Ubuntu Linux Unleashed 2021 Edition

Matthew Helmke has used Ubuntu since 2005. He has written about Linux for several magazines and websites, is a lead author of The Official Ubuntu Book, and has coauthored both A Practical Guide to Linux: Commands, Editors, and Shell Programming and The VMware Cookbook. In his day job, Matthew works for Gremlin (https://www.gremlin.com/) making the Internet more reliable. Matthew first used UNIX in 1987, while studying Lisp on a Vax at the university. He has run a business using only free and open source software, has consulted, and teaches as an adjunct professor for the University of Arizona. You can find out more about Matthew at https://www.linkedin.com/in/matthewhelmke/ or drop him a line with errata or suggestions at matthew@matthewhelmke.com.

• Introduction xxxiPART I: GETTING STARTED Chapter 1 Installing Ubuntu and Post-Installation Configuration 1 Before You Begin the Installation 1Researching Your Hardware Specifications 2Installation Options 232-Bit Versus 64-Bit Ubuntu 4Planning Partition Strategies 5The Boot Loader 5Installing from DVD or USB Drive 6Step-by-Step Installation 6Installing 7First Update 11Shutting Down 11Finding Programs and Files 12Software Updater 12The sudo Command 14Configuring Software Repositories 15System Settings 17Detecting and Configuring a Printer 18Configuring Power Management in Ubuntu 18Setting the Time and Date 19Configuring Wireless Networks 20Troubleshooting Post-Installation Configuration Problems 21Chapter 2 Background Information and Resources 23 What Is Linux? 23Why Use Linux? 25What Is Ubuntu? 27Ubuntu for Business 27Ubuntu in Your Home 28Getting the Most from Linux and Ubuntu Documentation 28Linux 29Ubuntu 30PART II: DESKTOP UBUNTU Chapter 3 Foundations of the Linux GUI 31 Foundations and the X Server 31Basic X Concepts 32Using X 33Elements of the xorg conf File 34Starting X 39Using a Display Manager 39Changing Window Managers 39Chapter 4 Ubuntu Desktop Options 41 Desktop Environment 41Using GNOME: A Primer 42KDE and Kubuntu 45Xfce and Xubuntu 46LXDE and Lubuntu 47MATE and Ubuntu MATE 48Ubuntu Budgie 49Ubuntu Kylin 50Chapter 5 On the Internet 51 Getting Started with Firefox 52Checking Out Google Chrome and Chromium 53Chapter 6 Productivity Applications 55 Introducing LibreOffice 56Other Useful Productivity Software 58Working with PDFs 58Writing Scripts 59Working with XML and DocBook 59Working with LaTeX 60Creating Mind Maps 61Productivity Applications Written for Microsoft Windows 61Chapter 7 Multimedia Applications 63 Sound and Music 63Sound Cards 64Sound Formats 65Listening to Music 65Graphics Manipulation 66The GNU Image Manipulation Program 66Using Scanners in Ubuntu 67Working with Graphics Formats 67Capturing Screen Images 69Other Graphics Manipulation Options 70Using Digital Cameras with Ubuntu 70Handheld Digital Cameras 70Using Shotwell Photo Manager 71Burning CDs and DVDs in Ubuntu 71Creating CDs and DVDs with Brasero 71Creating CDs from the Command Line 72Creating DVDs from the Command Line 73Viewing Video 75Video Formats 75Viewing Video in Linux 76Recording and Editing Audio 76Editing Video 77Chapter 8 Games 79 Ubuntu Gaming 79Installing Proprietary Video Drivers 80Online Game Sources 81Steam 81GOG com 82Humble 82itch io 82LGDB 82Game Jolt 82Installing Games from the Ubuntu Repositories 82Warsow 82Scorched 3D 83Frozen Bubble 84SuperTux 84Battle for Wesnoth 85Frets on Fire 85FlightGear 87Speed Dreams 87Games for Kids 88Commercial Games 88Playing Windows Games 88PART III: SYSTEM ADMINISTRATION Chapter 9 Managing Software 91 Ubuntu Software 91Using Synaptic for Software Management 92Staying Up to Date 94Working on the Command Line 95Day-to-Day APT Usage 95Finding Software 98Using apt-get Instead of apt 99Compiling Software from Source 100Compiling from a Tarball 100Compiling from Source from the Ubuntu Repositories 101Configuration Management 102dotdee 102Ubuntu Core 103Using the Snappy