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	PlanetMath: regular expression
		Here is an example of a regular expression that specifies a grammar that generates the binary representation of all multiples of 3 (and only multiples of 3).
		A little further work is required to transform this grammar into an acceptable form for regular grammars, but it can be shown that this grammar (and any grammar specified by a regular expression) is equivalent to some regular grammar.
		This is version 12 of regular expression, born on 2002-02-24, modified 2007-11-13.
	planetmath.org /encyclopedia/RegularExpression.html (517 words)

	Pattern (Java 2 Platform SE v1.4.2)
		A regular expression, specified as a string, must first be compiled into an instance of this class.
		Compiles the given regular expression and attempts to match the given input against it.
		Returns the regular expression from which this pattern was compiled.
	java.sun.com /j2se/1.4.2/docs/api/java/util/regex/Pattern.html (1992 words)

	Regular expression - Wikipedia, the free encyclopedia
		The origins of regular expressions lies in automata theory and formal language theory, both of which are part of theoretical computer science.
		Part of the effort in the design of Perl 6 is to improve Perl's regular expression integration, and to increase their scope and capabilities to allow the definition of parsing expression grammars.
		Regular expressions can be expressed in terms of formal language theory.
	en.wikipedia.org /wiki/Regular_expression (3773 words)

	Regular Expressions
		Regular expressions are used when you want to search for specify lines of text containing a particular pattern.
		Regular expressions search for patterns on a single line, and not for patterns that start on one line and end on another.
		The regular expression "^A" will match all lines that start with a capital A. The expression "A$" will match all lines that end with the capital A. If the anchor characters are not used at the proper end of the pattern, then they no longer act as anchors.
	www.grymoire.com /Unix/Regular.html (2746 words)

	Regular Expressions
		Regular expressions are a context-independent syntax that can represent a wide variety of character sets and character set orderings, where these character sets are interpreted according to the current locale.
		While many regular expressions can be interpreted differently depending on the current locale, many features, such as character class expressions, provide for contextual invariance across locales.
		A bracket expression (an expression enclosed in square brackets, []) is an RE that matches a single collating element contained in the non-empty set of collating elements represented by the bracket expression.
	www.opengroup.org /onlinepubs/007908799/xbd/re.html (5095 words)

	Search and Replace Regular Expressions
		Regular Expressions use "special character operators," which are symbols that control the search, and "an expression," which is a combination of characters and operators that specifies a pattern.
		Regular Expressions can be used in replacements, they can be case sensitive, and they can use Binary Characters or special operators such as Counters, Insert Path and File Name, and environment variables.
		Regular expressions are supported using a subset of the UNIX grep notation for Searching and DOS style Batch %n input parameter notation, with some extensions, for Replacing.
	www.funduc.com /regexp.htm (1998 words)

	Boost.Regex: Perl Regular Expression Syntax
		An expression oftheform[[=col=]], matches any character or collating element whose primary sort key is the same as that for collating element col, as with colating elements the name col may be a symbolic name.
		If you view the regular expression as a directed (possibly cyclic) graph, then the best match found is the first match found by a depth-first-search performed on that graph, while matching the input text.
		There are a variety of flags that may be combined with the Perl option when constructing the regular expression, in particular note that the newline_alt option alters the syntax, while the collate, nosubs and icase options modify how the case and locale sensitivity are to be applied.
	www.boost.org /libs/regex/doc/syntax_perl.html (2069 words)

	Learning to Use Regular Expressions
		A space in a regular expression, by the way, matches a literal space in the target (this is unlike most programming languages or command-line tools, where spaces separate keywords).
		Extended regular expressions (which most tools support) add a few other useful numbers to "once exactly" and "zero or more times." The plus-sign ("+") means "one or more times" and the question-mark ("?") means "zero or one times." These quantifiers are by far the most common enumerations you wind up naming.
		Simply repeating the same grouped subexpression later in the regular expression does not match the same targets as using a backreference (but you have to decide what it is you actually want to match in either case).
	gnosis.cx /publish/programming/regular_expressions.html (4091 words)

