stripslashes

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

stripslashes — Rimuove gli slash aggiunti con addslashes()

Descrizione

stripslashes(string $str): string

Rimuove i backslash da una stringa. (\' diventa ' e così via.) I doppi backslash (\\) sono ridotti ad un singolo backslash (\).

Un esempio di uso di stripslashes() è dato dall'opzione PHP magic_quotes_gpc che, quando è impostata a on (come è per default), e non siinseriscono questi dati in una procedura (tipo in un database) che richiede il carattere di escape. Ad esempio, se si visualizza dati da un form HTML.

Example #1 Esempio di uso di stripslashes()

<?php
$str = "Is your name O\'reilly?";

// Outputs: Is your name O'reilly?
echo stripslashes($str);
?>

Nota:
La funzione stripslashes() non è ricorsiva Se si desidera utilizzare questa funzione su una matrice multi-dimensionale, occorre utilizzare una funzione ricorsiva.

Example #2 Esempio di utilizzo di stripslashes() su una matrice

<?php
function stripslashes_deep($value)
{
    $value = is_array($value) ?
                array_map('stripslashes_deep', $value) :
                stripslashes($value);
 
    return $value;
}
 
// Example
$array = array("f\\'oo", "b\\'ar", array("fo\\'o", "b\\'ar"));
$array = stripslashes_deep($array);
 
// Output
print_r($array);
?>

Il precedente esempio visualizzerà:

Array
(
    [0] => f'oo
    [1] => b'ar
    [2] => Array
        (
            [0] => fo'o
            [1] => b'ar
        )
 
)

Per maggiori dettagli su "magic quotes", vedere get_magic_quotes_gpc().

Vedere anche addslashes() e get_magic_quotes_gpc().

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User Contributed Notes 30 notes

down

ivijan dot stefan at gmail dot com ¶

10 years ago

Sometimes for some reason is happens that PHP or Javascript or some naughty insert a lot of  backslash. Ordinary function does not notice that. Therefore, it is necessary that the bit "inflate":

<?php
function removeslashes($string)
{
    $string=implode("",explode("\\",$string));
    return stripslashes(trim($string));
}

/* Example */

$text="My dog don\\\\\\\\\\\\\\\\'t like the postman!";
echo removeslashes($text);
?>

RESULT: My dog don't like the postman!

This flick has served me wery well, because I had this problem before.

down

shredder at technodrome dot com ¶

15 years ago

Hi, 

Here are recursive addslashes / stripslashes functions.
given a string - it will simply add / strip slashes
given an array - it will recursively add / strip slashes from the array and all of it subarrays. 
if the value is not a string or array - it will remain unmodified!

<?php

function add_slashes_recursive( $variable )
{
    if ( is_string( $variable ) )
        return addslashes( $variable ) ;

    elseif ( is_array( $variable ) )
        foreach( $variable as $i => $value )
            $variable[ $i ] = add_slashes_recursive( $value ) ;

    return $variable ;
}

function strip_slashes_recursive( $variable )
{
    if ( is_string( $variable ) )
        return stripslashes( $variable ) ;
    if ( is_array( $variable ) )
        foreach( $variable as $i => $value )
            $variable[ $i ] = strip_slashes_recursive( $value ) ;
    
    return $variable ; 
}

?>

down

tarmo at goyf dot de ¶

12 years ago

When matching strings with approstrophes against the mysql database, my query kept failing while it worked fine when I copied the same query directly to perform the database query. After several hours I found that stripslashes() made the string longer and hence it wasn't "equal" for the query.

This code shows the behavior (copy into "test.php"). Replacing stripslashes worked for me.

