Introduction

You can't learn Linux without using it.

I've come to that conclusion over more than a decade of teaching people to learn Linux. You can't just read a book; you can't just listen to a lecture. You need someone to guide you and you need to jump in and do it.

In 1999, Wiley published my Red Hat Linux Bible. The book's huge success gave me the opportunity to become a full-time, independent Linux author. For about a decade, I wrote dozens of Linux books and explored the best ways to explain Linux from the quiet of my small home office.

In 2008, I hit the road. I was hired by Red Hat, Inc. as a full-time instructor, teaching Linux to professional system administrators seeking Red Hat Certified Engineer (RHCE) certification. In my three years as a Linux instructor, I honed my teaching skills in front of live people whose Linux experience ranged from none to experienced professional.

In this book, I hope to turn my experience into text that takes you from someone who has never used Linux to someone with the skills to become a Linux professional.

Now in its eighth edition, this book had become too broad in range in earlier editions. The book covered multiple Linux distributions, described how to run applications, touched on system administration, and provided an entry into Linux software development. Despite having been voted one of the top five Linux books of all time three years ago, the Linux Bible had lost its way.

This eighth edition of the Linux Bible represents a major overhaul. Almost all of the previous content has been rewritten or, in most cases, replaced completely. The new focus of the book can be summed up in these ways:

• Beginner to certified professional: As long as you have used a computer, mouse, and keyboard, you can start with this book. We tell you how to get Linux, begin using it, step through critical topics, and ultimately excel at administering and securing it.
• System administrator–focused: When you are done with this book, you will not only know how to use Linux, but also modify and maintain it. All the topics needed to become a Red Hat Certified Engineer are covered in this book.
• Emphasis on command-line tools: Although point-and-click windows for managing Linux have improved greatly in recent years, many advanced features can only be utilized by typing commands and editing configuration files manually. We teach you how to become proficient with the Linux command-line shell.
• Aimed at fewer Linux distributions: In previous editions, I described about 18 different Linux distributions. With only a few notable exceptions, most popular Linux distributions are either Red Hat–based (Red Hat Enterprise Linux, Fedora, CentOS, and so on) or Debian-based (Ubuntu, Linux Mint, KNOPPIX, and so on). I've focused on Red Hat because that's where the well-paying Linux jobs are; I give a nod to Ubuntu throughout because that's what many of the biggest Linux fans start with.
• Many, many demos and exercises: Instead of just telling you what Linux does, I actually show you what it does. Then, to make sure you got it, you have the opportunity to try exercises yourself. Every procedure and exercise has been tested to work in Fedora or Red Hat Enterprise Linux. Many will work in Ubuntu as well.

How This Book Is Organized

The book is organized to enable you to start off at the very beginning with Linux and grow to become a professional Linux system administrator and power user.

Part I, “Getting Started,” includes two chapters designed to help you understand what Linux is and get you started with a Linux desktop:

• Chapter 1, “Starting with Linux,” covers topics such as what the Linux operating system is, where it comes from, and how to get started using it.
• Chapter 2, “Creating the Perfect Linux Desktop,” provides information on how you can create a desktop system and use some of the most popular desktop features.

Part II, “Becoming a Linux Power User,” provides in-depth details on how to use the Linux shell, work with filesystems, manipulate text files, manage processes, and use shell scripts:

• Chapter 3, “Using the Shell,” includes information on how to access a shell, run commands, recall commands (using history), and do tab completion. The chapter also describes how to use variables, aliases, and man pages.
• Chapter 4, “Moving Around the Filesystem,” includes commands for listing, creating, copying, and moving files and directories. More advanced topics in this chapter include filesystem security, such as file ownership, permissions, and access control lists.
• Chapter 5, “Working with Text Files,” includes everything from basic text editors to tools for finding files and searching for text within files.
• Chapter 6, “Managing Running Processes,” describes how to see what processes are running on your system and change those processes. Ways of changing processes include killing, pausing, and sending other types of signals.
• Chapter 7, “Writing Simple Shell Scripts,” includes shell commands and functions you can gather together into a file to run as a command itself.

