Regex/ code to fix corrupt serialized PHP data.

Question

I have a massive multidimensional array that has been serialised by PHP. It has been stored in MySQL and the data field wasn\'t large enough... the end has been cut off... I

Answer 1

Serializing is almost always bad because you can't search it in any way. Sorry, but it seems as though you're backed into a corner...

Answer 2

Best Solution for me:

$output_array = unserialize(My_checker($serialized_string));

code:

function My_checker($serialized_string){
    // securities
    if (empty($serialized_string))                      return '';
    if ( !preg_match('/^[aOs]:/', $serialized_string) ) return $serialized_string;
    if ( @unserialize($serialized_string) !== false ) return $serialized_string;

    return
    preg_replace_callback(
        '/s\:(\d+)\:\"(.*?)\";/s', 
        function ($matches){  return 's:'.strlen($matches[2]).':"'.$matches[2].'";';  },
        $serialized_string )
    ;
}

Answer 3

Based on @Emil M Answer Here is a fixed version that works with text containing double quotes .

function fix_broken_serialized_array($match) {
    return "s:".strlen($match[2]).":\"".$match[2]."\";"; 
}
$fixed = preg_replace_callback(
    '/s:([0-9]+):"(.*?)";/',
    "fix_broken_serialized_array",
    $serialized
);

Answer 4

This is recalculating the length of the elements in a serialized array:

$fixed = preg_replace_callback(
    '/s:([0-9]+):\"(.*?)\";/',
    function ($matches) { return "s:".strlen($matches[2]).':"'.$matches[2].'";';     },
    $serialized
);

However, it doesn't work if your strings contain ";. In that case it's not possible to fix the serialized array string automatically -- manual editing will be needed.

Answer 5

I have tried everything found in this post and nothing worked for me. After hours of pain here's what I found in the deep pages of google and finally worked:

function fix_str_length($matches) {
    $string = $matches[2];
    $right_length = strlen($string); // yes, strlen even for UTF-8 characters, PHP wants the mem size, not the char count
    return 's:' . $right_length . ':"' . $string . '";';
}
function fix_serialized($string) {
    // securities
    if ( !preg_match('/^[aOs]:/', $string) ) return $string;
    if ( @unserialize($string) !== false ) return $string;
    $string = preg_replace("%\n%", "", $string);
    // doublequote exploding
    $data = preg_replace('%";%', "µµµ", $string);
    $tab = explode("µµµ", $data);
    $new_data = '';
    foreach ($tab as $line) {
        $new_data .= preg_replace_callback('%\bs:(\d+):"(.*)%', 'fix_str_length', $line);
    }
    return $new_data;
}

You call the routine as follows:

//Let's consider we store the serialization inside a txt file
$corruptedSerialization = file_get_contents('corruptedSerialization.txt');

//Try to unserialize original string
$unSerialized = unserialize($corruptedSerialization);

//In case of failure let's try to repair it
if(!$unSerialized){
    $repairedSerialization = fix_serialized($corruptedSerialization);
    $unSerialized = unserialize($repairedSerialization);
}

//Keep your fingers crossed
var_dump($unSerialized);

Answer 6

I doubt anyone would write code to retrieve partially saved arrays:) I fixed a thing like this once but by hand and it took hours, and then i realized i don't need that part of the array...

Unless its really important data(and i mean REALLY important) you'd be better to leave this one go