Introduction

Welcome to Ubuntu Unleashed! This book covers the free Linux distribution named Ubuntu and includes a fully functional and complete operating system produced by the Ubuntu Community, sponsored by Canonical Software.

Ubuntu directly descends from one of the oldest and most revered Linux distributions ever: Debian. Those of you who know nothing about Linux will likely not have heard of Debian; it is enough to know that it is considered to be one of the most stable and secure Linux distributions currently available. Ubuntu benefits directly from many contributions from free software developers across the world.

If you are new to Linux, you have made a great decision by choosing this book. Sams Publishing's Unleashed books offer an in-depth look at their subject, taking in both beginner and advanced users and moving them to a new level of knowledge and expertise. Ubuntu is a fast-changing distribution that can be updated at least twice a year. We have tracked the development of Ubuntu from early on to make sure that the information in this book mirrors closely the development of the distribution. A full copy of Ubuntu is included on the enclosed disc, making it possible for you to install Linux in less than an hour! No longer an upstart, Linux now has an enviable position in today's modern computing world. It can be found on machines as diverse as mobile phones and wristwatches, all the way up to supercomputersin fact, Linux currently runs on more than half of the world's top 500 supercomputers.

Do not let the reputation of Linux discourage you, however. Most people who have heard of Linux think that it is found only on servers, looking after websites and email. Nothing could be further from the truth because Linux is making huge inroads in to the desktop market, too. Corporations are realizing the benefits of running a stable and powerful operating system that is easy to maintain and easy to secure. Add to that the hundreds of improvements in usability, and Linux becomes an attractive proposition that tempts many CIOs. The best part is that as large Linux vendors improve Linux, the majority of those improvements make it into freely available distributions, allowing you to benefit from the additions and refinements made. You can put Ubuntu to work today and be assured of a great user experience.

This book provides all the information that you need to get up and running with Ubuntu. It even tells you how to keep Ubuntu running in top shape and how to adapt Ubuntu to changes your own needs. You can use Ubuntu at home, in the workplace, or, with permission, at your school or college. In fact, you might want to poke around your school's computer rooms: You will probably find that someone has already beaten you to the punchLinux is commonly found in academic institutions. Feel free to make as many copies of the software as you want; because Ubuntu is freely distributable all over the world, no copyright lawyers are going to pound on your door.

After an introduction to Linux and Ubuntu, you will find out how to get started with Ubuntu, including installation and initial configuration. We also take you through installing software, managing users, and other common administrative tasks. For the more technically minded, we also cover some starting steps in programming across several languageswhy not pick one and try it out? Throughout this book, you will also find information about multimedia applications, digital graphics, and even gaming (for after-hours when you are finished tinkering). After you make it through this book, you will be well equipped with the knowledge needed to use Linux successfully. We do assume that you are at least familiar with an operating system already (even if it is not with Linux) and have some basic computer knowledge.

What Is Linux?

Linux is the core, or kernel, of a free operating system first developed and released to the world by Linus Benedict Torvalds in 1991. Torvalds, then a graduate student at the University of Helsinki, Finland, is now a Fellow at the Open Source Development Lab (http://www.osdl.org/). He is an engineer and previously worked for the CPU design and fabrication company Transmeta, Inc. Fortunately for all Linux users, Torvalds chose to distribute Linux under a free software license named the GNU General Public License (GPL).

Note

The free online resource Wikipedia has a great biography of Linus Torvalds that examines his life and notable achievements. You can find it at http://en.wikipedia.org/wiki/Linux_Torvalds. Or you can head on over to http://groups.google.com/group/comp.os.minix/msg/b813d52cbc5a044b?hl=en to read a copy of Linus's first post about Linux to the world.

The GNU GPL is the brainchild of Richard M. Stallman, the founder of the Free Software Foundation. Stallman, the famous author of the Emacs editing environment and GCC compiler system, crafted the GPL to ensure that software that used the GPL for licensing would always be free and available in source-code form. The GPL is the guiding document for Linux and its ownership, distribution, and copyright. Torvalds holds the rights to the Linux trademark, but thanks to a combination of his generosity, the Internet, thousands of programmers around the world, GNU software, and the GNU GPL, Linux will remain forever free and unencumbered by licensing or royalty issues. See the "Licensing" section later in this Introduction to learn more about the GNU GPL and other software licenses.

Linux, pronounced "lih-nucks," is free software. Combining the Linux kernel with GNU software toolsdrivers, utilities, user interfaces, and other software such as the X.Org Foundation's X Window Systemcreates a Linux distribution. There are many different Linux distributions from different vendors, but many derive from or closely mimic Red Hat's distribution of Linux: Red Hat Linux.

