Table of Contents

Chapter 1 Installing Linux 3
“Do I Know This Already?” Quiz 3
Understanding Your Hardware 6


Peripheral Compatibility 7


Enumerating Your Peripherals 7


The Proc Filesystem 8




Friends of procfs 10




Dealing with Integrated Peripherals 10
Laying Out the Hard Drive 11


Partitions and Devices 11


The Root Filesystem 12


Logical Volume Manager (LVM) 14


Commonly Used Mounts 16


Swap Files 16
Working with Boot Managers 17


GRUB Legacy 17


GRUB2 18




Installing GRUB2 18




Using the GRUB2 Command Line 19




Configuring GRUB2 20
Summary 21
Exam Preparation Tasks 22


Review All Key Topics 22


Define Key Terms 22


Review Questions 23

Chapter 2 Boot Process and Runlevels 27
“Do I Know This Already?” Quiz 27
The Linux Boot Process 30


What Is the Boot Process? 30


Boot Loaders 30


Common Commands at Boot Time 32
Boot Sequence from BIOS to Fully Running System 33


SysVinit 33
systemd 34


Units in systemd 36


systemd Targets and Runlevels 37


Wants and Requires 38
Booting with systemd 38


Upstart 39




Managing System Runlevels 40




Determining the Default Runlevel 40


Setting the Default Runlevels 41


Changing Runlevels 41
Shut Down and Reboot from the Command Line 42


Alerting Users 43
Properly Terminating Processes 44


kill and killall 44


Reloading or “Hanging Up” Processes 45
Logging Boot Events 45
Exam Preparation Tasks 46


Review All Key Topics 46


Define Key Terms 47


Review Questions 47

Chapter 3 Package Install and Management 51
“Do I Know This Already?” Quiz 51
Software in a Linux System 54


Shared Libraries 54


Working with Shared Libraries 56


Determining Required Libraries 56




Looking for Libraries in Other Places 57
Debian Package Management 58


Managing Local Debian Packages 58




Installing Packages with dpkg 59




Removing Packages 60




Dependency Issues 60




Querying Packages 61




Reconfiguring Packages 63


Using Remote Repositories 64




Installing Remote Packages 64




Working with the Cache 65




Upgrading the System 66




Removing Packages 67




Graphical Managers 67
RPM and YUM Package Management 68


The RPM Database 68




RPM Package Files 69




Package Name Conventions 69


The rpm Command 70




Validation of Packages 71




Installation of Packages 72




Additional Installation Options 72




Verifying a Package’s Integrity 73




Freshening Versus Upgrading 74




Removing Packages 75




Other Removal Options 76


Querying Packages 77


Package Management with YUM 80




Installing Packages 80




Fetching Updates 83




Finding Packages to Install 83


Configuring Yum 84
Summary 86
Exam Preparation Tasks 86


Review All Key Topics 86


Define Key Terms 87


Review Questions 88

Chapter 4 Basic Command Line Usage 91
“Do I Know This Already?” Quiz 91
What Is a Shell? 93
Global and User Settings 94


Sourcing Versus Executing 94




Executing a Script 94


Sourcing a Script 94


A Login Shell Session 95


A Non-Login Shell Session 96
Using the Command Line 97


There Are Commands and, Well, Commands 97


Structuring Commands 98


Breaking Long Command Lines 98


Command Completion 99


Special Characters in the Shell 99
Controlling Command Execution 100


Possible Exit Statuses 100
Environment Variables and Settings 101


The Path 102


Getting $HOME 102


bash’s History Feature 103


Important History Variables 104
Setting Options in bash 104


Important bash Options 104
Exam Preparation Tasks 105


Review All Key Topics 105


Define Key Terms 106


Review Questions 106

Chapter 5 File Management 109
“Do I Know This Already?” Quiz 109
Filesystem Overview 112


