CompTIA Linux+ / LPIC-1 Cert Guide

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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viii CompTIA Linux+ / LPIC-1 Cert Guide
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