1．What Is a Regular Expression? 1
Getting Started with Regexpal 2
Matching a North American Phone Number 2
Matching Digits with a Character Class 4
Using a Character Shorthand 5
Matching Any Character 5
Capturing Groups and Back References 6
Using Quantifiers 6
Quoting Literals 8
A Sample of Applications 9
What You Learned in Chapter 1 11
Technical Notes 11
2．Simple Pattern Matching 13
Matching String Literals 15
Matching Digits 15
Matching Non-Digits 17
Matching Word and Non-Word Characters 18
Matching Whitespace 20
Matching Any Character,Once Again 22
Marking Up the Text 24
Using sed to Mark Up Text 24
Using Perl to Mark Up Text 25
What You Learned in Chapter 2 27
Technical Notes 27
3．Boundaries 29
The Beginning and End of a Line 29
Word and Non-word Boundaries 31
Other Anchors 33
Quoting a Group of Characters as Literals 34
Adding Tags 34
Adding Tags with sed 36
Adding Tags with Perl 37
What You Learned in Chapter 3 38
Technical Notes 38
4．Alternation,Groups,and Backreferences 41
Alternation 41
Subpatterns 45
Capturing Groups and Backreferences 46
Named Groups 48
Non-Capturing Groups 49
Atomic Groups 50
What You Learned in Chapter 4 50
Technical Notes 51
5．Character Classes 53
Negated Character Classes 55
Union and Difference 56
POSIX Character Classes 56
What You Learned in Chapter 5 59
Technical Notes 60
6．Matching Unicode and Other Characters 61
Matching a Unicode Character 62
Using vim 63
Matching Characters with Octal Numbers 64
Matching Unicode Character Properties 65
Matching Control Characters 68
What You Learned in Chapter 6 70
Technical Notes 71
7．Quantifiers 73
Greedy,Lazy,and Possessive 74
Matching with*,+,and? 74
Matching a Specific Number of Times 75
Lazy Quantifiers 76
Possessive Quantifiers 76
What You Learned in Chapter 7 78
Technical Notes 79
8．Lookarounds 81
Positive Lookaheads 81
Negative Lookaheads 84
Positive Lookbehinds 85
Negative Lookbehinds 85
What You Learned in Chapter 8 86
Technical Notes 86
9．Marking Up a Document with HTML 87
Matching Tags 87
Transforming Plain Text with sed 88
Substitution with sed 89
Handling Roman Numerals with sed 90
Handling a Specific Paragraph with sed 91
Handling the Lines of the Poem with sed 91
Appending Tags 92
Using a Command File with sed 92
Transforming Plain Text with Perl 94
Handling Roman Numerals with Perl 95
Handling a Specific Paragraph with Perl 96
Handling the Lines of the Poem with Perl 96
Using a File of Commands with Perl 97
What You Learned in Chapter 9 98
Technical Notes 98
10．The End of the Beginning 101
Learning More 102
Notable Tools,Implementations,and Libraries 103
Perl 103
PCRE 103
Ruby(Oniguruma) 104
Python 104
RE2 105
Matching a North American Phone Number 105
Matching an Email Address 105
What You Learned in Chapter 10 106
Appendix:Regular Expression Reference 107
Regular Expression Glossary 123
Index 129