SunshinePHP Developer Conference 2015

stripslashes

(PHP 4, PHP 5)

stripslashesUn-quotes a quoted string

Description

string stripslashes ( string $str )

Un-quotes a quoted string.

Note:

If magic_quotes_sybase is on, no backslashes are stripped off but two apostrophes are replaced by one instead.

An example use of stripslashes() is when the PHP directive magic_quotes_gpc is on (it was on by default before PHP 5.4), and you aren't inserting this data into a place (such as a database) that requires escaping. For example, if you're simply outputting data straight from an HTML form.

Parameters

str

The input string.

Return Values

Returns a string with backslashes stripped off. (\' becomes ' and so on.) Double backslashes (\\) are made into a single backslash (\).

Examples

Example #1 A stripslashes() example

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

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

Note:

stripslashes() is not recursive. If you want to apply this function to a multi-dimensional array, you need to use a recursive function.

Example #2 Using stripslashes() on an array

<?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);
?>

The above example will output:

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

)

See Also

add a note add a note

User Contributed Notes 30 notes

up
10
ivijan dot stefan at gmail dot com
7 months 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.
up
3
mattyblah at gmail dot com
10 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);
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5
o-zone at zerozone dot it
5 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
up
5
StefanoAI
1 year 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);
}
?>
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2
michal at roszka dot pl
5 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 :)
up
2
alex dot launi at gmail dot com
6 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;
}
up
3
shredder at technodrome dot com
5 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 ;
}

?>
up
1
stoic
7 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.
up
1
Anonymous
9 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;
}
?>
up
2
jeremysawesome
3 years ago
I'm using this to clean the $_POST array:
<?php
array_walk_recursive
($_POST, create_function('&$val', '$val = stripslashes($val);'));
?>
up
2
gregory at nutt dot ca
7 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;
    }
up
1
lukas.skowronski at gmail dot com
7 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;   
    }
up
2
Kibby
8 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.
up
1
JAB Creations
7 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.
up
0
Anonymous
8 days ago
Rather use str_replace than explode/implode for your purpose.
up
0
todd at toddzebert dot com
2 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.
up
0
tarmo at goyf dot de
2 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"
up
0
eugene at ultimatecms dot co dot za
4 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?
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0
Tom Worster
5 years ago
A replacement that should be safe on utf-8 strings.
<?php
  preg_replace
(array('/\x5C(?!\x5C)/u', '/\x5C\x5C/u'), array('','\\'), $s);
?>
up
0
techdesk100
6 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;
        }
    }
up
0
dragonfly at networkinsight dot net
7 years ago
If you are having trouble with stripslashes() corrupting binary data, try using urlencode() and urldecode() instead.
up
-1
Aditya P Bhatt (adityabhai at gmail dot com)
6 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;
    }
}
?>
up
-1
Yousef Ismaeil Cliprz
1 year 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 )
*/

?>
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-1
hash at samurai dot fm
10 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!
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-1
jeremycook0 at googlemail dot com
4 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().
up
-1
JacobRas.nl
5 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'.
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-2
hauser dot j at gmail dot com
8 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) ""
up
-2
dragon[dot]dionysius[at]gmail[dot]com
5 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;
    }
?>
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-3
alf at mitose dot net
8 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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-4
Evgeny
6 years ago
extended version of stripslashes_deep. This allow to strip one also in the array_keys

    function stripslashes_deep($value) {
        if (is_array($value)) {
            if (count($value)>0) {
                $return = array_combine(array_map('stripslashes_deep', array_keys($value)),array_map('stripslashes_deep', array_values($value)));
            } else {
                $return = array_map('stripslashes_deep', $value);
            }
            return $return;
        } else {
            $return = stripslashes($value);
            return $return ;
        }
    }
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