unserialize

suman dot jis at gmail dot com (2012-03-13 09:12:16)

I was getting unserialize() Error at offset error.
If you face similar problem then use the following procedure
$auctionDetails = preg_replace('!s:(\d+):"(.*?)";!se', "'s:'.strlen('$2').':\"$2\";'", $dataArr[$i]['auction_details'] );
$auctionDetails = unserialize($auctionDetails);

frank at interactinet dot com (2011-08-30 09:32:54)

When dealing with sessions, try session_decode($data) instead of unserialize($data).

walf (2011-08-22 20:22:18)

a replacement for unserialize that returns whether it worked and populates the unserialized variable by reference:
<?php
function funserialize($serialized, &$into) {
    static $sfalse;
    if ($sfalse === null)
        $sfalse = serialize(false);
    $into = @unserialize($serialized);
    return $into !== false || rtrim($serialized) === $sfalse;//whitespace at end of serialized var is ignored by PHP
}

$s_foo = 'b:0;';
var_dump(funserialize($s_foo, $foo), $foo);

$s_bar = 'bar';
var_dump(funserialize($s_bar, $bar), $bar);

$s_foo = 'a:0:{};';
var_dump(funserialize($s_foo, $foo), $foo);

?>
gives:

bool(true)
bool(false)

bool(false)
bool(false)

bool(true)
array(0) {
}

MBa (2011-08-02 03:49:03)

To check if a string is serialized:
$blSerialized=(@unserialize($sText)||$sText=='b:0;');

chris at colourlovers dot com (2011-06-16 17:31:55)

Anyone having trouble serializing data with SimpleXMLElement objects stored within it, check this out:

This will traverse $data looking for any children which are instances of SimpleXMLElement, and will run ->asXML() on them, turning them into a string and making them serializable. Other data will be left alone.

<?php
function exportNestedSimpleXML($data) {
    if (is_scalar($data) === false) {
        foreach ($data as $k => $v) {
            if ($v instanceof SimpleXMLElement) {
                $v = str_replace("&#13;","\r",$v->asXML());
            } else {
                $v = exportNestedSimpleXML($v);
            }

            if (is_array($data)) {
                $data[$k] = $v;
            } else if (is_object($data)) {
                $data->$k = $v;
            }
        }
    }

    return $data;
}

$data = array (
    "baz" => array (
        "foo" => new stdClass(),
        "int" => 123,
        "str" => "asdf",
        "bar" => new SimpleXMLElement('<?xml version="1.0" encoding="UTF-8"?><foo>bar</foo>'),
    )
);

var_dump($data);
/*array(1) {
  ["baz"]=>
  array(4) {
    ["foo"]=>
    object(stdClass)#3 (0) {
    }
    ["int"]=>
    int(123)
    ["str"]=>
    string(4) "asdf"
    ["bar"]=>
    object(SimpleXMLElement)#4 (1) {
      [0]=>
      string(3) "bar"
    }
  }
}*/

var_dump(exportNestedSimpleXML($data));
/*array(1) {
  ["baz"]=>
  array(4) {
    ["foo"]=>
    object(stdClass)#3 (0) {
    }
    ["int"]=>
    int(123)
    ["str"]=>
    string(4) "asdf"
    ["bar"]=>
    string(54) "<?xml version="1.0" encoding="UTF-8"?>
<foo>bar</foo>
"
  }
}
*/
?>

daniel at fourstaples dot com (2010-03-23 20:46:26)

Here's a simple function to get the class of a serialized string (that is, the type of object that will be returned if it's unserialized):

<?php
function get_serial_class($serial) {
    $types = array('s' => 'string', 'a' => 'array', 'b' => 'bool', 'i' => 'int', 'd' => 'float', 'N;' => 'NULL');
    
    $parts = explode(':', $serial, 4);
    return isset($types[$parts[0]]) ? $types[$parts[0]] : trim($parts[2], '"'); 
}
?>

I use this when saving a serialized object to a cookie, to make sure it is the right type when I go to unserialize it.

