Beginning regular expressions

Beginning Regular Expressions......Page 1
Content......Page 10
Who This Book Is For......Page 24
How This Book Is Structured......Page 25
Conventions......Page 26
Errata......Page 27
p2p.wrox.com......Page 28
1: Introduction to Regular Expressions......Page 30
What Are Regular Expressions?......Page 31
Checking Input from Web Forms......Page 34
Adding Links to URLs......Page 35
Directory Listings......Page 36
Compact, Cryptic Syntax......Page 37
Whitespace Can Significantly Alter the Meaning......Page 38
Differences between Implementations......Page 41
Characters Change Meaning in Different Contexts......Page 42
Case-Sensitive and Case-Insensitive Matching......Page 44
Multiple Solutions for a Single Problem......Page 45
Replacing Text in Quantity......Page 46
Regular Expression Tools......Page 50
findstr......Page 51
Microsoft Word......Page 52
StarOffice Writer/OpenOffice.org Writer......Page 56
Microsoft Excel......Page 57
Visual Basic.NET......Page 58
MySQL......Page 59
An Analytical Approach to Using Regular Expressions......Page 60
Express and Document What You Want to Do in English......Page 61
Consider Sensitivity and Specificity......Page 63
Document All but Simple Regular Expressions......Page 64
Document What You Expect the Regular Expression to Do......Page 65
Use Whitespace to Aid in Clear Documentation of the Regular Expression......Page 66
Test the Results of a Regular Expression......Page 67
3: Simple Regular Expressions......Page 70
Matching Single Characters......Page 71
Matching Sequences of Characters That Each Occur Once......Page 76
Introducing Metacharacters......Page 78
Matching Sequences of Different Characters......Page 83
Matching Optional Characters......Page 85
Matching Multiple Optional Characters......Page 88
The * Quantifier......Page 91
The + Quantifier......Page 93
The {n} Syntax......Page 95
{0,m}......Page 96
{n,m}......Page 98
{n,}......Page 99
Exercises......Page 100
4: Metacharacters and Modifiers......Page 102
Thinking about Characters and Positions......Page 103
The Period (.) Metacharacter......Page 104
Matching Variably Structured Part Numbers......Page 107
Matching a Literal Period......Page 109
The \\w Metacharacter......Page 110
The \\W Metacharacter......Page 111
Digits and Nondigits......Page 112
The \\d Metacharacter......Page 113
Canadian Postal Code Example......Page 114
The \\D Metacharacter......Page 118
Alternatives to \\d and \\D......Page 119
Whitespace and Non-Whitespace Metacharacters......Page 121
The   Metacharacter......Page 122
Handling Optional Whitespace......Page 125
The \\t Metacharacter......Page 127
The \\n Metacharacter......Page 128
Finding the Backslash......Page 131
Global Search......Page 132
Exercises......Page 133
Introduction to Character Classes......Page 134
Choice between Two Characters......Page 137
Using Quantifiers with Character Classes......Page 140
Using the \\b Metacharacter in Character Classes......Page 141
Selecting Literal Square Brackets......Page 142
Using Ranges in Character Classes......Page 143
Alphabetic Ranges......Page 144
Use [A-z] With Care......Page 145
Digit Ranges in Character Classes......Page 146
Hexadecimal Numbers......Page 148
IP Addresses......Page 149
Reverse Ranges in Character Classes......Page 157
A Potential Range Trap......Page 158
Finding HTML Heading Elements......Page 161
The ^ metacharacter......Page 162
How to Use the - Metacharacter......Page 164
Negated Character Classes......Page 165
Combining Positive and Negative Character Classes......Page 166
The [:alnum:] Character Class......Page 168
Exercises......Page 170
6: String, Line, and Word Boundaries......Page 172
The ^ Metacharacter......Page 173
The ^ Metacharacter and Multiline Mode......Page 175
The $ Metacharacter......Page 178
The $ Metacharacter in Multiline Mode......Page 179
