Disabling Magic Quotes

The magic_quotes_gpc directive may only be disabled at the system level, and not at runtime. In otherwords, use of ini_set() is not an option.

Example #1 Disabling magic quotes server side

An example that sets the value of these directives to Off in php.ini. For additional details, read the manual section titled How to change configuration settings.

; Magic quotes
;

; Magic quotes for incoming GET/POST/Cookie data.
magic_quotes_gpc = Off

; Magic quotes for runtime-generated data, e.g. data from SQL, from exec(), etc.
magic_quotes_runtime = Off

; Use Sybase-style magic quotes (escape ' with '' instead of \').
magic_quotes_sybase = Off

If access to the server configuration is unavailable, use of .htaccess is also an option. For example:

php_flag magic_quotes_gpc Off

In the interest of writing portable code (code that works in any environment), like if setting at the server level is not possible, here's an example to disable magic_quotes_gpc at runtime. This method is inefficient so it's preferred to instead set the appropriate directives elsewhere.

Example #2 Disabling magic quotes at runtime


<?php
if (get_magic_quotes_gpc()) {
    $process = array(&$_GET, &$_POST, &$_COOKIE, &$_REQUEST);
    while (list($key, $val) = each($process)) {
        foreach ($val as $k => $v) {
            unset($process[$key][$k]);
            if (is_array($v)) {
                $process[$key][stripslashes($k)] = $v;
                $process[] = &$process[$key][stripslashes($k)];
            } else {
                $process[$key][stripslashes($k)] = stripslashes($v);
            }
        }
    }
    unset($process);
}
?>

User Contributed Notes

stuart at horuskol dot co dot uk

8 years ago


I have discovered that my host doesn't like either of the following directives in the .htaccess file:

php_flag magic_quotes_gpc Off
php_value magic_quotes_gpc Off

However, there is another way to disable this setting even if you don't have access to the server configuration - you can put a php.ini file in the directory where your scripts are with the directive:

magic_quotes_gpc = Off

However, these does not propogate unlike  .htaccess rules, so if you launch from a sub-directory, you need the php.ini file in each directory you have as script entry points.

mike at mawdesign dot com

2 years ago


Here's a couple tips when using scripts on different (often shared) hosts, where ini_set doesn't work and php directives in .htaccess causes a 500 Internal Server Error.

Firstly, copy the server's php.ini file to your domain's web-root folder. To find the correct paths, use phpinfo() and look for "Configuration File (php.ini) Path" and "DOCUMENT_ROOT"

It's unlikely you'll have access to the php.ini via FTP, so instead run a script with a simple copy command (obviously inserting your paths):

exec("cp /usr/local/php/etc/php.ini /home/LinuxPackage/public_html/php.ini);

Edit the now-accessible php.ini file, and add settings like 'magic_quotes_gpc = off' at the bottom (regardless of whether they've been set earlier in the file). I also set:

[PHP]
max_execution_time = 60
max_input_time = 90
memory_limit = 64M
post_max_size = 32M
upload_max_filesize = 31M
magic_quotes_gpc = Off

Finally add the below line to your web-root htaccess file, to make the local php.ini the web-root default (so you don't need a copy in every script sub-folder):

SetEnv PHPRC /home/LinuxPackage/public_html/php.ini

Hope that helps a few people save some time!

Mike.

P.S. Using the new php_ini_loaded_file() function the whole lot could be done in three lines:

exec("cp " . php_ini_loaded_file() . " " . $_SERVER['DOCUMENT_ROOT'] . "/php.ini");
fwrite(fopen("{$_SERVER['DOCUMENT_ROOT']}/php.ini", 'a'), PHP_EOL . '[PHP]' . PHP_EOL . "magic_quotes_gpc = Off" . PHP_EOL);
fwrite(fopen("{$_SERVER['DOCUMENT_ROOT']}/.htaccess", 'a'), PHP_EOL . "SetEnv PHPRC {$_SERVER['DOCUMENT_ROOT']}/php.ini" . PHP_EOL);

