RedHat Enterprise Linux group database is /etc/group file. It stores group information or defines the user groups in the Linux machine. The Linux group configuration file /etc/group defines the groups to which the Linux users belong. A sample /etc/group file is shown below.

Note: You should be familiar how to create a user in Linux using useradd command and how to create a group using using groupadd command before learning this lesson.

[root@RHEL2 ~]# cat /etc/group
root:x:0:root
bin:x:1:root,bin,daemon
daemon:x:2:root,bin,daemon
sys:x:3:root,bin,adm
adm:x:4:root,adm,daemon
tty:x:5:
disk:x:6:root
lp:x:7:daemon,lp
mem:x:8:
kmem:x:9:
wheel:x:10:root
mail:x:12:mail
news:x:13:news
uucp:x:14:uucp
man:x:15:
games:x:20:
gopher:x:30:
dip:x:40:
ftp:x:50:
lock:x:54:
nobody:x:99:
users:x:100:
rpm:x:37:
dbus:x:81:
utmp:x:22:
utempter:x:35:
avahi:x:70:
mailnull:x:47:
smmsp:x:51:
nscd:x:28:
floppy:x:19:
vcsa:x:69:
haldaemon:x:68:
rpc:x:32:
rpcuser:x:29:
nfsnobody:x:65534:
sshd:x:74:
pcap:x:77:
ntp:x:38:
slocate:x:21:
gdm:x:42:
xfs:x:43:
sabayon:x:86:
tintin:x:500:
engineering:x:501:tintin

 

The following table explains in detail, the different columns which are delimited by a ":" character in Linux group database file, /etc/group.

 

Column	Field	Description
1	Group name	It is the name of Linux group. If you run ls -l command, you will see this name printed in the group field.
2	Password	Generally password is not used; hence it is empty/blank. It can store encrypted password. An “x” in this field means the password is encrypted and kept in another file.
3	Group ID (GID)	The group id.  By default, Red Hat Linux starts normal group IDs at 500.
4	Group List	Comma separated list of user names of users who are members of the Linux group.

 

Related Topics...

• Introduction to Linux user administration

• How to add a user in Linux using useradd command

• How to use passwd command to manage user passwords

• How to modify a Linux user using usermod command

• How to set Linux password aging using chage command

• How to remove user from Linux using userdel command

• The Linux user database (/etc/passwd)

• The Linux password database (/etc/shadow)

• Introduction to Linux User Group

• How to create a new group in Linux using groupadd command

• How to manage Linux user group

 

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