RegularExpression—Wolfram Mathematica 9 Documentation

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RegularExpression can be used to represent classes of strings in functions like StringMatchQ, StringReplace, StringCases, and StringSplit.
RegularExpression supports standard regular expression syntax of the kind used in typical string manipulation languages.
The following basic elements can be used in regular expression strings:

	c	the literal character c
	.	any character except newline
	[c₁c₂...]	any of the characters
	[c₁-c₂]	any character in the range -
	[^c₁c₂...]	any character except the
	p*	p repeated zero or more times
	p+	p repeated one or more times
	p?	zero or one occurrence of p
	p{m,n}	p repeated between m and n times
	p*?,p+?,p??	the shortest consistent strings that match
	(p₁p₂...)	strings matching the sequence , , ...
	p₁\|p₂	strings matching or

	\\d	digit 0-9
	\\D	nondigit
	\\s	space, newline, tab, or other whitespace character
	\\S	non-whitespace character
	\\w	word character (letter, digit, or )
	\\W	nonword character
	[[:class:]]	characters in a named class
	[^[:class:]]	characters not in a named class

	(?i)	treat uppercase and lowercase as equivalent (ignore case)
	(?m)	make and match start and end of lines (multiline mode)
	(?s)	allow to match newline
	(?-c)	unset options

, , etc. represent literal characters , , etc.
Analogs of named Mathematica patterns such as can be set up in regular expression strings using (regex).
Within a regular expression string, \\n represents the substring matched by the parenthesized regular expression object (regex).
For the purpose of functions such as StringReplace and StringCases, any appearing in the right-hand side of a rule RegularExpression["regex"]->rhs is taken to correspond to the substring matched by the parenthesized regular expression object in regex. represents the whole matched string.