access, but you should use a regular user account most of the time. You’ll mostly work at the command line,
in a terminal window or a remote session. If you haven’t worked much in this environment, no problem;
Chapter 2 will bring you up to speed.
Commands in this book will typically look like this:
$ ls /
[some output]
Enter the text in bold; the non-bolded text that follows is what the machine spits back. The $ is the prompt for
your regular user account. If you see a # as a prompt, you should be superuser. (More on that in Chapter 2.)
How This Book is Organized
I’ve grouped the book’s chapters into three basic parts. The first is introductory, giving you a bird’s-eye view
of the system and then offering hands-on experience with some tools you’ll need for as long as you run Linux.
Next, you’ll explore each part of the system in more detail, from device management to network configuration,
following the general order in which the system starts. Finally, you’ll get a tour of some pieces of a running
system, learn some essential skills, and get some insight into the tools that programmers use.
With the exception of Chapter 2, most of the early chapters heavily involve the Linux kernel, but you’ll work
your way into user space as the book progresses. (If you don’t know what I’m talking about here, don’t worry;
I’ll explain in Chapter 1.)
The material here is meant to be as distribution-agnostic as possible. Having said this, it can be tedious to
cover all variations in systems software, so I’ve tried to cover the two major distribution families: Debian
(including Ubuntu) and RHEL/Fedora/CentOS. It’s also focused on desktop and server installations. There is
a significant amount of carryover into embedded systems, such as Android and OpenWRT, but it’s up to you
to discover the differences on those platforms.
What’s New in the Second Edition?
The first edition of this book dealt primarily with the user-centric side of a Linux system. It focused on
understanding how the parts worked and how to get them humming. At that time, many parts of Linux were
difficult to install and configure properly.
This is happily no longer the case thanks to the hard work of the people who write software and create Linux
distributions. With this in mind, I have omitted some older and perhaps less relevant material (such as a
detailed explanation of printing) in favor of an expanded discussion of the Linux kernel’s role in every Linux
distribution. You probably interact with the kernel more than you realize, and I’ve taken special care to note
where.
Of course, so much of the original subject matter in this book has changed over the years, and I’ve taken pains
to sort through the material in the first edition in search of updates. Of particular interest is how Linux boots
and how it manages devices. I’ve also taken care to rearrange material to match the interests and needs of
current readers.
One thing that hasn’t changed is the size of this book. I want to give you the stuff that you need to get on the
fast track, and that includes explaining certain details along the way that can be hard to grasp, but I don’t want
you to have to become a weightlifter in order to pick up this book. When you’re on top of the important
subjects here, you should have no trouble seeking out and understanding more details.
I’ve also omitted some of the historical information that was in the first edition, primarily to keep you focused.
If you’re interested in Linux and how it relates to the history of Unix, pick up Peter H. Salus’s The Daemon,
www.it-ebooks.info
