Chapter 4. The Command Shell

As you have seen, a large part of using UNIX is issuing commands. When you enter a command, you are dealing with the shell, the interface through which you control the resources of the UNIX operating system. The shell provides many of the features that make the UNIX System a uniquely powerful and flexible environment. It is a command interpreter, a programming language, and more.

This chapter describes the basic features that the shell provides, focusing on how it interprets your commands and how you can use its features to simplify your interactions with the UNIX System. It explains what the shell does for you, how it works, and how you use it to issue commands and to control how they are run. You will learn all of the basic shell commands and features that you need to understand in order to use the UNIX System effectively and confidently.