Linux Administration: A Beginner’s Guide, Seventh Edition, 7th Edition

CHAPTER 5

Managing Users and Groups

Linux/UNIX was designed from the ground up to be a multiuser operating system. But a multiuser operating system would not be much good without users! And this brings us to the topic of managing users in Linux.

On computer systems, a system administrator sets up user accounts, which determine who has access to what. The ability of a person to access a system is determined by whether that user exists and has the proper permissions to use the system.

Associated with each user is some “baggage,” which can include files, processes, resources, and other information. When dealing with a multiuser system, a system administrator needs to understand what constitutes a user (and the user’s baggage) and a group, how they ...