Package Manager 103Chapter 10 Command-Line Beginner's Class 105 What Is the Command Line? 106Accessing the Command Line 107Text-Based Console Login 107Logging Out 108Logging In and Out from a Remote Computer 108User Accounts 109Reading Documentation 111Using Man Pages 111Using apropros 112Using whereis 112Understanding the Linux File System Hierarchy 112Essential Commands in /bin and /sbin 114Configuration Files in /etc 114User Directories: /home 115Using the Contents of the /proc Directory to Interact with or Obtain Information from the Kernel 115Working with Shared Data in the /usr Directory 117Temporary File Storage in the /tmp Directory 117Accessing Variable Data Files in the /var Directory 117Navigating the Linux File System 117Listing the Contents of a Directory with ls 118Changing Directories with cd 120Finding Your Current Directory with pwd 120Working with Permissions 120Assigning Permissions 121Directory Permissions 122Altering File Permissions with chmod 123File Permissions with umask 124File Permissions with chgrp 125Changing File Permissions with chown 125Understanding Set User ID, Set Group ID, and Sticky Bit Permissions 125Setting Permissions with Access Control Lists 127Working with Files 128Creating a File with touch 128Creating a Directory with mkdir 129Deleting a Directory with rmdir 129Deleting a File or Directory with rm 130Moving or Renaming a File with mv 131Copying a File with cp 131Displaying the Contents of a File with cat 132Displaying the Contents of a File with less 132Using Wildcards and Regular Expressions 133Working as Root 133Understanding and Fixing sudo 134Creating Users 136Deleting Users 137Shutting Down the System 137Rebooting the System 138Commonly Used Commands and Programs 139Chapter 11 Command-Line Master Class, Part 1 141 Why Use the Command Line? 142Using Basic Commands 143Printing the Contents of a File with cat 144Changing Directories with cd 145Changing File Access Permissions with chmod 147Copying Files with cp 147Printing Disk Usage with du 148Using echo 148Finding Files by Searching with find 149Searches for a String in Input with grep 151Paging Through Output with less 152Creating Links Between Files with ln 154Finding Files from an Index with locate 156Listing Files in the Current Directory with ls 156Listing System Information with lsblk, lshw, lsmod, lspci, and neofetch 158Reading Manual Pages with man 159Making Directories with mkdir 160Moving Files with mv 161Renaming Files with rename 161Deleting Files and Directories with rm 161Sorting the Contents of a File with sort 162Printing the Last Lines of a File with tail 163Printing the Location of a Command with which 164Downloading Files with wget 164Chapter 12 Command-Line Master Class, Part 2 167 Redirecting Output and Input 167stdin, stdout, stderr, and Redirection 169Comparing Files 170Finding Differences in Files with diff 170Finding Similarities in Files with comm 170Limiting Resource Use and Job Control 171Listing Processes with ps 171Listing Jobs with jobs 173Running One or More Tasks in the Background 173Moving Jobs to the Background or Foreground with bg and fg 174Printing Resource Usage with top 175Setting Process Priority with nice 177Combining Commands 178Pipes 178Combining Commands with Boolean Operators 180Running Separate Commands in Sequence 180Process Substitution 181Executing Jobs in Parallel 181Using Environment Variables 182Using Common Text Editors 185Working with nano 186Working with vi 187Working with emacs 188Working with sed and awk 189Working with Compressed Files 191Using Multiple Terminals with byobu192Doing a Polite System Reset Using REISUB 194Fixing an Ubuntu System That Will Not Boot 195Checking BIOS 195Checking GRUB 195Reinstalling GRUB 195Using Recovery Mode 196Reinstalling Ubuntu 196Tips and Tricks 196Running the Previous Command 196Running Any Previous Command 197Running a Previous Command That Started with Specific Letters 197Running the Same Thing