Introduction
We are pleased to present the 2021 edition of Ubuntu Unleashed. Ubuntu is a Linux-based computer operating system that has taken the world by storm. From its humble beginning in 2004, Ubuntu has risen to become a perennial favorite for desktop Linux, as well as a popular choice for servers.
Ubuntu descends from one of the oldest and most revered Linux distributions, Debian. Debian is assembled by a team of talented volunteers, is one of the most stable and customizable distributions of Linux, and is well respected for its quality and technological prowess. It is, however, an operating system for geeks; the bar for entry into the Debian realm is set high, and its user base tends to be highly proficient and expects new users to learn the ropes before joining in. That is both appropriate and okay.
Ubuntu has leveraged the quality of Debian to create an operating system that ordinary people can use. This doesn’t mean that Ubuntu users are not technologically proficient, just that they do not have to be. In fact, many talented and respected software developers love Ubuntu because it enables them to concentrate on their specific interests instead of the details of the operating system. This book is for these people and for those who aspire to join their ranks.
If you are new to Linux, you have made a great decision by choosing this book. Unleashed books offer an in-depth look at their subjects, helping both beginner and advanced users move to a new level of knowledge and expertise. Ubuntu is a fast-changing distribution that has an updated release twice a year. We have tracked the development of Ubuntu from early on to make sure the information in this book mirrors closely the development of the distribution.
A Quick Word About Marketing
Almost all of the content in this book applies regardless of what Ubuntu release version you are using, as long as it is reasonably current. The book has been written to try to focus on information that is useful for the longest amount of time possible. Some chapters, like those covering installation or the basics of the default Ubuntu graphical user interface, will have their information change frequently. These chapters are the exception. The blurb on the cover of the book about which editions this book covers was added to account for these chapters and to denote clearly when the book was most recently revised.
Do not let the highly technical reputation of Linux discourage you, however. Many people who have heard of Linux think that it is found only on servers, used to look after websites and email. But that is far from the truth. Distributions like Ubuntu are making huge inroads into the desktop market. Corporations are realizing the benefits of running a stable and powerful operating system that is easy to maintain and easy to secure. The best part is that as Linux distributions are improved, the majority of those improvements are shared freely, allowing you to benefit from the additions and refinements made by one distribution, such as Red Hat, while continuing to use a different distribution, such as Ubuntu, which in turn shares its improvements. You can put Ubuntu to work today and be assured of a great user experience. Feel free to make as many copies of the software as you want; Ubuntu is freely and legally distributable all over the world, so no copyright lawyers are going to pound on your door.
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 that 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 open source software covered in this book. You are entirely free to make copies, share copies, and install the software on as many computers as you want. (We encourage you to purchase additional copies of this book to give as gifts, however.)
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 are licensed under other terms. Those packages are subject to a variety of software licenses, and many of them fall under a broad definition known as open source. Some of these licenses 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 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 www.opensource.org.
Who This Book Is For
This book varies in coverage from deep to shallow over a wide range of topics. This is intentional. Some topics are Ubuntu specific and are not covered by any other book, and they deserve deep coverage here. There are some topics that every power user really must master. Other topics are things power users should know about so that they understand some history, know some other options, or simply have what they need to be able to listen and participate in further discussions with other technical people without being completely confused.
Some topics, like using the Linux command line, receive deep and extensive coverage because we believe that information to be vital to anyone who wants to be a power user or become a skilled DevOps guru. That topic gets three full chapters.
Other topics get only brief coverage so that people who are interested get a few guideposts to help them continue if they are interested. For example, Chapter 39, “Using Popular Programming Languages,” describes languages such as Ada and Fortran, along with more than 20 other programming languages. In that chapter, dozens of programming languages are covered in just a few pages. These are useful topics to some but not topics we would consider vital.
In addition, some topics are just too broad to be covered in great depth in this book, but they deserve mention because, again, an intermediate to advanced user should have at least a foundational knowledge of them. These are covered briefly and then information is provided to help you find more resources and expand your understanding, as needed.
Those Wanting to Become Intermediate or Advanced Users
Ubuntu Unleashed is intended for intermediate and advanced users or those who want to become intermediate and advanced users. Our goal is to give you a nudge in the right direction, to help you enter the higher stages by exposing you to as many different tools and ideas as possible; we give you some thoughts and methods to consider and spur you on to seek out more. Although the contents are aimed at intermediate to advanced users, new users who pay attention 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. Most importantly, it helps you overcome your fear of the system by telling you more about what it is and how it works.
We would like to take a moment to introduce a concept called “The Three Levels of Listening” from Alistair Cockburn’s Agile Software Development. This concept describes how a person learns and masters a technique, passing through three levels:
▸ Following—The level where the learner looks for one very detailed process that works and sticks to it to accomplish a task.
▸ Detaching—The level where the learner feels comfortable with one method and begins to learn other ways to accomplish the same task.
