Practical Guide To Ubuntu Linux

The Most Complete, Easy-to-Follow Guide to Ubuntu Linux  

“As an in-depth guide to Ubuntu, this book does an exceptional job of covering everything from using the Unity desktop to exploring key server configurations.”

–Elizabeth K. Joseph, Systems Administrator & Ubuntu Community Member 

• The #1 Ubuntu resource, fully updated for Ubuntu 14.04 (Trusty Tahr)–the Long Term Support (LTS) release Canonical will support into 2019
• Extensive new coverage of installation, security, virtualization, MariaDB, Python Programming, and much more
• Updated JumpStarts help you set up many complex servers in minutes
• Hundreds of up-to-date examples, plus four updated indexes deliver fast access to reliable answers 

Mark Sobell’s A Practical Guide to Ubuntu Linux®, Fourth Edition, is the most thorough and up-to-date reference to installing, configuring, securing, and working with Ubuntu desktops and servers.

This edition has been fully updated for Ubuntu 14.04 (Trusty Tahr), a milestone LTS (Long Term Support) release, which Canonical will support on both desktops and servers into 2019.

Sobell walks you through every essential feature and technique, from installing Ubuntu to working with the latest Ubuntu Unity desktop, and from configuring servers and monitoring networks to handling day-to-day system administration. His exceptionally clear explanations demystify everything from Apache, Samba, and postfix, to ufw, virtualization, and MariaDB/MySQL database management. PLUS a new chapter on programming in Python, today’s most popular system automation tool!

Fully updated JumpStart sections quickly help you get complex servers running–often in minutes. You’ll also find up-to-date guidance on new LPI and CompTIA Linux certification pathways for Linux professionals.

Sobell draws on his immense Linux knowledge to explain both the “hows” and the “whys” of Ubuntu. He’s taught hundreds of thousands of readers and never forgets what it’s like to be new to Linux. Whether you’re a user, administrator, or programmer, you’ll find everything you need here–now, and for years to come.

The world’s most practical Ubuntu Linux book is now even more useful!

This book delivers

• Completely revamped installation coverage reflecting Ubuntu 14.04’s improved ubiquity (graphical) and debian-installer (textual) installers
• Updated JumpStarts for quickly setting up Samba, Apache, postfix, FTP, NFS, CUPS, OpenSSH, DNS, and other complex servers
• Revamped and updated explanations of the ufw, gufw, and iptables firewall tools
• An all-new chapter on creating VMs (virtual machines) locally and in the cloud
• New coverage of the MariaDB open source plug-in replacement for MySQL
• Comprehensive networking coverage, including DNS/BIND, NFS, NIS, FTP, LDAP, and Cacti network monitoring
• Expert coverage of Internet server configuration and customization, including apache2 (Web) and postfix (mail)
• A new chapter covering state-of-the-art security techniques, including sudo, cryptography, hash functions, SSL certificates, plus a section on using GPG (GNU Privacy Guard) to protect documents in transit
• Deep coverage of essential administration tasks–from managing users to CUPS printing, and from configuring LANs and LDAP to building VMs (virtual machines)
• Complete instructions on keeping systems up to date using apt-get, dpkg, and other tools
• And much more . . . including a revised 500+ term glossary and four indexes

“I have said before on several occasions that Sobell does really good work. Well, [A Practical Guide to Ubuntu Linux®, Third Edition,] holds true to my words. This is a big book with some 1250+ pages in it absolutely filled to the brim with useful information. The review on the front cover mentions that the book is ‘comprehensive’ and that just might be understating it a little. This book has practically anything you might want to know about Ubuntu, and references a lot of really helpful general Linux and userland program information and it’s put together in a very straight forward and understandable way. Having the word ‘Practical’ in the name is also a really good fit as the book offers great walk-throughs on things people will want to do with their Ubuntu install from beginner things like configuring a printer all the way up to things like some Perl programming and running your own Web server. All in all, this book is not only worth a look, but it is a keeper. It’s a good read and great technical reference.”