The type names are the same format/case as you would see if you did a var_dump().

Fagzal (2010-03-09 10:10:29)

To all who have problem with quoting and slashes when storing serialized data in MySQL: you are probably doing it wrong.
Use e.g. PDO with placeholders and the blob column type, and it will Just Work.

matty dot burke75 at gmail dot com (2009-09-21 03:18:16)

I've been having horrendous problems getting my saved to mysql serialized data to unserialize. All I got back was false.

However, one handy tip saved the day.

<?php
//to safely serialize
$safe_string_to_store = base64_encode(serialize($multidimensional_array));

//to unserialize...
$array_restored_from_db = unserialize(base64_decode($encoded_serialized_string));
?>

arbie samong (2009-09-10 07:42:15)

__PHP_Incomplete_Class Object Demystified

1. First take note of the output. A simple example:

__PHP_Incomplete_Class Object (
[__PHP_Incomplete_Class_Name] => SomeObject1
[obj1property1] => somevalue1 [obj1property2] => __PHP_Incomplete_Class Object ( [__PHP_Incomplete_Class_Name] => SomeObject2 [obj2property1] => somevalue1 [obj2property2] => Array (
['key1'] => somevalue3, ['key2'] => somevalue4 ) ) )

2. We analyze this and break it down. 
__PHP_Incomplete_Class Object tells you there is an object that needs to be declared somehow. 
__PHP_Incomplete_Class_Name simply tells you the expected class name. It is just one of the properties for now.

So we have:
a) an unknown object that has a class name SomeObject1 (first class)
b) it has 2 properties, namely obj1property1 and obj2property2
c) obj2property2 is itself an object whose class name is SomeObject2 (the second class)
d) SomeObject2 has two properties, obj2property1 and obj2property2
e) obj2property2 is an array that contains two elements

3. Now that we have an idea of the structure, we shall create class definitions based from it. We will just create properties for now, methods are not required as a minimum.

<?php
class SomeObject1 {
        public $obj1property1;
        public $obj1property2;
}
class SomeObject2 {
        public $obj2property1;
        public $obj2property2;
}
?>

4. Have that accessible to your script and it will solve the __PHP_Incomplete_Class Object problem as far as the output is concerned. Now you will have:

SomeObject1 ( [obj1property1] => somevalue1 [obj1property2] => SomeObject2 ( [obj2property1] => somevalue1 [obj2property2] => Array ( ['key1'] => somevalue3, ['key2'] => somevalue4 ) ) )

As you will notice, __PHP_Incomplete_Class Object is gone and replaced by the class name. The property __PHP_Incomplete_Class_Name is also removed.

5. As for the array property obj2property2, we can directly access that and just assume that it is an array and loop through it:

<?php

// this will be SomeObject1 
$data = unserialize($serialized_data);

// this will be SomeObject2
$data2 = $data->obj1property2();

foreach($data2->obj2property2 as $key => $value):
         print $key.' : '. $value .'<br>'; 
endforeach;

?>

Outputs:
key1 : somevalue3
key2 : somevalue4

That's it. You can add more methods on the class declarations for the given properties, provided you keep your original output as basis for the data types.

w dot laurencine at teknoa dot net (2009-04-07 05:54:42)

When dealing with a string which contain "\r", it seems that the length is not evaluated correctly. The following solves the problem for me :

<?php
// remove the \r caracters from the $unserialized string
$unserialized = str_replace("\r","",$unserialized);

// and then unserialize()
unserialize($unserialized);
?>

chris AT cmbuckley DOT co DOT uk (2008-08-14 06:47:33)

As mentioned in the notes, unserialize returns false in the event of an error and for boolean false. Here is the first solution mentioned, without using error handling:

<?php
function isSerialized($str) {
    return ($str == serialize(false) || @unserialize($str) !== false);
}

var_dump(isSerialized('s:6:"foobar";')); // bool(true)
var_dump(isSerialized('foobar'));        // bool(false)
var_dump(isSerialized('b:0;'));          // bool(true)
?>

jsa1971 at gmail dot com (2007-09-14 07:41:32)

Ignore all the advice to implement __autoload-ers or magical handlers, to solve problems when retrieving class instances from sessions. It leads to terrible debugging nightmares.
After fussing with all sorts of such solutions and getting nowhere, I\'ve found a very simple solution that works correctly and explicitly:
$_SESSION[\'myInstance\'] = serialize($myInstance);
....
$myInstance_s = @$_SESSION[\'myInstance\']
if (!is_null($myInstance_s)) {
$myInstance = unserialize($myInstance_s);
}
In other words, serialize the thing as a string, and put it in the session in this state - you regain control of the unserialization process and can code to handle exception cases rather than praying php\'s black magic does the right thing (and being sorely disappointed when it doesn\'t).

Ates Goral (2007-05-04 11:02:29)

If instead of using JSON, you'd like to stick with PHP-style serialization, here's some JavaScript code I posted at http://magnetiq.com for serializing JavaScript objects in PHP fashion:
/* Returns the class name of the argument or undefined if
it's not a valid JavaScript object.
*/
function getObjectClass(obj)
{
if (obj && obj.constructor && obj.constructor.toString)
{
var arr = obj.constructor.toString().match(
/function\s*(\w+)/);
if (arr && arr.length == 2)
{
return arr[1];
}
}
return undefined;
}
/* Serializes the given argument, PHP-style.
The type mapping is as follows:
JavaScript Type PHP Type
--------------- --------
Number Integer or Decimal
String String
Boolean Boolean
Array Array
Object Object
undefined Null
The special JavaScript object null also becomes PHP Null.
This function may not handle associative arrays or array
objects with additional properties well.
*/
function phpSerialize(val)
{
switch (typeof(val))
{
case "number":
return (Math.floor(val) == val ? "i" : "d") + ":" +
val + ";";
case "string":
return "s:" + val.length + ":\"" + val + "\";";
case "boolean":
return "b:" + (val ? "1" : "0") + ";";
case "object":
if (val == null)
{
return "N;";
}
else if ("length" in val)
{
var idxobj = { idx: -1 };
return "a:" + val.length + ":{" + val.map(
function (item)
{
this.idx++;
var ser = phpSerialize(item);
return ser ?
phpSerialize(this.idx) + ser :
false;
}, idxobj).filter(
function (item)
{
return item;
}).join("") + "}";
}
else
{
var class_name = getObjectClass(val);
if (class_name == undefined)
{
return false;
}
var props = new Array();
for (var prop in val)
{
var ser = phpSerialize(val[prop]);
if (ser)
{
props.push(phpSerialize(prop) + ser);
}
}
return "O:" + class_name.length + ":\"" +
class_name + "\":" + props.length + ":{" +
props.join("") + "}";
}
case "undefined":
return "N;";
}
return false;
}
On the client side, you can pass in a complex (nested) JavaScript object to the phpSerialize function to get a PHP-style serialized representation. This string can be posted back and directly passed to the unserialize function to yield a representation of the complex object in PHP realm. Use of this technique requires caution on security matters.

BenBE at omorphia dot de (2007-03-02 06:20:29)

When trying to serialize or unserialize recursive arrays or otherwise linked data you might find the undocumented R data type quite useful.

If you want a array like the one produced with
<?
$a = array();
$a[0] =& $a;
?>
serialized you can store it using a string simular to this one:
<?
$a = unserialize("a:1:{i:0;R:1;}");
?>

Both sources will make $a hold an array that self-references itself in index 0.

The argument for R is the index of the created sub-variable of the serialize-string beginning with 1.

double at dumpit dot com (2006-12-19 05:09:24)

This little function will check whether the serialized string is well formed. 

PHP < 6 because i'd heard changes will be made in this php-intern function, 
maybe it could be edited easy for it.