<?php
echo '<h2>Post-Data</h2>';
var_dump($_POST);

$f1 = trim(filter_var(stripslashes($_POST[form]), FILTER_SANITIZE_STRING));
echo '<h2>stripslashes</h2>';
var_dump($f1);

$f2 = trim(str_replace("|","'",filter_var(str_replace("\'","|",$_POST[form]), FILTER_SANITIZE_STRING)));
echo '<h2>workaround</h2>';
var_dump($f2);
    
echo '<form action="test.php" method="post">
    <input type="text" name="form">
    <input type="submit">
    </form>';
?>

Entering "foo'bar" creates this output:
// Post-Data
// array(1) { ["form"]=> string(8) "foo\'bar" }
// stripslashes
// string(11) "foo'bar"
// workaround
// string(7) "foo'bar"

down

jeremycook0 at googlemail dot com ¶

14 years ago

Here's a way of stripping slashes in PHP 5.3 using a recursive closure:

<?php
  if (get_magic_quotes_gpc()) {
      $strip_slashes_deep = function ($value) use (&$strip_slashes_deep) {
          return is_array($value) ? array_map($strip_slashes_deep, $value) : stripslashes($value);
      };
      $_GET = array_map($strip_slashes_deep, $_GET);
      $_POST = array_map($strip_slashes_deep, $_POST);
      $_COOKIE = array_map($strip_slashes_deep, $_COOKIE);
  }
?>

Note that the variable '$strip_slashes_deep' has to be passed to the closure by reference. I think that this is because at the time the closure is created the variable '$strip_slashes_deep' doesn't exist: the closure itself becomes the value of the variable. Passing by reference solves this issue. This closure could easily be adapted to use other methods of stripping slashes such as preg_replace().

down

Tom Worster ¶

15 years ago

A replacement that should be safe on utf-8 strings.
<?php
  preg_replace(array('/\x5C(?!\x5C)/u', '/\x5C\x5C/u'), array('','\\'), $s);
?>

down

Anonymous ¶

10 years ago

Rather use str_replace than explode/implode for your purpose.

down

o-zone at zerozone dot it ¶

15 years ago

If you need to remove all slashes from a string, here's a quick hack:



<?php

function stripallslashes($string) {

    while(strchr($string,'\\')) {

        $string = stripslashes($string);

    }

}

?>



Hope it's usefull , O-Zone

down

stoic ¶

17 years ago

in response to crab dot crab at gmail dot com:

$value need not be passed by reference. The 'stripped' value is returned. The passed value is not altered.

down

eugene at ultimatecms dot co dot za ¶

14 years ago

This is a simple function to remove the slashes added by functions such as magic_quotes_gpc and mysql_escape_string etc.

<?php

function no_magic_quotes($query) {
        $data = explode("\\",$query);
        $cleaned = implode("",$data);
        return $cleaned;
}

// I'm using mysql_escape_string as a simple example, but this function would work for any escaped string.
$query = "It's amaizing! Who's to say this isn't a simple function?";
$badstring = mysql_escape_string($query);

echo '<b>Without funtion:</b> '.$badstring;
echo '<br><br>';
echo '<b>With function:</b> '.no_magic_quotes($badstring);

?>

Output:
Without funtion: It\'s amaizing! Who\'s to say this isn\'t a simple function?

With function: It's amaizing! Who's to say this isn't a simple function?

down

Aditya P Bhatt (adityabhai at gmail dot com) ¶

16 years ago

Here is simple example code which you can use as a common function in your functions file:

<?php
function stripslashes_if_gpc_magic_quotes( $string ) {
    if(get_magic_quotes_gpc()) {
        return stripslashes($string);
    } else {
        return $string;
    }
}
?>

down

dragonfly at networkinsight dot net ¶

17 years ago

If you are having trouble with stripslashes() corrupting binary data, try using urlencode() and urldecode() instead.

down

JAB Creations ¶

17 years ago

When writing to a flatfile such as an HTML page you'll notice slashes being inserted. When you write to that page it's interesting how to apply stripslashes...