—Lincoln C. Fessenden, Linux Guy / I.T. Manager

“The third updated edition of A Practical Guide to Ubuntu Linux® offers a fine reference perfect for any Ubuntu Linux computer collection, packing in hundreds of practical applications for Ubuntu with keys to security, Perl scripting, common administration tasks, and more. From keeping Ubuntu systems current to handling configuration issues, this is a solid reference to the latest Ubuntu applications and challenges.”

—Jim Cox, Midwest Book Review

“This is an excellent text and I am using it as of this term as the textbook for the class in Linux that I am teaching at the local Community College. The first book on UNIX that I used twenty-five years ago was written by Sobell. He hasn’t lost his touch.”

—James J. Sherin, Part-Time Faculty, Westmoreland County Community College

“When I first started working with Linux just a short 10 years or so ago, it was a little more difficult than now to get going. . . . Now, someone new to the community has a vast array of resources available on the web, or if they are inclined to begin with Ubuntu, they can literally find almost every single thing they will need in the single volume of Mark Sobell’s A Practical Guide to Ubuntu Linux®.

“Overall, I think it’s a great, comprehensive Ubuntu book that’ll be a valuable resource for people of all technical levels.”

—John Dong, Ubuntu Forum Council Member, Backports Team Leader

“I would so love to be able to use this book to teach a class about not just Ubuntu or Linux but about computers in general. It is thorough and well written with good illustrations that explain important concepts for computer usage.”

—Nathan Eckenrode, New York Local Community Team

“Ubuntu is gaining popularity at the rate alcohol did during Prohibition, and it’s great to see a well-known author write a book on the latest and greatest version. Not only does it contain Ubuntu-specific information, but it also touches on general computer-related topics, which will help the average computer user to better understand what’s going on in the background. Great work, Mark!”

—Daniel R. Arfsten, Pro/ENGINEER Drafter/Designer

“This is well-written, clear, comprehensive information for the Linux user of any type, whether trying Ubuntu on for the first time and wanting to know a little about it, or using the book as a very good reference when doing something more complicated like setting up a server. This book’s value goes well beyond its purchase price and it’ll make a great addition to the Linux section of your bookshelf.”

—Linc Fessenden, Host of The LinuxLink TechShow, tllts.org

“Overall, A Practical Guide to Ubuntu Linux® by Mark G. Sobell provides all of the information a beginner to intermediate user of Linux would need to be productive. The inclusion of the Live DVD of Ubuntu makes it easy for the user to test-drive Linux without affecting his installed OS. I have no doubts that you will consider this book money well spent.”

—Ray Lodato, Slashdot contributor, www.slashdot.org

“I’m sure this sounds a bit like hyperbole. Everything a person would need to know? Obviously not everything, but this book, weighing in at just under 1200 pages, covers so much so thoroughly that there won’t be much left out. From install to admin, networking, security, shell scripting, package management, and a host of other topics, it is all there. GUI and command line tools are covered. There is not really any wasted space or fluff, just a huge amount of information. There are screen shots when appropriate but they do not take up an inordinate amount of space. This book is information-dense.”

—JR Peck, Editor, GeekBook.org

“Sobell tackles a massive subject, the vast details of a Linux operating system, and manages to keep the material clear, interesting and engaging. . . . If you want to know how to get the most out of your Red Hat, Fedora, or CentOS system, then this is one of the best texts available, in my opinion.”

—Jesse Smith, Feature Writer for DistroWatch

“I had the chance to use your UNIX books when I when was in college years ago at Cal Poly, San Luis Obispo, CA. I have to say that your books are among the best! They’re quality books that teach the theoretical aspects and applications of the operating system.”

—Benton Chan, IS Engineer

“I currently own one of your books, A Practical Guide to Linux®. I believe this book is one of the most comprehensive and, as the title says, practical guides to Linux I have ever read. I consider myself a novice and I come back to this book over and over again.”

—Albert J. Nguyen

“The book has more than lived up to my expectations from the many reviews I read, even though it targets FC2. I have found something very rare with your book: It doesn’t read like the standard technical text, it reads more like a story. It’s a pleasure to read and hard to put down. Did I say that?! :-)”

—David Hopkins, Business Process Architect

“Thanks for your work and for the book you wrote. There are really few books that can help people to become more efficient administrators of different workstations. We hope (in Russia) that you will continue bringing us a new level of understanding of Linux/UNIX systems.”

