preg_match_all

(PHP 4, PHP 5, PHP 7, PHP 8)

preg_match_allExpression rationnelle globale

Description

preg_match_all(
    string $pattern,
    string $subject,
    array &$matches = null,
    int $flags = 0,
    int $offset = 0
): int|false

Analyse subject pour trouver l'expression pattern et met les résultats dans matches, dans l'ordre spécifié par flags.

Après avoir trouvé un premier résultat, la recherche continue jusqu'à la fin de la chaîne.

Liste de paramètres

pattern

Le masque à chercher, sous la forme d'une chaîne de caractères.

subject

La chaîne d'entrée.

matches

Tableau contenant tous les résultats, dans un tableau multidimensionnel ordonné suivant le paramètre flags.

flags

Peut prendre une des deux valeurs suivantes (notez bien qu'il est incohérent d'utiliser PREG_PATTERN_ORDER avec PREG_SET_ORDER ) :

PREG_PATTERN_ORDER

L'ordre est tel que $matches[0] est un tableau qui contient les résultats qui satisfont le masque complet, $matches[1] est un tableau qui contient les résultats qui satisfont la première parenthèse capturante, etc.

<?php
preg_match_all
("|<[^>]+>(.*)</[^>]+>|U",
"<b>exemple : </b><div align=left>ceci est un test</div>",
$out, PREG_PATTERN_ORDER);
echo
$out[0][0] . ", " . $out[0][1] . "\n";
echo
$out[1][0] . ", " . $out[1][1] . "\n";
?>

L'exemple ci-dessus va afficher :

<b>exemple : </b>, <div align=left>ceci est un test</div>
exemple : , ceci est un test

Ainsi, $out[0] est un tableau qui contient les résultats qui satisfont le masque complet, et $out[1] est un tableau qui contient les balises entre > et <.

Si le masque contient des sous-masque nommés, $matches contiendra en plus des entrées qui auront pour clés les noms des sous-masques.

Si le masque contient des sous-masques nommés en double, seul le sous-masque le plus à droite sera enregistré dans $matches[NAME].

<?php
preg_match_all
(
'/(?J)(?<match>foo)|(?<match>bar)/',
'foo bar',
$matches,
PREG_PATTERN_ORDER
);
print_r($matches['match']);
?>

L'exemple ci-dessus va afficher :

Array
(
    [0] => 
    [1] => bar
)

PREG_SET_ORDER

Les résultats sont classés de telle façon que $matches[0] contient la première série de résultats, $matches[1] contient la deuxième, etc.

<?php
preg_match_all
("|<[^>]+>(.*)</[^>]+>|U",
"<b>exemple : </b><div align=\"left\">ceci est un test</div>",
$out, PREG_SET_ORDER);
echo
$out[0][0] . ", " . $out[0][1] . "\n";
echo
$out[1][0] . ", " . $out[1][1] . "\n";
?>

L'exemple ci-dessus va afficher :

<b>exemple : </b>, exemple :
<div align="left">ceci est un test</div>, ceci est un test

PREG_OFFSET_CAPTURE

Si ce drapeau est passé, toutes les sous-chaînes qui satisfont le masque seront aussi identifiées par leur offset (en octets). Notez que cela modifie la valeur de matches en un tableau de tableau où chaque élément est un tableau contenant la sous-chaîne satisfaite à l'index 0 et l'index de celle-ci dans la chaîne subject à l'index 1.

<?php
preg_match_all
('/(foo)(bar)(baz)/', 'foobarbaz', $matches, PREG_OFFSET_CAPTURE);
print_r($matches);
?>

L'exemple ci-dessus va afficher :

Array
(
    [0] => Array
        (
            [0] => Array
                (
                    [0] => foobarbaz
                    [1] => 0
                )

        )

    [1] => Array
        (
            [0] => Array
                (
                    [0] => foo
                    [1] => 0
                )

        )

    [2] => Array
        (
            [0] => Array
                (
                    [0] => bar
                    [1] => 3
                )

        )

    [3] => Array
        (
            [0] => Array
                (
                    [0] => baz
                    [1] => 6
                )

        )

)

PREG_UNMATCHED_AS_NULL

Si ce drapeau est passé, les sous-masques non satisfait sont rapportés en tant que null ; sinon ils sont rapportés en tant que chaîne de caractères vide.

Si order est omis, PREG_PATTERN_ORDER est utilisé par défaut.

offset

Normalement, la recherche commence au début de la chaîne subject. Le paramètre optionnel offset peut être utilisé pour spécifier une position pour le début de la recherche (en octets).

Note:

Utiliser le paramètre offset ne revient pas à passer substr($subject, $offset) à preg_match_all() à la place de la chaîne subject, car pattern peut contenir des assertions comme ^, $ ou (?<=x). Lisez la documentation sur la fonction preg_match() pour des exemples.