What Belongs Where 112




The Root of the System 112




Classifying Data 113




Where Programs Live 114
File Management Commands 114


Tips for Working with Linux Files 115


Basic Navigation 115


Advanced Navigation 116


Listing Files and Directories 116


Determining File Types 118


Touching Files 120


Copying Files and Directories 121


Moving Objects 123


Transforming Data Formats 126


Creating and Removing Directories 127


Removing Objects 128
Where Are Those Files? 128


Locating Files with Locate 128


Finding Files 130


Which Command Will Run? 132


Researching a Command 132


Linking Files 133




Symbolic Links 134




Hard Links 135
Backup Commands 136


Using tar 137


Taking Pity on the Unarchiver 139




Useful Creation Options 140




Listing Archive Files 140




Using cpio 141


Compression Utilities 143
Summary 144
Exam Preparation Tasks 144


Review All Key Topics 144


Define Key Terms 145


Review Questions 146

Chapter 6 Text Processing/Advanced Command Line 151
“Do I Know This Already?” Quiz 151
Working with Input/Output Streams 154


Standard In 154


Standard Out 154


Standard Error 155


Redirection of Streams 156
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Redirecting Standard Input 157


Redirecting Standard Output 157


Redirecting Standard Error 157


Redirection Redux 158
Pipes 159
Executing Multiple Commands 161


Multiple Command Operators 161


Command Substitution 162
Splitting and Processing Streams 163


Splitting Streams with the tee Command 163


Processing Output with the xargs Command 163
Filters 165


Sorting 165


Numbering Lines 166


Tabs 167


Cutting Columns 168


Pasting and Joining 168


Unique Data 169


Heads or Tails? 170


Splitting Files 172


When cat Goes Backward 173


Viewing Binary Files Safely 173
Formatting Commands 174


Translating Files 175


He sed, She sed 176


Getting a grep 178




Examples of Using grep 179


Expanding grep with egrep and fgrep 184
Using Regular Expressions and grep 185
Summary 188
Exam Preparation Tasks 188


Review All Key Topics 188


Define Key Terms 189


Review Questions 189



Chapter 7 Process Management 193
“Do I Know This Already?” Quiz 193
Managing Processes 196


Viewing Processes 196


What’s the Diff? 197


The free Command 198


Blocks and Buffers 199


Pages, Slabs, and Caches 199


Interpreting Displayed Information from free 200


System Uptime 201
Sending Signals to Processes 202


Killing Processes by PID 203


Killing Processes by Other Criteria 204
Job Control 205
Managing Process Priorities 207
Leaving Programs Running after Logout 209


Using screen for Multiple Console Sessions 210




Taking Control-a of screen Windows 211




Creating Windows in screen 211




Detaching and Reattaching from screen 212




Locking Your Console via screen 213
Summary 213
Exam Preparation Tasks 214


Review All Key Topics 214


Define Key Terms 215


Review Questions 215

Chapter 8 Editing Text 219
“Do I Know This Already?” Quiz 219
A Tour of the vim Editor 222


The Message Line 222


Editing in vi 222




Opening a File for Editing 223




Navigating Within a File 224




Force Multipliers 225




Undo Operations 225




Saving Files 226




Quitting vi 226




Changing or Replacing Text 227




Deleting Text and Lines 227




The Cut, Copy, and Paste Commands 228




Named and Unnamed Buffers 229


Searching in vi 230




Searching and Replacing 231




Regular Expression Searches 231


Options in vi 232


Advanced vi 234




Running External Commands in vi 234




Joining Lines 234




Split Windows 234
Exam Preparation Tasks 236


Review All Key Topics 236


Review Questions 236

Chapter 9 Partitions and Filesystems 241
“Do I Know This Already?” Quiz 241
Creating Partitions 244


