Learn C the Hard Way

Acknowledgments xiv


This Book Is Not Really about C xv



The Undefined Behaviorists xvi

C Is a Pretty and Ugly Language xvii

What You Will Learn xviii

How to Read This Book xviii

The Videos xix



Exercise 0: The Setup 2

Linux 2

Mac OS X 2

Windows 3

Text Editor 3



Exercise 1: Dust Off That Compiler 6

Breaking It Down 6

What You Should See 7

How to Break It 8

Extra Credit 8



Exercise 2: Using Makefiles to Build 10

Using Make 10

What You Should See 11

How to Break It 12

Extra Credit 12



Exercise 3: Formatted Printing 14

What You Should See 15

External Research 15

How to Break It 15

Extra Credit 16



Exercise 4: Using a Debugger 18

GDB Tricks 18

GDB Quick Reference 18

LLDB Quick Reference 19



Exercise 5: Memorizing C Operators 20

How to Memorize 20

The List of Operators 21



Exercise 6: Memorizing C Syntax 26

The Keywords 26

Syntax Structures 27

A Word of Encouragement 30

A Word of Warning 31



Exercise 7: Variables and Types 32

What You Should See 34

How to Break It 34

Extra Credit 34



Exercise 8: If, Else-If, Else 36

What You Should See 37

How to Break It 37

Extra Credit 38



Exercise 9: While-Loop and Boolean Expressions 40

What You Should See 40

How to Break It 41

Extra Credit 41



Exercise 10: Switch Statements 42

What You Should See 43

How to Break It 44

Extra Credit 44



Exercise 11: Arrays and Strings 46

What You Should See 47

How to Break It 48

Extra Credit 48



Exercise 12: Sizes and Arrays 50

What You Should See 51

How to Break It 52

Extra Credit 53



Exercise 13: For-Loops and Arrays of Strings 54

What You Should See 56

Understanding Arrays of Strings 56

How to Break It 57

Extra Credit 57



Exercise 14: Writing and Using Functions 58

What You Should See 59

How to Break It 60

Extra Credit 60



Exercise 15: Pointers, Dreaded Pointers 62

What You Should See 64

Explaining Pointers 65

Practical Pointer Usage 66

The Pointer Lexicon 66

Pointers Aren't Arrays 67

How to Break It 67

Extra Credit 67



Exercise 16: Structs and Pointers to Them 68

What You Should See 71

Explaining Structures 71

How to Break It 72

Extra Credit 72



Exercise 17: Heap and Stack Memory Allocation 74

What You Should See 79

Heap versus Stack Allocation 80

How to Break It 81

Extra Credit 82




Exercise 18: Pointers to Functions 84

What You Should See 88

How to Break It 88

Extra Credit 89



Exercise 19: Zed's Awesome Debug Macros 90

The C Error-Handling Problem 90

The Debug Macros 91

Using dbg.h 93

What You Should See 95

How the CPP Expands Macros 96

Extra Credit 98



Exercise 20: Advanced Debugging Techniques 100

Debug Printing versus GDB 100

A Debugging Strategy 101

Extra Credit 102



Exercise 21: Advanced Data Types and Flow Control 104

Available Data Types 104

Available Operators 108

Available Control Structures 110

Extra Credit 111



Exercise 22: The Stack, Scope, and Globals 112

ex22.h and ex22.c 112

ex22_main.c 114

What You Should See 117

Scope, Stack, and Bugs 118

How to Break It 119

Extra Credit 119



Exercise 23: Meet Duff's Device 120

What You Should See 124

Solving the Puzzle 124

Extra Credit 125



Exercise 24: Input, Output, Files 126

What You Should See 128

How to Break It 129

The I/O Functions 129

Extra Credit 130



Exercise 25: Variable Argument Functions 132

What You Should See 135

How to Break It 136

Extra Credit 136



Exercise 26: Project logfind 138

The logfind Specification 138



Exercise 27: Creative and Defensive Programming 140

The Creative Programmer Mind-Set 140

The Defensive Programmer Mind-Set 141

The Eight Defensive Programmer Strategies 141

Applying the Eight Strategies 142

Order Is Not Important 149

Extra Credit 150



Exercise 28: Intermediate Makefiles 152

The Basic Project Structure 152

Makefile 153

What You Should See 159

Extra Credit 159



Exercise 29: Libraries and Linking 160

Dynamically Loading a Shared Library 161

What You Should See 163

How to Break It 164

Extra Credit 164



Exercise 30: Automated Testing 166

Wiring Up the Test Framework 167

Extra Credit 171



Exercise 31: Common Undefined Behavior 172

UB 20 173



Exercise 32: Double Linked Lists 174

What Are Data Structures 178

Making the Library 178

Doubly Linked Lists 179

Tests 185

What You Should See 187

How to Improve It 188

Extra Credit 188



Exercise 33: Linked List Algorithms 190

Bubble and Merge Sort 190

The Unit Test 191

The Implementation 193

What You Should See 195

How to Improve It 196

Extra Credit 197



Exercise 34: Dynamic Array 198

Advantages and Disadvantages 205

How to Improve It 206

Extra Credit 206



Exercise 35: Sorting and Searching 208

Radix Sort and Binary Search 211

How to Improve It 221

Extra Credit 222



Exercise 36: Safer Strings 224

Why C Strings Were a Horrible Idea 224

Using bstrlib 225

Learning the Library 226



Exercise 37: Hashmaps 228

The Unit Test 235

How to Improve It 238

Extra Credit 238



Exercise 38: Hashmap Algorithms 240

What You Should See 245

How to Break It 246

Extra Credit 247



Exercise 39: String Algorithms 248

What You Should See 255

Analyzing the Results 257

Extra Credit 258



Exercise 40: Binary Search Trees 260

How to Improve It 273

Extra Credit 273



Exercise 41: Project devpkg 274

What Is devpkg? 274

Project Layout 277

The Makefile 277

The Source Files 278

The Final Challenge 295



Exercise 42: Stacks and Queues 296

What You Should See 299

How to Improve It 299

Extra Credit 299



Exercise 43: A Simple Statistics Engine 300

Rolling Standard Deviation and Mean 300

Implemention 301

How to Use It 306

Extra Credit 307



Exercise 44: Ring Buffer 310

The Unit Test 313

What You Should See 313

How to Improve It 314

Extra Credit 314



Exercise 45: A Simple TCP/IP Client 316

Augment the Makefile 316

The netclient Code 316

What You Should See 320

How to Break It 320

Extra Credit 321



Exercise 46: Ternary Search Tree 322

Advantages and Disadvantages 330

How to Improve It 331

Extra Credit 331



Exercise 47: A Fast URL Router 332

What You Should See 335

How to Improve It 335

Extra Credit 336



Exercise 48: A Simple Network Server 338

The Specification 338



Exercise 49: A Statistics Server 340

Specification 340



Exercise 50: Routing the Statistics 342



Exercise 51: Storing the Statistics 344

The Specification 344



Exercise 52: Hacking and Improving Your Server 346





Next Steps 348



Index 349