Using the ^ and $ Metacharacters Together......Page 182
Matching Blank Lines......Page 184
Working with Dollar Amounts......Page 187
Revisiting the IP Address Example......Page 190
The \\< Syntax......Page 193
The \\>Syntax......Page 195
The \\B Metacharacter......Page 197
Exercises......Page 198
Grouping Using Parentheses......Page 200
Parentheses and Quantifiers......Page 202
U.S. Telephone Number Example......Page 204
Alternation......Page 206
Choosing among Multiple Options......Page 209
Unexpected Alternation Behavior......Page 211
Numbering of Captured Groups......Page 214
Numbering When Using Nested Parentheses......Page 215
Named Groups......Page 216
Non-Capturing Parentheses......Page 217
Back References......Page 219
Exercises......Page 222
8: Lookahead and Lookbehind......Page 224
The (? metacharacters......Page 225
Lookahead......Page 226
Positive Lookahead-Star Training Example......Page 228
Positive Lookahead-Later in Same Sentence......Page 229
Negative Lookahead......Page 231
Positive Lookahead in the Same Document......Page 232
Inserting an Apostrophe......Page 234
Positive Lookbehind......Page 238
Negative Lookbehind......Page 242
How to Match Positions......Page 243
Adding Commas to Large Numbers......Page 245
Exercises......Page 249
9: Sensitivity and Specificity of Regular Expressions......Page 250
Extreme Sensitivity, Awful Specificity......Page 251
Email Addresses Example......Page 253
Replacing Hyphens Example......Page 257
How Metacharacters Affect Sensitivity and Specificity......Page 259
Sensitivity, Specificity, and Positional Characters......Page 260
How Much Should the Regular Expressions Do?......Page 261
Knowing the Data, Sensitivity, and Specificity......Page 262
Characters from Other Languages......Page 263
Names......Page 264
Revisiting the Star Training Company Example......Page 265
Exercises......Page 269
10: Documenting and Debugging Regular Expressions......Page 270
Document the Problem Definition......Page 271
Making Use of Extended Mode......Page 272
Proper Names......Page 275
Creating Test Cases......Page 276
Treacherous Whitespace......Page 277
Considering Other Causes......Page 280
The User Interface......Page 282
Quantifiers......Page 285
The @ Quantifier......Page 287
The {n,m} Syntax......Page 289
Modes......Page 291
Lazy Matching versus Greedy Matching......Page 294
Character Class Examples, Including Ranges......Page 297
Whole Word Searches......Page 298
Changing Name Structure Using Back References......Page 299
Manipulating Dates......Page 302
The Star Training Company Example......Page 304
Regular Expressions in Visual Basic for Applications......Page 307
Exercises......Page 309
12: Regular Expressions in StarOffice/OpenOffice.org Writer......Page 310
The User Interface......Page 311
Metacharacters Available......Page 313
Quantifiers......Page 314
Character Classes......Page 315
Alternation......Page 318
Back References......Page 321
Search Example......Page 323
Online Chats......Page 326
POSIX Character Classes......Page 330
Matching Numeric Digits......Page 331
Exercises......Page 333
Introducing findstr......Page 334
Finding Literal Text......Page 335
Metacharacters Supported by findstr......Page 337
Quantifiers......Page 339
Character Classes......Page 340
Word-Boundary Positions......Page 342
Beginning- and End-of-Line Positions......Page 344
The /v Switch......Page 345
The /a Switch......Page 347
Single File Examples......Page 348
Find Protocols Example......Page 349
Multiple File Example......Page 350
A Filelist Example......Page 351
Exercises......Page 352
The PowerGREP Interface......Page 354
A Simple Find Example......Page 355
The Replace Tab......Page 357
The File Finder Tab......Page 358
Syntax Coloring......Page 359
Metacharacters Supported......Page 360
Numeric Digits and Alphabetic Characters......Page 361
Quantifiers......Page 362
Back References......Page 364
