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

Provided by: adduser_3.113+nmu3ubuntu3_all

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

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.