Skip to main content

Group Management

Groups are collection of users that have a commonality. They are defined in:

/etc/group

And attributes are:

groupname:password:GID:user1,user2,...

Managing Groups​

Some examples:

# Create system group named staff with GID 215
sudo groupadd -r -g 215 staff

# Change the GID to 101 of group named blah
sudo groupmod -g 101 blah

# Delete a group named newgroup
sudo groupdel newgroup

# Add user student to 3 groups
sudo usermod -G student,group1,group2 student

# Add user rocky to group friends
sudo usermod -G friends rocky

User Private Groups (UPG)​

UPG means that each user has their own (primary) group. Upon user creation using useradd, the user will get created and added to a group by the same name with GID = UID.

Group Memberships​

Group memberships can be identified by:

groups [$username]
id -Gn [$username]