Partitions 244


Swap 245


Disk Partitioning Tools 245




fdisk 246




gdisk 250




Parted 254
Filesystems 255


Filesystem Types 255


Superblocks 256


Inodes and Files 256


Inodes and Directories 258


Inodes and Disk Space 259


Creating Filesystems 260




The mkfs Command 260




Filesystem Creation Options 261


Advanced Filesystem Commands 263




Filesystem Checker 263




Tuning Filesystems 266




XFS Commands 267




Debugging Filesystems 268




Mounting and Unmounting 269


The Filesystem Table 270




Manually Mounting Filesystems 272




Automatically Mounting Filesystems 273




Unmounting Filesystems 273
Space Utilization 274


Using du 274


Using df 275


Using Disk Quotas 277




Quota Commands and Files 277




Quota Concepts 277




Configuring Quotas 278




Hard and Soft Limits 280




Setting the Grace Period 281




Getting Quota Information 281
Summary 282
Exam Preparation Tasks 282


Review All Key Topics 282


Define Key Terms 284


Review Questions 284

Chapter 10 Permissions and Ownership 289
“Do I Know This Already?” Quiz 289
Working with Permissions 292


Permission Trio Bits 292
Manipulating Permissions 294


Numeric Mode 294




Symbolic Mode 296
Special File Permissions 297


Special Bit Permissions 298


Setting the SUID Bit on Files 299


Setting the SGID Bit on Files 300


Setting the SGID Bit on Directories 301


Setting the Sticky Bit 302
Finding Files by Permission 302
Default Permissions 303
Changing User Ownership 305
Changing Group Ownership 306
Summary 307
Exam Preparation Tasks 307


Review All Key Topics 307


Define Key Terms 308


Review Questions 308

Chapter 11 Customizing Shell Environments 311
“Do I Know This Already?” Quiz 311
Working Within the Shell 314


Environment Variables 315


Variable Scope 316




Setting Variables from a Child 316


Setting and Unsetting Variables 317


Subshells 318




The env Wrapper 319
Extending the Shell 320


Global and User Settings 320




A Login Shell Session 321




A Non-Login Shell Session 321


The PATH 322




Aliases and Functions 323




Functions 323


PS1 324




Adding More Dynamic Content 325




PS2 326


Creating New Users (skeleton) 326
Localization and Internationalization 327


Time Zones 327




Displaying Time 328




Setting Time Zones 328


Character Encoding 329


Representing Locales 330




Fallback Locales 331


Contents of a Locale 331


How Linux Uses the Locale 332




Converting Files Between Encodings 334
Exam Preparation Tasks 334


Review All Key Topics 334


Define Key Terms 335


Review Questions 335

Chapter 12 Shell Scripting 339
“Do I Know This Already?” Quiz 339
Basics of Scripting 342


Running a Script 343


Good Design 343


Managing Your Scripts 344
Shell Script Commands 344


Use the Output of Another Command 344


Do Math 345


Conditions 346


Testing Files 348


An Easier Test Syntax 348


Testing Strings 349


Testing Integers 350


Combining Multiple Tests 351


Case Statements 351


Loops 353




For Loops 353




Sequences 354




While Loops 355




Reading from stdin in a Loop 356


Interacting with Other Programs 356


Returning an Error Code 357


Accepting Arguments 357


Transferring Control to Another Program 358
Exam Preparation Tasks 359


Review All Key Topics 359






Define Key Terms 360


Review Questions 360

Chapter 13 Basic SQL Management 365
“Do I Know This Already?” Quiz 365
Database Basics 368


Types of Databases 368




Key-Value Databases 368




Relational Databases 369




Schemaless Databases 370
Learning SQL 371


Using SQLite 371


SQL Basics 372




Keywords Versus Data 372


Selecting Data 373




Being Choosy 374




Multiple Conditions 376




Sorting 377


Limiting Results 378


Working with Multiple Tables 378




Writing Queries with Joins 379




Cleaning Up the Query 381


Advanced Joins 381




Left Versus Right Joins 384




Null 384


Subselects 385


Grouping Data 386


Inserting Data 387


Updating Data 388


Deleting Data 388


Creating Tables 388
Summary 390
Exam Preparation Tasks 390


Review All Key Topics 390


Define Key Terms 391


Review Questions 392

Chapter 14 Configuring User Interfaces and Desktops 397
“Do I Know This Already?” Quiz 397
Quick Overview of X 400


