1.1 About This Book

This book starts with a general introduction to regular expressions. The first section of this book describes and defines the constructs used in regular expressions and establishes the common principles of pattern matching. The remaining sections of the book are devoted to the syntax, features, and usage of regular expressions in various implementations.

The implementations covered in this book are Perl, Java, .NET and C#, Python, PCRE, PHP, the vi editor, JavaScript, and shell tools.

1.1.1 Conventions Used in This Book

The following typographical conventions are used in this book:

Italic

Used for emphasis, new terms, program names, and URLs

Constant width

Used for options, values, code fragments, and any text that should be typed literally

Constant width italic

Used for text that should be replaced with user-supplied values

1.1.2 Acknowledgments

The world of regular expressions is complex and filled with nuance. Jeffrey Friedl has written the definitive work on the subject, Mastering Regular Expressions (O'Reilly), a work on which I relied heavily when writing this book. As a convenience, this book provides page references to Mastering Regular Expressions, Second Edition (MRE) for expanded discussion of regular expression syntax and concepts.

This book simply would not have been written if Jeffrey Friedl had not blazed a trail ahead of me. Additionally, I owe him many thanks for allowing me to reuse the structure of his book and for his suggestions on improving this book. Nat Torkington's early guidance raised the bar for this book. Philip Hazel, Ron Hitchens, A.M. Kuchling, and Brad Merrill reviewed individual chapters. Linda Mui saved my sanity and this book. Tim Allwine's constant regex questions helped me solidify my knowledge of this topic. Thanks to Schuyler Erle and David Lents for letting me bounce ideas off of them. Lastly, many thanks to Sarah Burcham for her contributions to Section 1.11 and for providing the inspiration and opportunity to work and write for O'Reilly.