PHP: string to regex

Question

I try use string as a regular expression pattern but I've following errors

PHP Warning:  preg_match(): Unknown modifier '>' in /Applications/MAMP/htdocs/cruncher/Plugins/wordpress/WPDetect.php on line 22
PHP Warning:  preg_match(): Unknown modifier '/' in /Applications/MAMP/htdocs/cruncher/Plugins/wordpress/WPDetect.php on line 22

The code

$str = "<meta name=\"generator\" content=\"WordPress.com\" />"
preg_match("/".$str."/", $content->content)

I also tried to use preg_quote function but I've similar problems.

What is the correct way to make it work?

Sultan

piotrekkr · Accepted Answer · 2017-01-18 07:57:19Z

16

Use preg_quote function and pattern enclosed with |...|

preg_match("|" . preg_quote($str, "|") . "|", $content->content)

edited Jan 18, 2017 at 7:57

answered Mar 26, 2012 at 13:39

piotrekkr

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2 Comments

piotrekkr Over a year ago

Ok sorry did'n tknow there was a time limit :)

Walter Tross Over a year ago

This will fail as soon as $str contains a |. My advice is to always supply the second argument. In this case: '|'.preg_quote($str, '|').'|'

Abdutahir · Accepted Answer · 2016-12-06 09:51:28Z

6

This worked for me

$pattern = "/" . preg_quote($source, "/") . "/";

answered Dec 6, 2016 at 9:51

Abdutahir

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Comments

Tchoupi · Accepted Answer · 2012-03-26 13:39:14Z

0

You must escape your limiter

$str = "<meta name=\"generator\" content=\"WordPress.com\" \/>"

answered Mar 26, 2012 at 13:39

Tchoupi

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Comments

grifos · Accepted Answer · 2012-03-26 13:40:36Z

0

Regular expression contain a set of special char like \ - * . ? $ ^ + () []and more, you have to escape them from your string before using it (you esacpe by adding a \ before the char)

answered Mar 26, 2012 at 13:40

grifos

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