groupadd

# Create a group
groupadd "group"

/etc/group

• Store all groups information

• group name

• name of the group
• group password
• group password as "x" means the password is stored at /etc/gshadow
• group password blank means no password
• group id (gid)
• the group-id is also stored at /etc/passwd
• root (0), whell (998), $USER (1000)
• group members
• Users that are part of this group

root:x:0:brltty,root

/etc/gshadow

• Contains encrypted password for each group

• Contains group membership and administrator information

• group name

• name of the group
• encrypted password
• if not, non-members can join the group by typing the password (using newgrp)
• if ! is set, no user is allowed to join using newgrp
• if null, only group members can log into the group
• group administrators
• users that can add or remove group members using the gpasswd
• group members
• group members

root:::brltty,root