I replaced this line...
<?php fwrite($file, $_POST['textarea']); ?>

With...
<?php if (get_magic_quotes_gpc()) {fwrite ($file, stripslashes($_POST['textarea']));}?>

You have to directly apply stripslashes to $_POST, $_GET, $_REQUEST, and $_COOKIE.

down

StefanoAI ¶

11 years ago

Recursive stripslashes
<?php
if (get_magic_quotes_gpc()) {

    function stripslashes_array(&$arr) {
        foreach ($arr as $k => &$v) {
            $nk = stripslashes($k);
            if ($nk != $k) {
                $arr[$nk] = &$v;
                unset($arr[$k]);
            }
            if (is_array($v)) {
                stripslashes_array($v);
            } else {
                $arr[$nk] = stripslashes($v);
            }
        }
    }

    stripslashes_array($_POST);
    stripslashes_array($_GET);
    stripslashes_array($_REQUEST);
    stripslashes_array($_COOKIE);
}
?>

down

powerofBBC at gmail dot com ¶

5 years ago

$regex_pattern = "/<a href=\"(.*)\">(.*)<\/a>/";

if( (strlen($_POST['query']) > 0) && (preg_match_all($regex_pattern, $_POST['query']) )
{ echo "Tags found"; }

down

gregory at nutt dot ca ¶

17 years ago

Here is code I use to clean the results from a MySQL query using the stripslashes function.

I do it by passing the sql result and the sql columns to the function strip_slashes_mysql_results.  This way, my data is already clean by the time I want to use it.

    function db_query($querystring, $array, $columns)
    {
      if (!$this->connect_to_mysql())
       return 0;

     $queryresult = mysql_query($querystring, $this->link)
        or die("Invalid query: " . mysql_error());
    
      if(mysql_num_rows($queryresult))
      {
          $columns = mysql_field_names ($queryresult);
    
          if($array)
          {
              while($row = mysql_fetch_row($queryresult))
                $row_meta[] = $this->strip_slashes_mysql_results($row, $columns);
              return $row_meta;
          }
          else
          {
              while($row = mysql_fetch_object($queryresult))
                $row_meta[] = $this->strip_slashes_mysql_results($row, $columns);
              return $row_meta;
          }
      }
      else
        return 0;
    }
    
    function strip_slashes_mysql_results($result, $columns)
    {
        foreach($columns as $column)
        {
              if($this->debug)
                  printp(sprintf("strip_slashes_mysql_results: %s",strip_slashes_mysql_results));
              $result->$column = stripslashes($result->$column);
        }
        return $result;
    }

down

hash at samurai dot fm ¶

20 years ago

Might I warn readers that they should be vary careful with the use of stripslashes on Japanese text. The shift_jis character set includes a number of two-byte code charcters that contain the hex-value 0x5c (backslash) which will get stripped by this function thus garbling those characters.

What a nightmare!

down

todd at toddzebert dot com ¶

12 years ago

Attempting to use stripslashes on an array in 5.2.17 returns the string "Array", but in 5.3.6 it returns NULL.

down

michal at roszka dot pl ¶

15 years ago

The goal is to leave the input untouched in PHP 5.2.8. Let's have this sample text given in $_POST['example']:

a backslash ( \ ), a single-quote ( ' ), a double-quote ( " ) and a null character ( \0 )

Let's have two simple scripts:

Script A:
<?php echo $_POST['example']; ?>

Script B:
<?php echo stripslashes($_POST['example']); ?>

Let's have four different configurations and corresponding output:

Case #1:

 * magic_quotes_gpc = Off
 * magic_quotes_sybase = Off

A: a backslash ( \ ), a single-quote ( ' ), a double-quote ( " ) and a null character ( \0 )
B: a backslash (  ), a single-quote ( ' ), a double-quote ( " ) and a null character ( � )

Case #2

 * magic_quotes_gpc = On
 * magic_quotes_sybase = Off

A: a backslash ( \\ ), a single-quote ( \' ), a double-quote ( \" ) and a null character ( \\0 )
B: a backslash ( \ ), a single-quote ( ' ), a double-quote ( " ) and a null character ( \0 )