<?php

function wd_check_serialization( $string, &$errmsg ) 
{

    $str = 's';
    $array = 'a';
    $integer = 'i';
    $any = '[^}]*?';
    $count = '\d+';
    $content = '"(?:\\\";|.)*?";';
    $open_tag = '\{';
    $close_tag = '\}';
    $parameter = "($str|$array|$integer|$any):($count)" . "(?:[:]($open_tag|$content)|[;])";            
    $preg = "/$parameter|($close_tag)/";
    if( !preg_match_all( $preg, $string, $matches ) ) 
    {            
        $errmsg = 'not a serialized string';
        return false;
    }    
    $open_arrays = 0;
    foreach( $matches[1] AS $key => $value )
    {
        if( !empty( $value ) && ( $value != $array xor $value != $str xor $value != $integer ) ) 
        {
            $errmsg = 'undefined datatype';
            return false;
        }
        if( $value == $array )
        {
            $open_arrays++;                                
            if( $matches[3][$key] != '{' ) 
            {
                $errmsg = 'open tag expected';
                return false;
            }
        }
        if( $value == '' )
        {
            if( $matches[4][$key] != '}' ) 
            {
                $errmsg = 'close tag expected';
                return false;
            }
            $open_arrays--;
        }
        if( $value == $str )
        {
            $aVar = ltrim( $matches[3][$key], '"' );
            $aVar = rtrim( $aVar, '";' );
            if( strlen( $aVar ) != $matches[2][$key] ) 
            {
                $errmsg = 'stringlen for string not match';
                return false;
            }
        }
        if( $value == $integer )
        {
            if( !empty( $matches[3][$key] ) ) 
            {
                $errmsg = 'unexpected data';
                return false;
            }
            if( !is_integer( (int)$matches[2][$key] ) ) 
            {
                $errmsg = 'integer expected';
                return false;
            }
        }
    }        
    if( $open_arrays != 0 ) 
    {
        $errmsg = 'wrong setted arrays';
        return false;
    }
    return true;
}

?>

Are Pedersen (2006-08-09 01:46:36)

Be aware that if useing serialize/unserialize in a serverfarm with both 32bit and 64bit servers you can get unexpected results.
Ex: if you serialize an integer with value of 2147483648 on a 64bit system and then unserialize it on a 32bit system you will get the value -2147483648 instead. This is because an integer on 32bit cannot be above 2147483647 so it wraps.

chad 0x40 herballure 0x2e com (2006-05-05 09:08:54)

When unserializing in PHP5 (behavior observed with 5.1.2), __autoload() will be checked first, and unserialize_callback_func called only if __autoload failed to load the class definition.

martin dot goldinger at netserver dot ch (2005-08-15 04:48:39)

When you use sessions, its very important to keep the sessiondata small, due to low performance with unserialize. Every class shoud extend from this class. The result will be, that no null Values are written to the sessiondata. It will increase performance.

<?
class BaseObject
{
    function __sleep()
    {
        $vars = (array)$this;
        foreach ($vars as $key => $val)
        {
            if (is_null($val))
            {
                unset($vars[$key]);
            }
        }    
        return array_keys($vars);
    }
};
?>

Chris Hayes (chris at hypersites dot com) (2004-10-23 09:27:58)

In reply to the earlier post about having to include object definitions *before* using unserialize. There is a workaround for this.
When an object is serialized, the first bit of the string is actually the name of the class. When an unknown object is unserialized, this is maintained as a property. So if you serialize it again, you get back the exact same string as if you'd serialized the original object. Basically, to cut to the point...
If you use
$_SESSION['my_object'] = unserialize(serialize($_SESSION['my_object']))
then you get back an object of the correct type, even if the session had originally loaded it as an object of type stdClass.

aderyn at nowhere dot tld (2003-10-30 10:02:07)

A quick note:
If you store a serialized object in a session, you have to include the class _before_ you initialize (session_start()) the session.