Linux All-In-One For Dummies

LINUX IS FOR EVERYONE!Linux All-in-One For Dummies breaks down the ever-popular operating system to its basics and trains users on the art of Linux. This handy reference covers all the latest updates and operating system features. It presents content on Linux desktops, applications, and more. With eight books in one, you’ll have access to the most comprehensive overview of Linux around. Explore the inner workings of Linux machines, so you’ll know Linux front to back. This all-inclusive handbook also walks you through solving Linux problems—complete with hands-on examples—so you’ll be a Linux whiz before you know it.

* Get familiar with Linux as you install and customize the operating system
* Learn how to navigate the file system, use the Linux shell, and get online
* Become a Linux guru with server hosting, scripting, and security how-tos
* Study for your Linux certification by using this complete guide as your reference

This book is a massive source of support for beginning and intermediate Linux users, as well as those looking to brush up on their knowledge for certification. And, thanks to the signature Dummies approach, it’s also a lot of fun. RICHARD BLUM has more than 30 years’ experience in the IT industry working as a systems and network administrator. He is an online instructor for Linux and programming courses and is the author of Linux Command Line and Shell Scripting Bible, Linux Essentials, and Linux For Dummies.INTRODUCTION 1

About This Book 1

Foolish Assumptions 2

Icons Used in This Book 3

Beyond the Book 4

Where to Go from Here 4

BOOK 1: GETTING STARTED WITH LINUX 5

CHAPTER 1: INTRODUCING LINUX 7

What Is Linux? 7

The Linux kernel 8

GNU utilities 11

Linux user interfaces 12

Linux Distributions: Why So Many? 16

Core Linux distributions 17

Specialized Linux distributions 18

CHAPTER 2: INSTALLING LINUX 21

Dual-Booting with Linux and Microsoft Windows 23

Installing a second hard drive 24

Partitioning an existing drive 24

Partitioning using Windows tools 25

Partitioning using Linux tools 26

Finally, Finally, Before You Get Started 27

Disabling the secure boot feature 27

Creating a boot disk 28

Installing Ubuntu 30

Your First Ubuntu Boot 36

CHAPTER 3: LIVING IN A VIRTUAL WORLD 39

What Are Virtual Servers? 39

Installing VirtualBox 40

Creating a Linux Virtual Machine 42

Installing Linux on a Virtual Machine 45

Changing settings 45

Loading the operating system 47

Working with the sandbox 50

CHAPTER 4: TRYING OUT LINUX 53

Starting Linux 53

Playing with the Shell 56

Starting the bash shell 56

Understanding shell commands 58

Trying a few Linux commands 58

Shutting Down 60

CHAPTER 5: TROUBLESHOOTING AND CUSTOMIZING LINUX 63

Using Text Mode Installation 64

Lookin’ for Trouble 64

Using the kernel ring buffer 65

Using log files 66

Using the journal 67

Resolving Other Installation Problems 68

Using KNOPPIX boot commands 68

Handling the fatal signal 11 error 71

Getting around the PC reboot problem 71

Using Linux kernel boot options 71

Setting Up Printers 74

Managing DVDs, CD-ROMs, and Flash Drives 76

Updating the Operating System 77

Updating Ubuntu 77

Updating openSUSE 78

Installing New Software 79

Adding applications 80

Adding packages 81

BOOK 2: LINUX DESKTOPS 85

CHAPTER 1: THE GNOME DESKTOP 87

Looking at the History of GNOME 87

Breaking Down the GNOME Desktop 88

Menu, please! 88

The desktop 90

Exploring the Activities Overview 91

Customizing Your Ride 92

CHAPTER 2: THE KDE PLASMA DESKTOP 93

The KDE Plasma Desktop 93

The Application launcher 95

The panel 96

The desktop 96

Using Widgets 98

Adding widgets 98

Getting more widgets 99

Plasma System Settings 99

Desktop Settings 100

CHAPTER 3: OTHER POPULAR DESKTOPS 103

Spicing Things Up with Cinnamon 103

Reviewing the history of Cinnamon 104

Looking at the menu 105

Changing settings 105

Adding more spice 106

Working with MATE 107

The history of MATE 107

Looking at the menu 109

Changing desktop settings 109

Applets 110

The Xfce Desktop Interface 111

The history of Xfce 111

The Whisker menu 112

Changing Xfce settings 113

Applets 113

CHAPTER 4: LINUX DESKTOP APPLICATIONS 115

The LibreOffice Suite 115

Browsing the Web with Firefox 117

Configuring Firefox 117

Communicating with Email 119

Evolving into email 120

Working with KMail 121

The amazing Thunderbird 123

Listening to Audio 124

Listening to downloaded music 127

Viewing Movie Files 129

Creating and Modifying Graphics 130

CHAPTER 5: THE LINUX FILE SYSTEM 133

Pieces of the Puzzle 133

