preg_quote
Simple function to remove a SHOUT in an input text.
Input: "This is so AWESOME!"
Output: "This is so awesome!"
<?php
function remove_shout($_text,$_max_caps=3)
{
return preg_replace_callback('/[A-Z]{$_max_caps,}/',create_function('$matches','return strtolower($matches[0]);'),$_text);
}
?>
preg_replace_callback
(PHP 4 >= 4.0.5, PHP 5)
preg_replace_callback — 콜백을 이용한 정규 표현식 검색과 치환을 수행
설명
mixed preg_replace_callback
( mixed $pattern
, callback $callback
, mixed $subject
[, int $limit
[, int &$count
]] )
이 함수의 작동은 replacement 대신 callback을 지정하는 것을 제외하면, preg_replace()와 거의 동일합니다.
인수
- pattern
-
검색할 패턴. 문자열이나 문자열을 가진 배열일 수 있습니다.
- callback
-
string 문자열에서 매치한 요소의 배열이 넘겨져서 호출될 콜백. 콜백은 치환할 문자열을 반환해야 합니다.
종종 단 한번만 preg_replace_callback()에만 사용할 callback 함수가 필요합니다. 이러한 경우에 preg_replace_callback() 호출 안에서 create_function()을 사용해서 익명 함수를 선언할 수 있습니다. 이 방법으로 호출에 필요한 모든 정보를 한 군데 위치하게 할 수 있고, 다른 곳에서 사용하지 않는 콜백 함수의 이름으로 함수 이름공간을 어지럽히는 일을 막을 수 있습니다.
Example #1 preg_replace_callback()과 create_function()
/* 유닉스 형식 명령줄 필터로
* 문단의 첫 대문자를 소문자로 바꿉니다. */
$fp = fopen("php://stdin", "r") or die("stdin을 읽을 수 없습니다");
while (!feof($fp)) {
$line = fgets($fp);
$line = preg_replace_callback(
'|<p>\s*\w|',
create_function(
// 여기에서 홑따옴표가 중요합니다.
// 혹은 모든 $를 \$로 회피해야 합니다.
'$matches',
'return strtolower($matches[0]);'
),
$line
);
echo $line;
}
fclose($fp);
?> - subject
-
검색 치환할 문자열이나 문자열로 이루어진 배열.
- limit
-
각 subject 문자열에 대한 각 패턴의 최대 가능 치환수. 기본값은 -1. (무제한)
- count
-
지정하면, 이 변수는 치환을 마친 수로 채워집니다.
반환값
preg_replace_callback()은 subject 인수에 따라 배열이나 문자열을 반환합니다.
매치가 발견되면 새 subject가 반환되고, 그렇지 않으면 변경되지 않은 subject가 반환됩니다.
변경점
| 버전 | 설명 |
|---|---|
| 5.1.0 | count 인수 추가 |
예제
Example #2 preg_replace_callback() 예제
<?php
// 이 문장은 2002년에 사용되었습니다.
// 2003년에 적합하게 업데이트합니다.
$text = "April fools day is 04/01/2002\n";
$text.= "Last christmas was 12/24/2001\n";
// 콜백 함수
function next_year($matches)
{
// 보통: $matches[0]는 전채 매치입니다.
// $matches[1]은 첫번째 '(...)'에 들어있는
// 서브 패턴 매치로 이어집니다.
return $matches[1].($matches[2]+1);
}
echo preg_replace_callback(
"|(\d{2}/\d{2}/)(\d{4})|",
"next_year", $text);
?>
위 예제의 출력:
April fools day is 04/01/2003 Last christmas was 12/24/2002
Example #3 BB 코드를 다루기 위해 재귀 구조를 사용하는 preg_replace_callback()
<?php
$input = "plain [indent] deep [indent] deeper [/indent] deep [/indent] plain";
function parseTagsRecursive($input)
{
$regex = '#\[indent]((?:[^[]|\[(?!/?indent)|(?R))+)\[/indent]#';
if (is_array($input)) {
$input = '<div style="margin-left: 10px">'.$input[1].'</div>';
}
return preg_replace_callback($regex, 'parseTagRecursive', $input);
}
$output = parseTagsRecursive($input);
echo $output;
?>
참고
- preg_replace() - 정규 표현식 검색과 치환을 수행
- create_function() - Create an anonymous (lambda-style) function
- callback형에 대한 정보
add a note
User Contributed Notes
preg_replace_callback
dvb
02-Mar-2012 10:40
Florian Arndt
26-Jan-2012 12:26
This small class allows PHP users to read JSON files with include statements in them. For instance the include {{{ "relative/to/including.json" }}} is replaced by the content of the json file located at "relative/to/including.json".