Note

To see just how many distributions are based on Debian Linux, go to http://www.linux.org/, click Distributions, and search for "Debian-based." At the time of writing, 52 distributions owe their existence to Debian.

What Is Ubuntu?

Ubuntu is an operating system based on the Linux kernel; created, improved, refined, and distributed by the Ubuntu Community at http://www/ubuntu.com/. Ubuntu, sponsored by Canonical Software, is an open-source project supported by a worldwide community of software developers.

Roots of Ubuntu

Ubuntu is one of the newer Linux distributions currently available today, having released its first version in October 2004. It quickly gained a reputation for ease of installation and use, combined with the slightly wacky code names given to each release. However, Ubuntu itself is based on Debian, which is a much older distribution steeped in respect from the wider Linux community. Ubuntu describes Debian as being the rock on which it is founded, and this is a good way to describe the relationship between the two. It is also worth noting that Debian garnered a reputation for infrequent releases. The move from Debian 3.0 to 3.1 took almost 3 years, during which time many other Linux distros had moved far ahead of Debian.

Sponsored by Canonical Software and with the formidable resources of Mark Shuttleworth, Ubuntu got off to a great start with version 4.10, the Warty Warthog. From the start, Ubuntu specified clear goals: to provide a distribution that was easy to install and use, that did not overly confuse the user, and that came on a single CD (something increasingly rare these days when a distro can occupy four or five CDs). Releasing every 6 months, Ubuntu made rapid progress into the Linux community and is now one of the most popular Linux distros across the world.

Ubuntu Versions

As mentioned earlier, Ubuntu has chosen some peculiar code names for their releases since the first launch in October 2004. Doing away with the typical version numbering found elsewhere, Ubuntu decided to take the month and year of release and reverse them. Hence, the first release in October 2004 became 4.10, followed quickly by 5.04, 5.10, and 6.06.

The code names are even better: 4.10 was christened the Warty Warthog in recognition that it was a first release, warts and all. The second release, 5.04, was dubbed the Hoary Hedgehog. Things got slightly better with 5.10, code-named the Breezy Badger. However, with 6.06, Dapper Drake (a release supported on the desktop for a full 3 years), Ubuntu really started to shine.

Licensing

Software licensing is an important issue for all computer users and can entail moral, legal, and financial considerations. Many consumers think that purchasing a copy of a commercial or proprietary operating system, productivity application, utility, or game conveys ownership, but this is not true. In the majority of cases, the end user license agreement (EULA) included with a commercial software package states that you have paid only for the right to use the software according to specific terms. This generally means you may not examine, make copies, share, resell, or transfer ownership of the software package. More onerous software licenses enforce terms that preclude you from distributing or publishing comparative performance reviews of the software. Even more insidious licensing schemes (and supporting legislation, especially in the United States) contain provisions allowing onsite auditing of the software's use!

This is not the case with the software included with this book. You are entirely free to make copies, share them with friends, and install the software on as many computers as you wantwe encourage you to purchase additional copies of this book to give as gifts, however. Be sure to read the README file on the disc included with this book for important information regarding the included software and disk contents. After you install Ubuntu, go to http://www.gnu.org/licenses/gpl.html to find a copy of the GNU GPL. You will see that the GPL provides unrestricted freedom to use, duplicate, share, study, modify, improve, and even sell the software.

You can put your copy of Ubuntu to work right away in your home or at your place of business without worrying about software licensing, per-seat workstation or client licenses, software auditing, royalty payments, or any other type of payments to third parties. However, be aware that although much of the software included with Ubuntu is licensed under the GPL, some packages on this book's disc are licensed under other terms. There is a variety of related software licenses, and many software packages fall under a broad definition known as open source. Some of these include the Artistic License, the BSD License, the Mozilla Public License, and the Q Public License.

For additional information about the various GNU software licenses, browse to http://www.gnu.org/. For a definition of open-source and licensing guidelines, along with links to the terms of nearly three dozen open-source licenses, browse to http://www.opensource.org/.

Why Use Linux?

