Preg match all word

Regex quick reference
[abc]     A single character: a, b or c
[^abc]     Any single character but a, b, or c
[a-z]     Any single character in the range a-z
[a-zA-Z]     Any single character in the range a-z or A-Z
^     Start of line
$     End of line
A     Start of string
z     End of string
.     Any single character
s     Any whitespace character
S     Any non-whitespace character
d     Any digit
D     Any non-digit
w     Any word character (letter, number, underscore)
W     Any non-word character
b     Any word boundary character
(...)     Capture everything enclosed
(a|b)     a or b
a?     Zero or one of a
a*     Zero or more of a
a+     One or more of a
a{3}     Exactly 3 of a
a{3,}     3 or more of a
a{3,6}     Between 3 and 6 of a

options: i case insensitive m make dot match newlines x ignore whitespace in regex o perform #{...} substitutions only once

(?:(?!string).)

?: makes a subpattern (see http://www.php.net/manual/en/regexp.reference.subpatterns.php) and ?! is a negative look ahead. You put the negative look ahead in front of the dot because you want the regex engine to first check if there is an occurrence of the string you are negating. Only if it is not there, you want to match an arbitrary character.

Hope this helps some ppl.

preg_match_all('/regular expr/sim',$text).

The s i m being the location for and available switches (I know about)

The i is to ignore letter cases (this is commonly known - I think)

The s tells the code NOT TO stop searching when it encounters n (line break) - this is important with multi-line entries for example text from an editor that needs search.

The m tells the code it is a multi-line entry, but importantly allows the use of ^ and $ to work when showing start and end.

I am hoping this will save someone from the 4 hours of torture that I endured, trying to workout this issue.

<?php
$pattern ='/^([-a-zA-Z0-9_p{Katakana}p{Hiragana}p{Han}]*)$/u'; // Didn't work
?>

So I tried with ranges and it worked:

<?php
$pattern ='/^[-a-zA-Z0-9_x{30A0}-x{30FF}'
         .'x{3040}-x{309F}x{4E00}-x{9FBF}s]*$/u';
$match_string = '印刷最安 ニキビ跡除去 ゲームボーイ';

if (

preg_match($pattern, $match_string)) {
    echo "Found - pattern $pattern";
} else {
    echo "Not found - pattern $pattern";
}
?>

U+4E00–U+9FBF Kanji
U+3040–U+309F Hiragana
U+30A0–U+30FF Katakana

Hope its useful, it took me several hours to figure it out.

for instance : '#(*UTF8)[[:alnum:]]#' will return TRUE for 'é' where '#[[:alnum:]]#' will return FALSE

found this very very useful tip after hours of research over the web directly in pcre website right here : http://www.pcre.org/pcre.txt
there are many further informations about UTF-8 support in the lib

hop that will help!

--
cedric

Check for Persian digits
preg_match( "/[^x{06F0}-x{06F9}x]+/u" , '۱۲۳۴۵۶۷۸۹۰' );

<?php
   preg_match("/[x{0600}-x{06FF}x]{1,32}/u", 'محمد');
?>

http://www.regular-expressions.info/named.html

<?php
   preg_match("/(?P<foo>abc)(.*)(?P<bar>xyz)/",
                       'abcdefghijklmnopqrstuvwxyz',
                       $matches);
   print_r($matches);
?>

will produce:

Array
(
    [0] => abcdefghijklmnopqrstuvwxyz
    [foo] => abc
    [1] => abc
    [2] => defghijklmnopqrstuvw
    [bar] => xyz
    [3] => xyz
)

Note that you actually get the named group as well as the numerical key
value too, so if you do use them, and you're counting array elements, be
aware that your array might be bigger than you initially expect it to be.

<?php
$email = "someone@domain .local";

if(!

filter_var($email, FILTER_VALIDATE_EMAIL)) {
    echo "E-mail is not valid";
} else {
    echo "E-mail is valid";
}
?>

Here is a workaround: Assign a name to all subpatterns you are interested in, and merge $match afterwards with an constant array containing some reasonable default values:

<?php
if (preg_match('/^(?P<lang>[^;*][^;]*){1}(?:;q=(?P<qval>[0-9.]+))?$/u', 'de', $match))
{
  $match = array_merge(array('lang' => '', 'qval' => ''), $match);
  print_r($match);
}
?>

This outputs:
Array
(
    [lang] => de
    [qval] =>
    [0] => de
    [1] => de
)

Instead of:
Array
(
    [0] => de
    [lang] => de
    [1] => de
)

<?php

if(ereg('[^0-9A-Za-z]',$test_string)) // will be true if characters arnt 0-9, A-Z or a-z.
if(preg_match('/[^0-9A-Za-z]/',$test_string)) // this is the preg_match version. the /'s are now required.

?>

if( preg_match("#^([a-z]{1}:{1})?[\/]?([-w]+[\/]?)*$#i",$_GET['path'],$matches) !== 1 ){
    echo("Invalid value");
}else{
    echo("Valid value");
}

The parts are:

#^ and $i            Make the string matches at all the pattern, from start to end for ensure a complete match.
([a-z]{1}:{1})?        The string may starts with one letter and a colon, but only 1 character for eachone, this is for the drive letter (C:)
[\/]?            The string may contain, but not require 1 slash or backslash after the drive letter, (/)
([-w]+[\/]?)*    The string must have 1 or more of any character like hyphen, letter, number, underscore, and may contain a slash or back slash at the end, to have a directory like ("/" or "folderName" or "folderName/"), this may be repeated one or more times.

e.g.: decremente_chaine("somenode->anode[2]->achildnode[3]") will return "somenode->anode[1]->achildnode[2]"

the numbering of the nodes in simplexml starts from zero, but from 1 in DOM xpath objects

<?php
function decremente_chaine($chaine)
    {
        //récupérer toutes les occurrences de nombres et leurs indices
        preg_match_all("/[0-9]+/",$chaine,$out,PREG_OFFSET_CAPTURE);
            //parcourir les occurrences
            for($i=0;$i<sizeof($out[0]);$i++)
            {
                $longueurnombre = strlen((string)$out[0][$i][0]);
                $taillechaine = strlen($chaine);
                // découper la chaine en 3 morceaux
                $debut = substr($chaine,0,$out[0][$i][1]);
                $milieu = ($out[0][$i][0])-1;
                $fin = substr($chaine,$out[0][$i][1]+$longueurnombre,$taillechaine);
                 // si c'est 10,100,1000 etc. on décale tout de 1 car le résultat comporte un chiffre de moins
                 if(preg_match('#[1][0]+$#', $out[0][$i][0]))
                 {
                    for($j = $i+1;$j<sizeof($out[0]);$j++)
                    {
                        $out[0][$j][1] = $out[0][$j][1] -1;
                    }
                 }
                $chaine = $debut.$milieu.$fin;
            }
        return $chaine;
    }
?>

//trying to match "'" (2 characters) in a text file, '\'' as PHP string:

$subject = file_get_contents('myfile.txt');
preg_match('/\'/',$subject);    //DOESN'T MATCH!!! stored as 0x5C,0x27 (escaped apostrophe), this only matches apostrophe
preg_match('/\\'/',$subject);  //matches, stored as 0x5C,0x5C,0x27 (escaped backslash and unescaped apostrophe)
preg_match('/\\\/',$subject); //also matches, stored as 0x5C,0x5C,0x5C,0x27 (escaped backslash and escaped apostrophe)

//matching "n" (2 characters):

<?php
if(strpos($url, "http") === 0)
{
//do something
}
?>

As I guessed, strpos() is always faster (about 2x) for short strings like a URL but for very long strings of several paragraphs (e.g. a block of XML) when the string doesn't start with the needle preg_match as twice as fast as strpos() as it doesn't scan the entire string.