<?php
/**
* Handles JSON files with includes
* Purpose: handle bigger JSON files by featuring "includes"
*
* @author Florian Arndt
*/
class JWI {
/**
* Parses a JSON file and returns its contents
* @param String $filename
*/
static function read($filename) {
if(!file_exists($filename))
throw new Exception('<b>JWI Error: JSON file <tt>'.$filename.'</tt> not found!</b>');
$content = join('', file($filename));
$dir = dirname($filename);
/**
* replace
* include statements
* with
* content of the file to include
* recursively
*/
$content = preg_replace_callback(
'/{{{\s*"\s*(.+)\s*"\s*}}}/', // >include file< - pattern
create_function(
'$matches', // callback parameter
sprintf(
'$fn = "%s/".$matches[1];'.
'return JWI::read($fn);',
realpath(dirname($filename))
)
),
$content
);
return $content;
}
}
henzeberkheij at gmail dot com
23-Nov-2011 08:23
also note that when you are using this functionality in a class and you need variables in that class, you can use a non static function as callback. array($this, functionName) should be enough to call an function of the class.
Either use create_function if you require the code only once,
use a static class function if no need for accessing variables in that class. or use the array metioned earlier in my post for having access to class variables or other functions!
webmaster at mp3s dot pl
28-Jul-2011 12:57
I noticed that 'e' modifier use addslashed on result
<?
function wyczysc_strongi($string) {
if(mb_strlen($string,'UTF-8')>60) {
return $string;
} else {
return '<strong>'.$string.'</strong>';
}
}
$tresc = "<strong>fajna dupa's</strong>";
$tresc = preg_replace("/<strong>(.*?)<\/strong>/ie",'wyczysc_strongi("$1")',$tresc);
echo $tresc will give: <strong>fajna dupa\'s</strong>
?>
solution: $tresc = stripslashes($tresc);
after callback
aleksander at throw dot pl
10-Jan-2011 02:59
I needed a simple code to tidy up a string. It simply had to upper-case letters after dot. Simple code to do so:
<?php
$string = preg_replace_callback(
'|(?:\.)(?:\s*)(\w{1})|Ui',
create_function('$matches', 'return ". ".strtoupper($matches[1]);'), ucfirst($string)
);
?>
<?php
$string = 'lorem ipsum dolor sit amet, consectetur adipiscing elit. sed ullamcorper diam eu lorem varius nec porta elit iaculis.';
echo preg_replace_callback(
'|(?:\.)(?:\s*)(\w{1})|Ui',
create_function('$matches', 'return ". ".strtoupper($matches[1]);'), ucfirst($string)
);
?>
Will output: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed ullamcorper diam eu lorem varius nec porta elit iaculis.
<?php
$string = 'lorem ipsum dolor sit amet, consectetur adipiscing elit. sed ullamcorper diam eu lorem varius nec porta elit iaculis.';
echo preg_replace_callback(
'|(?:\.)(?:\s*)(\w{1})|Ui',
create_function('$matches', 'return ". ".strtoupper($matches[1]);'), ucfirst($string)
);
?>
Will output: Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed ullamcorper diam eu lorem varius nec porta elit iaculis.
Nothing fancy, but useful :)
alex dot cs00 at yahoo dot ca
06-Oct-2010 02:09
Don't use this function to fetch BBCode, as explained. If you have some text that runs over 5000 chars (average), it will run out of its limit and makes you download the PHP page.
According to this, you should instead use something more advanced yet complex. You will need a function called "str_replace_once()" (search for it), one called "countWord()", the famous "after()", "before()", "between()".
str_replace_once does same as str_replace, but only replace first occurence. As for countWord, I guess you know how to count the number of a word occurence. As for after, before and between, this is a function that you may find easily somewhere on the site by a user. Else, you can do it.
The following function is able to do all blocks, supposing [code] and [/code], you might wish things between parents dont get parsed, including [code] if inside of another [code].
