preg_quote

(PHP 4, PHP 5)

preg_quote — 정규 표현식 문자를 인용

설명

string preg_quote ( string $str [, string $delimiter ] )

preg_quote()는 str에서 정규 표현식 문법에 포함되는 모든 문자의 앞에 백슬래시를 덧붙입니다. 어떠한 텍스트에 특수 정규 표현식 문자를 포함하는 런타임 문자열을 처리할 때 유용합니다.

정규 표현식 특수 문자는: . \ + * ? [ ^ ] $ ( ) { } = ! < > | :

인수

str: 입력 문자열.
delimiter: delimiter를 정의하면, 그 문자들도 이스케이프합니다. PCRE 함수에서 요구하는 구분자를 이스케이프 할 때 유용합니다. /는 가장 널리 사용되는 구분자입니다.

반환값

인용한 문자열을 반환합니다.

예제

Example #1 preg_quote() 예제


<?php
$keywords = '$40 for a g3/400';
$keywords = preg_quote($keywords, '/');
echo $keywords; // \$40 for a g3\/400 를 반환합니다.
?>

Example #2 텍스트 안의 단어를 기울임꼴로


<?php
// 이 예제에서, preg_quote($word)는 정규 표현식에서
// 특별한 의미를 지니는 애스터라이크(*)의 처리에 사용됩니다.

$textbody = "This book is *very* difficult to find.";
$word = "*very*";
$textbody = preg_replace("/" . preg_quote($word) . "/",
                         "<i>" . $word . "</i>",
                         $textbody);
?>

주의

Note: 이 함수는 바이너리 안전입니다.

preg_replace_callback

preg_match

[edit] Last updated: Sat, 07 Jan 2012

add a note User Contributed Notes preg_quote

billadoid at gmail dot com 12-Jan-2012 05:11


If you need to quote everything but a wildcard, maybe this function will come handy to you:





<?php


protected function _ruleOptionIsMatched($option, $subject)


{


    $option = preg_quote($option, '#');


    $option = str_replace('\*', '.*', $option);





    if(preg_match("#^$option$#", $subject))


    {


        return true;


    }


    else


    {


        return false;


    }


}


?>

admin at nilamo dot com 04-Aug-2010 08:21


@zooly:



And what if $myvar = 'te\\E.t'?  It will match, when it shouldn't.  That's why you should use preg_quote().

zooly 21-Jul-2009 01:07


To escape characters with special meaning, like: .-[]() and so on, use \Q and \E.



For example:



<?php echo ( preg_match('/^'.( $myvar = 'te.t' ).'$/i', 'test') ? 'match' : 'nomatch' ); ?>



Will result in: match



But:



<?php echo ( preg_match('/^\Q'.( $myvar = 'te.t' ).'\E$/i', 'test') ? 'match' : 'nomatch' ); ?>



Will result in: nomatch

alexc223 at NOSPAM dot googlemail dot com 15-Jun-2009 12:41


Not sure why this note got deleted, but hey lets try again:



As of PHP 5.3, bug #47229 has been fixed and preg_quote *will* escape a hyphen (-). This may effect your code so ensure this is one thing you check when moving to 5.3.

frostschutz 20-Mar-2009 02:01


I wanted to escape a string of characters so I could match them in [], i.e. [.,-!"§$%\\\[\]\^].



Unfortunately preg_quote does not escape the - character which has a special meaning in [], i.e. [a-z].



So I used this hack: make - the delimiter of the expression, i.e.



preg_quote(userinput, "-")

preg_replace("-[$userinput]-u", "", $str)



Apparently using a special char as a delimiter of a regular expression disables this character, i.e. even if it's escaped it's not understood as special character for the expression anymore.



so the pattern "-[a\\-z]-u" matches the characters a, - and z, and not abc...xyz.



It would be nice if preg_quote also escaped characters that have special meanings even if they have this meaning only under certain conditions, such as inside [].

krishoog at gmail dot com 13-Oct-2008 07:51


To bizzigul at hotmail dot fr:

It's not a good practice to make somthing work *almost* all of the time. If the input contains a '`' you will still get an error. I recommend using the default delimiter ('/') and also feed this to preg_quote as second argument.

bizzigul at hotmail dot fr 30-Jul-2008 09:10


To prevent any problems, try to always use a delimiter that will *almost* not be used inside the regex, such as ` (back quote)





for example: instead of 


<?php preg_match('/foo\/bar\//',$somevar); ?>





use





<?php preg_match('`foo/bar/`',$somevar); ?>





it's that simple! like this, you won't have to bother with delimiters anymore...

Anonymous 26-Dec-2007 03:13


Wondering why your preg_replace fails, even if you have used preg_quote?



Try adding the delimiter / - preg_quote($string, '/');

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