Valeurs de retour

Retourne le nombre de résultats qui satisfont le masque complet, ou false si une erreur survient.

Erreurs / Exceptions

Si le masque regex passé ne compile pas à une regex valide, une E_WARNING est émise.

Historique

Version Description
7.2.0 PREG_UNMATCHED_AS_NULL est maintenant supporté pour le paramètre $flags.

Exemples

Exemple #1 Extraction de tous les numéros de téléphone d'un texte

<?php
preg_match_all
("/\(? (\d{3})? \)? (?(1) [\-\s] ) \d{3}-\d{4}/x",
"Call 555-1212 or 1-800-555-1212", $phones);
?>

Exemple #2 Recherche les couples de balises HTML (gourmand)

<?php
// Cet exemple utilise les références arrières (\\2).
// Elles indiquent à l'analyseur qu'il doit trouver quelque chose qu'il
// a déjà repéré un peu plus tôt
// le nombre 2 indique que c'est le deuxième jeu de parenthèses
// capturante qui doit être utilisé (ici, ([\w]+)).
// L'antislash est nécessaire ici, car la chaîne est entre guillemets doubles

$html = "<b>texte en gras</b><a href=howdy.html>cliquez moi</a>";

preg_match_all("/(<([\w]+)[^>]*>)(.*?)(<\/\\2>)/", $html, $matches, PREG_SET_ORDER);

foreach (
$matches as $val) {
echo
"matched: " . $val[0] . "\n";
echo
"part 1: " . $val[1] . "\n";
echo
"part 2: " . $val[2] . "\n";
echo
"part 3: " . $val[3] . "\n";
echo
"part 4: " . $val[4] . "\n\n";
}
?>

L'exemple ci-dessus va afficher :

matched: <b>texte en gras</b>
part 2: b
part 3: texte en gras
part 4: </b>

matched: <a href=howdy.html>cliquez moi</a>
part 1: <a href=howdy.html>
part 2: a
part 3: cliquez moi
part 4: </a>

Exemple #3 Utilisation d'un sous-masque nommé

<?php

$str
= <<<FOO
a: 1
b: 2
c: 3
FOO;

preg_match_all('/(?P<name>\w+): (?P<digit>\d+)/', $str, $matches);

/* Alternative */
// preg_match_all('/(?<name>\w+): (?<digit>\d+)/', $str, $matches);

print_r($matches);

?>

L'exemple ci-dessus va afficher :

Array
(
    [0] => Array
        (
            [0] => a: 1
            [1] => b: 2
            [2] => c: 3
        )

    [name] => Array
        (
            [0] => a
            [1] => b
            [2] => c
        )

    [1] => Array
        (
            [0] => a
            [1] => b
            [2] => c
        )

    [digit] => Array
        (
            [0] => 1
            [1] => 2
            [2] => 3
        )

    [2] => Array
        (
            [0] => 1
            [1] => 2
            [2] => 3
        )

)

Voir aussi

  • Masques PCRE
  • preg_quote() - Protection des caractères spéciaux des expressions régulières
  • preg_match() - Effectue une recherche de correspondance avec une expression rationnelle standard
  • preg_replace() - Rechercher et remplacer par expression rationnelle standard
  • preg_split() - Éclate une chaîne par expression rationnelle
  • preg_last_error() - Retourne le code erreur de la dernière expression PCRE exécutée

add a note add a note

User Contributed Notes 33 notes

up
14
buuh
13 years ago
if you want to extract all {token}s from a string:

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

output:

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

)
up
12
Daniel Klein
8 years ago
The code that john at mccarthy dot net posted is not necessary. If you want your results grouped by individual match simply use:

<?
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 => '!'))
?>
up
8
phpnet at sinful-music dot com
18 years ago
Here's some fleecy code to 1. validate RCF2822 conformity of address lists and 2. to extract the address specification (the part commonly known as 'email'). I wouldn't suggest using it for input form email checking, but it might be just what you want for other email applications. I know it can be optimized further, but that part I'll leave up to you nutcrackers. The total length of the resulting Regex is about 30000 bytes. That because it accepts comments. You can remove that by setting $cfws to $fws and it shrinks to about 6000 bytes. Conformity checking is absolutely and strictly referring to RFC2822. Have fun and email me if you have any enhancements!

<?php
function mime_extract_rfc2822_address($string)
{
       
//rfc2822 token setup
       
$crlf           = "(?:\r\n)";
       
$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;
};
?>
up
8
mnc at u dot nu
18 years ago
PREG_OFFSET_CAPTURE always seems to provide byte offsets, rather than character position offsets, even when you are using the unicode /u modifier.
up
6
chuckie
17 years ago
This is a function to convert byte offsets into (UTF-8) character offsets (this is reagardless of whether you use /u modifier:

<?php

function 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;
  }

?>
up
7
fab
11 years ago
Here is a function that replaces all occurrences of a number in a string by the number--

<?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;
    }
?>
up
4
sledge NOSPAM
15 years ago
Perhaps you want to find the positions of all anchor tags.  This will return a two dimensional array of which the starting and ending positions will be returned.