<?php
function prepareCode($code, $op, $end)
{
$ix = 0;
$iy = 0;
$nbr_Op = countWord($op, $code);
while($ix < $nbr_Op)
{
if(in_string($op, before($end, $code), false))
{
// The following piece of code replace the default [tag] by [tag:#]
$code = str_replace_once($op, substr($op, 0, -1).':'.$ix.']', $code);
$iy++;
}
elseif(in_string($end, before($op, $code), false))
{
$iy = $iy-1;
$code = str_replace_once($end, substr($end, 0, -1).':'.($ix-1).']', $code);
$ix = $ix-2;
}
$ix++;
}
while(in_string($end, $code))
{
$code = str_replace_once($end, substr($end, 0, -1).':'.($iy-1).']', $code);
$iy=$iy-1;
}
$code = preg_replace('#\\'.substr($end, 0, 1).':-[0-9]\]#i', '', $code);
if(in_string(substr($op, 0, -1).':0]', $code) && !in_string(substr($end, 0, -1).':0]', $code))
{
$code .= substr($end, 0, -1).":0]";
}
return $code;
}
?>
$code returns the whole text semi-formated. You only need to use it as :
$code = prepareCode($code="Your text", $op="[tag]" , $end="[/tag]");
Then just replace the parent tags :
str_replace("[tag:0]", "<tag>", $code);
str_replace("[/tag:0]", "</tag>", $code);
So at the end something like :
[
chris at ocproducts dot com
02-Jul-2010 07:39
The pcre.backtrack_limit option (added in PHP 5.2) can trigger a NULL return, with no errors. The default pcre.backtrack_limit value is 100000. If you have a match that exceeds about half this limit it triggers a NULL response.
e.g. My limit was at 100000 but 500500 triggered a NULL response. I'm not running unicode but I *guess* PCRE runs in utf-16.
Anonymous
09-Jun-2010 12:01
Created this to fetch the link and name of an anchor tag. I use this when cleaning an HTML email to text. Using regex for HTML is not recommended but for this purpose I see no issue with it. This is not designed to work for nested anchors.
A note to keep in mind:
I was primarily concerned with valid HTML so if attributes do no use ' or " to contain the values then this will need to be tweaked.
If you can edit this to work better, please let me know.
<?php
/**
* Replaces anchor tags with text
* - Will search string and replace all anchor tags with text (case insensitive)
*
* How it works:
* - Searches string for an anchor tag, checks to make sure it matches the criteria
* Anchor search criteria:
* - 1 - <a (must have the start of the anchor tag )
* - 2 - Can have any number of spaces or other attributes before and after the href attribute
* - 3 - Must close the anchor tag
*
* - Once the check has passed it will then replace the anchor tag with the string replacement
* - The string replacement can be customized
*
* Know issue:
* - This will not work for anchors that do not use a ' or " to contain the attributes.
* (i.e.- <a href=http: //php.net>PHP.net</a> will not be replaced)
*/
function replaceAnchorsWithText($data) {
/**
* Had to modify $regex so it could post to the site... so I broke it into 6 parts.
*/
$regex = '/(<a\s*'; // Start of anchor tag
$regex .= '(.*?)\s*'; // Any attributes or spaces that may or may not exist
$regex .= 'href=[\'"]+?\s*(?P<link>\S+)\s*[\'"]+?'; // Grab the link
$regex .= '\s*(.*?)\s*>\s*'; // Any attributes or spaces that may or may not exist before closing tag
$regex .= '(?P<name>\S+)'; // Grab the name
$regex .= '\s*<\/a>)/i'; // Any number of spaces between the closing anchor tag (case insensitive)
if (is_array($data)) {
// This is what will replace the link (modify to you liking)
$data = "{$data['name']}({$data['link']})";
}
return preg_replace_callback($regex, 'replaceAnchorsWithText', $data);
}
$input = 'Test 1: <a href="http: //php.net1">PHP.NET1</a>.<br />';
$input .= 'Test 2: <A name="test" HREF=\'HTTP: //PHP.NET2\' target="_blank">PHP.NET2</A>.<BR />';
$input .= 'Test 3: <a hRef=http: //php.net3>php.net3</a><br />';
$input .= 'This last line had nothing to do with any of this';
echo replaceAnchorsWithText($input).'<hr/>';
?>
Will output:
Test 1: PHP.NET1(http: //php.net1).
Test 2: PHP.NET2(HTTP: //PHP.NET2).
