Computer Science


USERADD(8)                                             USERADD(8)

NAME
       useradd  -  Create  a  new user or update default new user
       information

SYNOPSIS
       useradd [-c comment] [-d home_dir]
               [-e expire_date] [-f inactive_time]
               [-g initial_group] [-G group[,...]]
               [-m [-k skeleton_dir] | -M] [-s shell]
               [-u uid [ -o]] [-n] [-r] login

       useradd -D [-g default_group] [-b default_home]
               [-f default_inactive] [-e default_expire_date]
               [-s default_shell]

DESCRIPTION
   Creating New Users
       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.
       The new user account will be entered into the system files
       as needed, the home directory will be created, and initial
       files  copied, depending on the command line options.  The
       version provided with Red Hat Linux will  create  a  group
       for  each  user  added  to the system, unless -n option is
       given.  The options which apply to the useradd command are

       -c comment
              The new user's password file comment field.

       -d 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 default_home and use
              that as the login directory name.

       -e expire_date
              The date on which the user  account  will  be  dis-
              abled.    The  date  is  specified  in  the  format
              MM/DD/YY.

       -f inactive_days
              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 initial_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.

       -G group,[...]
              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.

       -m     The user's home directory will  be  created  if  it
              does  not  exist.   The  files  contained in skele-
              ton_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 skeleton_dir or /etc/skel will be cre-
              ated 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.

       -M     The  user  home directory will not be created, even
              if the system wide settings from /etc/login.defs is
              to create home dirs.

       -n     A  group  having  the  same  name as the user being
              added to the system will  be  created  by  default.
              This  option  will turn off this Red Hat Linux spe-
              cific behavior.

       -r     This flag is used to create a system account.  That
              is, an user with an UID lower than value of UID_MIN
              defined in /etc/login.defs. Note that useradd  will
              not  create  a  home  directory  for  such an user,
              regardless    of    the    default    setting    in
              /etc/login.defs.   You have to specify -m option if
              you want a home directory for a system  account  to
              be created.  This is an option added by Red Hat.

       -s 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 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 99  and  greater
              than every other user.  Values between 0 and 99 are
              typically reserved for system accounts.

   Changing the default values
       When invoked with the -D option, useradd will either  dis-
       play  the  current  default  values, or update the default
       values from the command line.  The valid options are

       -b default_home
              The initial path  prefix  for  a  new  user's  home
              directory.   The user's name will be affixed to the
              end of default_home to  create  the  new  directory
              name  if  the -d option is not used when creating a
              new account.

       -e default_expire_date
              The date on which the user account is disabled.

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

       -g default_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 default_shell
              The  name of the new user's 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.
       This  version  of  useradd was modified by Red Hat to suit
       Red Hat user/group convention.

CAVEATS
       You may not add a user to an NIS group.  This must be per-
       formed on the NIS server.

FILES
       /etc/passwd - user account information
       /etc/shadow - secure user account information
       /etc/group - group information
       /etc/default/useradd - default information
       /etc/login.defs - system-wide settings
       /etc/skel - directory containing default files

SEE ALSO
       chfn(1),  chsh(1),  groupadd(8), groupdel(8), groupmod(8),
       passwd(1), userdel(8), usermod(8)

AUTHOR
       Julianne Frances Haugh (jfh@tab.com)

                                                                1

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