	Regular Expression Basics \| evolt.org
		Regular expressions, sometimes referred to as regex, grep, or pattern matching, can be a very powerful tool and a tremendous time-saver with a broad range of application.
		There are a number of applications and languages that support regular expressions, but unfortunately, not all of them support regex in quite the same way.
		Although regular expressions had their origins in neurophysiology in the 1940s and were developed by theoretical mathematicians in the 1950s and 1960s, the evolution and subsequent divergence of regex implementations was due to the independent development of various Unix tools such as grep, awk, sed, Emacs, and others.
	www.evolt.org /article/rating/20/22700/index.html (7052 words)

	UTS #18: Unicode Regular Expressions
		This is not adequate for Unicode regular expressions.
		When using names in regular expressions, the main data is supplied in the Name property in the UCD, as described in [UDataDoc], or computed as in the case of CJK Ideographs or Hangul Syllables.
		Because tailored regular expression patterns are usually quite specific to the locale, and will generally not work across different locales, the syntax should also specify the particular locale or other tailoring customization that the pattern was designed for.
	www.unicode.org /reports/tr18 (9590 words)

	A Tao of Regular Expressions
		A regular expression is a formula for matching strings that follow some pattern.
		Regular expressions are supported by many text editors, class libraries such as Rogue Wave's Tools.h++, scripting tools such as awk, grep, sed, and increasingly in interactive development environments such as Microsoft's Visual C++.
		Regular expressions usage is explained by examples in the sections that follow.
	jmason.org /software/sitescooper/tao_regexps.html (2493 words)

	Etext Center: Services
		Regular expressions ("regex's" for short) are sets of symbols and syntactic elements used to match patterns of text.
		Regular expressions tend to be easier to write than they are to read.
		Regular expressions don't constitute a "language" in the way that C or Perl are languages or a tool in the way that sed or grep are tools; instead, regular expressions constitute a syntax which many languages and tools (including these) support.
	etext.lib.virginia.edu /helpsheets/regex.html (3310 words)

	ColdFusion MX : Regular expression syntax
		The pattern within the square brackets of a regular expression defines a character set that is used to match a single character.
		The regular expression [A-Z][a-z]* matches any word that starts with an uppercase letter and is followed by zero or more lowercase letters.
		The regular expression "[0-9]{3,}" specifies to match any integer number containing three or more digits: "123", "45678", etc. However, this regular expression does not match a one-digit or two-digit number.
	livedocs.adobe.com /coldfusion/6/Developing_ColdFusion_MX_Applications_with_CFML/regexp3.htm (2444 words)

	Core JavaScript 1.5 Guide:Regular Expressions - MDC
		Regular expression literals provide compilation of the regular expression when the script is evaluated.
		Use the constructor function when you know the regular expression pattern will be changing, or you don't know the pattern and are getting it from another source, such as user input.
		Including parentheses in a regular expression pattern causes the corresponding submatch to be remembered.
	developer.mozilla.org /en/docs/Core_JavaScript_1.5_Guide:Regular_Expressions (2411 words)

	XML.com: Regular Expression Matching in XSLT 2
		For example, to replace all dollars and cents expressions with the string "$xx.xx", you can assemble a regular expression to show that you want to search for any string consisting of a dollar sign followed by one or more numeric digits, a period, and then two more digits.
		Regular Expression Syntax section of the XQuery 1.0 and XPath 2.0 Functions and Operators specification describes these flags in more detail; it also provides g background on the roots of the XPath regular expression support in the W3C Schema specification.
		In regular expressions, a period can be used to represent any character (as we saw at the very beginning of this regular expression) but we're looking for an actual period here, so it has a backslash like the one before the dollar sign.
	www.xml.com /pub/a/2003/06/04/tr.html (1887 words)

	Regular Expression Library (Site not responding. Last check: )
		Regular expressions are a central element of UNIX utilities like egrep and programming languages such as Perl.
		Mastering Regular Expressions quickly covers the basics of regular-expression syntax, then delves into the mechanics of expression-processing, common pitfalls, performance issues, and implementation-specific differences.
		RegexAdvice.com is a community devoted to the topic of regular expressions.
	regexlib.com /Default.aspx (219 words)