Test 3: php.net3 (is still an anchor)
This last line had nothing to do with any of this
Drake
21-Mar-2010 05:48
The good version of the class PhpHex2Str
<?php
class PhpHex2Str
{
private $strings;
private static function x_hex2str($hex) {
$hex = substr($hex[0], 1);
$str = '';
for($i=0;$i < strlen($hex);$i+=2) {
$str.=chr(hexdec(substr($hex,$i,2)));
}
return $str;
}
public function decode($strings = null) {
$this->strings = (string) $strings;
return preg_replace_callback('#\%[a-zA-Z0-9]{2}#', 'PhpHex2Str::x_hex2str', $this->strings);
}
}
// Exemple
$obj = new PhpHex2Str;
$strings = $obj->decode($strings);
var_dump($strings);
?>
Drake
21-Mar-2010 12:05
Decode Hexa to Strings =)
<?php
class PhpHex2Str
{
private $strings;
private function x_hex2str($hex) {
$hex = substr($hex[0], 1);
$str = '';
for($i=0;$i < strlen($hex);$i+=2) {
$str.=chr(hexdec(substr($hex,$i,2)));
}
return $str;
}
public function decode($strings = null) {
$this->strings = (string) $strings;
return preg_replace_callback('#\%[a-zA-Z0-9]{2}#', 'x_hex2str', $this->strings);
}
}
// Example
$strings = 'a %20 b%0A h %27 h %23';
$obj = new PhpHex2Str;
$strings = $obj->decode($strings);
var_dump($strings);
?>
Matt
14-Sep-2009 09:24
If you're looking to show only the first digit and last four digits of a credit card number (4xxxxxxxxxxxx2331) use something like this:
preg_replace_callback('/((.)(.*))?(.{4})/', create_function('$x', 'return $x[2].str_repeat("x", strlen($x[3])).$x[4];'), '$CCNUMBER')
ixiter at gmail dot com
28-Jul-2009 07:06
When you use preg_replace_callback in a class and have the callback function as a private method of that class, you need to set the callback function name like className::CallBack.
self::CallBack does not work and returns an error:
"Cannot call method self::CallBack() or method does not exist"!
<?php
class myClass{
public function parsetext($text){
// parses text and sets literals A - C to lower case
// this works
return preg_replace_callback('|([a-c])|i', 'myClass::preg_tolower', $text);
}
public function parsefail($text){
// parses text and sets literals A - C to lower case
// this fails
return preg_replace_callback('|([a-c])|i', 'self::preg_tolower', $text);
}
private static function preg_tolower($matches){
return strtolower($matches[1]);
}
}
$parser = new myClass;
echo $parser->parsetext('ABCDEFGH');
// echoes abcDEFGH
echo $parser->parsefail('ABCDEFGH');
// throws the error
?>
carlos dot ballesteros at softonic dot com
02-Jul-2009 08:02
A simple function to replace a list of complete words or terms in a string (for PHP 5.3 or above because of the closure):
<?php
function replace_words($list, $line, $callback) {
return preg_replace_callback(
'/(^|[^\\w\\-])(' . implode('|', array_map('preg_quote', $list)) . ')($|[^\\w\\-])/mi',
function($v) use ($callback) { return $v[1] . $callback($v[2]) . $v[3]; },
$line
);
}
?>
Example of usage:
<?php
$list = array('php', 'apache web server');
$str = "php and the apache web server work fine together. php-gtk, for example, won't match. apache web servers shouldn't too.";
echo replace_words($list, $str, function($v) {
return "<strong>{$v}</strong>";
});
?>
chris AT cmbuckley DOT co DOT uk
09-Jun-2009 07:44
This function does not support named subpatterns, so you can't do
<?php
preg_replace_callback('/(?<char>[a-z])/', 'callback', 'word');
function callback($matches) {
var_dump($matches);
}
?>
and expect to get $matches['char'] in your function.
mariush
12-May-2009 01:17
If you're planning to use preg_replace_callback inside a class, you need to use the array() function:
<?php
class MyClass
{
function preg_callback_url($matches)
{
//var_dump($matches);
$url = $matches[1].$matches[2];
$text = '';
$pos = strpos($url,' ');
if ($pos!==FALSE) {
$text = trim(substr($url,$pos+1));
$url = substr($url,0,$pos);
}
return '<a href="'.$url.'" rel="nofollow">'.(($text!='') ? $text : $url).'</a>';
}
function ParseText($text)
{
return preg_replace_callback('/\[(http|https|ftp)(.*?)\]/iS',array( &$this, 'preg_callback_url'), $text);
}
}
?>
james dot records at gmail dot com
26-Apr-2009 12:22
This is what i use to read log files and do dns lookups on the ip's from the file.