Touring the Linux File System 134

The root of the tree 134

Where removable media lives 136

Managing Your File System without a Net (or Mouse) 136

Viewing information about files on the command line 136

Understanding file listing information 137

Comprehending file types 139

Navigating the file system in Linux 140

A Permissions Primer 141

Checking out the triplets 141

Beware of owners 143

Hanging out in groups 143

Clicking Your Way through the File System 144

Using files 145

Swimming with Dolphin 149

Don’t forget Xfce! 151

Finding Things 152

CHAPTER 6: TEXT EDITORS 155

Viewing the Contents of a Text File 155

Editing Text Files with nano 156

Going with gedit 157

Editing Text in the KDE Plasma Desktop 158

Writing with KWrite 159

Meet Kate 160

Text Editing with ed and vi 161

Using ed 162

Using vi 165

BOOK 3: NETWORKING 171

CHAPTER 1: CONNECTING TO THE INTERNET 173

Understanding the Internet 174

Deciding How to Connect to the Internet 175

Connecting with DSL 176

How DSL works 176

DSL alphabet soup: ADSL, IDSL, SDSL 177

Typical DSL setup 179

Connecting with a Cable Modem 180

How a cable modem works 181

Typical cable modem setup 182

CHAPTER 2: SETTING UP A LOCAL AREA NETWORK 185

Understanding TCP/IP 185

IP addresses 187

Internet services and port numbers 189

Setting Up an Ethernet LAN 190

How Ethernet works 191

Ethernet cables 192

Configuring TCP/IP Networking 195

Connecting Your LAN to the Internet 196

CHAPTER 3: GOING WIRELESS 199

Understanding Wireless Ethernet Networks 199

Understanding infrastructure and ad hoc modes 201

Understanding wireless security 201

Setting Up Wireless Hardware 203

Configuring the Wireless Access Point 204

Configuring Wireless Networks 205

CHAPTER 4: MANAGING THE NETWORK 207

Configuring Network Features 207

Manually editing network configuration files 208

Using a graphical tool 210

Using a command-line tool 212

Basic Network Troubleshooting 216

Advanced Network Troubleshooting 218

BOOK 4: ADMINISTRATION 223

CHAPTER 1: WORKING WITH THE SHELL 225

Opening Terminal Windows and Virtual Consoles 225

Using the Bash Shell 228

Understanding the syntax of shell commands 228

Working with files 230

Combining shell commands 231

Controlling command input and output 231

Going wild with asterisks and question marks 233

Discovering and Using Linux Commands 235

Becoming root (superuser) 240

Managing processes 241

Working with date and time 242

Processing files 243

Writing Shell Scripts 246

CHAPTER 2: INTRODUCING BASIC SYSTEM ADMINISTRATION 249

Taking Stock of System Administration Tasks 250

Becoming root 251

Using the su - command 251

Using the sudo command 252

Understanding How Linux Boots 252

Understanding the SysVinit method 253

Understanding the Systemd method 259

Monitoring System Performance 264

Using the top utility 264

Using the uptime command 266

Using the vmstat utility 267

Checking disk performance and disk usage 267

Viewing System Information with the /proc File System 270

Understanding Linux Devices 273

Device files 274

Persistent device naming with udev 275

Managing Loadable Driver Modules 276

Loading and unloading modules 276

Understanding the /etc/modprobe.d files 277

Scheduling Jobs in Linux 278

Scheduling one-time jobs 278

Scheduling recurring jobs 281

Introducing Some GUI System Administration Tools 284

CHAPTER 3: MANAGING USERS AND GROUPS 287

Adding User Accounts 288

Managing user accounts by using a GUI user manager 288

Managing user accounts by using commands 290

Managing Groups 291

Exploring the User Environment 292

Changing User and Group Ownership of Files 295

CHAPTER 4: MANAGING FILE SYSTEMS 297

Exploring the Linux File System 297

Understanding the file-system hierarchy 298

Mounting a device on the file system 299

Examining the /etc/fstab file 303

Sharing Files with NFS 304

Installing NFS 305

Exporting a file system with NFS 306

Mounting an NFS file system 307

Accessing a DOS or Windows File System 308

Mounting a DOS or Windows disk partition 308

Mounting an NTFS partition 309

BOOK 5: MANAGING LINUX SERVERS 311

CHAPTER 1: HOSTING INTERNET SERVICES 313

What Is a Linux Server? 313

Launching services 314

Listening for clients 316

Serving the Basics 318

Web services 319

Database services 320

Mail services 322

Serving Local Networks 324

File servers 325

Print servers 326

Network resource servers 326

CHAPTER 2: MANAGING A WEB SERVER 331

Linux Web Servers 331

Apache 331

NGINX 333

The Apache Web Server 333

Installing an Apache server 333