Line Position Metacharacters......Page 368
Word-Boundary Metacharacters......Page 369
Lookahead and Lookbehind......Page 371
Finding HTML Horizontal Rule Elements......Page 372
Matching Time Example......Page 375
Exercises......Page 378
The Excel Find Interface......Page 380
The Wildcards Excel Supports......Page 384
Escaping Wildcard Characters......Page 388
Using Wildcards in Data Forms......Page 389
Using Wildcards in Filters......Page 391
Exercises......Page 392
16: Regular Expression Functionality in SQL Server 2000......Page 394
The % Metacharacter......Page 395
The _ Metacharacter......Page 401
Character Classes......Page 402
Negated Character Classes......Page 405
Using Full-Text Search......Page 408
Using The CONTAINS Predicate......Page 415
Exercises......Page 420
Getting Started with MySQL......Page 422
The Metacharacters MySQL Supports......Page 425
Using the _ and % Metacharacters......Page 426
Testing Matching of Literals: _ and % Metacharacters......Page 429
Using the REGEXP Keyword and Metacharacters......Page 430
Using Positional Metacharacters......Page 433
Using Character Classes......Page 435
Quantifiers......Page 437
Social Security Number Example......Page 439
Exercises......Page 440
The Interface to Metacharacters in Microsoft Access......Page 442
Creating a Hard-Wired Query......Page 443
Creating a Parameter Query......Page 448
Using the ? Metacharacter......Page 451
Using the * Metacharacter......Page 452
Using the # Metacharacter......Page 453
Using the # Character with Date/Time Data......Page 454
Using Character Classes in Access......Page 455
Exercises......Page 457
19: Regular Expressions in JScript and JavaScript......Page 458
Using Regular Expressions in JavaScript and JScript......Page 459
The RegExp Object......Page 461
The Other Properties of the RegExp Object......Page 467
The exec() Method of the RegExp Object......Page 470
The String Object......Page 477
Metacharacters in JavaScript and JScript......Page 480
SSN Validation Example......Page 481
Exercises......Page 483
The RegExp Object and How to Use It......Page 484
The RegExp Object\'s Pattern Property......Page 485
The RegExp Object\'s Global Property......Page 487
The RegExp Object\'s IgnoreCase Property......Page 491
The RegExp Object\'s Test() Method......Page 493
The RegExp Object\'s Replace() Method......Page 494
The RegExp Object\'s Execute() Method......Page 496
Using the Match Object and the Matches Collection......Page 500
Supported Metacharacters......Page 502
Quantifiers......Page 503
Positional Metacharacters......Page 504
Character Classes......Page 507
Lookahead......Page 508
Grouping and Nongrouping Parentheses......Page 511
Exercises......Page 512
21: Visual Basic .NET and Regular Expressions......Page 514
A Simple Visual Basic .NET Example......Page 515
The Regex Object......Page 519
Using the Match Object and Matches Collection......Page 521
Using the Match.Success Property and Match.NextMatch Method......Page 524
The GroupCollection and Group Classes......Page 526
The CaptureCollection and Capture Class......Page 528
Case-Insensitive Matching: The IgnoreCase Option......Page 531
Inline Documentation Using the IgnorePatternWhitespace Option......Page 534
Right to Left Matching: The RightToLeft Option......Page 536
The Metacharacters Supported in Visual Basic .NET......Page 537
Exercises......Page 539
22: C# and Regular Expressions......Page 540
An Introductory Example......Page 541
The Regex Class......Page 546
Regex Class Methods......Page 547
GroupNumberFromName() and GroupNameFromNumber() Methods......Page 548
The IsMatch() Method......Page 549
The Match() Method......Page 550
The Matches() Method......Page 551
The Replace() Method......Page 555
The Split() Method......Page 557
The Matches() Method as a Static......Page 560
The Match Class......Page 561
The GroupCollection and Group Classes......Page 565
