preg_quote
preg_quote
(PHP 4, PHP 5, PHP 7)
preg_quote — Quote regular expression characters
Description
string preg_quote ( string $str [, string $delimiter = NULL ] )
preg_quote() takes str and puts a backslash in front of every character that is part of the regular expression syntax. This is useful if you have a run-time string that you need to match in some text and the string may contain special regex characters.
The special regular expression characters are: . \ + * ? [ ^ ] $ ( ) { } = ! < > | : -
Note that / is not a special regular expression character.
Note:
Note that preg_quote() is not meant to be applied to the $replacement string(s) of preg_replace() etc.
Parameters
-
str -
The input string.
-
delimiter -
If the optional
delimiteris specified, it will also be escaped. This is useful for escaping the delimiter that is required by the PCRE functions. The / is the most commonly used delimiter.
Return Values
Returns the quoted (escaped) string.
Changelog
| Version | Description |
|---|---|
| 5.3.0 | The - character is now quoted |
Examples
Example #1 preg_quote() example
<?php $keywords = '$40 for a g3/400'; $keywords = preg_quote($keywords, '/'); echo $keywords; // returns \$40 for a g3\/400 ?>
Example #2 Italicizing a word within some text
<?php
// In this example, preg_quote($word) is used to keep the
// asterisks from having special meaning to the regular
// expression.
$textbody = "This book is *very* difficult to find.";
$word = "*very*";
$textbody = preg_replace ("/" . preg_quote($word, '/') . "/",
"<i>" . $word . "</i>",
$textbody);
?> Notes
Note: This function is binary-safe.
See Also
- PCRE Patterns
- escapeshellcmd() - Escape shell metacharacters
© 1997–2017 The PHP Documentation Group
Licensed under the Creative Commons Attribution License v3.0 or later.
https://secure.php.net/manual/en/function.preg-quote.php