So, if you are searching long strings and expect it to normally be true (e.g. validating XML), strpos() is a much faster BUT if you expect if to often fail, preg_match is the better choice.

Possible workaround: Use mb_strpos to get the correct offset, instead of the flag.

UTF-8 support would be nice.

(?P<type>w+)($|((?P<length>(d+|(.*)))))

For example, if you are have a such type as "varchar(255)" or "text", the next fragment

<?php
   $type = 'varchar(255)';  // type of field
   preg_match('/(?P<type>w+)($|((?P<length>(d+|(.*)))))/', $type, $field);
   print_r($field);
?>

will output something like this:
Array ( [0] => varchar(255) [type] => varchar [1] => varchar [2] => (255) [length] => 255 [3] => 255 [4] => 255 )

The Unix directory separator must be escaped once and the windows directory separator must be escaped twice.

This will match path/to/file and pathtofile.exe

preg_match('/^[a-z0-9_./\]*$/i', $file_string);

<?php

    $regex = "((https?|ftp)://)?"; // SCHEME

    $regex .= "([a-z0-9+!*(),;?&=$_.-]+(:[a-z0-9+!*(),;?&=$_.-]+)?@)?"; // User and Pass

    $regex .= "([a-z0-9-.]*).([a-z]{2,3})"; // Host or IP

    $regex .= "(:[0-9]{2,5})?"; // Port

    $regex .= "(/([a-z0-9+$_-].?)+)*/?"; // Path

    $regex .= "(?[a-z+&$_.-][a-z0-9;:@&%=+/$_.-]*)?"; // GET Query

    $regex .= "(#[a-z_.-][a-z0-9+$_.-]*)?"; // Anchor

?>



Then, the correct way to check against the regex ist as follows:

<?php

       if(preg_match("/^$regex$/", $url))

       {

               return true;

       }

?>

*** Note: Only matches U.S. phone numbers. ***

<?php
// all on one line...

$regex = '/^(?:1(?:[. -])?)?(?:((?=d{3})))?([2-9]d{2})(?:(?<=(d{3})))? ?(?:(?<=d{3})[.-])?([2-9]d{2})[. -]?(d{4})(?: (?i:ext).? ?(d{1,5}))?$/';
// or broken up

$regex = '/^(?:1(?:[. -])?)?(?:((?=d{3})))?([2-9]d{2})'

        .'(?:(?<=(d{3})))? ?(?:(?<=d{3})[.-])?([2-9]d{2})'

        .'[. -]?(d{4})(?: (?i:ext).? ?(d{1,5}))?$/';
?>



If you're wondering why all the non-capturing subpatterns (which look like this "(?:", it's so that we can do this:

<?php

$formatted

= preg_replace($regex, '($1) $2-$3 ext. $4', $phoneNumber);
// or, provided you use the $matches argument in preg_match
$formatted = "($matches[1]) $matches[2]-$matches[3]";

if ($matches[4]) $formatted .= " $matches[4]";
?>



*** Results: ***

520-555-5542 :: MATCH

520.555.5542 :: MATCH

5205555542 :: MATCH

520 555 5542 :: MATCH

520) 555-5542 :: FAIL

(520 555-5542 :: FAIL

(520)555-5542 :: MATCH

(520) 555-5542 :: MATCH

(520) 555 5542 :: MATCH

520-555.5542 :: MATCH

520 555-0555 :: MATCH

(520)5555542 :: MATCH

520.555-4523 :: MATCH

19991114444 :: FAIL

19995554444 :: MATCH

514 555 1231 :: MATCH

1 555 555 5555 :: MATCH

1.555.555.5555 :: MATCH

1-555-555-5555 :: MATCH

520-555-5542 ext.123 :: MATCH

520.555.5542 EXT 123 :: MATCH

5205555542 Ext. 7712 :: MATCH

520 555 5542 ext 5 :: MATCH

520) 555-5542 :: FAIL

(520 555-5542 :: FAIL

(520)555-5542 ext .4 :: FAIL

(512) 555-1234 ext. 123 :: MATCH

1(555)555-5555 :: MATCH

<?php//echoes 1 (adding u would not alter the result)
echo preg_match('/^áéíóúñ$/', 'áéíóúñ');//echoes 0 (unless with [ó]+ or [ó]* or adding u)
echo preg_match('/^áéí[ó]úñ$/', 'áéíóúñ');//so to match 'espana' or 'españa', add u or this won't match
//echoes 1
echo preg_match('/^espa[nñ]a$/u', 'españa');?>

In most cases, the following example will show one of two PHP-bugs discovered with preg_match depending on your PHP-version and configuration.

<?php

$text

= "test=";
// creates a rather long text
for ($i = 0; $i++ < 100000;)
    $text .= "%AB";// a typical URL_query validity-checker (the pattern's function does not matter for this example)
$pattern    = '/^(?:[;/?:@&=+$,]|(?:[^W_]|[-_.!~*()[] ])|(?:%[da-fA-F]{2}))*$/';var_dump( preg_match( $pattern, $text ) );?>

Possible bug (1):
=============
On one of our Linux-Servers the above example crashes PHP-execution with a C(?) Segmentation Fault(!). This seems to be a known bug (see http://bugs.php.net/bug.php?id=40909), but I don't know if it has been fixed, yet.
If you are looking for a work-around, the following code-snippet is what I found helpful. It wraps the possibly crashing preg_match call by decreasing the PCRE recursion limit in order to result in a Reg-Exp error instead of a PHP-crash.

<?php
[...]// decrease the PCRE recursion limit for the (possibly dangerous) preg_match call
$former_recursion_limit = ini_set( "pcre.recursion_limit", 10000 );// the wrapped preg_match call
$result = preg_match( $pattern, $text );// reset the PCRE recursion limit to its original value
ini_set( "pcre.recursion_limit", $former_recursion_limit );// if the reg-exp fails due to the decreased recursion limit we may not make any statement, but PHP-execution continues
if ( PREG_RECURSION_LIMIT_ERROR === preg_last_error() )
{
    // react on the failed regular expression here
    $result = [...];// do logging or email-sending here
    [...]
} //if?>

Possible bug (2):
=============
On one of our Windows-Servers the above example does not crash PHP, but (directly) hits the recursion-limit. Here, the problem is that preg_match does not return boolean(false) as expected by the description / manual of above.
In short, preg_match seems to return an int(0) instead of the expected boolean(false) if the regular expression could not be executed due to the PCRE recursion-limit. So, if preg_match results in int(0) you seem to have to check preg_last_error() if maybe an error occurred.