—Anton Petukhov

“Mark Sobell has written a book as approachable as it is authoritative.”

—Jeffrey Bianchine, Advocate, Author, Journalist

“Since I’m in an educational environment, I found the content of Sobell’s book to be right on target and very helpful for anyone managing Linux in the enterprise. His style of writing is very clear. He builds up to the chapter exercises, which I find to be relevant to real-world scenarios a user or admin would encounter. An IT/IS student would find this book a valuable complement to their education. The vast amount of information is extremely well balanced and Sobell manages to present the content without complicated asides and meandering prose. This is a ‘must have’ for anyone managing Linux systems in a networked environment or anyone running a Linux server. I would also highly recommend it to an experienced computer user who is moving to the Linux platform.”

—Mary Norbury, IT Director, Barbara Davis Center, University of Colorado at Denver, from a review posted on slashdot.org

“Excellent reference book, well suited for the sysadmin of a Linux cluster, or the owner of a PC contemplating installing a recent stable Linux. Don’t be put off by the daunting heft of the book. Sobell has striven to be as inclusive as possible, in trying to anticipate your system administration needs.”

—Wes Boudville, Inventor

“The JumpStart sections really offer a quick way to get things up and running, allowing you to dig into the details of the book later.”

—Scott Mann, Aztek Networks

“A Practical Guide to Red Hat® Linux® is a brilliant book. Thank you Mark Sobell.”

—C. Pozrikidis, University of California at San Diego

“Overall I found this book to be quite excellent, and it has earned a spot on the very front of my bookshelf. It covers the real ‘guts’ of Linux—the command line and its utilities—and does so very well. Its strongest points are the outstanding use of examples, and the Command Reference section. Highly recommended for Linux users of all skill levels. Well done to Mark Sobell and Prentice Hall for this outstanding book!”

—Dan Clough, Electronics Engineer and Slackware Linux User

“This book presents the best overview of the Linux operating system that I have found. . . . [It] should be very helpful and understandable no matter what the reader’s background: traditional UNIX user, new Linux devotee, or even Windows user. Each topic is presented in a clear, complete fashion and very few assumptions are made about what the reader knows. . . . The book is extremely useful as a reference, as it contains a 70-page glossary of terms and is very well indexed. It is organized in such a way that the reader can focus on simple tasks without having to wade through more advanced topics until they are ready.”

—Cam Marshall, Marshall Information Service LLC, Member of Front Range UNIX, Users Group [FRUUG], Boulder, Colorado

“Conclusively, this is THE book to get if you are a new Linux user and you just got into RH/Fedora world. There’s no other book that discusses so many different topics and in such depth.”

—Eugenia Loli-Queru, Editor in Chief, OSNews.com

“This book is a very useful tool for anyone who wants to ‘look under the hood’ so to speak, and really start putting the power of Linux to work. What I find particularly frustrating about man pages is that they never include examples. Sobell, on the other hand, outlines very clearly what the command does and then gives several common, easy-to-understand examples that make it a breeze to start shell programming on one’s own. As with Sobell’s other works, this is simple, straight-forward, and easy to read. It’s a great book and will stay on the shelf at easy arm’s reach for a long time.”

—Ray Bartlett, Travel Writer

“Totally unlike most Linux books, this book avoids discussing everything via GUI and jumps right into making the power of the command line your friend.”

—Bjorn Tipling, Software Engineer, ask.com

“This book is the best distro-agnostic, foundational Linux reference I’ve ever seen, out of dozens of Linux-related books I’ve read. Finding this book was a real stroke of luck. If you want to really understand how to get things done at the command line, where the power and flexibility of free UNIX-like OSes really live, this book is among the best tools you’ll find toward that end.”

—Chad Perrin, Writer, TechRepublic

“Thank you for writing a book to help me get away from Windows XP and to never touch Windows Vista. The book is great; I am learning a lot of new concepts and commands. Linux is definitely getting easier to use.”

