addgroup(8)
NAME
adduser, addgroup - add a user or group to the system
SYNOPSIS
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 COMMON OPTIONS [--quiet] [--debug] [--force-badname] [--help|-h] [--version] [--conf FILE]
DESCRIPTION
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 group. 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 rule: 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 added. 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.
OPTIONS
--conf FILE
Use FILE instead of /etc/adduser.conf.
--disabled-login
Do not run passwd to set the password. The user won't be able
to use her account until the password is set.
--disabled-password
Like --disabled-login, but logins are still possible (for
example using SSH RSA keys) but not using password
authentication.
--force-badname
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.
--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
--no-create-home
Do not create the home directory, even if it doesn't exist.
--quiet
Suppress informational messages, only show warnings and errors.
--debug
Be verbose, most useful if you want to nail down a problem with
adduser.
--system
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_extra_groups
Add new user to extra groups defined in the configuration file.
--version
Display version and copyright information.
EXIT VALUES
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
signal.
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.
FILES
/etc/adduser.conf
Default configuration file for adduser and addgroup
SEE ALSO
adduser.conf(5), deluser(8), useradd(8), groupadd(8), usermod(8), Debian Policy 9.2.2.
COPYRIGHT
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.
Opportunity
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.
Education
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.