Case #3

 * magic_quotes_gpc = On
 * magic_quotes_sybase = On
 
A: a backslash ( \ ), a single-quote ( '' ), a double-quote ( " ) and a null character ( \0 )
B: a backslash ( \ ), a single-quote ( ' ), a double-quote ( " ) and a null character ( � )

Case #4

 * magic_quotes_gpc = Off
 * magic_quotes_sybase = On

A: a backslash ( \ ), a single-quote ( ' ), a double-quote ( " ) and a null character ( \0 )
B: a backslash (  ), a single-quote ( ' ), a double-quote ( " ) and a null character ( � )

Conclusions:

1) we do not need to do anything, if the magic_quotes_gpc is disabled (cases 1 and 4);
2) stripslashes($_POST['example']) only works, if the magic_quotes_gpc is enabled, but the magic_quotes_sybase is disabled (case 2);
3) str_replace("''", "'", $_POST['example']) will do the trick if both the magic_quotes_gpc and the magic_quotes_sybase are enabled (case 3);

<?php
function disable_magic_quotes_gpc()
{
    if (TRUE == function_exists('get_magic_quotes_gpc') && 1 == get_magic_quotes_gpc())
    {
        $mqs = strtolower(ini_get('magic_quotes_sybase'));

        if (TRUE == empty($mqs) || 'off' == $mqs)
        {
            // we need to do stripslashes on $_GET, $_POST and $_COOKIE
        }
        else
        {
            // we need to do str_replace("''", "'", ...) on $_GET, $_POST, $_COOKIE
        }
    }
    // otherwise we do not need to do anything
}
?>

Important notes:

1) arrays need to be processed recursively;

2) both stripslashes and str_replace functions always return strings, so:

* TRUE will become a string "1",
* FALSE will become an empty string,
* integers and floats will become strings,
* NULL will become an empty string.

On the other hand you only need to process strings, so use the is_string function to check;

3) when dealing with other (than GPC) data sources, such as databases or text files, remember to play with the magic_quotes_runtime setting as well, see, what happens and write a corresponding function, i.e. disable_magic_quotes_runtime() or something.

4) VERY IMPORTANT: when testing, remember the null character. Otherwise your tests will be inconclusive and you may end up with... well, serious bugs :)

down

alex dot launi at gmail dot com ¶

16 years ago

kibby: I modified the stripslashes_deep() function so that I could use it on NULL values.

function stripslashes_deep($value)
{
    if(isset($value)) {
        $value = is_array($value) ?
            array_map('stripslashes_deep', $value) :
            stripslashes($value);
    }
    return $value;
}

down

lukas.skowronski at gmail dot com ¶

17 years ago

If You want to delete all slashes from any table try to use my function:

function no_slashes($array)
    {
        foreach($array as $key=>$value)
            {
                if(is_array($value))
                    {
                        $value=no_slashes($value);
                        $array_temp[$key]=$value;                        
                    }
                else
                    {
                        $array_temp[$key]=stripslashes($value);
                    }
            }        
        return $array_temp;    
    }

down

Kibby ¶

18 years ago

Okay, if using stripslashes_deep, it will definitely replace any NULL to "".  This will affect to coding that depends isset().  Please provide a workaround based on recent note.

down

mattyblah at gmail dot com ¶

20 years ago

It should be of note that if you are stripping slashes to get rid of the slashes added by magic_quotes_gpc then it will also remove slashes from \. This may not seem that bad but if you have someone enter text such as 'testing\' with a slash at the end, this will cause an error if not corrected. It's best to strip the slashes, then add a slash to every single slash using $text = str_replace('\\', '\\\\', $text);

down

-1

Yousef Ismaeil Cliprz ¶

11 years ago

If you want to use stripslashes(); function for a string or array you can create a user function

as in example:

