This chapter is a guide to the Unix commands and utilities that you must know to get anything out of this book. This is preliminary material, and you may already know a substantial amount. Even if you think you're up to speed, though, take a few seconds to flip through the sections just to make sure.

You may be asking yourself, "I thought this was a book about Linux, not Unix?" Don't worry; this chapter is just getting you ready for working with the Linux system. Linux is a Unix flavor at heart. You will see the word "Unix" in this chapter more than "Linux" because you can take the information straight over to Solaris, BSD, and other Unix-flavored systems. Special care has been taken to avoid too many Linux-specific user interface extensions, not only so you will have a better background with other operating systems, but also because these extensions tend to be extremely unstable. You will be able to adapt to new Linux releases much more quickly if you know the core that does not change.

Although the material here may seem sparse, you need to convince yourself that Unix is not hard. Yes, most reports from the field are to the contrary, but in the end, Unix is nothing but a bunch of files and a few commands for manipulating those files. If you are familiar with other operating systems, you shouldn't have a problem. However, if you find the information in this preliminary chapter somewhat lacking, there are books with much more detail for beginners, such as UNIX for the Impatient [Abrahams] and Learning the UNIX Operating System [Peek].