Configuring an Apache server 336

The NGINX Server 344

Installing NGINX 344

Configuring NGINX 346

CHAPTER 3: MANAGING A DATABASE SERVER 349

Using the MySQL/MariaDB Database 349

Installing MariaDB 350

Looking at the MariaDB command prompt 353

Using the mysql commands 356

Creating database objects 360

Using the PostgreSQL Database 363

Installing PostgreSQL 364

Looking at the PostgreSQL command interface 366

Creating PostgreSQL database objects 370

CHAPTER 4: WORKING WITH SAMBA AND NFS 373

Sharing Files with NFS 373

Installing NFS 374

Exporting a file system with NFS 375

Mounting an NFS file system 378

Setting Up a Windows Server Using Samba 378

Installing Samba 380

Configuring Samba 382

Trying out Samba 383

CHAPTER 5: MANAGING MAIL SERVERS 385

Working with sendmail 385

The sendmail configuration file 386

Syntax of the sendmail.cf file 391

Other sendmail files 393

The forward file 395

The sendmail alias file 395

Working with Postfix 396

A Mail-Delivery Test 398

Using the mail command 399

The mail-delivery mechanism 400

BOOK 6: SECURITY 401

CHAPTER 1: INTRODUCING LINUX SECURITY 403

Why Worry about Security? 404

Establishing a Security Framework 404

Determining business requirements for security 406

Performing risk analysis 406

Establishing a security policy 408

Implementing security solutions (mitigation) 409

Managing security 410

Securing Linux 410

Understanding the host-security issues 411

Understanding network-security issues 412

Delving Into Computer Security Terminology and Tools 413

Keeping Up with Security News and Updates 418

CHAPTER 2: SECURING LINUX 419

Securing Passwords 420

Shadow passwords 420

Pluggable authentication modules (PAMs) 421

Protecting Files and Directories 422

Viewing ownerships and permissions 423

Changing file ownerships 423

Changing file permissions 423

Setting default permission 424

Checking for set user ID permission 426

Encrypting and Signing Files with GnuPG 427

Understanding public key encryption 427

Understanding digital signatures 428

Using GPG 429

Monitoring System Security 433

Securing Internet Services 434

Turning off stand-alone services 434

Configuring the Internet super server 435

Configuring TCP wrapper security 436

Using Secure Shell for Remote Logins 437

Setting Up Simple Firewalls 439

Using NAT 442

Enabling packet filtering on your Linux system 443

Security Files to Be Aware Of 447

CHAPTER 3: VULNERABILITY TESTING AND COMPUTER SECURITY AUDITS 449

Understanding Security Audits 450

Nontechnical aspects of security audits 450

Technical aspects of security audits 451

Implementing a Security Test Methodology 452

Some common computer vulnerabilities 453

Host-security review 454

Network-security review 458

Vulnerability Testing Types 460

Exploring Security Testing Tools 461

BOOK 7: SCRIPTING 465

CHAPTER 1: INTRODUCTORY SHELL SCRIPTING 467

Trying Out Simple Shell Scripts 468

Exploring the Basics of Shell Scripting 469

Storing stuff 470

Calling shell functions 471

Controlling the flow 471

Exploring bash’s built-in commands 475

CHAPTER 2: ADVANCED SHELL SCRIPTING 479

Trying Out sed 479

Working with awk and sed 482

Step 1: Pull out the ISBN 483

Step 2: Calculate the 13th digit 484

Step 3: Add the 13th digit to the other 12 485

Step 4: Finish the process 485

Final Notes on Shell Scripting 486

CHAPTER 3: PROGRAMMING IN LINUX 487

An Overview of Programming 488

Exploring the Software-Development Tools in Linux 489

GNU C and C++ compilers 490

The GNU make utility 493

The GNU debugger 502

Understanding the Implications of GNU Licenses 509

The GNU General Public License 510

The GNU Library General Public License 511

BOOK 8: LINUX CERTIFICATION 513

CHAPTER 1: STUDYING FOR THE LINUX PROFESSIONAL INSTITUTE EXAMS 515

Overview of LPI Certification Exams 515

Overview of the Linux Essentials Exam 516

Getting involved in the Linux community and finding a career in open source 517

Finding your way on a Linux system 518

The power of the command line 520

The Linux operating system 521

Security and file permissions 522

Overview of the Linux Professionals Exams 524

The LPIC-1 exams 524

The LPIC-2 exams 527

The LPIC-3 exams 528

CHAPTER 2: STUDYING FOR THE COMPTIA LINUX+ EXAM 529

Overview of the CompTIA Linux+ Exam 530

System Management 531

Security 532

Scripting, Containers, and Automation 533

Troubleshooting 533

CHAPTER 3: OTHER LINUX CERTIFICATIONS 535

Vendor-Neutral Certifications 535

The Linux Foundation 535

The GIAC Certifications 536

Vendor-Specific Certifications 537

Index 539