<?php

if (!function_exists('strip_slashes'))
{
    /**
     * Un-quotes a quoted string.
     *
     * @param (mixed) $str - The input string.
     * @author Yousef Ismaeil Cliprz
     */
    function strip_slashes($str)
    {
        if (is_array($str))
        {
            foreach ($str as $key => $val)
            {
                $str[$key] = strip_slashes($val);
            }
        }
        else
        {
            $str = stripslashes($str);
        }

        return $str;
    }
}

$arr = array('Yousef\\\'s','\"PHP.net\"','user\\\'s');

echo 'With strip_slashes() function:<br />';
print_r(strip_slashes($arr));
echo '<br />';
echo 'Without strip_slashes() function:<br />';
print_r($arr);

/** You will get
With strip_slashes() function:
Array ( [0] => Yousef's [1] => "PHP.net" [2] => user's )
Without strip_slashes() function:
Array ( [0] => Yousef\'s [1] => \"PHP.net\" [2] => user\'s )
*/

?>

down

-1

JacobRas.nl ¶

15 years ago

Hi,

Here's an function that strips not only \', but also \\' and \\\' and so on (depending on $times). $text = the text that needs to be stripped, $times = how much backslashes should be stripped.

<?php

function stripslashes_deep ($text, $times) {
    
    $i = 0;
    
    // loop will execute $times times.
    while (strstr($text, '\\') && $i != $times) {
        
        $text= stripslashes($text);
        $i++;
        
    }
    
    return $text;
    
}

?>

Example: $text = \\'quote\\' . <?php stripslashes_deep($text, 2); ?> will return 'quote'.
Note: <?php stripslashes_deep($text, 3); ?> will also return 'quote'.

down

-1

Anonymous ¶

19 years ago

If you want to deal with slashes in double-byte encodings, such as shift_jis or big5, you may use this:

<?
function stripslashes2($string) {
    $string = str_replace("\\\"", "\"", $string);
    $string = str_replace("\\'", "'", $string);
    $string = str_replace("\\\\", "\\", $string);
    return $string;
}
?>

down

-1

techdesk100 ¶

16 years ago

Function which checks if $input has correct slashes,
otherwise adds slashes. For cases when you are not sure the input is not already addslashed.

    public function addslashes_once($input){
        //These characters are single quote ('), double quote ("), backslash (\) and NUL (the NULL byte).
        $pattern = array("\\'", "\\\"", "\\\\", "\\0");
        $replace = array("", "", "", "");
        if(preg_match("/[\\\\'\"\\0]/", str_replace($pattern, $replace, $input))){
            return addslashes($input);
        }
        else{
            return $input;
        }
    }

down

-3

jeremysawesome ¶

13 years ago

I'm using this to clean the $_POST array:
<?php
array_walk_recursive($_POST, create_function('&$val', '$val = stripslashes($val);'));
?>

down

-4

hauser dot j at gmail dot com ¶

18 years ago

Don't use stripslashes if you depend on the values NULL.

Apparently stripslashes converts NULL to string(0) "" 

<?php
$a = null;
var_dump($a);

$b = stripslashes($a);
var_dump($b);
?>
Will output

NULL
string(0) ""

down

-3

dragon[dot]dionysius[at]gmail[dot]com ¶

15 years ago

I use this function in my class to stripslashes arrays including NULL-check:

<?php
    private function stripslashes_deep($value) {
        if(is_array($value)) {
            foreach($value as $k => $v) {
                $return[$k] = $this->stripslashes_deep($v);
            }
        } elseif(isset($value)) {
            $return = stripslashes($value);
        }
        return $return;
    }
?>

down

-5

alf at mitose dot net ¶

19 years ago

Take care using stripslashes() if the text you want to insert in the database contain \n characters ! You'll see "n" instead of (not seeing) "\n".

It should be no problem for XML, but is still boring ...

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