This document provides an introduction to regular expressions (regex) for text parsing. It discusses how regex is used for parsing text across different programming languages and environments. It also presents some basic regex syntax like anchors, quantifiers, character classes, and grouping with examples. The document recommends using an online regex tester to learn the basics and get to an intermediate "journeyman" level within a few hours. It concludes by providing a link to view a talk about introductory regex.

1. TEXT PARSING THE EASY WAY
Regular Expressions
March 7-8, 2015
Copyright © Jeff Hart, 2015
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J e f f H a r t
V a n i s h i n g C l o u d s , I n c .

2. Levels of Pain
 Regular expressions by copying
 Leveraging (special) metachars
 Advanced topics
 Environment
 Substitutions
 Automating testing
 Syntax influences
Novice
Apprentice
Journeyman
Master
Copyright © Jeff Hart, 2015
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3. Why?
 Language for parsing text
 Spawned Perl
 Native type in JavaScript
 First class (class) in .Net
 Largely independent of host environment
 Line breaks, case sensitivity, etc.
 Replace a ton of .indexOf(), .substring(), .contains() …
var regex = /hello/ig
var regex = new System.Text.RegularExpressions.RegEx(@"hello");
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4. RegEx on a Page
^ $
?*+ {}
()
|
[<{
.
(anchors) From the beginning to the end
(cardinality) …count on
(backslash) …escaping
(both) …parenthesis
(pipe) …or
(starting) …opening brackets
(period) …and anything in between
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5. Scanning Method
Search: "The levels of confusion: SNAFU, SUSFU, TARFU and FUBAR"
FU
FU FU FU FU
RegEx:
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6. RegEx
 Brief, terse, powerful
 Getting to a “journeyman” level takes only a few hours
 Use a REPL tool like PowerShell or sites like:
 http://regexpal.com/
 http://regexhero.net/tester/
 When the only tool you know…
^$ . *+? () | <{[
Copyright © Jeff Hart, 2015
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7. SpeakerRate.com
• Search for “regex” or “socalcodecamp”
• http://speakerrate.com/talks/49311 -socalcodecamp -intro-to-regex
Thank YOU!
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