I believe the limit is 1 or 2 GB because I was using a 2.2GB string.
While a parameter might exist to alter this limit, in my case it was possible and wiser to use <500MB strings instead.

# preg_substr($pattern,$subject,[$offset]) function
# @author   aer0s
#  return a specific sub-string in a string using
#   a regular expression
# @param   $pattern   regular expression pattern to match
# @param   $subject   string to search
# @param   [$offset]   zero based match occurrence to return
#                            
# [$offset] is 0 by default which returns the first occurrence,
# if [$offset] is -1 it will return the last occurrence

function preg_substr($pattern,$subject,$offset=0){
    preg_match_all($pattern,$subject,$matches,PREG_PATTERN_ORDER);
    return $offset==-1?array_pop($matches[0]):$matches[0][$offset];
}

example:

             $pattern = "/model(s|-)[a-z0-9]/i";
             $subject = "Is there something wrong with model 654, Model 732, and model 43xl or is Model aj45B the preferred choice?";

             echo preg_substr($pattern,$subject);
             echo preg_substr($pattern,$subject,1);
             echo preg_substr($pattern,$subject,-1);

Returns something like:

             model 654
             Model 732
             Model aj45B

(for 12 words, 100,000 iterations, no word found)
stripos - Taken 1.4876 seconds.
strpos - Taken 1.4207 seconds.
preg_match - Taken 0.189 seconds.

Interesting fact:
With long words ('averylongwordtospitepreg'), the difference is only much less. Only about a 2/3rd of the time instead of 1/6th

<?php

$words

= array('word1', 'word2', 'word3', 'word4', 'word5', 'word6', 'word7', 'word8', 'word9', 'word10', 'word11', 'word12' );
$teststring = 'ThIs Is A tEsTsTrInG fOr TeStInG.';
$count = 100000;
$find = 0;$start = microtime(TRUE);
for ($i = 0; $i < $count; $i++) {
    foreach ($words as $word) {
        if (stripos($teststring, $word) !== FALSE) {
            $find++;
            break;
        }
    }
}
echo 'stripos - Taken ' . round(microtime(TRUE) - $start, 4) . ' seconds.' . PHP_EOL;$start = microtime(TRUE);
for ($i = 0; $i < $count; $i++) {
    foreach ($words as $word) {
        if (strpos($teststring, $word) !== FALSE) {
            $find++;
            break;
        }
    }
}
echo 'strpos - Taken ' . round(microtime(TRUE) - $start, 4) . ' seconds.' . PHP_EOL;$start = microtime(TRUE);
$pattern = '/';
$div = '';
foreach ($words as $word) {
    $pattern .= $div . preg_quote($word);
    $div = '|';
}
$pattern .= '/i';
//Pattern could easily be done somewhere else if words are static.
for ($i = 0; $i < $count; $i++) {
    if (preg_match($pattern, $teststring)) {
        $find++;
    }
}
$end = microtime(TRUE);
echo 'preg_match - Taken ' . round($end - $start, 4) . ' seconds.' . PHP_EOL;
?>

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  = '/(<as*'; // 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

Posting to this site is painful...
Had to break up the regex and had to break the test links since it was being flagged as spam...

in this function we use

unlink() - http://php.net/unlink

after you upload file check a file with below function.

<?php/**
* A simple function to check file from bad codes.
*
* @param (string) $file - file path.
* @author Yousef Ismaeil - Cliprz[at]gmail[dot]com.
*/
function is_clean_file ($file)
{
    if (file_exists($file))
    {
        $contents = file_get_contents($file);
    }
    else
    {
        exit($file." Not exists.");
    }

    if (

preg_match('/(base64_|eval|system|shell_|exec|php_)/i',$contents))
    {
        return true;
    }
    else if (preg_match("#&#x([0-9a-f]+);#i", $contents))
    {
        return true;
    }
    elseif (preg_match('#&#([0-9]+);#i', $contents))
    {
        return true;
    }
    elseif (preg_match("#([a-z]*)=([`'"]*)script:#iU", $contents))
    {
        return true;
    }
    elseif (preg_match("#([a-z]*)=([`'"]*)javascript:#iU", $contents))
    {
        return true;
    }
    elseif (preg_match("#([a-z]*)=(['"]*)vbscript:#iU", $contents))
    {
        return true;
    }
    elseif (preg_match("#(<[^>]+)style=([`'"]*).*expression([^>]*>#iU", $contents))
    {
        return true;
    }
    elseif (preg_match("#(<[^>]+)style=([`'"]*).*behaviour([^>]*>#iU", $contents))
    {
        return true;
    }
    elseif (preg_match("#</*(applet|link|style|script|iframe|frame|frameset|html|body|title|div|p|form)[^>]*>#i", $contents))
    {
        return true;
    }
    else
    {
        return false;
    }
}
?>

Use

<?php
// If image contains a bad codes
$image   = "simpleimage.png";

if (

is_clean_file($image))
{
    echo "Bad codes this is not image";
    unlink($image);
}
else
{
    echo "This is a real image.";
}
?>

<?php

if(preg_match($pattern,$haystack,$out,PREG_OFFSET_CAPTURE)) {

    $offset = strlen(utf8_decode(substr($haystack,0,$out[0][1])));

}

?>

With PREG_UNMATCHED_AS_NULL, count( $matches ) will always be the maximum number of subpatterns.
However, without PREG_UNMATCHED_AS_NULL the $matches array will omit any unmatched subpatterns at the tail end.

Result forthe first two out of three matches with PREG_OFFSET_CAPTURE flag only:

array (size=3)
  0 =>
    array (size=2)
      0 => string 'may/02' (length=6)
      1 => int 0
  1 =>
    array (size=2)
      0 => string 'may' (length=3)
      1 => int 0
  2 =>
    array (size=2)
      0 => string '02' (length=2)
      1 => int 4

Result for two out of three matches with additional PREG_UNMATCHED_AS_NULL flags:

array (size=4)
  0 =>
    array (size=2)
      0 => string 'may/02' (length=6)
      1 => int 0
  1 =>
    array (size=2)
      0 => string 'may' (length=3)
      1 => int 0
  2 =>
    array (size=2)
      0 => string '02' (length=2)
      1 => int 4
  3 =>
    array (size=2)
      0 => null
      1 => int -1

<?php

/**

* @param integer $country Country name

* @param integer $vat_number VAT number to test e.g. GB123 4567 89

* @return integer -1 if country not included OR 1 if the VAT Num matches for the country OR 0 if no match

*/

function checkVatNumber( $country, $vat_number ) {

    switch($country) {

        case 'Austria':

