adduser, addgroup - add a user or group to the system


   adduser  [options]  [--home  DIR]  [--shell  SHELL]  [--no-create-home]
   [--uid ID] [--firstuid ID] [--lastuid ID] [--ingroup GROUP | --gid  ID]
   [--disabled-password]      [--disabled-login]      [--gecos      GECOS]
   [--add_extra_groups] [--encrypt-home] user

   adduser --system [options] [--home DIR] [--shell  SHELL]  [--no-create-
   home]  [--uid  ID]  [--group | --ingroup GROUP | --gid ID] [--disabled-
   password] [--disabled-login] [--gecos GECOS] user

   addgroup [options] [--gid ID] group

   addgroup --system [options] [--gid ID] group

   adduser [options] user group

   [--quiet] [--debug] [--force-badname] [--help|-h]  [--version]  [--conf


   adduser  and  addgroup  add users and groups to the system according to
   command    line    options    and    configuration    information    in
   /etc/adduser.conf.   They  are  friendlier  front ends to the low level
   tools like useradd, groupadd and usermod programs, by default  choosing
   Debian  policy conformant UID and GID values, creating a home directory
   with  skeletal  configuration,  running  a  custom  script,  and  other
   features.  adduser and addgroup can be run in one of five modes:

   Add a normal user
   If  called  with  one  non-option  argument and without the --system or
   --group options, adduser will add a normal user.

   adduser will choose the first available UID from  the  range  specified
   for  normal users in the configuration file.  The UID can be overridden
   with the --uid option.

   The range specified in the configuration file may  be  overridden  with
   the --firstuid and --lastuid options.

   By  default,  each  user  in  Debian GNU/Linux is given a corresponding
   group with the same name.  Usergroups allow group writable  directories
   to  be  easily  maintained  by placing the appropriate users in the new
   group, setting the set-group-ID bit in the directory, and ensuring that
   all  users use a umask of 002.  If this option is turned off by setting
   USERGROUPS to no, all users' GIDs are set to USERS_GID.  Users' primary
   groups  can  also be overridden from the command line with the --gid or
   --ingroup options to set the group by id or name, respectively.   Also,
   users can be added to one or more groups defined in adduser.conf either
   by setting  ADD_EXTRA_GROUPS  to  1  in  adduser.conf,  or  by  passing
   --add_extra_groups on the commandline.

   adduser  will create a home directory subject to DHOME, GROUPHOMES, and
   LETTERHOMES.  The home directory can be  overridden  from  the  command
   line with the --home option, and the shell with the --shell option. The
   home directory's set-group-ID bit is set if USERGROUPS is yes  so  that
   any  files  created  in the user's home directory will have the correct

   adduser will copy files from SKEL into the home  directory  and  prompt
   for  finger  (gecos) information and a password.  The gecos may also be
   set with the --gecos option.  With  the  --disabled-login  option,  the
   account  will  be created but will be disabled until a password is set.
   The --disabled-password option will not set a password,  but  login  is
   still possible (for example with SSH RSA keys).  To set up an encrypted
   home directory for the new user, add the  --encrypt-home  option.   For
   more information, refer to the -b option of ecryptfs-setup-private(1).

   If  the  file /usr/local/sbin/adduser.local exists, it will be executed
   after the user account has been set up in order to do any local  setup.
   The arguments passed to adduser.local are:
   username uid gid home-directory
   The  environment  variable  VERBOSE  is  set according to the following

   0 if --quiet is specified

   1 if neither --quiet nor --debug is specified

   2 if --debug is specified

          (The same applies to the variable DEBUG, but DEBUG is deprecated
          and will be removed in a later version of adduser.)

   Add a system user
   If called with one non-option argument and the --system option, adduser
   will add a system user. If a user with the same name already exists  in
   the  system uid range (or, if the uid is specified, if a user with that
   uid already exists), adduser will exit with a warning. This warning can
   be suppressed by adding "--quiet".

   adduser  will  choose  the first available UID from the range specified
   for system  users  in  the  configuration  file  (FIRST_SYSTEM_UID  and
   LAST_SYSTEM_UID).  If  you want to have a specific UID, you can specify
   it using the --uid option.

   By default, system users are placed in the nogroup group.  To place the
   new  system  user  in  an  already  existing  group,  use  the --gid or
   --ingroup options.  To place the new system user in a  new  group  with
   the same ID, use the --group option.

