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
       When invoked without the -D option, the useradd command creates a new
       user account using the values specified on the command line and the
       default values from the system. Depending on command line options, the
       useradd command will update system files and may also create the new
       users 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 users 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, --home HOME_DIR
	  The new user will be created using HOME_DIR as the value for the
	  users 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 users 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.

       -m, --create-home
	  The users 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 users 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.

       -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 doesnt work yet.

	  For the compatibility with previous Debians 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 users 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 users 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 the -D option, useradd will either display the
       current default values, or update the default values from the command
       line. The valid options are

       -b, --base-dir BASE_DIR
	  The initial path prefix for a new users home directory. The users
	  name will be affixed to the end of HOME_DIR to create the new
	  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 users initial group. The named group
	  must exist, and a numerical group ID must have an existing entry.

       -s, --shell SHELL
	  The name of the new users login shell. The named program will be
	  used for all future new user accounts.

       If no options are specified, useradd displays the current default
       values.

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 an end of line (0).

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
	  cant update password file

       2
	  invalid command syntax

       3
	  invalid argument to option

       4
	  UID already in use (and no -o)

       6
	  specified group doesnt exist

       9
	  username already in use

       10
	  cant update group file

       12
	  cant create home directory

       13
	  cant 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	  02/27/2007			    USERADD(8)