            $regex = '/^(AT){0,1}U[0-9]{8}$/i';

            break;

        case 'Belgium':

            $regex = '/^(BE){0,1}[0]{0,1}[0-9]{9}$/i';

            break;

        case 'Bulgaria':

            $regex = '/^(BG){0,1}[0-9]{9,10}$/i';

            break;

        case 'Cyprus':

            $regex = '/^(CY){0,1}[0-9]{8}[A-Z]$/i';

            break;

        case 'Czech Republic':

            $regex = '/^(CZ){0,1}[0-9]{8,10}$/i';

            break;

        case 'Denmark':

            $regex = '/^(DK){0,1}([0-9]{2}[ ]{0,1}){3}[0-9]{2}$/i';

            break;

        case 'Estonia':

        case 'Germany':

        case 'Greece':

        case 'Portugal':

            $regex = '/^(EE|EL|DE|PT){0,1}[0-9]{9}$/i';

            break;

        case 'France':

            $regex = '/^(FR){0,1}[0-9A-Z]{2}[ ]{0,1}[0-9]{9}$/i';

            break;

        case 'Finland':

        case 'Hungary':

        case 'Luxembourg':

        case 'Malta':

        case 'Slovenia':

            $regex = '/^(FI|HU|LU|MT|SI){0,1}[0-9]{8}$/i';

            break;

        case 'Ireland':

            $regex = '/^(IE){0,1}[0-9][0-9A-Z+*][0-9]{5}[A-Z]$/i';

            break;

        case 'Italy':

        case 'Latvia':

            $regex = '/^(IT|LV){0,1}[0-9]{11}$/i';

            break;

        case 'Lithuania':

            $regex = '/^(LT){0,1}([0-9]{9}|[0-9]{12})$/i';

            break;

        case 'Netherlands':

            $regex = '/^(NL){0,1}[0-9]{9}B[0-9]{2}$/i';

            break;

        case 'Poland':

        case 'Slovakia':

            $regex = '/^(PL|SK){0,1}[0-9]{10}$/i';

            break;

        case 'Romania':

            $regex = '/^(RO){0,1}[0-9]{2,10}$/i';

            break;

        case 'Sweden':

            $regex = '/^(SE){0,1}[0-9]{12}$/i';

            break;

        case 'Spain':

            $regex = '/^(ES){0,1}([0-9A-Z][0-9]{7}[A-Z])|([A-Z][0-9]{7}[0-9A-Z])$/i';

            break;

        case 'United Kingdom':

            $regex = '/^(GB){0,1}([1-9][0-9]{2}[ ]{0,1}[0-9]{4}[ ]{0,1}[0-9]{2})|([1-9][0-9]{2}[ ]{0,1}[0-9]{4}[ ]{0,1}[0-9]{2}[ ]{0,1}[0-9]{3})|((GD|HA)[0-9]{3})$/i';

            break;

        default:

            return -1;

            break;

    }

   
    return

preg_match($regex, $vat_number);

}

?>

<?php

  $url 

= 'http://name:pass@';

  $url .= 'example.com:10000';

  $url .= '/path/to/file.php?a=1&amp;b=2#anchor';
$url_data = parse_url ( $url );
print_r ( $url_data );
?>

___

prints out something like:

Array

(

    [scheme] => http

    [host] => wild.subdomain.orgy.domain.co.uk

    [port] => 10000

    [user] => name

    [pass] => pass

    [path] => /path/to/file.php

    [query] => a=1&b=2

    [fragment] => anchor

)

In my tests parse_url is up to 15x faster than preg_match(_all)!

Just a warning regarding the conversion, the two functions behave very similarly, but not exactly alike. Obviously, you will need to delimit your pattern with '/' or '|' characters.

The difference that stumped me was that preg_replace overwrites the $matches array regardless if a match was found. If no match was found, $matches is simply empty.

ereg(), however, would leave $matches alone if a match was not found. In my code, I had repeated calls to ereg, and was populating $matches with each match. I was only interested in the last match. However, with preg_match, if the very last call to the function did not result in a match, the $matches array would be overwritten with a blank value.

Here is an example code snippet to illustrate:

<?php

$test = array('yes','no','yes','no','yes','no');

foreach (

$test as $key=>$value) {

  ereg("yes",$value,$matches1);

  preg_match("|yes|",$value,$matches2);

}

  print "ereg result: $matches1[0]<br>";

  print "preg_match result: $matches2[0]<br>";

?>



The output is:

ereg result: yes

preg_match result:

($matches2[0] in this case is empty)

I believe the preg_match behavior is cleaner. I just thought I would report this to hopefully save others some time.

The function allows you to pass through flags (in this version it applies to all expressions tested), and generates an array of search results.

Enjoy!

<?php/**
* Allows multiple expressions to be tested on one string.
* This will return a boolean, however you may want to alter this.
*
* @author William Jaspers, IV <wjaspers4@gmail.com>
* @created 2009-02-27 17:00:00 +6:00:00 GMT
* @access public
*
* @param array $patterns An array of expressions to be tested.
* @param String $subject The data to test.
* @param array $findings Optional argument to store our results.
* @param mixed $flags Pass-thru argument to allow normal flags to apply to all tested expressions.
* @param array $errors A storage bin for errors
*
* @returns bool Whether or not errors occurred.
*/
function preg_match_multiple(
  array $patterns=array(),
  $subject=null,
  &$findings=array(),
  $flags=false,
  &$errors=array()
) {
  foreach( $patterns as $name => $pattern )
  {
    if( 1 <= preg_match_all( $pattern, $subject, $found, $flags ) )
    {
      $findings[$name] = $found;
    } else
    {
      if( PREG_NO_ERROR !== ( $code = preg_last_error() ))
      {
        $errors[$name] = $code;
      } else $findings[$name] = array();
    }
  }
  return (0===sizeof($errors));
}
?>

<?php

preg_match("/^[a-zA-Zp{Cyrillic}0-9s-]+$/u", "ABC abc 1234 АБВ абв");

?>

Status: Implemented (in PHP 7.3)

SELinux will prevent PREG_* functions from working

Feb  8 12:40:51 servername setroubleshoot: SELinux is preventing httpd from using the execmem access on a process.

you need to add preg.jit=0 to php.ini or init_set('preg.jit', 0) if you can't do that

try the [PCRE] section so you can find it

<?php
$search = isset($_POST['search'])?$_POST['search']:"//";
$match = isset($_POST['match'])?$_POST['match']:"<>";

echo

'<form method="post">';
echo 's: <input style="width:400px;" name="search" type="text" value="'.$search.'" /><br />';
echo 'm:<input style="width:400px;" name="match" type="text" value="'.$match.'" /><input type="submit" value="go" /></form><br />';
if (preg_match($search, $match)){echo "matches";}else{echo "no match";}
?>

<?php

function highlight($word, $subject) {
$split_subject = explode(" ", $subject);

    $split_word = explode(" ", $word);

    foreach (

$split_subject as $k => $v){

           foreach ($split_word as $k2 => $v2){

               if($v2 == $v){
$split_subject[$k] = "<span class='highlight'>".$v."</span>";

              
               }

           }

      }

     
      return

implode(' ', $split_subject);

}

?>

Instead still results in an array for each unmatched subpattern, in turn containing:

array (size=2)
      0 => null
      1 => int -1

Consequently your code needs to expect NULL as the string value:
$matches[ {subpattern+1} ][0] === null
and/or a negative string offset:
$matches[ {subpattern+1} ][1] < 0
to detect any unmatched subpattern!