The IgnorePatternWhitespace Option......Page 568
Metacharacters Supported in Visual C# .NET......Page 571
Using Named Groups......Page 573
Using Back References......Page 574
Exercise......Page 576
Getting Started with PHP 5.0......Page 578
The ereg() Set of Functions......Page 582
The ereg() Function......Page 583
The ereg() Function with Three Arguments......Page 585
The eregi() Function......Page 588
The ereg_replace() Function......Page 590
The eregi_replace() Function......Page 592
The split() Function......Page 593
The spliti() Function......Page 595
The sql_regcase() Function......Page 596
Pattern Delimiters in PCRE......Page 597
Matching Modifiers in PCRE......Page 599
Using the preg_match() Function......Page 600
Using the preg_match_all() Function......Page 603
Using the preg_grep() Function......Page 605
Using the preg_replace() Function......Page 608
Using the preg_split() Function......Page 609
The Metacharacters Supported in PHP......Page 610
Using POSIX Character Classes with PHP......Page 611
Supported Metacharacters with PCRE......Page 614
Positional Metacharacters......Page 615
Character Classes in PHP......Page 616
Documenting PHP Regular Expressions......Page 618
Exercises......Page 619
24: Regular Expressions in W3C XML Schema......Page 620
Tools for Using W3C XML Schema......Page 621
Comparing XML Schema and DTDs......Page 622
How Constraints Are Expressed in W3C XML Schema......Page 627
W3C XML Schema Datatypes......Page 628
Derivation by Restriction......Page 631
Unicode Overview......Page 633
Using Unicode Character Classes......Page 634
Matching Decimal Numbers......Page 635
Mixing Unicode Character Classes with Other Metacharacters......Page 636
Unicode Character Blocks......Page 637
Using Unicode Character Blocks......Page 638
Metacharacters Supported in W3C XML Schema......Page 641
Positional Metacharacters......Page 642
Matching Numeric Digits......Page 643
Using the \\w and   Metacharacters......Page 644
Exercises......Page 645
25: Regular Expressions in Java......Page 648
The Pattern Class......Page 649
Two Simple Java Examples......Page 650
The CASE_INSENSITIVE Flag......Page 658
Using the COMMENTS Flag......Page 659
The UNIX_LINES Flag......Page 661
The matches() Method......Page 662
The Matcher Class......Page 663
The appendReplacement() Method......Page 664
The group() Method......Page 667
The lookingAt() Method......Page 668
The replaceAll() Method......Page 671
The PatternSyntaxException Class......Page 673
Using the \\d Metacharacter......Page 674
Character Classes......Page 676
The POSIX Character Classes in the java.util.regex Package......Page 680
Unicode Character Classes and Character Blocks......Page 681
Using Escaped Characters......Page 682
Using the matches() Method......Page 683
Using the replaceFirst() Method......Page 685
Exercises......Page 687
Obtaining and Installing Perl......Page 688
Creating a Simple Perl Program......Page 692
Using the m// Operator......Page 696
Using Other Regular Expression Delimiters......Page 704
Matching Using Variable Substitution......Page 705
Using the s/// Operator......Page 707
Using s/// with the Global Modifier......Page 708
Using s/// with the Default Variable......Page 710
Using the split Operator......Page 711
The Metacharacters Supported in Perl......Page 713
Using Quantifiers in Perl......Page 714
Using Positional Metacharacters......Page 715
Captured Groups in Perl......Page 716
Using Back References in Perl......Page 718
Using Alternation......Page 719
Using Character Classes in Perl......Page 721
Using Lookahead......Page 725
Using Lookbehind......Page 727
Using the Regular Expression Matching Modes in Perl......Page 729
Escaping Metacharacters......Page 730
A Simple Perl Regex Tester......Page 732
Exercises......Page 734
Appendix A: Exercise Answers......Page 736
Index......Page 756