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       useradd [options] LOGIN

       useradd -D

       useradd -D [options]


       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.

       By default, a group will also be created for the new user (see -g, -N,
       -U, and USERGROUPS_ENAB).


       The options which apply to the useradd command are:

       -b, --base-dir BASE_DIR
           The default base directory for the system if -dHOME_DIR is not
           specified.  BASE_DIR is concatenated with the account name to
           define the home directory. The BASE_DIR must exist otherwise the
           home directory cannot be created.

           If this option is not specified, useradd will use the base
           directory specified by the HOME variable in /etc/default/useradd,
           or /home by default.

       -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.

       -d, --home-dir 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.

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

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

           If not specified, useradd will use the default expiry date
           specified by the EXPIRE variable in /etc/default/useradd, or an
           empty string (no expiry) by default.

       -f, --inactive INACTIVE
           The number of days after a password expires until the account is
           set to yes (or -U/--user-group is specified on the command line), a
           group will be created for the user, with the same name as her
           loginname. If the variable is set to no (or -N/--no-user-group is
           specified on the command line), useradd will set the primary group
           of the new user to the value specified by the GROUP variable in
           /etc/default/useradd, or 100 by default.

       -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

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

           If possible, the ACLs and extended attributes are copied.

       -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

       -l, --no-log-init
           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

       -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, if this option is not specified and CREATE_HOME is not

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

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

           This option is only valid in combination with the -u option.

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

           Note: This option is not recommended because the password (or
           encrypted password) will be visible by users listing the processes.

           You should make sure the password respects the system's password

       -r, --system
           Create a system account.

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

           Note that useradd will not create a home directory for such an
           user, regardless of the default setting in /etc/login.defs
           (CREATE_HOME). You have to specify the -m options if you want a
           home directory for a system account to be created.

       -R, --root CHROOT_DIR
           Apply changes in the CHROOT_DIR directory and use the configuration
           files from the CHROOT_DIR directory.

       -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 specified by the SHELL variable in /etc/default/useradd, or
           an empty string by default.

       -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 or equal to
           UID_MIN and greater than every other user.

           See also the -r option and the UID_MAX description.

   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

           This option sets the HOME variable in /etc/default/useradd.

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

           This option sets the EXPIRE variable in /etc/default/useradd.

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

           This option sets the INACTIVE variable in /etc/default/useradd.

       -g, --gid GROUP
           The group name or ID for a new user's initial group (when the
           -N/--no-user-group is used or when the USERGROUPS_ENAB variable is
           set to no in /etc/login.defs). The named group must exist, and a
           numerical group ID must have an existing entry.

           This option sets the GROUP variable in /etc/default/useradd.

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

           This option sets the SHELL variable in /etc/default/useradd.


       The system administrator is responsible for placing the default user
       files in the /etc/skel/ directory (or any other skeleton directory
       specified in /etc/default/useradd or on the command line).


       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

       Usernames may only be up to 32 characters long.
           useradd, groupadd, or newusers.

           The default value for GID_MIN (resp.  GID_MAX) is 1000 (resp.

       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.

       If MAIL_CHECK_ENAB is set to yes, they are also used to define the MAIL
       environment variable.

       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
           (resp.  UID_MIN-1).

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

           The default value for UID_MIN (resp.  UID_MAX) is 1000 (resp.

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

           useradd and newusers use this mask to set the mode of the home
           directory they create

           It is also used by login to define users' initial umask. Note that
           this mask can be overridden by the user's GECOS line (if
           QUOTAS_ENAB is set) or by the specification of a limit with the K
           identifier in limits(5).

       USERGROUPS_ENAB (boolean)
           Enable setting of the umask group bits to be the same as owner bits
           (examples: 022 -> 002, 077 -> 007) for non-root users, if the uid
           is the same as gid, and username is the same as the primary group

           If set to yes, userdel will remove the user's group if it contains
           no more members, and useradd will create by default a group with
           the name of the user.


           User account information.

           Secure user account information.

           Group account information.

           Secure group account information.

           Default values for account creation.

           Directory containing default files.

           Shadow password suite configuration.
           invalid argument to option

           UID already in use (and no -o)

           specified group doesn't exist

           username already in use

           can't update group file

           can't create home directory

           can't update SELinux user mapping


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

shadow-utils 11/05/2016 USERADD(8)

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