How X Works 400




Window Managers 401




Linux Desktops 402
The Xorg System 402


The Xorg Configuration File 402


Fonts in X 405


Tuning X 406
X Display Managers 408
Into and Out of X 409
Accessibility Options 410


Sticky/Repeat Keys 410


Slow/Bounce/Toggle Keys 411


Mouse Keys 411


High Contrast/Large Print Desktop Themes 412


Screen Reader 412


Braille Display 413


Screen Magnifier 413


Onscreen Keyboard 413
Remote Clients 413
Summary 415
Exam Preparation Tasks 415


Review All Key Topics 415


Define Key Terms 415


Review Questions 416

Chapter 15 Managing Users and Groups 419
“Do I Know This Already?” Quiz 419
User Account Fundamentals 422


What Accounts Are What? 422




Normal User Accounts 423




User Entries in /etc/passwd 423




Special Login Files 424
Group Accounts 425


Group Entries in /etc/group 427


Group Passwords 427
Adding Users and Groups 428


Adding Users with useradd 428


The useradd Defaults 429


Adding Groups with groupadd 431
Modifying Users and Groups 431


Modifying User Accounts with usermod 431


Modifying Groups with groupmod 432
Removing Users and Groups 433


Removing Users 433


Removing Groups 434
The Shadow Suite 435


Encrypted Passwords and Shadow Fields 435


shadow File Permissions 437
Changing Accounts 437


Aging Passwords 438


User Variables 440
Summary 440
Exam Preparation Tasks 441


Review All Key Topics 441


Define Key Terms 442


Review Questions 442

Chapter 16 Schedule and Automate Tasks 445
“Do I Know This Already?” Quiz 445
The Cron System 447


Configuring crontabs 447




Using the crontab Command 447




Matching Times 448




Spelling Out Month and Day Names 449




Making Multiple Matches 449




Step Values 450




Putting the crontab Together 450




Issues About Path 450




Dealing with Output 451




Nicknames 452


Other Files 452




System crontabs 453




Convenience crontabs 454


Restricting Access 454
Anacron 455
Running Ad-hoc Jobs 456


The at Command 456


The batch Command 458
Summary 459
Exam Preparation Tasks 460


Review All Key Topics 460


Define Key Terms 460


Review Questions 461

Chapter 17 Configuring Print and Email Services 465
“Do I Know This Already?” Quiz 465
Managing Printers and Printing 467


The Print Spooler 467




Network Printing Protocols 467


The CUPS Daemon 468




The CUPS Pipeline 468


Configuring CUPS 470


CUPS Maintenance 474




Printer State 475




Maintenance and Administration Pull-downs 476




Administration Menu 476




Jobs List 477


Command Line Tools 477




Legacy Tools 477




lp/lpr 478




lpstat 478




lpq 479




lprm 479




CUPS Tools 480




cupsaccept/cupsreject 480




cupsenable/cupsdisable 481




cupsctl 481




Configuration Files 482


Troubleshooting Printing 482




Try Printing from the Command Line 482




Was the Job Queued? 483




Can CUPS Send the Job to the Printer? 483




Turn On Debugging 483
Mail Transfer Agent Basics 484


How Email Flows 484




Mail User Agent 484




Mail Transfer Agent 485




The Language of Email 485




Linux MTAs 486




Domain Name System 487




Mail Delivery Agent 488




Mail Server 488


Creating Aliases and Forwarding Email 489




Committing Changes 489




Other Types of Aliases 490




User-Defined Forwarding 491


Managing Queues 491
Summary 492
Exam Preparation Tasks 492


Review All Key Topics 492


Define Key Terms 493


Review Questions 493

Chapter 18 Logging and Time Services 497
“Do I Know This Already?” Quiz 497
Maintain System Time 500


