Difference between revisions of "regular expressions"

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(→‎Articles: an example)
(→‎Examples: corrected MediaWiki example; added example of detecting repetitions)
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* [[regex manpage]]
 
* [[regex manpage]]
 
==Examples==
 
==Examples==
* \[http://[a-z|.|\-]+\.[a-z|.|\-]+[a-z|.|\-/]* [a-z|A-Z| ]+\]
+
* \[http://[a-z|0-9|\.|\-]+\.[a-z|0-9|.|\-]+[a-z|0-9|\.|\-\/]* [a-z|0-9| ]+\]( )*
 
** matches a link in [[MediaWiki]] markup (it could probably be more precise, but catches most of them)
 
** matches a link in [[MediaWiki]] markup (it could probably be more precise, but catches most of them)
 +
* (\[http://[a-z|0-9|\.|\-]+\.[a-z|0-9|.|\-]+[a-z|0-9|\.|\-\/]* [a-z|0-9| ]+\]( )*){5,}
 +
** matches at least 6 links in a row with nothing except spaces between them; good for detecting spam

Revision as of 16:14, 30 September 2007

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computing: software: programming: regex

Overview

Regex is shorthand for "Regular Expressions", a syntax used in string matching and replacement. It is especially heavily used in Perl, and the Linux utility grep is basically a front end for regex geared towards file-searching.

Articles

Examples

  • \[http://[a-z|0-9|\.|\-]+\.[a-z|0-9|.|\-]+[a-z|0-9|\.|\-\/]* [a-z|0-9| ]+\]( )*
    • matches a link in MediaWiki markup (it could probably be more precise, but catches most of them)
  • (\[http://[a-z|0-9|\.|\-]+\.[a-z|0-9|.|\-]+[a-z|0-9|\.|\-\/]* [a-z|0-9| ]+\]( )*){5,}
    • matches at least 6 links in a row with nothing except spaces between them; good for detecting spam