	4GuysFromRolla.com - An Introduction to Regular Expression with VBScript
		I have used regular expression on only a few occasions, and that was when writing some small Perl utilities for my Linux box.
		Regular expression use to be a thing that only UNIX users knew about.
		Regular expression is, technically, a defined grammar for use in complex pattern searching.
	www.4guysfromrolla.com /webtech/090199-1.shtml (941 words)

	NAME regular expression regex regexp - search.cpan.org
		It tells the regular expression parser to ignore whitespace that is neither backslashed nor within a character class.
		This was once used in a common idiom to disable or quote the special meanings of regular expression metacharacters in a string that you want to use for a pattern.
		All the substrings which may be matched by the given regular expression can be sorted from the "best" match to the "worst" match, and it is the "best" match which is chosen.
	search.cpan.org /dist/perl/pod/perlre.pod (6093 words)

	Regular Expression HOWTO
		Since regular expressions are used to operate on strings, we'll begin with the most common task: matching characters.
		Regular expressions are often used to dissect strings by writing a RE divided into several subgroups which match different components of interest.
		Regular expressions are a powerful tool for some applications, but in some ways their behaviour isn't intuitive and at times they don't behave the way you may expect them to.
	www.amk.ca /python/howto/regex (6489 words)

	Regular Expression Tutorial - Learn How to Use Regular Expressions
		In practice, you can use regular expressions with whatever data you can access using the application or programming language you are working with.
		A regular expression "engine" is a piece of software that can process regular expressions, trying to match the pattern to the given string.
		Use regular expressions to search through large numbers of text and binary files, such as source code, correspondence, server or system logs, reference texts, archives, etc. Quickly find the files you are looking for, or extract the information you need.
	www.regular-expressions.info /tutorial.html (1113 words)

	Regular Expressions: Methods - Doc JavaScript
		Some are invoked as a method of a regular expression, whereas others are called as a string's method.
		Use the compile method when you know the regular expression will remain constant (after getting its pattern) and will be used repeatedly throughout the script.
		The delimiters are determined by repeated pattern matching, using the given regular expression.
	www.webreference.com /js/column5/methods.html (1143 words)

	oreilly.com -- Online Catalog: Regular Expression Pocket Reference (Site not responding. Last check: )
		Regular expressions are such a powerful tool for manipulating text and data that anyone who uses a computer can benefit from them.
		While a command of regular expressions is an invaluable skill, all there is to know about them fills a very large volume, and you don't always have time to thumb through hundreds of pages each time a question arises.
		The "Regular Expression Pocket Reference" is designed to be a quick reference tool, and it serves this purpose very well.
	www.oreilly.com /catalog/regexppr (968 words)

	PHP: PCRE - Manual
		The expression should be enclosed in the delimiters, a forward slash (/), for example.
		PHP also supports regular expressions using a POSIX-extended syntax using the POSIX-extended regex functions.
		Regular Expressions Tutorial on russian language is accessible on http://www.pcre.ru
	www.php.net /manual/en/ref.pcre.php (1608 words)

	4.2 re -- Regular expression operations
		This module provides regular expression matching operations similar to those found in Perl.
		Regular expression pattern strings may not contain null bytes, but can specify the null byte using the
		The second edition of the book no longer covers Python at all, but the first edition covered writing good regular expression patterns in great detail.
	docs.python.org /lib/module-re.html (196 words)

	Regular-Expressions.info - Regex Tutorial, Examples and Reference - Regexp Patterns
		A regular expression (regex or regexp for short) is a special text string for describing a search pattern.
		While you can't learn to efficiently use regular expressions from this brief overview, it's enough to be able to throw together a bunch of simple regular expressions.
		If you're hungry for more information on regular expressions after reading this website, there are a variety of books on the subject.
	www.regular-expressions.info (697 words)

	Regular Expression Examples
		If you are new to regular expressions, you can take a look at these examples to see what is possible.
		But you will earn back that time quickly when using regular expressions to automate searching or editing tasks in EditPad Pro or PowerGREP, or when writing scripts or applications in a variety of languages.
		If your regular expression seems to take forever, or simply crashes your application, it has likely contracted a case of catastrophic backtracking.
	www.regular-expressions.info /examples.html (992 words)

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