<?php preg_match('/(foo)?(bar)?(baz)?/', 'bar', $matches);
print_r($matches); // outputs
// Array
// (
//     [0] => bar
//     [1] =>
//     [2] => bar
// )
?>
Note that there is no element with key '3' in $matches, but an element with key '1' (the empty string). This inconsistent behavior also applies to named groups.

<?php

$string = "$table_name";

if (preg_match("/[^\d\sa-zA-Z$_]/", $string))

  echo "Failed validation";

?>

      ^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(?([^#]*))?(#(.*))?
       12            3  4          5       6  7        8 9

Source: ietf.org/rfc/rfc2396.txt

If you work with named subpatterns and dont want to bother with unnamed match result entries and unmatched subpatterns, just replace preg_match() with named_preg_match(). This filters all unwanted stuff out.

<?php
function named_preg_match(string $pattern , string $subject, array &$matches = null, int $flags = 0, int $offset = 0) {
    $retval = preg_match($pattern, $subject, $localmatches, PREG_UNMATCHED_AS_NULL | $flags, $offset);
    if ($retval) {
        foreach ($localmatches as $key => $value) {
            if (is_int($key)) $value = null;
            if (is_null($value)) unset($localmatches[$key]);
        }
        $matches = $localmatches;
    }
    return $retval;
}
?>

Hope this will be useful.

<?php

        $email_address

= "phil.taylor@a_domain.tv";

    if (

preg_match("/^[^@]*@[^@]*.[^@]*$/", $email_address)) {

        return "E-mail address";       

    }
?>

<?php
$pattern = "/{[^}]*}/";
$subject = "{token1} foo {token2} bar";
preg_match_all($pattern, $subject, $matches);
print_r($matches);
?>

output:

Array
(
    [0] => Array
        (
            [0] => {token1}
            [1] => {token2}
        )

)

<?
preg_match_all($pattern, $string, $matches, PREG_SET_ORDER);
?>

E.g.

<?
preg_match_all('/([GH])([12])([!?])/', 'G1? H2!', $matches); // Default PREG_PATTERN_ORDER
// $matches = array(0 => array(0 => 'G1?', 1 => 'H2!'),
//                  1 => array(0 => 'G', 1 => 'H'),
//                  2 => array(0 => '1', 1 => '2'),
//                  3 => array(0 => '?', 1 => '!'))

preg_match_all('/([GH])([12])([!?])/', 'G1? H2!', $matches, PREG_SET_ORDER);
// $matches = array(0 => array(0 => 'G1?', 1 => 'G', 2 => '1', 3 => '?'),
//                  1 => array(0 => 'H2!', 1 => 'H', 2 => '2', 3 => '!'))
?>

<?php
function mime_extract_rfc2822_address($string)
{
        //rfc2822 token setup
        $crlf           = "(?:rn)";
        $wsp            = "[t ]";
        $text           = "[\x01-\x09\x0B\x0C\x0E-\x7F]";
        $quoted_pair    = "(?:\\$text)";
        $fws            = "(?:(?:$wsp*$crlf)?$wsp+)";
        $ctext          = "[\x01-\x08\x0B\x0C\x0E-\x1F" .
                          "!-'*-[\]-\x7F]";
        $comment        = "(\((?:$fws?(?:$ctext|$quoted_pair|(?1)))*" .
                          "$fws?\))";
        $cfws           = "(?:(?:$fws?$comment)*(?:(?:$fws?$comment)|$fws))";
        //$cfws           = $fws; //an alternative to comments
        $atext          = "[!#-'*+\-\/0-9=?A-Z\^-~]";
        $atom           = "(?:$cfws?$atext+$cfws?)";
        $dot_atom_text  = "(?:$atext+(?:\.$atext+)*)";
        $dot_atom       = "(?:$cfws?$dot_atom_text$cfws?)";
        $qtext          = "[\x01-\x08\x0B\x0C\x0E-\x1F!#-[\]-\x7F]";
        $qcontent       = "(?:$qtext|$quoted_pair)";
        $quoted_string  = "(?:$cfws?"(?:$fws?$qcontent)*$fws?"$cfws?)";
        $dtext          = "[\x01-\x08\x0B\x0C\x0E-\x1F!-Z\^-\x7F]";
        $dcontent       = "(?:$dtext|$quoted_pair)";
        $domain_literal = "(?:$cfws?\[(?:$fws?$dcontent)*$fws?]$cfws?)";
        $domain         = "(?:$dot_atom|$domain_literal)";
        $local_part     = "(?:$dot_atom|$quoted_string)";
        $addr_spec      = "($local_part@$domain)";
        $display_name   = "(?:(?:$atom|$quoted_string)+)";
        $angle_addr     = "(?:$cfws?<$addr_spec>$cfws?)";
        $name_addr      = "(?:$display_name?$angle_addr)";
        $mailbox        = "(?:$name_addr|$addr_spec)";
        $mailbox_list   = "(?:(?:(?:(?<=:)|,)$mailbox)+)";
        $group          = "(?:$display_name:(?:$mailbox_list|$cfws)?;$cfws?)";
        $address        = "(?:$mailbox|$group)";
        $address_list   = "(?:(?:^|,)$address)+";//output length of string (just so you see how f**king long it is)
        echo(strlen($address_list) . " ");//apply expression
        preg_match_all("/^$address_list$/", $string, $array, PREG_SET_ORDER);

        return

$array;
};
?>

$count = preg_match_all("/[[:print:]pL]/u", $str, $pockets);

where
[:print:] - printing characters, including space
pL - UTF-8 Letter
/u - UTF-8 string
other unicode character properties on http://www.pcre.org/pcre.txt

<?php
function decremente_chaine($chaine)
    {
        //récupérer toutes les occurrences de nombres et leurs indices
        preg_match_all("/[0-9]+/",$chaine,$out,PREG_OFFSET_CAPTURE);
            //parcourir les occurrences
            for($i=0;$i<sizeof($out[0]);$i++)
            {
                $longueurnombre = strlen((string)$out[0][$i][0]);
                $taillechaine = strlen($chaine);
                // découper la chaine en 3 morceaux
                $debut = substr($chaine,0,$out[0][$i][1]);
                $milieu = ($out[0][$i][0])-1;
                $fin = substr($chaine,$out[0][$i][1]+$longueurnombre,$taillechaine);
                 // si c'est 10,100,1000 etc. on décale tout de 1 car le résultat comporte un chiffre de moins
                 if(preg_match('#[1][0]+$#', $out[0][$i][0]))
                 {
                    for($j = $i+1;$j<sizeof($out[0]);$j++)
                    {
                        $out[0][$j][1] = $out[0][$j][1] -1;
                    }
                 }
                $chaine = $debut.$milieu.$fin;
            }
        return $chaine;
    }
?>