<?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)."\n\n");
           
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 )
)
*****/
?>
up
4
stas kuryan aka stafox
8 years ago
Here is a awesome online regex editor https://regex101.com/
which helps you test your regular expressions (prce, js, python) with real-time highlighting of regex match on data input.
up
2
spambegone at cratemedia dot com
15 years ago
I found simpleXML to be useful only in cases where the XML was extremely small, otherwise the server would run out of memory (I suspect there is a memory leak or something?). So while searching for alternative parsers, I decided to try a simpler approach. I don't know how this compares with cpu usage, but I know it works with large XML structures. This is more a manual method, but it works for me since I always know what structure of data I will be receiving.

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;
   
   
}

?>
up
3
meaneye at mail dot com
15 years ago
Recently I had to write search engine in hebrew and ran into huge amount of problems. My data was stored in MySQL table with utf8_bin encoding.

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!
up
2
no at bo dot dy
13 years ago
For parsing queries with entities use:

<?php
preg_match_all
("/(?:^|(?<=\&(?![a-z]+\;)))([^\=]+)=(.*?)(?:$|\&(?![a-z]+\;))/i",
 
$s, $m, PREG_SET_ORDER );
?>
up
3
stamster at gmail dot com
8 years ago
Be careful with this pattern match and large input buffer on preg_match_* functions.

<?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."
up
2
bruha
16 years ago
To count str_length in UTF-8 string i use

$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
up
4
john at mccarthy dot net
13 years ago
I needed a function to rotate the results of a preg_match_all query, and made this. Not sure if it exists.

<?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
        )
)
up
2
ad
14 years ago
i have made up a simple function to extract a number from a string..

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;
}
?>
up
1
marc
11 years ago
Better use preg_replace to convert text in a clickable link with tag <a>

$html = preg_replace('"\b(http://\S+)"', '<a href="$1">$1</a>', $text);
up
1
phektus at gmail dot com
16 years ago
If you'd like to include DOUBLE QUOTES on a regular expression for use with preg_match_all, try ESCAPING THRICE, as in: \\\"

For example, the pattern:
'/<table>[\s\w\/<>=\\\"]*<\/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.
up
1
qdinar at gmail dot com
5 years ago
when regex is for longer and shorter version of a string,
only one of that long and short versions is catched.
when regex match occurs in one position of string,
only one match is saved in matches[0] for that position.
if ? is used, regex is greedy, and catches more long version,
if | is used, most first matching variant is catched:
<?php
preg_match_all
('/ab|abc/','abc',$m);
var_dump($m);
preg_match_all('/abc?/','abc',$m);
var_dump($m);
?>
['ab', 'abc'] in $m[0] for both can be expected, but it is not so,
actually they output [['ab']] and [['abc']]:
array(1) {
  [0]=>
  array(1) {
    [0]=>
    string(2) "ab"
  }
}
array(1) {
  [0]=>
  array(1) {
    [0]=>
    string(3) "abc"
  }
}
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0
mojo
2 years ago
Why <?php preg_match_all('/(?:^|\s)(ABC|XYZ)(?:\s|$)/i', 'ABC  XYZ', $match) ?> finds only 'ABC'?

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?>
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0
chris at ocproducts dot com
3 years ago
If PREG_OFFSET_CAPTURE is set then unmatched captures (i.e. ones with '?') will not be present in the result array. This is presumably because there is no offset, and thus the original PHP dev decided best to just leave it out.
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0
matt at lvl99 dot com
8 years ago
I had been crafting and testing some regexp patterns online using the tools Regex101 and a `preg_match_all()` tester and found that the regexp patterns I wrote worked fine on them, just not in my code.

My problem was not double-escaping backslash characters:

<?php
// Input test
$input = "\"something\",\"something here\",\"some\nnew\nlines\",\"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"
  }
}
*/
?>
up
0
ajeet dot nigam at icfaitechweb dot com
10 years ago
Here http://tryphpregex.com/ is a  php based online regex editor which helps you test your regular expressions with real-time highlighting of regex match on data input.
up
0
fseverin at free dot fr
11 years ago
As I intended to create for my own purpose a clean PHP class to act on XML files, combining the use of DOM and simplexml functions, I had that small problem, but very annoying, that the offsets in a path is not numbered the same in both.

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;
    }
?>
up
0
royaltm75 at gmail dot com
14 years ago
I have received complains, that my html2a() code (see below) doesn't work in some cases.
It is however not the problem with algorithm or procedure, but with PCRE recursive stack limits.

