User group management under Linux

User group management is divided into two categories

If you assign to a group what permissions, then the members will have what permissions

1. Private Groups

When you create a new user, you specify the group for the user. If not specified, a user group with the same user name is created by default, which is called a private group only if the user is a user.

2. Standard Group

accommodate multiple users in a group. If you use a standard group, you should specify the standard group that the user uses when creating a new user.

The configuration file for a group is/ETC/GRP, which is readable by all users, so only the name of the group is stored.

Each row represents a group, and each line is divided into 4 parts by 3 colons

The first column is the group name: the group name where the user is logged in

The second column is the password for the group, but generally does not set the password (setting the password for the group is generally insignificant)

The third column is the ID of the group, the identification number of the group

The fourth column is the list of users in the group, which belongs to all user names in the reorganization table

How do I add a user group?

Groupadd Group account Name

Change group account name: Groupmod-n newName oldname

Delete Group account number: The account name of the Groupdel group (the deleted account must exist and cannot be a private group for a user)

A user cannot delete a group that exists in the group.

User group management under Linux