Not One, But Two Clocks 500


Working with the System Clock 500


Working with the Hardware Clock 503




The hwclock Command 503




Synchronizing Time Between Clocks 504


Network Time Protocol 504




Setting the Time from the Command Line 505




The pool.ntp.org Servers 505




Configuring ntpd 506




Monitoring ntpd 507
System Logging 508


systemd and syslog 508




syslog 509




The logger Command 512




Configuring syslogd 512




Other syslog Implementations 514


systemd Logging 514




Querying the Log 515




Configuring journald 519
Rotating Logs 520






Configuring Log Rotation 520


Dealing with Open Files 522
Summary 522
Exam Preparation Tasks 523


Review All Key Topics 523


Define Key Terms 524


Review Questions 524

Chapter 19 Networking Fundamentals 529
“Do I Know This Already?” Quiz 529
Conceptual Overview of Networking 532


Necessary Configuration Information 533


IP Addresses 533


Networks and Hosts 534


Address Class Ranges 534




Using the Bits to Determine Class 535


Network Masks 536


Using Default Network Masks 536


Gateway Addresses, or “Do I Dial with the Area Code?” 537


Broadcast Addresses 538


Custom Network Masks 538


Determining a Custom Network Mask 538


Additional Protocols 541




Common Ports 542


IPv6 544
Managing Interfaces 545


Viewing IP Information 545


Red Hat Interface Configuration 547


Debian Interface Configuration 548


Viewing and Configuring Gateway Addresses 550




Viewing the Default Gateway 550




Configuring a Default Gateway 550




Local Name Configuration 551
Network Configuration Utilities 553


Network Utility Examples 554




The ifconfig Command 555




The route Command 555




DHCP Client Tools 556




The host, getent, and dig Commands 557




Hostname Utilities 559




Using netstat 559




The ping Command 562




Using traceroute 563




Using tcpdump 565
Summary 566
Exam Preparation Tasks 566


Review All Key Topics 566


Define Key Terms 567


Review Questions 567

Chapter 20 System Security 571
“Do I Know This Already?” Quiz 571
Gaining Access to the root Account 574


The su Command 574


The sudo Command 575
Providing Services on Demand 576


Using inetd and xinetd 576


inetd Configuration Files 577


xinetd Configuration Files 578
Using TCP Wrappers for Securing Services 581


inetd and TCP Wrappers 581


xinetd and TCP Wrappers 582


The hosts.allow and hosts.deny Files 582


Wrapper Read Order 583


Format of hosts.allow and hosts.deny 583


Sample Configurations 583


Using Rule Options 585
Understanding Permission Problems 586


Finding Files by Permissions 587
GnuPG Keys 587
Secure Shell 590


SSH Components 591




Using SSH Client Utilities 592
Additional Security Features 596
Summary 597
Exam Preparation Tasks 598


Review All Key Topics 598


Define Key Terms 599


Review Questions 599

Chapter 21 Final Preparation 603
How to Prepare for the LPI Exams 604


Caveat and Warning 604


Exam Objectives 604


Important Exam Facts 605


Right Before Your Exam Starts 605


How to Look at the Objectives 606


Studying for the Exams—What to Do 608


Machines or Virtual Machines? 609


Studying for the Exams—What Not to Do 609


Don’t Believe Everything 610


Don’t Worry, Be Happy 610


LPI Certifications and Distributions 610


You Have to Install Something 611


LPI Exam Question Types 611


Single Answer Multiple Choice 612


Choose Two/Choose Three 613


Choose All That Apply 613


Fill in the Blank 615


Final Recommendations 616
Summary 617

Appendix A Answers to the “Do I Know This Already?” Quizzes and Review Questions 619

Glossary 659

Index 693