<?phpfunction mb_preg_match_all($ps_pattern, $ps_subject, &$pa_matches, $pn_flags = PREG_PATTERN_ORDER, $pn_offset = 0, $ps_encoding = NULL) {
  // WARNING! - All this function does is to correct offsets, nothing else:
  //
  if (is_null($ps_encoding))
    $ps_encoding = mb_internal_encoding();$pn_offset = strlen(mb_substr($ps_subject, 0, $pn_offset, $ps_encoding));
  $ret = preg_match_all($ps_pattern, $ps_subject, $pa_matches, $pn_flags, $pn_offset);

  if (

$ret && ($pn_flags & PREG_OFFSET_CAPTURE))
    foreach($pa_matches as &$ha_match)
      foreach($ha_match as &$ha_match)
        $ha_match[1] = mb_strlen(substr($ps_subject, 0, $ha_match[1]), $ps_encoding);
    //
    // (code is independent of PREG_PATTER_ORDER / PREG_SET_ORDER)return $ret;
  }?>

So, to be able to write hebrew in utf8 table you need to do
<?php
$prepared_text = addslashes(urf8_encode($text));
?>

But then I had to find if some word exists in stored text. This is the place I got stuck. Simple preg_match would not find text since hebrew doesnt work that easy. I've tried with /u and who kows what else.

Solution was somewhat logical and simple...
<?php
$db_text = bin2hex(stripslashes(utf8_decode($db_text)));
$word = bin2hex($word);$found = preg_match_all("/($word)+/i", $db_text, $matches);
?>

I've used preg_match_all since it returns number of occurences. So I could sort search results acording to that.

Hope someone finds this useful!

Essentially I just preg_match() unique nodes to find the values I am looking for, or I preg_match_all to find multiple nodes. This puts the results in an array and I can then process this data as I please.

I was unhappy though, that preg_match_all() stores the data twice (requiring twice the memory), one array for all the full pattern matches, and one array for all the sub pattern matches. You could probably write your own function that overcame this. But for now this works for me, and I hope it saves someone else some time as well.

// SAMPLE XML

<RETS ReplyCode="0" ReplyText="Operation Successful">

  <COUNT Records="14" />

  <DELIMITER value="09" />

  <COLUMNS>PropertyID</COLUMNS>

  <DATA>521897</DATA>

  <DATA>677208</DATA>

  <DATA>686037</DATA>

</RETS>

<?PHP
// SAMPLE FUNCTION

function parse_xml($xml) {
// GET DELIMITER (single instance)

    $match_res = preg_match('/<DELIMITER value ?= ?"(.*)" ?/>/', $xml, $matches);

    if(!empty($matches[1])) {

        $results["delimiter"] = chr($matches[1]);

    } else {

        // DEFAULT DELIMITER

        $results["delimiter"] = "t";

    }

    unset($match_res, $matches);
// GET MULTIPLE DATA NODES (multiple instances)

    $results["data_count"] = preg_match_all("/<DATA>(.*)</DATA>/", $xml, $matches);

    // GET MATCHES OF SUB PATTERN, DISCARD THE REST

    $results["data"]=$matches[1];

    unset($match_res, $matches);
// UNSET XML TO SAVE MEMORY (should unset outside the function as well)

    unset($xml);
// RETURN RESULTS ARRAY

    return $results;

   
   
}

?>

<?php

preg_match_all("/(?:^|(?<=&(?![a-z]+;)))([^=]+)=(.*?)(?:$|&(?![a-z]+;))/i",

  $s, $m, PREG_SET_ORDER );

?>

I am not sure how good it is, but it works.

It gets only the numbers 0-9, the "-", " ", "(", ")", "."

characters.. This is as far as I know the most widely used characters for a Phone number.

<?php

function clean_phone_number($phone) {

       if (!empty($phone)) {

               //var_dump($phone);

               preg_match_all('/[0-9()+.- ]/s', $phone, $cleaned);

               foreach($cleaned[0] as $k=>$v) {

                       $ready .= $v;

               }

               var_dump($ready);

               die;

               if (mb_strlen($cleaned) > 4 && mb_strlen($cleaned) <=25) {

                       return $cleaned;

               }

               else {

                       return false;

               }

       }

       return false;

}

?>

<?php

function turn_array($m)

{

    for ($z = 0;$z < count($m);$z++)

    {

        for ($x = 0;$x < count($m[$z]);$x++)

        {

            $rt[$x][$z] = $m[$z][$x];

        }

    }   

   
    return

$rt;

}

?>



Example - Take results of some preg_match_all query:

Array

(

    [0] => Array

        (

            [1] => Banff

            [2] => Canmore

            [3] => Invermere

        )

    [1] => Array

        (

            [1] => AB

            [2] => AB

            [3] => BC

        )

    [2] => Array

        (

            [1] => 51.1746254

            [2] => 51.0938416

            [3] => 50.5065193

        )

    [3] => Array

        (

            [1] => -115.5719757

            [2] => -115.3517761

            [3] => -116.0321884

        )

    [4] => Array

        (

            [1] => T1L 1B3

            [2] => T1W 1N2

            [3] => V0B 2G0

        )

)

Rotate it 90 degrees to group results as records:

Array

(

    [0] => Array

        (

            [1] => Banff

            [2] => AB

            [3] => 51.1746254

            [4] => -115.5719757

            [5] => T1L 1B3

        )

    [1] => Array

        (

            [1] => Canmore

            [2] => AB

            [3] => 51.0938416

            [4] => -115.3517761

            [5] => T1W 1N2

        )

    [2] => Array

        (

            [1] => Invermere

            [2] => BC

            [3] => 50.5065193

            [4] => -116.0321884

            [5] => V0B 2G0

        )

)

<?php
function getTagPositions($strBody)
{
    define(DEBUG, false);
    define(DEBUG_FILE_PREFIX, "/tmp/findlinks_");preg_match_all("/<[^>]+>(.*)</[^>]+>/U", $strBody, $strTag, PREG_PATTERN_ORDER);
    $intOffset = 0;
    $intIndex = 0;
    $intTagPositions = array();

    foreach(

$strTag[0] as $strFullTag) {
        if(DEBUG == true) {
            $fhDebug = fopen(DEBUG_FILE_PREFIX.time(), "a");
            fwrite($fhDebug, $fulltag."n");
            fwrite($fhDebug, "Starting position: ".strpos($strBody, $strFullTag, $intOffset)."n");
            fwrite($fhDebug, "Ending position: ".(strpos($strBody, $strFullTag, $intOffset) + strlen($strFullTag))."n");
            fwrite($fhDebug, "Length: ".strlen($strFullTag)."nn");
            fclose($fhDebug);
        }
        $intTagPositions[$intIndex] = array('start' => (strpos($strBody, $strFullTag, $intOffset)), 'end' => (strpos($strBody, $strFullTag, $intOffset) + strlen($strFullTag)));
        $intOffset += strlen($strFullTag);
        $intIndex++;
    }
    return $intTagPositions;
}$strBody = 'I have lots of <a href="http://my.site.com">links</a> on this <a href="http://my.site.com">page</a> that I want to <a href="http://my.site.com">find</a> the positions.';$strBody = strip_tags(html_entity_decode($strBody), '<a>');
$intTagPositions = getTagPositions($strBody);
print_r($intTagPositions);/*****
Output:

