Ubuntu® Linux® Bible

Chapter 4. Basic Linux System Concepts

IN THIS CHAPTER

• Understanding files and directories

• Understanding disks and disk partitions

• Linux filesystems

• Introduction to users and groups

• Privileged operations on Ubuntu systems

This chapter explains basic Linux system concepts, focusing on how data is stored and organized on all Linux systems and how the Linux operating system controls access to that data and to privileged operations. Aside from specific sections on how Ubuntu deals with and grants high-level permissions, the information in this chapter applies to any Linux system and to most other Unix-like systems.

This chapter errs on the side of caution. As impossible as it now sounds, I had never used a computer before deciding to study Computer Science at university. (I can be excused for this to some extent because this was a zillion years ago, just as personal computers were starting to become popular and long before DOS, Microsoft Windows, Apple Macintosh, and so on.) At any rate, I remember sitting in my first class while the professor said things such as, "Once you write your program, save it to a file" and thinking "What the heck is he talking about?"

This chapter therefore contains some sections, such as "Working with Files and Directories" that some might find insulting in their simplicity and exploration of basic concepts that "everybody knows," which is fine with me. Everybody who knows that stuff can skip over it, but the people who just got their Ubuntu Linux boxes at the local ...