—James Moritz

“I am so impressed by how Mark Sobell can approach a complex topic in such an understandable manner. His command examples are especially useful in providing a novice (or even an advanced) administrator with a cookbook on how to accomplish real-world tasks on Linux. He is truly an inspired technical writer!”

—George Vish II, Senior Education Consultant, Hewlett-Packard Company

“I read a lot of Linux technical information every day, but I’m rarely impressed by tech books. I usually prefer online information sources instead. Mark Sobell’s books are a notable exception. They’re clearly written, technically accurate, comprehensive, and actually enjoyable to read.”

—Matthew Miller, Senior Systems Analyst/Administrator, BU Linux Project, Boston University Office of Information Technology

“The author has done a very good job at clarifying such a detail-oriented operating system. I have extensive Unix and Windows experience and this text does an excellent job at bridging the gaps between Linux, Windows, and Unix. I highly recommend this book to both ‘newbs’ and experienced users. Great job!”

—Mark Polczynski, Information Technology Consultant

“I have been wanting to make the jump to Linux but did not have the guts to do so—until I saw your familiarly titled A Practical Guide to Red Hat® Linux® at the bookstore. I picked up a copy and am eagerly looking forward to regaining my freedom.”

—Carmine Stoffo, Machine and Process Designer to the pharmaceutical industry

“I am currently reading A Practical Guide to Red Hat® Linux® and am finally understanding the true power of the command line. I am new to Linux and your book is a treasure.”

—Juan Gonzalez

"As an in-depth guide to Ubuntu, this book does an exceptional job of covering everything from using the Unity desktop to exploring key server configurations."

• The #1 Ubuntu resource, fully updated for Ubuntu 14.04 (Trusty Tahr)-the Long Term Support (LTS) release Canonical will support into 2019
• Extensive new coverage of installation, security, virtualization, MariaDB, Python Programming, and much more
• Updated JumpStarts help you set up many complex servers in minutes
• Hundreds of up-to-date examples, plus four updated indexes deliver fast access to reliable answers

This edition has been fully updated for Ubuntu 14.04 (Trusty Tahr), a milestone LTS (Long Term Support) release, which Canonical will support on both desktops and servers into 2019.

Sobell walks you through every essential feature and technique, from installing Ubuntu to working with the latest Ubuntu Unity desktop, and from configuring servers and monitoring networks to handling day-to-day system administration. His exceptionally clear explanations demystify everything from Apache, Samba, and postfix, to ufw, virtualization, and MariaDB/MySQL database management. PLUS a new chapter on programming in Python, today's most popular system automation tool

Fully updated JumpStart sections quickly help you get complex servers running-often in minutes. You'll also find up-to-date guidance on new LPI and CompTIA Linux certification pathways for Linux professionals.

Sobell draws on his immense Linux knowledge to explain both the "hows" and the "whys" of Ubuntu. He's taught hundreds of thousands of readers and never forgets what it's like to be new to Linux. Whether you're a user, administrator, or programmer, you'll find everything you need here-now, and for years to come.

The world's most practical Ubuntu Linux book is now even more useful

This book delivers

• Completely revamped installation coverage reflecting Ubuntu 14.04's improved ubiquity (graphical) and debian-installer (textual) installers
• Updated JumpStarts for quickly setting up Samba, Apache, postfix, FTP, NFS, CUPS, OpenSSH, DNS, and other complex servers
• Revamped and updated explanations of the ufw, gufw, and iptables firewall tools
• An all-new chapter on creating VMs (virtual machines) locally and in the cloud
• New coverage of the MariaDB open source plug-in replacement for MySQL
• Comprehensive networking coverage, including DNS/BIND, NFS, NIS, FTP, LDAP, and Cacti network monitoring
• Expert coverage of Internet server configuration and customization, including apache2 (Web) and postfix (mail)
• A new chapter covering state-of-the-art security techniques, including sudo, cryptography, hash functions, SSL certificates, plus a section on using GPG (GNU Privacy Guard) to protect documents in transit
• Deep coverage of essential administration tasks-from managing users to CUPS printing, and from configuring LANs and LDAP to building VMs (virtual machines)
• Complete instructions on keeping systems up to date using apt-get, dpkg, and other tools
• And much more . . . including a revised 500+ term glossary and four indexes

Mark Sobell’s A Practical Guide to Ubuntu Linux®, Fourth Edition, is the most thorough and up-to-date reference to installing, configuring, and working with Ubuntu, and also offers comprehensive coverage of servers—critical for anybody interested in unleashing the full power of Ubuntu.

