# Users and groups (Српски)

User groups are used on GNU/Linux for access control – members of a group are granted access to devices and files belonging to that group. `/etc/group` is the file that defines the groups on the system (`man group` for details).

This article provides a list of common groups and their purpose along with an overview of group manipulation commands.

## Korisne grupe

Preporučene grupe koje korisnik treba da postavi za svoje korisnički nalog.

- audio - za pristup audio hardveru
- floppy - za pristup flopiu (ovo u slačaju samo ko ga poseduje)
- lp - za pristup štampačima
- optical - za pristup CD ili DVD čitačima (npr. puštanje CD-a)
- power - used with power options (e.g. shutdown with power button)
- storage - za uređivanje skladišnog prostora
- video - za video aceleraciju
- wheel - za sudo privilegije

## Group list

A list of groups and their function (sorted alphabetically)
Group | Affected files | Purpose
--- | --- | ---
adm | /var/log/* | Read access to log files in /var/log
audio | /dev/sound/*, /dev/snd/*, /dev/misc/rtc0 | Access to sound hardware.
avahi |  |
bin | /usr/bin/* | Right to modify binaries only by root, but right to read or executed by anyone. (Please modify this for better understanding...)
camera |  | Access to Digital Cameras.
clamav | /var/lib/clamav/*, /var/log/clamav/* |
daemon |  |
dbus | /var/run/dbus |
disk | /dev/sda[1-9], /dev/sdb[1-9], etc | Access to block devices not affected by other groups such as optical,floppy,storage.
floppy | /dev/fd[0-9] | Access to floppy drives.
ftp | /srv/ftp |
games | /var/games | Access to some game software.
gdm |  |
hal | /var/run/hald, /var/cache/hald |
http |  |
kmem | /dev/port, /dev/mem, /dev/kmem |
locate | /usr/bin/locate, /var/lib/locate, /var/lib/slocate, /var/lib/mlocate | Right to use updatedb command.
log | /var/log/* | Access to log files in /var/log,
lp | /etc/cups, /var/log/cups, /var/cache/cups, /var/spool/cups | Access to printer hardware
mem |  |
mail | /usr/bin/mail |
network |  | Right to change network settings such as when using a NetworkManager.
networkmanager |  | Requirement for your user to connect wirelessly with NetworkManager. This group is not included with Arch by default so it must be added manually.
nobody |  | Unprivileged group.
ntp |  |
optical | /dev/sr[0-9], /dev/sg[0-9] | Access to optical devices such as CD,CD-R,DVD,DVD-R.
policykit |  |
power |  | Right to use suspend utils.
rfkill |  |
root | /* -- ALL FILES! | Complete system administration and control (root, admin)
scanner | /var/lock/sane | Access to scanner hardware.
smmsp |  | sendmail group
storage |  | Access to removable drives such as USB hard drives, flash/jump drives, MP3 players.
stb-admin |  |
sys |  | Right to admin printers in CUPS.
thinkpad | /dev/misc/nvram | Right for ThinkPad users using tools such as tpb.
tty | /dev/tty, /dev/vcc, /dev/vc, /dev/ptmx |
users |  | Standard users group.
uucp | /dev/ttyS[0-9] /dev/tts/[0-9] | Serial & USB devices such as modems, handhelds, RS 232/serial ports.
vboxusers | /dev/vboxdrv | Right to use VirtualBox software.
video | /dev/fb/0, /dev/misc/agpgart | Access to video capture devices, DRI/3D hardware acceleration.
vmware |  | Right to use VMware software.
wheel |  | Right to use sudo (setup with visudo), Also affected by PAM

## Group manipulation

### List groups

Display group membership with the `groups` command:

    $ groups [user]

If `user` is omitted, the current user's group names are displayed.

The `id` command provides additional detail, such as the user's UID and associated GIDs:

    $ id [user]

To list all groups on the system:

    $ cat /etc/group

### Find group ownership

List files owned by a group with the `find` command:

    # find / -group [group]

### Manage group membership

Add users to a group with the `gpasswd` command:

    # gpasswd -a [user] [group]

To remove users from a group:

    # gpasswd -d [user] [group]

If the user is currently logged in, he/she must log out and in again for the change to have effect.

### Manage groups

Create new groups with the `groupadd` command:

    # groupadd [group]

To delete existing groups:

    # groupdel [group]

Category:

- Српски