In Part III, “Becoming a Linux System Administrator,” you learn how to administer Linux systems:

• Chapter 8, “Learning System Administration,” provides information on basic graphical tools, commands, and configuration files for administering Linux systems.
• Chapter 9, “Installing Linux,” covers common installation tasks, such as disk partitioning and initial software package selection, as well as more advanced installation tools, such as installing from kickstart files.
• Chapter 10, “Getting and Managing Software,” provides an understanding of how software packages work and how to get and manage software packages.
• Chapter 11, “Managing User Accounts,” discusses tools for adding and deleting users and groups, as well as how to centralize user account management.
• Chapter 12, “Managing Disks and Filesystems,” provides information on adding partitions, creating filesystems, and mounting filesystems, as well as working with logical volume management.

In Part IV, “Becoming a Linux Server Administrator,” you learn to create powerful network servers and the tools needed to manage them:

• Chapter 13, “Understanding Server Administration,” covers remote logging, monitoring tools, and the Linux boot process.
• Chapter 14, “Administering Networking” discusses configuring networking.
• Chapter 15, “Starting and Stopping Services,” provides information on starting and stopping network services.
• Chapter 16, “Configuring a Print Server,” describes how to configure printers to use locally on your Linux system or over the network from other computers.
• Chapter 17, “Configuring a Web Server,” describes how to configure an Apache Web server.
• Chapter 18, “Configuring an FTP Server,” covers procedures for setting up an FTP server that can be used to enable others to download files from your Linux system over the network.
• Chapter 19, “Configuring a Windows File Sharing (Samba) Server,” covers Windows file server configuration with Samba.
• Chapter 20, “Configuring an NFS File Server,” describes how to use Network File System features to share folders of files among systems over a network.
• Chapter 21, “Troubleshooting Linux,” covers popular tools for troubleshooting your Linux system.

In Part V, “Learning Linux Security Techniques,” you learn how to secure your Linux systems and services:

• Chapter 22, “Understanding Basic Linux Security,” covers basic security concepts and techniques.
• Chapter 23, “Understanding Advanced Linux Security,” provides information on using Pluggable Authentication Modules (PAM) and cryptology tools to tighten system security and authentication.
• Chapter 24, “Enhancing Linux Security with SELinux,” shows you how to enable Security Enhanced Linux (SELinux) to secure system services.
• Chapter 25, “Securing Linux on the Network,” covers network security features, such as iptables firewalls, to secure system services.

Part VI contains two appendixes to help you get the most from your exploration of Linux. Appendix A, “Media,” provides guidance on downloading a Linux distributions. Appendix B, “Exercise Answers,” provides sample solutions to the exercises included in chapters 2 through 25.

Conventions Used in This Book

Throughout the book, special typography indicates code and commands. Commands and code are shown in a monospaced font:

This is how code looks.

In the event that an example includes both input and output, the monospaced font is still used, but input is presented in bold type to distinguish the two. Here's an example:

$ ftp ftp.handsonhistory.com
Name (home:jake): jake
Password: ******

As for styles in the text:

• New terms and important words appear in italics when introduced.
• Keyboard strokes appear like this: Ctrl+A.
• Filenames, URLs, and code within the text appear like so: persistence.properties.

The following items call your attention to points that are particularly important.

Jumping into Linux

If you are new to Linux, you might have vague ideas about what it is and where it came from. You may have heard something about it being free (as in cost) or free (as in freedom to use it as you please). Before you start putting your hands on Linux (which we will do soon enough), Chapter 1 seeks to answer some of your questions about the origins and features of Linux.

Take your time and work through this book to get up to speed on Linux and how you can make it work to meet your needs. This is your invitation to jump in and take the first step to becoming a Linux expert!