<?php
function resolve_logs($arr) {
return gethostbyaddr($arr[0]);
}
$logent=file('yourlogfile');
$ipaddr = '/\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}/';
$logent = preg_replace_callback($ipaddr, resolve_logs, $logent);
?>
long2hu3 ATT yahoo DOTT com
01-Apr-2009 11:25
When you access variables from outside in a callback function, use the $global keyword:
<?php
// global # 1:
global $x;
$x = 0;
$str = '&Bla bla. ►';
$find = '/(\&)([^#])/';
// global # 2:
$replace = create_function('$f',
'global $x; $x ++; return $f[2];';
$str2 = preg_replace_callback($find, $replace, $str);
// $x == 1
// $str2 == 'Bla bla. ►'
// without global, $x would be 0
?>
tijn at q-go dot com
06-Jan-2009 02:01
To access a local variable within a callback, use currying (delayed argument binding). For example
<?php
function curry($func, $arity) {
return create_function('', "
\$args = func_get_args();
if(count(\$args) >= $arity)
return call_user_func_array('$func', \$args);
\$args = var_export(\$args, 1);
return create_function('','
\$a = func_get_args();
\$z = ' . \$args . ';
\$a = array_merge(\$z,\$a);
return call_user_func_array(\'$func\', \$a);
');
");
}
function on_match($transformation, $matches)
{
return $transformation[strtolower($matches[1])];
}
$transform = array('a' => 'Well,', 'd'=>'whatever', 'b'=>' ');
$callback = curry(on_match, 2);
echo preg_replace_callback('/([a-z])/i', $callback($transform), 'Abcd');
echo "\n";
?>
outputs:
"Well, whatever"
The magic lies in this curry function I found here: http://www.sitepoint.com/forums/showthread.php?threadid=336758
tijn at q-go dot com
05-Jan-2009 08:48
To access a local variable within a callback, use currying (delayed argument binding). For example
<?php
function curry($func, $arity) {
return create_function('', "
\$args = func_get_args();
if(count(\$args) >= $arity)
return call_user_func_array('$func', \$args);
\$args = var_export(\$args, 1);
return create_function('','
\$a = func_get_args();
\$z = ' . \$args . ';
\$a = array_merge(\$z,\$a);
return call_user_func_array(\'$func\', \$a);
');
");
}
function on_match($transformation, $matches)
{
return $transformation[strtolower($matches[1])];
}
$transform = array('a' => 'Well,', 'd'=>'whatever', 'b'=>' ');
$callback = curry(on_match, 2);
echo preg_replace_callback('/([a-z])/i', $callback($transform), 'Abcd');
echo "\n";
?>
outputs:
"Well, whatever"
The magic lies in this curry function I found here: http://www.sitepoint.com/forums/showthread.php?threadid=336758
nicolaspar at gmail dot com
19-Dec-2008 06:33
To spend more than one parameter can do the following (note the "e" parameter in preg_replace function)
<?
$array = array(
1=>'ONE',
2=>'TWO',
3=>'Three'
);
function search(&$array, $str, $foo, $bar){
return ( empty($array[$str]) ? '['.$foo.'-'.$bar.']' : $array[$str] );
}
function keys(&$array, $str,$foo,$bar){
return preg_replace('/\[(.*?)\]/e',"search(\$array,$1,\$foo,\$bar)",$str);
}
$str = "One [1] Two [2] Three [3], Other parameter [22]";
echo keys($array, $str,'Foo','Bar');
?>
Nice
nene at triin dot net
20-May-2008 03:14
The first example is bad, because it creates function for every line it processes. When the file has many lines, you could easily run out of memory. The code should be changed so, that create_function() is used outside of loop.
Sjon at hortensius dot net
24-Jun-2007 04:56
preg_replace_callback returns NULL when pcre.backtrack_limit is reached; this sometimes occurs faster then you might expect. No error is raised either; so don't forget to check for NULL yourself
matt at mattsoft dot net
26-Apr-2006 02:16
it is much better on preformance and better practice to use the preg_replace_callback function instead of preg_replace with the e modifier.
function a($text){return($text);}
// 2.76 seconds to run 50000 times
preg_replace("/\{(.*?)\}/e","a('\\1','\\2','\\3',\$b)",$a);
// 0.97 seconds to run 50000 times
preg_replace_callback("/\{(.*?)\}/s","a",$a);