unserialize

(PHP 4, PHP 5)

unserialize Creează o valoare PHP dintr-o reprezentare stocată

Descrierea

mixed unserialize ( string $str )

unserialize() preia o singură variabilă serializată și o convertește invers într-o valoare PHP.

Parametri

str

String-ul serializat.

Dacă variabila ce se deserializează este un obiect, după ce se reconstituie cu succes, PHP automat va încerca să apeleze funcția-membru __wakeup() (dacă aceasta există).

Notă: directiva unserialize_callback_func

Este posibil de a stabili o funcție de apel invers ce se va apela când o clasă nedefinită trebuie instanțiată în timpul deserializării. (pentru a preveni obținerea unui object incomplet "__PHP_Incomplete_Class".) Utilizați php.ini, ini_set() sau .htaccess pentru a defini 'unserialize_callback_func'. De fiecare dată când o clasă nedefinită va trebui instanțiată, această funcție va fi apelată. Pentru a dezactiva această facilitate lăsați această opțiune vidă.

Valorile întoarse

Valoarea convertită este întoarsă, și poate fi de tip boolean, integer, float, string, array sau object.

În caz că string-ul furnizat nu poate fi deserializat se va întoarce FALSE și se va emite o eroare E_NOTICE.

Istoria schimbărilor

Versiunea Descriere
4.2.0 Directiva unserialize_callback_func a devenit disponibilă.

Exemple

Example #1 Exemplu unserialize()

<?php
// Aici vom utiliza unserialize() pentru a încărca datele sesiunii în tabloul
// $session_data din string-ul selectat dintr-o bază de date.
// Acest exemplu îl complementează pe cel descris în funcția serialize().

$conn odbc_connect("webdb""php""chicken");
$stmt odbc_prepare($conn"SELECT data FROM sessions WHERE id = ?");
$sqldata = array($_SERVER['PHP_AUTH_USER']);
if (!
odbc_execute($stmt$sqldata) || !odbc_fetch_into($stmt$tmp)) {
    
// dacă execute sau fetch eșuează, se inițializează un tablou vid
    
$session_data = array();
} else {
    
// acum trebuie să avem datele serializate în $tmp[0].
    
$session_data unserialize($tmp[0]);
    if (!
is_array($session_data)) {
        
// ceva nu este în regulă, inițializează într-un tablou vid
        
$session_data = array();
    }
}
?>

Example #2 Exemplu unserialize_callback_func

<?php
$serialized_object
='O:1:"a":1:{s:5:"value";s:3:"100";}';

// directiva unserialize_callback_func este disponibilă începând cu PHP 4.2.0
ini_set('unserialize_callback_func''mycallback'); // stabilește funcția de apel invers

function mycallback($classname)
{
    
// doar includeți un fișier ce conține definiția clasei
    // veți lăsa ca $classname să-și dea seama care definiție a clasei este necesară
}
?>

Note

Avertizare

FALSE este întors atât în cazul unei erori, cât și în cazul deserializării unei valori FALSE serializate. Este posibil de a intercepta acest caz special comparând str cu serialize(false) sau interceptând eroarea E_NOTICE emisă.

Vedeți de asemenea

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User Contributed Notes 20 notes

up
7
chris AT cmbuckley DOT co DOT uk
5 years ago
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)
?>
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7
double at dumpit dot com
7 years ago
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;
}

?>
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4
ErnestV
8 months ago
Just a note - if the serialized string contains a reference to a class that cannot be instantiated (e.g. being abstract) PHP will immediately die with a fatal error. If the unserialize() statement is preceded with a '@' to avoid cluttering the logs with warns or notices there will be absolutely no clue as to why the script stopped working. Cost me a couple of hours...
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3
Ray.Paseur often uses Gmail
8 months ago
In the Classes and Objects docs, there is this: In order to be able to unserialize() an object, the class of that object needs to be defined.

Prior to PHP 5.3, this was not an issue.  But after PHP 5.3 an object made by SimpleXML_Load_String() cannot be serialized.  An attempt to do so will result in a run-time failure, throwing an exception.  If you store such an object in $_SESSION, you will get a post-execution error that says this:

Fatal error: Uncaught exception 'Exception' with message 'Serialization of 'SimpleXMLElement' is not allowed' in [no active file]:0 Stack trace: #0 {main} thrown in [no active file] on line 0

The entire contents of the session will be lost.  Hope this saves someone some time!

<?php // RAY_temp_ser.php
error_reporting(E_ALL);
session_start();
var_dump($_SESSION);
$_SESSION['hello'] = 'World';
var_dump($_SESSION);

// AN XML STRING FOR TEST DATA
$xml = '<?xml version="1.0"?>
<families>
  <parent>
    <child index="1" value="Category 1">Child One</child>
  </parent>
</families>'
;

// MAKE AN OBJECT (GIVES SimpleXMLElement)
$obj = SimpleXML_Load_String($xml);

// STORE THE OBJECT IN THE SESSION
$_SESSION['obj'] = $obj;
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3
Chris Hayes (chris at hypersites dot com)
9 years ago
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.
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3
arbie samong
4 years ago
__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.
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2
daniel at fourstaples dot com
4 years ago
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().
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0
suman dot jis at gmail dot com
2 years ago
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);
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0
frank at interactinet dot com
2 years ago
When dealing with sessions, try session_decode($data) instead of unserialize($data).
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0
Fagzal
4 years ago
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.
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0
w dot laurencine at teknoa dot net
5 years ago
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);
?>
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0
Are Pedersen
7 years ago
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.
up
0
martin dot goldinger at netserver dot ch
8 years ago
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);
    }
};
?>
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-1
BenBE at omorphia dot de
7 years ago
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.
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-1
chris at colourlovers dot com
2 years ago
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($data));
/*array(1) {
  ["baz"]=>
  array(4) {
    ["foo"]=>
    object(stdClass)#3 (0) {
    }
    ["int"]=>
    int(123)
    ["str"]=>
    string(4) "asdf"
    ["bar"]=>
    string(54) "<?xml version="1.0" encoding="UTF-8"?>
<foo>bar</foo>
"
  }
}
*/
?>
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-1
chad 0x40 herballure 0x2e com
7 years ago
When unserializing in PHP5 (behavior observed with 5.1.2), __autoload() will be checked first, and unserialize_callback_func called only if __autoload failed to load the class definition.
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-1
walf
2 years ago
a replacement for unserialize that returns whether it worked and populates the unserialized variable by reference:
<?php
function funserialize($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) {
}
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-3
MBa
2 years ago
To check if a string is serialized:

$blSerialized=(@unserialize($sText)||$sText=='b:0;');
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-3
Ates Goral
6 years ago
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.
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-3
aderyn at nowhere dot tld
10 years ago
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.
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