You Just Ran with a Different First Word 197Viewing Your History and More 197Doing Two or More Things 198Using Shortcuts 198Confining a Script to a Directory 198Using Coreutils 199Reading the Contents of the Kernel Ring Buffer with dmesg 200Chapter 13 Managing Users 201 User Accounts 201The Super User/Root User 202User IDs and Group IDs 204File Permissions 204Managing Groups 205Group Listing 205Group Management Tools 206Managing Users 207User Management Tools 208Adding New Users 209Monitoring User Activity on the System 211Managing Passwords 212System Password Policy 212The Password File 212Shadow Passwords 214Managing Password Security for Users 216Changing Passwords in a Batch 216Granting System Administrator Privileges to Regular Users 217Temporarily Changing User Identity with the su Command 217Granting Root Privileges on Occasion: The sudo Command 219Disk Quotas 222Implementing Quotas 222Manually Configuring Quotas 223Related Ubuntu Commands 223Chapter 14 Automating Tasks and Shell Scripting 225 What Is a Shell? 225Scheduling Tasks 226Using at and batch to Schedule Tasks for Later 227Using cron to Run Jobs Repeatedly 229Using rtcwake to Wake Your Computer from Sleep Automatically 231Basic Shell Control 233The Shell Command Line 233Shell Pattern-Matching Support 235Redirecting Input and Output 236Piping Data 237Background Processing 237Writing and Executing a Shell Script 237Running the New Shell Program 239Storing Shell Scripts for System-wide Access 240Interpreting Shell Scripts Through Specific Shells 240Using Variables in Shell Scripts 242Assigning a Value to a Variable 242Accessing Variable Values 243Positional Parameters 243A Simple Example of a Positional Parameter 243Using Positional Parameters to Access and Retrieve Variables from the Command Line 244Using a Simple Script to Automate Tasks 244Built-in Variables 246Special Characters 247Comparison of Expressions in pdksh and bash 250Comparing Expressions with tcsh 255The for Statement 259The while Statement 261The until Statement 263The repeat Statement (tcsh) 263The select Statement (pdksh) 264The shift Statement 264The if Statement 265The expr Statement 266The case Statement 267The break and exit Statements 269Using Functions in Shell Scripts 269Chapter 15 The Boot Process 271 Running Services at Boot 271Beginning the Boot Loading Process 272Loading the Linux Kernel 274Starting and Stopping Services with systemd 275Controlling Services at Boot with Administrative Tools 278Troubleshooting Runlevel Problems 278Boot-Repair 278Chapter 16 System-Monitoring Tools 281 Console-Based Monitoring 281Using the kill Command to Control Processes 283Using Priority Scheduling and Control 285Displaying Free and Used Memory with free 286Disk Space 286Disk Quotas 287Checking Log Files 287Rotating Log Files 289Graphical Process- and System-Management Tools 292System Monitor 292Conky 292Other Graphical Process- and System-Monitoring Tools 297KDE Process- and System-Monitoring Tools 298Enterprise Server Monitoring 298Chapter 17 Backing Up 301 Choosing a Backup Strategy 301Why Data Loss Occurs 302Assessing Your Backup Needs and Resources 303Evaluating Backup Strategies 304Making the Choice 308Choosing Backup Hardware and Media 308External Hard Drive 308Network Storage 308Tape Drive Backups 309Cloud Storage 309Using Backup Software 309tar: The Most Basic Backup Tool 310The GNOME File Roller 312The KDE ark Archiving Tool 312Déjà Dup 313Back In Time 314Unison 315Amanda 315Alternative Backup Software 316Copying Files 316Copying Files Using tar 317Compressing, Encrypting, and Sending tar Streams 318Copying Files Using cp 318Using rsync 319Version Control for Configuration Files 320System Rescue 323The Ubuntu Rescue Disc 323Restoring the GRUB2 Boot Loader 323Saving Files from a Nonbooting Hard Drive 324Chapter 18 Networking 325 Laying the Foundation: The localhost Interface 326Checking for the Availability of the Loopback Interface 326Configuring