This edition has been fully updated for Ubuntu 14.04 (Tasty Tahr), a milestone Long Term Support (LTS) release, which Canonical will support on desktops until 2013 and on servers until 2015.

You’ll find full chapters on running Ubuntu from the command line and desktop (GUI), administrating systems, setting up networks and Internet servers, and much more. Fully updated JumpStart sections help you get complex servers running—often in as little as five minutes.

Sobell draws on his immense Linux knowledge to explain both the “hows” and the “whys” of Ubuntu. He’s taught hundreds of thousands of readers and never forgets what it’s like to be new to Linux. Whether you’re a user, administrator, or programmer, you’ll find everything you need here—now, and for many years to come.

Includes DVD!  Get the full version of Tasty Tahr, the latest Ubuntu LTS release!

Preface xliii

Chapter 1: Welcome to Linux 1

The History of UNIX and GNU–Linux 2

Overview of Linux 11

Choosing an Operating System 19

Chapter Summary 21

Exercises 21

Part I: Installing Ubuntu Linux 23

Chapter 2: Installation Overview 25

Conventions Used in This Book 26

More Information 29

Planning the Installation 30

Ubuntu Releases, Editions, and Derivatives 35

Setting Up the Hard Disk 38

Downloading an Image File and Burning/Writing the Installation Medium 47

Chapter Summary 53

Exercises 54

Advanced Exercises 54

Chapter 3: Step-by-Step Installation 55

Booting Ubuntu and Running a Live Session 56

Basic Installation 59

Advanced Installation 71

Chapter Summary 93

Exercises 94

Advanced Exercises 94

Part II: Using Ubuntu Linux 95

Chapter 4: Introduction to Ubuntu 97

Curbing Your Power: root Privileges/sudo 98

Logging In on the System 99

Working with the Unity Desktop 104

Using the Nautilus File Manager 108

The System Settings Window 113

Getting Help 118

Installing, Removing, and Updating Software Packages 121

Working from the Command Line 125

More About Logging In and Passwords 142

Chapter Summary 145

Exercises 146

Advanced Exercises 147

Chapter 5: The Shell 149

Special Characters 150

Ordinary Files and Directory Files 151

The Command Line 152

Standard Input and Standard Output 159

Running a Command in the Background 171

Filename Generation/Pathname Expansion 173

Builtins 178

Chapter Summary 178

Exercises 179

Advanced Exercises 181

Chapter 6: The Linux Filesystem 183

The Hierarchical Filesystem 184

Ordinary Files and Directory Files 185

Pathnames 189

Working with Directories 191

Access Permissions 199

ACLs: Access Control Lists 206

Links 211

Chapter Summary 217

Exercises 219

Advanced Exercises 220

Chapter 7: The Linux Utilities 223

Basic Utilities 224

Working with Files 232

Compressing and Archiving Files 253

Displaying User and System Information 260

Miscellaneous Utilities 263

Editing Files 270

Chapter Summary 280

Exercises 282

Advanced Exercises 283

Chapter 8: Networking and the Internet 285

Introduction to Networking 286

Types of Networks and How They Work 288

Communicate over a Network 307

Network Utilities 308

Distributed Computing 315

WWW: World Wide Web 325

Chapter Summary 327

Exercises 328

Advanced Exercises 328

Part III: System Administration 331

Chapter 9: The Bourne Again Shell (bash) 333

Background 334

Startup Files 335

Commands That Are Symbols 339

Redirecting Standard Error 339

Writing and Executing a Shell Script 342

Control Operators: Separate and Group Commands 347

Job Control 352

Manipulating the Directory Stack 355

Parameters and Variables 358

Special Characters 372

Locale 374

Time 377

Processes 379