Millions of clever computer users have been putting Linux to work for more than 14 years. Over the past year, many individuals, small office/home office (SOHO) users, businesses and corporations, colleges, nonprofits, and government agencies (local, state, and federal) in a number of countries have incorporated Linux with great success. And, today, Linux is being incorporated into many information service/information technology (IS/IT) environments as part of improvements in efficiency, security, and cost savings. Using Linux is a good idea for a number of reasons, including the following:

• Linux provides an excellent return on investment (ROI) There is little or no cost on a per-seat basis. Unlike commercial operating systems, Linux has no royalty or licensing fees, and a single Linux distribution on CD-ROM or network shared folder can form the basis of an enterprise-wide software distribution, replete with applications and productivity software. Custom corporate CD-ROMs can be easily crafted or network shares can be created to provide specific installs on enterprisewide hardware. This feature alone can save hundreds of thousands, if not millions, of dollars in IS/IT costsall without the threat of a software audit from the commercial software monopoly or the need for licensing accounting and controls of base operating system installations.

• Linux can be put to work on the desktop Linux, in conjunction with its supporting graphical networking protocol and interface (the X Window System), has worked well as a consumer UNIX-like desktop operating system since the mid-1990s. The fact that UNIX is ready for the consumer desktop is now confirmed with the introduction, adoption, and rapid maturation of Apple Computer BSD UNIXbased on Mac OS Xsupported, according to Apple, by more than 3,000 Mac OS X-specific programs that are known as native applications. This book's disc contains more than 800 software packages, including Internet connection utilities, games, a full office suite, many different fonts, and hundreds of graphics applications.

• Linux can be put to work as a server platform Linux is fast, secure, stable, scalable, and robust. The latest versions of the Linux kernel easily support multiple-processor computers (optimized for eight CPUs), large amounts of system memory (up to 64GB RAM), individual file sizes in excess of hundreds of gigabytes, a choice of modern journaling file systems, hundreds of process monitoring and control utilities, and the (theoretical) capability to simultaneously support more than four billion users. IBM, Oracle, and other major database vendors all have versions of their enterprise software available for Linux.

• Linux has a low entry and deployment cost barrier Maintenance costs can also be reduced because Linux works well on a variety of PCs, including legacy hardware, such as some Intel-based 486 and early Pentium CPUs. Although the best program performance will be realized with newer hardware, because clients can be recompiled and optimized for Pentium-class CPUs, base installs can even be performed on lower-end computers or embedded devices with only 8MB of RAM. This feature provides for a much wider user base; extends the life of older working hardware; and can help save money for home, small business, and corporate users.

• Linux appeals to a wide audience in the hardware and software industry Versions of Linux exist for nearly every CPU. Embedded-systems developers now turn to Linux when crafting custom solutions using ARM, MIPS, and other low-power processors. Linux is the first full operating system available for Intel's Itanium CPU, as well as the AMD64 group of CPUs; ports have also been available for HP/Compaq's Alpha and Sun Microsystems SPARC CPUs for some time. PowerPC users regularly use the PPC port of Linux on IBM and Apple hardware.

• Linux provides a royalty-free development platform for cross-platform development Because of the open-source development model and availability of free, high-quality development tools, Linux provides a low-cost entry point to budding developers and tech industry start-ups.

• Big-player support in the computer hardware industry from such titans as IBM now lends credibility to Linux as a viable platform IBM has enabled Linux on the company's entire line of computers, from low-end laptops through "Big Iron" mainframes. New corporate customers are lining up and using Linux as part of enterprise-level computing solutions. It has been used on some of the world's fastest computers, including IBM's Blue Gene/L. HP also certifies Linux across a large portion of its hardware offering.

Look forward to even more support as usage spreads worldwide throughout all levels of business in search of lower costs, better performance, and stable and secure implementations.

Who This Book Is For

This book is for anyone searching for guidance on using Ubuntu and primarily focuses on Intel-based PC platforms. Although the contents are aimed at intermediate to advanced users, even new users with a bit of computer savvy will benefit from the advice, tips, tricks, traps, and techniques presented in each chapter. Pointers to more detailed or related information are also provided at the end of each chapter.

If you are new to Linux, you might need to learn some new computer skills, such as how to research your computer's hardware, how to partition a hard drive, and (occasionally) how to use a command line. This book helps you learn these skills and shows you how to learn more about your computer, Linux, and the software included with Ubuntu. System administrators with experience using other operating systems can use the information in this book to install, set up, and run common Linux software services, such as the Network File System (NFS), a File Transfer Protocol (FTP) server, and a web server (using Apache, among others).

What This Book Contains

Ubuntu Unleashed is organized into six parts, covering installation and configuration, Ubuntu on the desktop, system administration, programming and housekeeping, and a reference section. A disc containing the entire distribution is included so that you have everything you need to get started. This book starts by covering the initial and essential tasks required to get Ubuntu installed and running on a target system.