the Loopback Interface Manually 327Checking Connections with ping, traceroute, and mtr 328Networking with TCP/IP 330TCP/IP Addressing 331Using IP Masquerading in Ubuntu 332Ports 333IPv6 Basics 334Network Organization 337Subnetting 337Subnet Masks 337Broadcast, Unicast, and Multicast Addressing 338Hardware Devices for Networking 338Network Interface Cards 338Network Cable 340Hubs and Switches 342Routers and Bridges 343Initializing New Network Hardware 343Using Network Configuration Tools 345Command-Line Network Interface Configuration 346Network Configuration Files 350Using Graphical Configuration Tools 355Dynamic Host Configuration Protocol 355How DHCP Works 356Activating DHCP at Installation and Boot Time 357DHCP Software Installation and Configuration 358Using DHCP to Configure Network Hosts 359Other Uses for DHCP 361Wireless Networking 361Support for Wireless Networking in Ubuntu 361Choosing from Among Available Wireless Protocols 363Beyond the Network and onto the Internet 363Common Configuration Information 364Configuring Digital Subscriber Line Access 365Understanding PPP over Ethernet 366Configuring a PPPoE Connection Manually 366Configuring Dial-up Internet Access 367Troubleshooting Connection Problems 368Chapter 19 Remote Access with SSH and VNC 371 Setting Up an SSH Server 371SSH Tools 372Using scp to Copy Individual Files Between Machines 372Using sftp to Copy Many Files Between Machines 373Using ssh-keygen to Enable Key-Based Logins 373Virtual Network Computing 375Guacamole 377Chapter 20 Securing Your Machines 379 Understanding Computer Attacks 379Assessing Your Vulnerability 381Protecting Your Machine 382Securing a Wireless Network 382Passwords and Physical Security 383Configuring and Using Tripwire 384Securing Devices 385Viruses 385Configuring Your Firewall 386AppArmor 388Forming a Disaster Recovery Plan 390Chapter 21 Performance Tuning 393 Storage Disk 394Linux File Systems 394The hdparm Command 395File System Tuning 396The tune2fs Command 396The e2fsck Command 397The badblocks Command 397Disabling File Access Time 397Kernel 398Tuned 399Chapter 22 Kernel and Module Management 401 The Linux Kernel 402The Linux Source Tree 403Types of Kernels 405Managing Modules 406When to Recompile 408Kernel Versions 409Obtaining the Kernel Sources 409Patching the Kernel 410Compiling the Kernel 412Using xconfig to Configure the Kernel 414Creating an Initial RAM Disk Image 418When Something Goes Wrong 418Errors During Compile 418Runtime Errors, Boot Loader Problems, and Kernel Oops 419PART IV: UBUNTU AS A SERVER Chapter 23 Sharing Files and Printers 421 Using Network File System 422Installing and Starting or Stopping NFS 422NFS Server Configuration 422NFS Client Configuration 423Putting Samba to Work 424Manually Configuring Samba with /etc/samba/smb conf 426Testing Samba with the testparm Command 429Starting, Stopping, and Restarting the smbd Daemon 429Mounting Samba Shares 430Network and Remote Printing with Ubuntu 431Creating Network Printers 431Using the CUPS GUI 433Avoiding Printer Support Problems 434Chapter 24 Common Web Server Stacks 437 LAMP 437LEMP 439MEAN 440Chapter 25 Apache Web Server Management 443 About the Apache Web Server 443Installing the Apache Server 444Starting and Stopping Apache 444Runtime Server Configuration Settings 446Runtime Configuration Directives 446Editing apache2 conf 447Apache Multiprocessing Modules 449Using htaccess Configuration Files 450File System Authentication and Access Control 452Restricting Access with Require 452Authentication 453Final Words on Access Control 455Apache Modules 455mod_access 456mod_alias 456mod_asis 456mod_auth 457mod_auth_anon 457mod_auth_dbm 457mod_auth_digest 457mod_autoindex4 58mod_cgi 458mod_dir and mod_env 458mod_expires 458mod_headers 458mod_include 459mod_info and mod_log_config 459mod_mime and mod_mime_magic 459mod_negotiation 459mod_rewrite 459mod_setenvif 460mod_speling 460mod_status 460mod_ssl 460mod_unique_id 460