History 382

Aliases 398

Functions 402

Controlling bash: Features and Options 404

Processing the Command Line 409

Chapter Summary 420

Exercises 421

Advanced Exercises 423

Chapter 10: System Administration: Core Concepts 425

The Upstart Event-Based init Daemon 427

System Operation 437

GRUB: The Linux Boot Loader 444

Recovery (Single-User) Mode 450

Textual System Administration Utilities 454

Setting Up a Server 460

DHCP: Configures Network Interfaces 464

nsswitch.conf: Which Service to Look at First 468

X Window System 471

Getting Help 476

Chapter Summary 477

Exercises 478

Advanced Exercises 478

Chapter 11: Files, Directories, and Filesystems 479

Important Files and Directories 480

File Types 493

Filesystems 497

The XFS Filesystem 506

Chapter Summary 507

Exercises 508

Advanced Exercises 508

Chapter 12: Finding, Downloading, and Installing Software 509

Introduction 510

JumpStart: Installing and Removing Software Packages Using apt-get 512

Finding the Package That Holds an Application or File You Need 514

APT: Keeps the System Up to Date 515

dpkg: The Debian Package Management System 524

BitTorrent 531

Installing Non-dpkg Software 533

Keeping Software Up to Date 535

curl: Downloads Files Noninteractively 536

Chapter Summary 536

Exercises 537

Advanced Exercises 537

Chapter 13: Printing with CUPS 539

Introduction 540

The System Configures a Local Printer Automatically 542

JumpStart I: Configuring a Printer Using system-config-printer 542

JumpStart II: Setting Up a Local or Remote Printer 544

Working with the CUPS Web Interface 548

Configuring Printers 549

Traditional UNIX Printing 557

Printing from Windows 558

Printing to Windows 560

Chapter Summary 560

Exercises 561

Advanced Exercises 561

Chapter 14: Administration Tasks 563

Configuring User and Group Accounts 564

Backing Up Files 568

Scheduling Tasks 573

System Reports 576

Maintaining the System 578

Chapter Summary 593

Exercises 594

Advanced Exercises 594

Chapter 15: System Security 595

Running Commands with root Privileges 596

Passwords 615

Securing a Server 616

PAM 621

Cryptography 626

GPG (GNU Privacy Guard) 641

Security Resources 656

Chapter Summary 659

Exercises 660

Advanced Exercises 660

Chapter 16: Configuring and Monitoring a LAN 661

More Information 662

Setting Up the Hardware 662

Configuring the Systems 666

NetworkManager: Configures Network Connections 667

Setting Up Servers 672

Introduction to Cacti 674

Chapter Summary 683

Exercises 684

Advanced Exercises 685

Chapter 17: Setting Up Virtual Machines Locally and in the Cloud 687

VMs (Virtual Machines) 688

gnome-boxes 690

QEMU/KVM 691

VMware Player: Installing Ubuntu on VMware 698

Cloud Computing 703

Chapter Summary 708

Exercises 709

Advanced Exercises 709

Part IV: Using Clients and Setting Up Servers 711

Chapter 18: The OpenSSH Secure CommunicationUtilities 713

Introduction to OpenSSH 714

Running the ssh, scp, and sftp OpenSSH Clients 716

Setting Up an OpenSSH Server (sshd) 727

Troubleshooting 735

Tunneling/Port Forwarding 735

Chapter Summary 738

Exercises 739

Advanced Exercises 739

Chapter 19: The rsync Secure Copy Utility 741

Syntax 742

Arguments 742

Options 742

Examples 745

Chapter Summary 752

Exercises 752

Chapter 20: FTP: Transferring Files Across a Network 753

Introduction to FTP 754

Running the ftp and sftp FTP Clients 756

Setting Up an FTP Server (vsftpd) 764

Chapter Summary 777

Exercises 778

Advanced Exercises 778

Chapter 21: postfix: Setting Up Mail Servers, Clients, and More 779

Overview 780

Introduction to postfix 781