If you are new to Linux, and more specifically Ubuntu, first read the chapters in Part I, "Installation and Configuration." You will get valuable information on the following:

• An overview of Ubuntu and Linux and their roles in various computing environments

• Planning for an installation by examining hardware requirements and the need for organizing how the system is installed

• Detailed steps that walk you through various types of installations

• Critical advice on key configuration steps to fully install and configure Linux to work with your system's subsystems or peripherals, such as pointers, keyboards, modems, USB devices, power management, andfor laptop usersPCMCIA devices

• Initial steps needed by new users transitioning from other computing environments

• Configuration and use of the X Window System, the graphical interface for Linux

Part II, "Desktop Ubuntu," is aimed at users who want to get productive with Ubuntu and covers the following:

• Becoming familiar with the X Window System and looking at GNOME and KDE

• Discovering the many productivity applications that come with Ubuntu

• Surfing the Internet and working with email and newsgroups

• Using Ubuntu to listen to music and watch video

• Using Ubuntu to download and manipulate images from digital cameras

• Setting up local printers for Ubuntu

• Understanding the current state of gaming for Linux

Moving beyond the productivity and desktop areas of Ubuntu, Part III, "System Administration," covers the following:

• Managing users and groups

• Automating tasks and using shell scripts

• Monitoring system resources and availability

• Backup strategies and software

• Network connectivity, including sharing folders and securing the network

• Internet connectivity via dial-up and broadband connections

• Building and deploying web servers

• Database creation, management, and manipulation

• File and print servers

• Using FTP for serving files across the Internet and local networks

• Building and deploying email servers using Postfix and managing mailing lists

• Creating remote access gateways and services

• Configuring DNS for your network

• Using LDAP for storing information on users and security

• Configuring a local news server

Part IV, "Programming Linux," provides a great introduction to how you can extend Ubuntu capabilities even further using the development tools supplied with it. This part covers the following:

• Programming in Perl, using variables and scripting

• An introduction to the Python language

• Writing PHP scripts and linking them to databases

• C and C++ programming tools available with Ubuntu and how to use the GNU C Compiler (gcc)

Part V, "Ubuntu Housekeeping," looks at some of the more advanced skills you need to keep your system running in perfect condition, including the following:

• Securing your machine against attack from outsiders and viruses

• Performance tuning

• Command-line masterclass

• Advanced apt

• Kernel and module management and compilation

An extensive reference in Part VI, "Appendix," gives you scope to explore in even more depth some of the topics covered in this book.

Conventions Used in This Book

A lot of documentation is included with every Linux distribution, and Ubuntu is certainly no exception. Although the intent of Ubuntu Unleashed is to be as complete as possible, it is impossible to cover every option of every command included in the distribution. However, this book offers numerous tables of various options, commands, and keystrokes to help condense, organize, and present information about a variety of subjects.

This edition is also packed full of screenshots to illustrate nearly all Ubuntu-specific graphical utilitiesespecially those related to system administration or the configuration and administration of various system and network services.

To help you better understand code listing examples and sample command lines, several formatting techniques are used to show input and ownership. For example, if the command or code listing example shows typed input, the input is formatted in boldface, as follows:

$ ls

If typed input is required, as in response to a prompt, the sample typed input also is in boldface, like so:

Delete files? [Y/n] y

All statements, variables, and text that should appear on your display use the same boldface formatting. In addition, command lines that require root or super user access are prefaced with a pound sign, as follows:

# printtool &

Command-line examples that any user can run are prefaced with a dollar sign ($), like so:

$ ls

The following elements provide you with useful tidbits of information that relate to the discussion of the text:

Note

A note provides additional information you might want to make note of as you are working; augments a discussion with ancillary details; or points you to an article, a whitepaper, or another online reference for more information about a specific topic.

Tip

A tip can contain special insight or a timesaving technique, as well as information about items of particular interest to you that you might not find elsewhere.

Caution

A caution warns you about pitfalls or problems before you run a command, edit a configuration file, or choose a setting when administering your system.

Sidebars Can Be Goldmines

Just because it is in a sidebar does not mean that you will not find something new here. Be sure to watch for these elements that bring in outside content that is an aside to the discussion in the text. You will read about other technologies, Linux-based hardware, and special procedures to make your system more robust and efficient.

Other formatting techniques used to increase readability include the use of italics for placeholders in computer command syntax. Computer terms or concepts are also italicized upon first introduction in text.

Finally, you should know that all text, sample code, and screenshots in Ubuntu Unleashed were developed using Ubuntu and open-source tools.

Read on to start learning about and using the latest version of Ubuntu. Experienced users will want to consider the new information in this edition when planning or considering upgrades. There are many different Linux distributions from different vendors, but many derive from, or closely mimic, the Debian distribution.