Learn C on the Mac

363 Pages·2009·3.677 MB·English

by  Dave Mark (auth.)

Learn C
on the Mac
DAVE MARK
Learn C on the Mac
Copyright © 2009 by Dave Mark
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To my incredible family, D3KR4FR
Contents at a Glance
About the Author . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xv
About the Technical Reviewer .................................................xvii
Acknowledgments ........................................................... xix
Preface ....................................................................... xxi
CHAPTER 1 Welcome Aboard ..............................................1
CHAPTER 2 Go Get the Tools! ...............................................5
CHAPTER 3 Programming Basics ..........................................17
CHAPTER 4 C Basics: Functions ............................................25
CHAPTER 5 C Basics: Variables and Operators ..............................49
CHAPTER 6 Controlling Your Program’s Flow ...............................85
CHAPTER 7 Pointers and Parameters .................................... 121
CHAPTER 8 Variable Data Types ......................................... 161
CHAPTER 9 Designing Your Own Data Structures ........................ 207
CHAPTER 10 Working with Files .......................................... 249
CHAPTER 11 Advanced Topics ............................................ 283
CHAPTER 12 Where Do You Go from Here? ................................ 317
APPENDIX Answers to Exercises ........................................ 323
INDEX ...................................................................... 336
v
Contents
About the Author . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xv
About the Technical Reviewer .................................................xvii
Acknowledgments ........................................................... xix
Preface ....................................................................... xxi
CHAPTER 1 Welcome Aboard................................1
Who Is This Book For? ..........................................1
The Lay of the Land ............................................2
CHAPTER 2 Go Get the Tools! ................................5
Create an ADC Account ........................................5
Download the Tools ............................................6
Installing the Tools .............................................8
Take Your Tools for aTest Drive ................................10
The Xcode Welcome Screen ..............................11
Creating Your First Xcode Project .........................11
Saving Your New Project. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Running the Project ......................................14
Your First Program .......................................14
Downloading the Book Projects ...............................16
Let’s Move On ................................................16
CHAPTER 3 Programming Basics........................... 17
Programming .................................................17
Some Alternatives to C ...................................18
What About Objective-C, C++, and Java?. . . . . . . . . . . . . . . . . .18
What’s the Best Language for Programming
the Mac or iPhone? ....................................20
The Programming Process. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Source Code .............................................21
Compiling Your Source Code .............................22
What’s Next? ..................................................24
vii
viii CONTENTS
CHAPTER 4 C Basics: Functions ............................ 25
C Functions ...................................................25
The Function Definition ..................................26
Syntax Errors and Algorithms .............................27
Calling aFunction .............................................29
A Brief History of C ............................................32
The Standard Library ..........................................33
Exploring Unix and Your Mac’s Built-In Manual .................34
Same Program, Two Functions .................................36
The hello2 Project ........................................37
The hello2 Source Code ..................................40
Running hello2 ..........................................42
Let’s Do That Again, Again, Again ..............................43
Generating Some Errors .......................................44
C Is Case Sensitive ............................................47
What’s Next? ..................................................47
CHAPTER 5 C Basics: Variables and Operators............... 49
An Introduction to Variables ...................................50
Working with Variables ...................................51
Variable Names ..........................................51
The Size of aType ........................................52
Bytes and Bits ............................................53
Going from 1 Byte to 2 Bytes .............................55
Operators ....................................................56
The +, -, ++, and -- Operators .............................57
The += and -= Operators .................................58
The *,/,*=,and /= Operators .............................59
Using Parentheses ............................................60
Operator Precedence .........................................61
Sample Programs .............................................63
Opening operator.xcodeproj .............................63
Stepping Through the operator Source Code ..............64
Opening postfix.xcode ...................................67
Stepping Through the postfix Source Code ...............68
Backslash Combinations ..................................70
Support for Backslash Combinations ......................71
Running slasher ..........................................72
Stepping Through the slasher Source Code ...............73
CONTENTS ix
Building slasher the Unix Way ............................74
Which Compiler Did You Run? ............................76
Running the Unix Version of slasher .......................77
Sprucing Up Your Code .......................................77
Source Code Spacing .....................................78
Comment Your Code .....................................80
The Curly Brace Controversy ..............................81
What’s Next? ..................................................82
CHAPTER 6 Controlling Your Program’s Flow................ 85
