore, and are only followed by lower case
       letters, digits, underscores, dashes, and optionally terminated by a
       dollar sign. In regular expression terms: [a-z_][a-z0-9_-]*[$]?

       On Debian, the only constraints are that usernames must neither start
       with a dash (´-´) nor contain a colon (´:´) or a whitespace (space:´ ´,
       end of line: ´\n´, tabulation: ´\t´, etc.).

       Usernames may only be up to 32 characters long.

CONFIGURATION

       The following configuration variables in /etc/login.defs change the
       behavior of this tool:

       GID_MAX (number), GID_MIN (number)
           Range of group IDs used for the creation of regular groups by
           useradd, useradd, or newusers.

       MAIL_DIR (string)
           The mail spool directory. This is needed to manipulate the mailbox
           when its corresponding user account is modified or deleted. If not
           specified, a compile-time default is used.

       MAIL_FILE (string)
           Defines the location of the users mail spool files relatively to
           their home directory.

       The MAIL_DIR and MAIL_FILE variables are used by useradd, usermod, and
       userdel to create, move, or delete the user´s mail spool.

       MAX_MEMBERS_PER_GROUP (number)
           Maximum members per group entry. When the maximum is reached, a new
           group entry (line) is started in /etc/group (with the same name,
           same password, and same GID).

           The default value is 0, meaning that there are no limits in the
           number of members in a group.

           This feature (split group) permits to limit the length of lines in
           the group file. This is useful to make sure that lines for NIS
           groups are not larger than 1024 characters.

           If you need to enforce such limit, you can use 25.

           Note: split groups may not be supported by all tools (even in the
           Shadow toolsuite. You should not use this variable unless you
           really need it.

       PASS_MAX_DAYS (number)
           The maximum number of days a password may be used. If the password
           is older than this, a password change will be forced. If not
           specified, -1 will be assumed (which disables the restriction).

       PASS_MIN_DAYS (number)
           The minimum number of days allowed between password changes. Any
           password changes attempted sooner than this will be rejected. If
           not specified, -1 will be assumed (which disables the restriction).

       PASS_WARN_AGE (number)
           The number of days warning given before a password expires. A zero
           means warning is given only upon the day of expiration, a negative
           value means no warning is given. If not specified, no warning will
           be provided.

       SYS_GID_MAX (number), SYS_GID_MIN (number)
           Range of group IDs used for the creation of system groups by
           useradd, groupadd, or newusers.

       SYS_UID_MAX (number), SYS_UID_MIN (number)
           Range of user IDs used for the creation of system users by useradd
           or newusers.

       UID_MAX (number), UID_MIN (number)
           Range of user IDs used for the creation of regular users by useradd
           or newusers.

       UMASK (number)
           The permission mask is initialized to this value. If not specified,
           the permission mask will be initialized to 022.

       USERGROUPS_ENAB (boolean)

FILES

       /etc/passwd
           User account information.

       /etc/shadow
           Secure user account information.

       /etc/group
           Group account information.

       /etc/default/useradd
           Default values for account creation.

       /etc/skel/
           Directory containing default files.

       /etc/login.defs
           Shadow password suite configuration.

EXIT VALUES

       The useradd command exits with the following values:

       0
           success

       1
           can´t update password file

       2
           invalid command syntax

       3
           invalid argument to option

       4
           UID already in use (and no -o)

       6
           specified group doesn´t exist

       9
           username already in use

       10
           can´t update group file

       12
           can´t create home directory

       13
           can´t create mail spool

SEE ALSO

       chfn(1), chsh(1), passwd(1), crypt(3), groupadd(8), groupdel(8),
       groupmod(8), login.defs(5), newusers(8), userdel(8), usermod(8).