Learn Raspberry Pi with Linux

272 Pages·7.418 MB·English

by  Membrey, Peter;Hows, David

Learn Raspberry Pi
with Linux
Peter Membrey
David Hows
Apress
Learn Raspberry Pi with Linux
Copyright © 2013 by Peter Membrey and David Hows
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To my parents, Peter and Bev, for all their support.
— David Hows
For my wife Sarah, son Kaydyn, and my close friends Jacqui Koo and Mark Stephens,
who together make my world go ‘round.
— Peter Membrey
Contents at a Glance
About the Authors ..............................................................................................................xv
About the Technical Reviewer ..........................................................................................xvii
Acknowledgments .............................................................................................................xix
Introduction .......................................................................................................................xxi
■ Chapter 1: Your First Bite of Raspberry Pi .........................................................................1
■ Chapter 2: Surveying the Landscape ...............................................................................31
■ Chapter 3: Getting Comfortable .......................................................................................53
■ Chapter 4: The File-Paths to Success ..............................................................................69
■ Chapter 5: Essential Commands ......................................................................................89
■ Chapter 6: Editing Files on the Command Line ..............................................................109
■ Chapter 7: Managing Your Pi .........................................................................................129
■ Chapter 8: A LAMP of Your Own ....................................................................................149
■ Chapter 9: WiPi: Wireless Computing ............................................................................181
■ Chapter 10: The Raspberry sPi ......................................................................................199
■ Chapter 11: Pi Media Center ..........................................................................................223
Index .................................................................................................................................243
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Contents
About the Authors ..............................................................................................................xv
About the Technical Reviewer ..........................................................................................xvii
Acknowledgments .............................................................................................................xix
Introduction .......................................................................................................................xxi
■ Chapter 1: Your First Bite of Raspberry Pi .........................................................................1
Your Freshly Baked Pi Arrives ........................................................................................................1
List of Ingredients .........................................................................................................................3
Micro USB lead ......................................................................................................................................................4
USB Power Adapter ...............................................................................................................................................4
HDMI Lead .............................................................................................................................................................5
HDMI Capable Display ...........................................................................................................................................5
SD Card ..................................................................................................................................................................5
SD Card Reader .....................................................................................................................................................6
USB Keyboard and Mouse .....................................................................................................................................7
Whew, We’re Done! ................................................................................................................................................7
Don’t Panic! ...........................................................................................................................................................8
Linux ..............................................................................................................................................8
What Is Linux? .......................................................................................................................................................9
Downloading Raspbian ........................................................................................................................................10
Getting Raspbian onto Your SD Card ...........................................................................................10
Using Image Writer on Windows ..........................................................................................................................11
Using dd on the Mac ............................................................................................................................................14
First Boot .....................................................................................................................................17
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■ CONTENTS
Confi guring Your Pi ......................................................................................................................18
Expanding the Filesystem ....................................................................................................................................19
Confi guring the Keyboard ....................................................................................................................................20
Changing the Password .......................................................................................................................................23
Confi guring the Locale .........................................................................................................................................24
Changing the Time Zone ......................................................................................................................................26
Allocating Memory ...............................................................................................................................................27
At Last! It’s Confi gured! .......................................................................................................................................28
Summary .....................................................................................................................................30
■ Chapter 2: Surveying the Landscape ...............................................................................31
Welcome to LXDE ........................................................................................................................31
What Do We Have Here? ......................................................................................................................................32
The Start Menu and Bottom Left of the Task Bar .................................................................................................33
And on the Right Side… ......................................................................................................................................33
The Start Menu ............................................................................................................................34
Accessories .........................................................................................................................................................36
Education .............................................................................................................................................................43
Internet ................................................................................................................................................................46
Programming .......................................................................................................................................................47
System Tools ........................................................................................................................................................49
Preferences .........................................................................................................................................................50
Summary .....................................................................................................................................52
■ Chapter 3: Getting Comfortable .......................................................................................53
Ye Olde Computer ........................................................................................................................54
Say Hello to the Dumb Terminal ..........................................................................................................................54
Modern Terminals ................................................................................................................................................55
Why Do We Still Care About These Things? .........................................................................................................56
Three Terminals ...........................................................................................................................58
Console ................................................................................................................................................................58
Opening a Virtual Terminal in the GUI ..................................................................................................................59
Connecting via SSH .............................................................................................................................................59
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■ CONTENTS
Welcome to the Command Line ..................................................................................................66
Different Shells ............................................................................................................................68
Summary .....................................................................................................................................68
■ Chapter 4: The File-Paths to Success ..............................................................................69
What Is a Filing System? .............................................................................................................69
More than One Filesystem ...................................................................................................................................70
Separate Roots ....................................................................................................................................................70
Unifi ed Filesystem ...............................................................................................................................................71
The Mac has to be Different ................................................................................................................................71
Bring it All Together .............................................................................................................................................71
Everything as a File .....................................................................................................................72
Filesystem Layout .......................................................................................................................73