   A home directory is created by the same rules as for normal users.  The
   new system user will have the shell /bin/false (unless overridden  with
   the  --shell option), and have logins disabled.  Skeletal configuration
   files are not copied.

   Add a user group
   If adduser is called with the --group option and without  the  --system
   option, or addgroup is called respectively, a user group will be added.

   A  GID  will  be chosen from the range specified for system GIDS in the
   configuration file (FIRST_GID, LAST_GID). To  override  that  mechanism
   you can give the GID using the --gid option.

   The group is created with no users.

   Add a system group
   If  addgroup is called with the --system option, a system group will be

   A GID will be chosen from the range specified for system  GIDS  in  the
   configuration  file  (FIRST_SYSTEM_GID,  LAST_SYSTEM_GID).  To override
   that mechanism you can give the GID using the --gid option.

   The group is created with no users.

   Add an existing user to an existing group
   If called with two non-option arguments, adduser will add  an  existing
   user to an existing group.


   --conf FILE
          Use FILE instead of /etc/adduser.conf.

          Do  not  run passwd to set the password.  The user won't be able
          to use her account until the password is set.

          Like  --disabled-login,  but  logins  are  still  possible  (for
          example   using   SSH   RSA   keys)   but   not  using  password

          By default,  user  and  group  names  are  checked  against  the
          configurable regular expression NAME_REGEX (or NAME_REGEX_SYSTEM
          if --system is specified) specified in the  configuration  file.
          This  option  forces  adduser  and addgroup to apply only a weak
          check for validity of the name.

   --gecos GECOS
          Set the gecos field for the new entry generated.   adduser  will
          not ask for finger information if this option is given.

   --gid ID
          When  creating a group, this option forces the new groupid to be
          the given number.  When creating a user, this  option  will  put
          the user in that group.

          When  combined  with --system, a group with the same name and ID
          as the system user is created.  If not combined with --system, a
          group  with  the  given  name  is  created.  This is the default
          action if the program is invoked as addgroup.

   --help Display brief instructions.

   --home DIR
          Use DIR as the user's home directory, rather  than  the  default
          specified  by the configuration file.  If the directory does not
          exist, it is created and skeleton files are copied.

   --shell SHELL
          Use SHELL as the user's login shell,  rather  than  the  default
          specified by the configuration file.

   --ingroup GROUP
          Add  the new user to GROUP instead of a usergroup or the default
          group defined by USERS_GID  in  the  configuration  file.   This
          affects  the users primary group.  To add additional groups, see
          the add_extra_groups option

          Do not create the home directory, even if it doesn't exist.

          Suppress informational messages, only show warnings and errors.

          Be verbose, most useful if you want to nail down a problem  with

          Create a system user or group.

   --uid ID
          Force  the new userid to be the given number.  adduser will fail
          if the userid is already taken.

   --firstuid ID
          Override the first uid in the range that the uid is chosen  from
          (overrides FIRST_UID specified in the configuration file).

   --lastuid ID
          Override the last uid in the range that the uid is chosen from (
          LAST_UID )

          Add new user to extra groups defined in the configuration file.

          Display version and copyright information.


   0      The user exists as specified. This can have 2 causes:  The  user
          was  created  by  adduser or the user was already present on the
          system before adduser was invoked. If adduser was returning 0  ,
          invoking  adduser  a  second  time  with  the same parameters as
          before also returns 0.

   1      Creating the user or group failed because it was already present
          with other UID/GID than specified. The username or groupname was
          rejected because of  a  mismatch  with  the  configured  regular
          expressions,  see adduser.conf(5). Adduser has been aborted by a
          Or for many other yet undocumented reasons which are printed  to
          console  then.  You  may then consider to remove --quiet to make
          adduser more verbose.


          Default configuration file for adduser and addgroup


   adduser.conf(5),  deluser(8),  useradd(8),   groupadd(8),   usermod(8),
   Debian Policy 9.2.2.


   Copyright  (C)  1997,  1998,  1999  Guy  Maor.  Modifications by Roland
   Bauerschmidt and Marc  Haber.  Additional  patches  by  Joerg  Hoh  and
   Stephen Gran.
   Copyright  (C)  1995  Ted  Hajek,  with  a great deal borrowed from the
   original Debian adduser
   Copyright (C) 1994 Ian Murdock.  adduser is free software; see the  GNU
   General  Public  Licence  version  2  or  later for copying conditions.
   There is no warranty.


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.