Special Edition Using Linux®, Sixth Edition

Groups

The purpose of a Group Identifier (GID) is to logically group resources or files to members of a given group. For example, source code files might need to be shared between users in the engineering department. By creating an engineering group and adding the appropriate members to this group, the files can be shared among the members of the engineering department, but secure from others accessing files that they can't see. It is the same with other departments or groups: files can be shared in the accounting, sales, or service departments without the risk of unauthorized users accessing the data.

Creating a Group

Groups are created by adding an entry to the /etc/group file. A default listing of this file is as follows:

 root::0: ...