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USERADD(8)                                    System Management Commands                                   USERADD(8)

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

       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 permanently disabled. A value of 0
           disables the account as soon as the password has expired, and a value of -1 disables the feature.

           If not specified, useradd will use the default inactivity period specified by the INACTIVE variable in
           /etc/default/useradd, or -1 by default.

       -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.

           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 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

       -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 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, if this option is not specified and CREATE_HOME is not enabled, no home directories are

           The directory where the user's home directory is created must exist and have proper SELinux context and
           permissions. Otherwise the user's home directory cannot be created or accessed.

       -M, --no-create-home
           Do not create the user's home directory, even if the system wide setting from /etc/login.defs
           (CREATE_HOME) is set to yes.

       -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 /etc/login.defs.

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

           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 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.

       -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 /etc/login.defs.

       -Z, --selinux-user SEUSER
           The SELinux user for the user's login. The default is to leave this field blank, which causes the system
           to select the default SELinux user.

   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.

           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

       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.

       Usernames may only be up to 32 characters long.

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

       CREATE_HOME (boolean)
           Indicate if a home directory should be created by default for new users.

           This setting does not apply to system users, and can be overridden on the command line.

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

           The default value for GID_MIN (resp.  GID_MAX) is 1000 (resp. 60000).

       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

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

           The default value for SYS_UID_MIN (resp.  SYS_UID_MAX) is 101 (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. 60000).

       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

       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 name.

           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.

       The useradd command exits with the following values:


           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)