USERADD(8)		  System Management Commands		    USERADD(8)



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 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
	   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.

       -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.

       -m, --create-home
	   The user's home directory will be created if it does not exist. The
	   files contained in SKEL_DIR will be copied to the home directory if
	   the -k option is used, otherwise the files contained in /etc/skel
	   will be used instead. Any directories contained in SKEL_DIR or
	   /etc/skel will be created in the user's home directory as well. The
	   -k option is only valid in conjunction with the -m option. The
	   default is to not create the directory and to not copy any files.
	   This option may not function correctly if the username has a / in
	   it.

       -n
	   A group having the same name as the user being added to the system
	   will be created by default (when -g is not specified). This option
	   will turn off this behavior. When this option is used, users by
	   default will be placed in whatever group is specified in the GROUP
	   variable of /etc/default/useradd. If no default group is defined,
	   group 100 (users) will be used.

       -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.

       -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.

       -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.

   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 group. This must be performed on the
       NIS server.

       Similarly, if the username already exists in an external user database
       such as NIS, 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.).

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).



System Management Commands	  12/08/2008			    USERADD(8)