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.
up
0
elyknosrac at gmail dot com
14 years ago
Using preg_match_all I made a pretty handy function.

<?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
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0
royaltm75 at NOSPAM dot gmail dot com
15 years ago
The power of pregs is limited only by your *imagination* :)
I wrote this html2a() function using preg recursive match (?R) which provides quite safe and bulletproof html/xml extraction:
<?php
function html2a ( $html ) {
  if ( !
preg_match_all( '
@
\<\s*?(\w+)((?:\b(?:\'[^\']*\'|"[^"]*"|[^\>])*)?)\>
((?:(?>[^\<]*)|(?R))*)
\<\/\s*?\\1(?:\b[^\>]*)?\>
|\<\s*(\w+)(\b(?:\'[^\']*\'|"[^"]*"|[^\>])*)?\/?\>
@uxis'
, $html = trim($html), $m, PREG_OFFSET_CAPTURE | PREG_SET_ORDER) )
    return
$html;
 
$i = 0;
 
$ret = array();
  foreach (
$m as $set) {
    if (
strlen( $val = trim( substr($html, $i, $set[0][1] - $i) ) ) )
     
$ret[] = $val;
   
$val = $set[1][1] < 0
     
? array( 'tag' => strtolower($set[4][0]) )
      : array(
'tag' => strtolower($set[1][0]), 'val' => html2a($set[3][0]) );
    if (
preg_match_all( '
/(\w+)\s*(?:=\s*(?:"([^"]*)"|\'([^\']*)\'|(\w+)))?/usix
'
, isset($set[5]) && $set[2][1] < 0
 
? $set[5][0]
  :
$set[2][0]
  ,
$attrs, PREG_SET_ORDER ) ) {
      foreach (
$attrs as $a) {
       
$val['attr'][$a[1]]=$a[count($a)-1];
      }
    }
   
$ret[] = $val;
   
$i = $set[0][1]+strlen( $set[0][0] );
  }
 
$l = strlen($html);
  if (
$i < $l )
    if (
strlen( $val = trim( substr( $html, $i, $l - $i ) ) ) )
     
$ret[] = $val;
  return
$ret;
}
?>

Now let's try it with this example: (there are some really nasty xhtml compliant bugs, but ... we shouldn't worry)

<?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
up
0
MonkeyMan
15 years ago
Here is a way to match everything on the page, performing an action for each match as you go. I had used this idiom in other languages, where its use is customary, but in PHP it seems to be not quite as common.

<?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]."\r\n";
           
       
// 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.
up
0
dolbegraeb
16 years ago
please note, that the function of "mail at SPAMBUSTER at milianw dot de" can result in invalid xhtml in some cases. think i used it in the right way but my result is sth like this:

<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. -.-
up
-1
satyavvd at ymail dot com
12 years ago
Extract fields out of csv string : ( since before php5.3 you can't use str_getcsv function )
Here is the regex :

<?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]);
?>
up
-1
mr davin
16 years ago
<?php
// Returns an array of strings where the start and end are found
   
function findinside($start, $end, $string) {
       
preg_match_all('/' . preg_quote($start, '/') . '([^\.)]+)'. preg_quote($end, '/').'/i', $string, $m);
        return
$m[1];
    }
   
   
$start = "mary has";
   
$end = "lambs.";
   
$string = "mary has 6 lambs. phil has 13 lambs. mary stole phil's lambs. now mary has all the lambs.";

   
$out = findinside($start, $end, $string);

   
print_r ($out);

/* Results in
(
    [0] =>  6
    [1] =>  all the
)
*/
?>
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-2
vojjov dot artem at ya dot ru
8 years ago
// Here is function that allows you to preg_match_all array of patters

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
        )

)
*/
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-2
DarkSide
9 years ago
This is very useful to combine matches:
$a = array_combine($matches[1], $matches[2]);
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-5
avengis at gmail dot com
14 years ago
The next function works with almost any complex xml/xhtml string

<?php
/**
* Find and close unclosed xml tags
**/
function close_tags($text) {
   
$patt_open    = "%((?<!</)(?<=<)[\s]*[^/!>\s]+(?=>|[\s]+[^>]*[^/]>)(?!/>))%";
   
$patt_close    = "%((?<=</)([^>]+)(?=>))%";
    if (
preg_match_all($patt_open,$text,$matches))
    {
       
$m_open = $matches[1];
        if(!empty(
$m_open))
        {
           
preg_match_all($patt_close,$text,$matches2);
           
$m_close = $matches2[1];
            if (
count($m_open) > count($m_close))
            {
               
$m_open = array_reverse($m_open);
                foreach (
$m_close as $tag) $c_tags[$tag]++;
                foreach (
$m_open as $k => $tag)    if ($c_tags[$tag]--<=0) $text.='</'.$tag.'>';
            }
        }
    }
    return
$text;
}
?>
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