adduser(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] 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).
- 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 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.