adduser, addgroup - add a user or group to the system
adduser [options] [--home DIR] [--shell|-s 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-createhome] [--uid ID] [--group | --ingroup GROUP | --gid ID] [--disabledpassword] [--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 FILE]
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.
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.
Use FILE instead of /etc/adduser.conf.
Default configuration file for adduser and addgroup
Copyright (C) 1997, 1998, 1999 Guy Maor. Modifications by Roland Bauerschmidt
and Marc Haber. Additional patches by Joerg Hoh and Stephen
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.