/ (Root Directory) ................................................................................................................................................73
/root .....................................................................................................................................................................73
/etc ......................................................................................................................................................................73
/proc ....................................................................................................................................................................73
/var ......................................................................................................................................................................74
/boot ....................................................................................................................................................................74
/bin and /sbin ......................................................................................................................................................74
/dev ......................................................................................................................................................................74
/home ..................................................................................................................................................................74
/lib .......................................................................................................................................................................75
/lost+found ..........................................................................................................................................................75
/mnt .....................................................................................................................................................................75
/media .................................................................................................................................................................75
/usr ......................................................................................................................................................................75
/opt ......................................................................................................................................................................75
/srv ......................................................................................................................................................................75
/sys ......................................................................................................................................................................76
/tmp .....................................................................................................................................................................76
Wrapping it Up .....................................................................................................................................................76
ix
■ CONTENTS
Putting it to Work .........................................................................................................................76
Where Are We? Using pwd ...................................................................................................................................76
What’s in Here with Us? Using ls .........................................................................................................................77
Creating Files to Play with: Using Touch ..............................................................................................................77
Somewhere to Store our Files: Using mkdir ........................................................................................................78
Making Use of a New Directory: Using the mv Command ...................................................................................79
Time for Some Cloning: How to Use the cp Command ........................................................................................79
The Power to Destroy: Using the rm Command ...................................................................................................80
Fully Qualifi ed and Relative Paths .......................................................................................................................81
Users and Groups ........................................................................................................................81
File Permissions ..........................................................................................................................82
Setting File Permissions ......................................................................................................................................84
Shortcuts and Links ....................................................................................................................87
Summary .....................................................................................................................................88
■ Chapter 5: Essential Commands ......................................................................................89
Become the Boss ........................................................................................................................89
RTFM ...........................................................................................................................................91
System Resource Monitoring ......................................................................................................91
Uptime and Load Average ....................................................................................................................................92
Tasks....................................................................................................................................................................93
CPU Utilization Percentage ..................................................................................................................................93
Memory Usage .....................................................................................................................................................94
Process Table .......................................................................................................................................................94
Using free to View Memory Allocation .................................................................................................................95
Disk Usage ...........................................................................................................................................................95
Managing Processes ...........................................................................................................................................97
File Commands ..........................................................................................................................100
Combining Commands.......................................................................................................................................102
User Environment ..............................................................................................................................................104
The cron Command ...........................................................................................................................................107
Summary ...................................................................................................................................107
x
■ CONTENTS
■ Chapter 6: Editing Files on the Command Line ..............................................................109
What is a Text File? ...................................................................................................................109
The Contenders .........................................................................................................................110
Starting out with nano ...............................................................................................................111
So What Does This All Mean? ............................................................................................................................112
Saving Your File .................................................................................................................................................113
Moving Around in nano ......................................................................................................................................115
Wrapping Up nano .............................................................................................................................................117
Getting Started with vim ...........................................................................................................117
The vim Modes ..................................................................................................................................................118
Saving Your Changes .........................................................................................................................................119
Getting Out of vim ..............................................................................................................................................120
Searching in vim ................................................................................................................................................121
Moving to a Specifi c Line Number .....................................................................................................................122
Moving About in vim ..........................................................................................................................................123
Deleting in vim ...................................................................................................................................................123
Miscellaneous Little Commands ........................................................................................................................126
Visual Mode .......................................................................................................................................................126
Indenting Text ....................................................................................................................................................126
Summary ...................................................................................................................................128
■ Chapter 7: Managing Your Pi .........................................................................................129
Remotely Accessing the Pi ........................................................................................................129
Networking ........................................................................................................................................................129
DNS ....................................................................................................................................................................130
SSH ....................................................................................................................................................................130
BASH: Basic Coding ...................................................................................................................130
What Is BASH? ...................................................................................................................................................131
Starting in BASH ................................................................................................................................................131
Interpreted versus Compiled .............................................................................................................................132
Output in BASH ..................................................................................................................................................132
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