Array (
    [0] => Array (
        [start] => 15
        [end] => 53 )
    [1] => Array (
        [start] => 62
        [end] => 99 )
    [2] => Array (
        [start] => 115
        [end] => 152 )
)
*****/

?>

<?php
$pattern = '/{(?:[^{}]|(?R))*}/';preg_match_all($pattern, $buffer, $matches);
?>

if $buffer is 80+ KB in size, you'll end up with segfault!

[89396.588854] php[4384]: segfault at 7ffd6e2bdeb0 ip 00007fa20c8d67ed sp 00007ffd6e2bde70 error 6 in libpcre.so.3.13.1[7fa20c8c3000+3c000]

This is due to the PCRE recursion. This is a known bug in PHP since 2008, but it's source is not PHP itself but PCRE library.

Rasmus Lerdorf has the answer: https://bugs.php.net/bug.php?id=45735#1365812629

"The problem here is that there is no way to detect run-away regular expressions
here without huge performance and memory penalties. Yes, we could build PCRE in a
way that it wouldn't segfault and we could crank up the default backtrack limit
to something huge, but it would slow every regex call down by a lot. If PCRE
provided a way to handle this in a more graceful manner without the performance
hit we would of course use it."

<?php // returns: the array of matches
// null if the string is not a repetition of the pattern
// false on error
function preg_match_entire( string $pattern, string $subject, int $flags = 0 ){
  // Rebuild and wrap the pattern
  $delimiter = $pattern[0];
  $ldp       = strrpos( $pattern, $delimiter );
  $pattern   = substr( $pattern, 1, $ldp - 1 );
  $modifiers = substr( $pattern,    $ldp + 1 );
  $pattern   = "{$delimiter}   Gz (*MARK:END)   |   G (?:{$pattern})   {$delimiter}x{$modifiers}";
  $r = preg_match_all( $pattern, $subject, $m, PREG_SET_ORDER | $flags );
  if( $r === false )  return false;  // error
  $end = array_pop( $m );
  if( $end === null || ! isset( $end['MARK']) || $end['MARK'] !== 'END')
    return null;  // end of string not reached
  return $m;  // return actual matches, may be an empty array
}// Same results:
test('#{d+}#', '');              // []
test('#{d+}#', '{11}{22}{33}');  // {11},{22},{33}

// Different results: preg_match_entire won't match this:

test('#{d+}#', '{11}{}{aa}{22},{{33}}');
// preg_match_entire: null
// preg_match_all:    {11},{22},{33}function test( $pattern, $subject ){
  echo "pattern:           $patternn";
  echo "subject:           $subjectn";
  print_matches('preg_match_entire: ', preg_match_entire( $pattern, $subject ));
  preg_match_all( $pattern, $subject, $matches, PREG_SET_ORDER );
  print_matches('preg_match_all:    ', $matches );
  echo "n";
}
function print_matches( $t, $m ){
  echo $t, is_array( $m ) && $m ? implode(',', array_column( $m, 0 )) : json_encode( $m ), "n";
} ?>

function

next_format($str)
{
     $array=array("text-decoration-line"=>"underline","font-weight"=>"bold","font-style"=>"italic");
    foreach ($array as $key=>$val)
    {
          if($str[1]==$key && $str[2]==$val)
        {
              return $str[1].': '.$str[2].";";
        }
     }
          return '';

  }
function

next_span($matches)
{
  $needFormat=preg_replace_callback('/([a-z-]+):s*([^;]+)(;|)/ism',"next_format",$matches[2]);
  return $matches[1].$needFormat.$matches[3];

  }
echo

Because the first full match is 'ABC ' - containing the trailing space. And that space is not available for further processing.

Use lookbehind and lookahead to solve this problem: <?php preg_match_all('/(?<=^|s)(ABC|XYZ)(?=s|$)/i', 'ABC XYZ', $match)  ?>

That is to say, for example, if i get a DOM xpath object it appears like:

/ANODE/ANOTHERNODE/SOMENODE[9]/NODE[2]

and as a simplexml object would be equivalent to:

ANODE->ANOTHERNODE->SOMENODE[8]->NODE[1]

So u see what I mean? I used preg_match_all to solve that problem, and finally I got this after some hours of headlock (as I'm french the names of variables are in French sorry), hoping it could be useful to some of you:

<?php

function decrease_string($string)

    {

        /* retrieve all occurrences AND offsets of numbers in the original string: */
preg_match_all("/[0-9]+/",$chaine,$out,PREG_OFFSET_CAPTURE);

            for($i=0;$i<sizeof($out[0]);$i++)

            {

                $longueurnombre = strlen((string)$out[0][$i][0]);

                $taillechaine = strlen($chaine);

                // cut the string in 3 pieces

                $debut = substr($chaine,0,$out[0][$i][1]);

                $milieu = ($out[0][$i][0])-1;

                $fin = substr($chaine,$out[0][$i][1]+$longueurnombre,$taillechaine);

                 /* if it's 10,100,1000, the problem is that the string gets shorter and it shifts all the offsets, so we have to decrease them of 1 */

                 if(preg_match('#[1][0]+$#', $out[0][$i][0]))

                 {

                    for($j = $i+1;$j<sizeof($out[0]);$j++)

                    {

                        $out[0][$j][1] = $out[0][$j][1] -1;

                    }

                 }

                $chaine = $debut.$milieu.$fin;

            }

        return $chaine;

    }

?>

$html = preg_replace('"b(http://S+)"', '<a href="$1">$1</a>', $text);

If you use recursive PCRE (?R) you should remember to increase those two ini settings:

ini_set('pcre.backtrack_limit', 10000000);
ini_set('pcre.recursion_limit', 10000000);

But be warned: (from php.ini)

;Please note that if you set this value to a high number you may consume all
;the available process stack and eventually crash PHP (due to reaching the
;stack size limit imposed by the Operating System).

I have written this example mainly to demonstrate the power of PCRE LANGUAGE, not the power of it's implementation  :)

But if you like it, use it, of course on your own risk.