Setting Up a postfix Mail Server 784

JumpStart: Configuring postfix to Use Gmail as a Smarthost 787

Configuring postfix 789

SpamAssassin 797

Additional Email Tools 801

dovecot: Setting Up an IMAP or POP3 Mail Server 807

Chapter Summary 810

Exercises 811

Advanced Exercises 812

Chapter 22: NIS and LDAP 813

Introduction to NIS 814

Running an NIS Client 817

Setting Up an NIS Server 822

Introduction to LDAP 830

Setting Up an LDAP Server 833

Chapter Summary 839

Exercises 840

Advanced Exercises 840

Chapter 23: NFS: Sharing Directory Hierarchies 843

Introduction to NFS 845

Running an NFS Client 847

Setting Up an NFS Server 853

automount: Mounts Directory Hierarchies on Demand 863

Chapter Summary 866

Exercises 867

Advanced Exercises 867

Chapter 24: Samba: Linux and Windows File and Printer Sharing 869

Introduction to Samba 870

Running Samba Clients 874

Setting Up a Samba Server 878

Troubleshooting 887

Chapter Summary 889

Exercises 890

Advanced Exercises 890

Chapter 25: DNS/BIND: Tracking Domain Names and Addresses 891

Introduction to DNS 892

Setting Up a DNS Server 904

Configuring a DNS Server 907

Chapter Summary 920

Exercises 921

Advanced Exercises 921

Chapter 26: ufw, gufw, and iptables: Setting Up a Firewall 923

ufw: The Uncomplicated Firewall 924

gufw: The Graphical Interface to ufw 927

Introduction to iptables 932

Building a Set of Rules Using iptables 937

Copying Rules to and from the Kernel 944

Sharing an Internet Connection Using NAT 945

Chapter Summary 948

Exercises 949

Advanced Exercises 949

Chapter 27: Apache (apache2): Setting Up a Web Server 951

Introduction 952

Running an Apache Web Server 954

Configuration Directives 961

Advanced Configuration 984

Troubleshooting 990

Modules 991

webalizer: Analyzes Web Traffic 997

Error Codes 997

Chapter Summary 998

Exercises 998

Advanced Exercises 999

Part V: Programming Tools 1001

Chapter 28: Programming the Bourne Again Shell (bash) 1003

Control Structures 1004

File Descriptors 1038

Parameters 1044

Variables 1053

Builtin Commands 1062

Expressions 1078

Implicit Command-Line Continuation 1085

Shell Programs 1086

Chapter Summary 1096

Exercises 1098

Advanced Exercises 1100

Chapter 29: The Python Programming Language 1103

Introduction 1104

Scalar Variables, Lists, and Dictionaries 1108

Control Structures 1114

Reading from and Writing to Files 1119

Regular Expressions 1123

Defining a Function 1124

Using Libraries 1125

Lambda Functions 1129

List Comprehensions 1130

Chapter Summary 1131

Exercises 1132

Advanced Exercises 1132

Chapter 30: The MariaDB SQL Database Management System 1135

History 1136

Notes 1136

Installing a MariaDB Server 1140

Setting Up MariaDB 1141

Examples 1145

Chapter Summary 1157

Exercises 1157

Advanced Exercises 1157

Part VI: Appendixes 1159

Appendix A: Regular Expressions 1161

Characters 1162

Delimiters 1162

Simple Strings 1162

Special Characters 1162

Rules 1165

Bracketing Expressions 1166

The Replacement String 1166

Extended Regular Expressions 1167

Appendix Summary 1169

Appendix B: Help 1171

Solving a Problem 1172

Finding Linux-Related Information 1173

Specifying a Terminal 1175

Appendix C: Keeping the System Up to Date Using yum 1177

Installing and Removing Software Packages Using yum 1178

Working with yum 1179

Appendix D: LPI and Comptia Certification 1183

More Information 1184

Linux Essentials 1184

Certification Exam 1 Objectives: LX0-101 1198

Certification Exam 2 Objectives: LX0-102 1214

Glossary 1231

JumpStart Index 1285

File Tree Index 1287

Utility Index 1291

Main Index 1297