Wondering why your preg_replace fails, even if you have used preg_quote?
Try adding the delimiter / - preg_quote($string, '/');
preg_quote
(PHP 4, PHP 5, PHP 7)
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.
add a note
User Contributed Notes 7 notes
Anonymous ¶
16 years ago
Anonymous ¶
3 years ago
I discovered that, in addition to escaping the special regular expression characters, preg_quote() encodes the NUL byte to its octal representation:
<?php
var_dump(preg_quote("\0"));
?>
Output:
string(4) "\000"
zooly ¶
15 years ago
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
ed at happysoftware dot com ¶
5 years ago
It should be noted that the forward slash is not escaped. Since many regexes are surrounded by forward slashes, if you have one in your regex as text you must escape it yourself otherwise it'll terminat the regex.
rwillmann at crooce dot com ¶
7 years ago
List of specials is incomplete:
--- sample code ---
$specials = '.\+*?[^]$(){}=!<>|:-';
for ($i = 0; $i <= 255; $i++) {
if (chr($i) !== preg_quote(chr($i))) {
printf("Character 0x%02x quoted%s\n",
$i,
(strpos($specials, chr($i)) === FALSE) ? ' (+)' : '');
} /* if */
} /* for */
--- sample code ---
--- output ---
Character 0x00 quoted (+)
Character 0x21 quoted
Character 0x24 quoted
Character 0x28 quoted
Character 0x29 quoted
Character 0x2a quoted
Character 0x2b quoted
Character 0x2d quoted
Character 0x2e quoted
Character 0x3a quoted
Character 0x3c quoted
Character 0x3d quoted
Character 0x3e quoted
Character 0x3f quoted
Character 0x5b quoted
Character 0x5c quoted
Character 0x5d quoted
Character 0x5e quoted
Character 0x7b quoted
Character 0x7c quoted
Character 0x7d quoted
--- output ---
rawr at t-regx dot com ¶
3 years ago
To have a higher level control of what your pattern looks like, try T-Regx:
Pattern::inject('This is (my|our) pattern: @', [$_GET['name']]);
noreply at t-regx dot com ¶
5 years ago
If you find yourself using too much of preg_quote(), it's a good sign you might want to use Prepared Patterns from T-Regx library: https://t-regx.com/docs/handling-user-input