Flow Control ..................................................85
The if Statement .........................................86
Expressions ...................................................88
True Expressions .........................................88
Comparative Operators ..................................89
Logical Operators ........................................90
truthTester.xcodeproj ....................................94
Compound Expressions ..................................94
Statements ..............................................95
The Curly Braces .........................................96
Where to Place the Semicolon ............................98
The Loneliest Statement ..................................98
The while Statement .....................................98
The for Statement ...................................... 101
loopTester.xcodeproj ................................... 104
The do Statement ...................................... 107
The switch Statement .................................. 107
Breaks in Other Loops .................................. 111
isOdd.xcodeproj ....................................... 111
Stepping Through the isOdd Source Code .............. 112
nextPrime.xcodeproj ................................... 114
Stepping Through the nextPrime Source Code .......... 115
What’s Next? ................................................ 118
CHAPTER 7 Pointers and Parameters...................... 121
What Is aPointer? ........................................... 121
Why Use Pointers? ..................................... 122
Checking Out of the Library ............................ 124
x CONTENTS
Pointer Basics ............................................... 124
Variable Addresses ..................................... 125
The & Operator ........................................ 126
Declaring aPointer Variable ............................ 126
Function Parameters ........................................ 131
What Are Function Parameters? ........................ 132
Variable Scope ......................................... 132
How Function Parameters Work ........................ 133
Parameters Are Temporary ............................. 135
The Difference Between Arguments and Parameters .... 136
What Does All This Have to Do with Pointers? ................ 137
Global Variables and Function Returns ....................... 140
Global Variables ........................................ 140
Adding Globals to Your Programs ....................... 141
Function Returns ....................................... 142
printf() Returns aValue ................................. 145
Danger! Avoid Uninitialized Return Values! .............. 145
To Return or Not to Return?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
More Sample Programs ..................................... 146
listPrimes.xcode ........................................ 147
power.xcodeproj ....................................... 149
Using the Debugger ........................................ 153
What’s Next? ................................................ 157
CHAPTER 8 Variable Data Types .......................... 161
Data Types Beyond int ...................................... 161
floatSizer .............................................. 162
Walking Through the floatSizer Source Code ............ 163
The Integer Types ...................................... 168
Type Value Ranges ..................................... 169
Memory Efficiency vs. Safety. . . . . . . . . . . . . . . . . . . . . . . . . . . . 170
Working with Characters .................................... 172
The ASCII Character Set ................................ 172
ascii.xcodeproj ......................................... 173
Stepping Through the acsii Source Code ................ 177
Arrays ...................................................... 178
Why Use Arrays? ....................................... 179
dice.xcode ............................................. 180
Stepping Through the dice Source Code ................ 181
Danger, Will Robinson! ...................................... 184
CONTENTS xi
Text Strings ................................................. 185
A Text String in Memory ................................ 185
nameBad.xcodeproj .................................... 186
Stepping Through the nameBad Source Code ........... 187
The Input Buffer ........................................ 188
On with the Program ................................... 190
The Problem with nameBad ............................ 191
The nameGood Source Code ........................... 193
The #define Directive ....................................... 194
Function-Like #define Macros .......................... 196
wordCount.xcodeproj .................................. 198
Stepping Through the wordCount Source Code ......... 199
What’s Next? ................................................ 203
CHAPTER 9 Designing Your Own Data Structures .......... 207
Bundling Your Data ......................................... 207
Model A: Three Arrays ....................................... 208
multiArray.xcodeproj ................................... 210
Stepping Through the multiArray Source Code .......... 211
Getting Rid of the Extra Carriage Return ................ 217
Adding Error Handling ................................. 217
Walking Through the multiArrayWithErrCode
Source Code ........................................ 218
Finishing Up With Model A .................................. 220
Model B: The Data Structure Approach ...................... 222
structSize.xcode. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223
Stepping Through the structSize Source Code ........... 223
Passing astruct As aParameter .............................. 226
Passing aCopy of the struct ............................ 228
paramAddress.xcodeproj ............................... 229
struct Arrays ........................................... 230
Allocating Your Own Memory ............................... 231
Using malloc() ......................................... 232
free() .................................................. 234
Keeping Track of That Address! ......................... 234
Working with Linked Lists ................................... 235
Why Use Linked Lists? .................................. 236
Creating aLinked List .................................. 236
dvdTracker.xcodeproj .................................. 237
Stepping Through the dvdTracker Source Code ......... 239
What’s Next? ................................................ 247