<?php
function reg_smart_replace($pattern, $replacement, $subject, $replacementChar = "$$$", $limit = -1)

{

    if (! $pattern || ! $subject || ! $replacement ) { return false; }
$replacementChar = preg_quote($replacementChar);
preg_match_all ( $pattern, $subject, $matches);

   
    if (

$limit > -1) {

        foreach ($matches as $count => $value )

        {

            if ($count + 1 > $limit ) { unset($matches[$count]); }

        }

    }

    foreach ($matches[0] as $match) {

        $rep = ereg_replace($replacementChar, $match, $replacement);

        $subject = ereg_replace($match, $rep, $subject);

    }

   
    return

$subject;

}

?>



This function can turn blocks of text into clickable links or whatever.  Example:

<?php

reg_smart_replace(EMAIL_REGEX, '<a href="mailto:$$$">$$$</a>', $description)

?>

will turn all email addresses into actual links.

Just substitute $$$ with the text that will be found by the regex.  If you can't use $$$ then use the 4th parameter $replacementChar

<?php
function custom_preg_match_all($pattern, $subject)
{
    $offset = 0;
    $match_count = 0;
    while(preg_match($pattern, $subject, $matches, PREG_OFFSET_CAPTURE, $offset))
    {
        // Increment counter
        $match_count++;// Get byte offset and byte length (assuming single byte encoded)
        $match_start = $matches[0][1];
        $match_length = strlen(matches[0][0]);// (Optional) Transform $matches to the format it is usually set as (without PREG_OFFSET_CAPTURE set)
        foreach($matches as $k => $match) $newmatches[$k] = $match[0];
        $matches = $new_matches;// Your code here
        echo "Match number $match_count, at byte offset $match_start, $match_length bytes long: ".$matches[0]."rn";// Update offset to the end of the match
        $offset = $match_start + $match_length;
    }

    return

$match_count;
}
?>

Note that the offsets returned are byte values (not necessarily number of characters) so you'll have to make sure the data is single-byte encoded. (Or have a look at paolo mosna's strByte function on the strlen manual page).
I'd be interested to know how this method performs speedwise against using preg_match_all and then recursing through the results.

<img src="./img.jpg" alt="nice picture" />foo foo foo foo </img>

correct me if i'm wrong.
i'll see when there's time to fix that. -.-

My problem was not double-escaping backslash characters:

<?php
// Input test
$input = ""something","something here","somennewnlines","this is the end"";// Work with online regexp testers, doesn't work in PHP
preg_match_all( "/(?:,|^)(?<!\)".*?(?<!\)"(?:(?=,)|$)/s", $input, $matches );/*
Outputs: NULL
*/

// Works with online regexp testers, does work in PHP

preg_match_all( "/(?:,|^)(?<!\\)".*?(?<!\\)"(?:(?=,)|$)/s", $input, $matches );/*
Outputs:
array(2) {
  [0]=>
  array(4) {
    [0]=>
    string(11) ""something""
    [1]=>
    string(17) ","something here""
    [2]=>
    string(17) ","some
new
lines""
    [3]=>
    string(18) ","this is the end""
  }
  [1]=>
  array(4) {
    [0]=>
    string(9) "something"
    [1]=>
    string(14) "something here"
    [2]=>
    string(14) "some
new
lines"
    [3]=>
    string(15) "this is the end"
  }
}
*/
?>

For example, the pattern:
'/<table>[sw/<>=\"]*</table>/'

Should be able to match:
<table>
<row>
<col align="left" valign="top">a</col>
<col align="right" valign="bottom">b</col>
</row>
</table>
.. with all there is under those table tags.

I'm not really sure why this is so, but I tried just the double quote and one or even two escape characters and it won't work. In my frustration I added another one and then it's cool.

function getMatches($pattern, $subject) {
    $matches = array();

    if (is_array($pattern)) {
        foreach ($pattern as $p) {
            $m = getMatches($p, $subject);

            foreach ($m as $key => $match) {
                if (isset($matches[$key])) {
                    $matches[$key] = array_merge($matches[$key], $m[$key]);   
                } else {
                    $matches[$key] = $m[$key];
                }
            }
        }
    } else {
        preg_match_all($pattern, $subject, $matches);
    }

    return $matches;
}

$patterns = array(
    '/<span>(.*?)</span>/',
    '/<a href=".*?">(.*?)</a>/'
);

$html = '<span>some text</span>';
$html .= '<span>some text in another span</span>';
$html .= '<a href="path/">here is the link</a>';
$html .= '<address>address is here</address>';
$html .= '<span>here is one more span</span>';

$matches = getMatches($patterns, $html);

print_r($matches); // result is below

/*
Array
(
    [0] => Array
        (
            [0] => <span>some text</span>
            [1] => <span>some text in another span</span>
            [2] => <span>here is one more span</span>
            [3] => <a href="path/">here is the link</a>
        )

    [1] => Array
        (
            [0] => some text
            [1] => some text in another span
            [2] => here is one more span
            [3] => here is the link
        )

)
*/

<?php

$csvData

= <<<EOF

10,'20',"30","'40","'50'",""60","70,80","09\/18,/"2011",'a,sdfcd'

EOF
$reg = <<<EOF

/

    (

        (

            (['"])

            (

               (

                [^'"]

                |

                (\\.)

               )*

            )

            (\3)

            |

            (

                [^,]

                |

                (\\.)

            )*

    ),)

    /x

EOF;
preg_match_all($reg,$csvData,$matches);
// to extract csv fields

print_r($matches[2]);

?>

<?php
$html = <<<EOT
some leftover text...
     < DIV class=noCompliant style = "text-align:left;" >
... and some other ...
< dIv > < empty>  </ empty>
  <p> This is yet another text <br  >
     that wasn't <b>compliant</b> too... <br   />
     </p>
<div class="noClass" > this one is better but we don't care anyway </div ><P>
    <input   type= "text"  name ='my "name' value  = "nothin really." readonly>
end of paragraph </p> </Div>   </div>   some trailing text
EOT;$a = html2a($html);
//now we will make some neat html out of it
echo a2html($a);

function

a2html ( $a, $in = "" ) {
  if ( is_array($a) ) {
    $s = "";
    foreach ($a as $t)
      if ( is_array($t) ) {
        $attrs="";
        if ( isset($t['attr']) )
          foreach( $t['attr'] as $k => $v )
            $attrs.=" ${k}=".( strpos( $v, '"' )!==false ? "'$v'" : ""$v"" );
        $s.= $in."<".$t['tag'].$attrs.( isset( $t['val'] ) ? ">n".a2html( $t['val'], $in."  " ).$in."</".$t['tag'] : "/" ).">n";
      } else
        $s.= $in.$t."n";
  } else {
    $s = empty($a) ? "" : $in.$a."n";
  }
  return $s;
}
?>
This produces:
some leftover text...
<div class="noCompliant" style="text-align:left;">
  ... and some other ...
  <div>
    <empty>
    </empty>
    <p>
      This is yet another text
      <br/>
      that wasn't
      <b>
        compliant
      </b>
      too...
      <br/>
    </p>
    <div class="noClass">
      this one is better but we don't care anyway
    </div>
    <p>
      <input type="text" name='my "name' value="nothin really." readonly="readonly"/>
      end of paragraph
    </p>
  </div>
</div>
some trailing text