▸ Fluent—The level where the learner has experience with or understanding of many methods and doesn’t think of any of them in particular while doing a task.
We all start at the first level and progress from there. Few reach the last level, but those who do are incredibly effective and efficient. People aiming for this level are the very ones for whom we intend this book.
Myriad books focus on the first set of users. This is not one of them. It is our goal in Ubuntu Unleashed to write just enough to get you from where you are to where you want or need to be. This is not a book for newcomers who want or need every step outlined in detail, although we do that occasionally. This is a book for people who want help learning about what can be done and a way to get started doing it. The Internet is an amazing reference tool, so this is not a comprehensive reference book. This book is a tool to help you see the landscape, to learn enough about what you seek to get you started in the right direction with a quality foundational understanding.
Sysadmins, Programmers, DevOps, and Site Reliability Engineering
System administrators, or sysadmins, are people who keep servers and networks up and running. Their role is sometimes called operations. They deal with software installation and configuration and security, and they do all the amazing things behind the scenes that let others use these systems for their work. They are often given less respect than they deserve, but the pay is good, and it is a ton of fun to wield the ultimate power over a computer system. It is also a great responsibility, and these amazing guys and gals work hard to make sure they do their jobs well, striving for incredible system uptime and availability. Ubuntu is an excellent operating system for servers and networks, and in this book you can find much of the knowledge needed to get started in this role.
Programmers are people who write software. They are sometimes called developers. Programmers work with others to create the applications that run on top of those systems. Ubuntu is a great platform for writing and testing software. This is true whether you are doing web application development or writing software for desktop or server systems. It also makes a great platform for learning new programming languages and trying out new ideas. This book can help you get started.
DevOps is a portmanteau of developer and operations. It signifies a blending of the two roles already described. The information technology (IT) world is changing, and roles are becoming less clear-cut and isolated from one another. In the past, it was common to witness battles between programmers excited about new technology and sysadmins in love with stability. DevOps realizes that neither goal is healthy in isolation but that seeking a balance between the two can yield great results by removing the barriers to communication and understanding that sometimes cause conflict within a team. Because of the rise of cloud computing and virtualization, which are also covered in this book, and more agile forms of development, DevOps is a useful perspective that enables people working in IT to do an even better job of serving their ultimate clients: end users. Site Reliability Engineering (SRE) began at a similar time as DevOps and from a distance looks almost the same. The major difference is that the SRE focus is solely on keeping sites and systems up and running, whereas DevOps has evolved a wider philosophy that may touch on people processes outside of the typical scope of SRE. This book is a great foundation for those who want to learn knowledge that will help with both roles and implementations, hopefully presented in a way that balances them nicely.
What This Book Contains
Ubuntu Unleashed is organized into six parts, described here:
▸ Part I, “Getting Started,” takes you through installing Ubuntu on your computer in the place of any other operating system you might be running, such as Windows.
▸ Part II, “Desktop Ubuntu,” is aimed at users who want to use Ubuntu on desktop systems.
▸ Part III, “System Administration,” covers both elementary and sophisticated details of setting up a system for specific tasks and maintaining that system.
▸ Part IV, “Ubuntu as a Server,” gives you the information you need to start building your own file, web, and other servers for use in your home or office.
▸ Part V, “Programming Linux,” provides a great introduction to how you can extend Ubuntu capabilities even further by using the development tools available.
▸ Part VI, “Bonus Chapters,” consists of three online chapters on using the Perl, Python, and PHP languages on Ubuntu. See informit.com/title/9780136778851.
Conventions Used in This Book
It is impossible to cover every option of every command included in Ubuntu. Besides, with the rise of the Internet and high-speed connections, reference materials are far less valuable today than they used to be because most of these details are only a quick Google search away. Instead, we focus on teaching you how to find information you need while giving a quality overview worthy of intermediate and advanced users. Sometimes this book offers tables of various options, commands, and keystrokes to help condense, organize, and present information about a variety of subjects.
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 a command or code listing example shows input that you as the user would type, the input is formatted in boldface after the sample command prompt, as follows:
matthew@seymour:~$ 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 the sudo command, as follows:
matthew@seymour:~$ sudo printtool &
Other formatting techniques include the use of italic for placeholders in computer command syntax, as shown here:
matthew@seymour:~$ ls directoryname
Computer terms or concepts are also italicized upon first introduction in text.
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 find useful as you are working. A note augments a discussion with ancillary details or may point you to an article, a white paper, or another online reference for more information about a specific topic.
Tip
Tips contain special insights or time-saving techniques, 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 something is in a sidebar does not mean that you will not find something new here. Be sure to watch for these elements, which bring in outside content that is an aside to the discussion in the text. In sidebars, you will read about other technologies, Linux-based hardware, and special procedures to make your system more robust and efficient.
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.