Dan dot gill at hotmail dot com

2 years ago


These instructions are great.  And if you have a site with an integrated shopping cart, then you will need to copy PHP.ini from the root of your site to the root folder of your shopping cart - otherwise you will still get errors on your cart pages.

booboogotu at gmail dot com

6 years ago


A php5 way:

<?php
if (get_magic_quotes_gpc()) {
    function stripslashes_gpc(&$value)
    {
        $value = stripslashes($value);
    }
    array_walk_recursive($_GET, 'stripslashes_gpc');
    array_walk_recursive($_POST, 'stripslashes_gpc');
    array_walk_recursive($_COOKIE, 'stripslashes_gpc');
    array_walk_recursive($_REQUEST, 'stripslashes_gpc');
}
?>

rdk

9 years ago


The function parse_str() (http://us3.php.net/manual/en/function.parse-str.php) is also affected by magic_quotes_gpc, so if that function is called anywhere, stripslashes_deep won't be sufficient by itself.

metala at metala dot org

6 years ago


I have recently found out that magic quotes affects not only the values of the GPC arrays, but also the keys.

For now, my way to solve with the problem is:

<?php
if (get_magic_quotes_gpc()) {
    function magicQuotes_awStripslashes(&$value, $key) {$value = stripslashes($value);}
    $gpc = array(&$_GET, &$_POST, &$_COOKIE, &$_REQUEST);
    array_walk_recursive($gpc, 'magicQuotes_awStripslashes');
}
?>

Unfortunately it doesn't fix the keys... and cannot determinate if the slashes are already stripped.

Anonymous

9 years ago


PHP's magic quotes function has the strange behavior of not adding slashes to top level keys in GPC key/value pairs but adding the slashes in deeper level keys. To demonstrate, a URI of:

example.php?a'b[c'd]=e'f
produces:
array("a'b" => array("c\'d" => "e\'f"))

The current example for removing magic quotes does not do anything to keys, so after running stripslashes_deep, you would end up with:
array("a'b" => array("c\'d" => "e'f"))

Which, needless to say, is wrong. As if you had magic quotes off, it would have been:
array("a'b" => array("c'd" => "e'f"))

I have written a snippet of code compatible with PHP 4.0.0 and above that handles this correctly:

if (get_magic_quotes_gpc()) {
    function undoMagicQuotes($array, $topLevel=true) {
        $newArray = array();
        foreach($array as $key => $value) {
            if (!$topLevel) {
                $key = stripslashes($key);
            }
            if (is_array($value)) {
                $newArray[$key] = undoMagicQuotes($value, false);
            }
            else {
                $newArray[$key] = stripslashes($value);
            }
        }
        return $newArray;
    }
    $_GET = undoMagicQuotes($_GET);
    $_POST = undoMagicQuotes($_POST);
    $_COOKIE = undoMagicQuotes($_COOKIE);
    $_REQUEST = undoMagicQuotes($_REQUEST);
}

dedlfix

9 years ago


The function stripslashes_deep() ignores slashes in the keys

For example a query string like this: ?foo'bar=baz'bal

Output of var_dump($_GET) is:

array(1) {
  ["foo\'bar"]=>
  string(8) "baz\'bal"
}

after stripslashes_deep():

array(1) {
  ["foo\'bar"]=>
  string(7) "baz'bal"
}

If you want the keys to be stripslashed too, you have to unset() the addslahed key and to add a stripslashed version. But keep in mind that this will change the order of the array.

H Patel

2 years ago


i do not check for get_magic_quotes_gpc is on of off as we should remove all slashes. another thing is to remove slashes using strip slash will only remove "\" to "" and "\\" to "\"

To over come this problem i use str_replace(array( '\\'), '', $v) 

Update Example 2
<?php

    $process = array(&$_GET, &$_POST, &$_COOKIE, &$_REQUEST);
    while (list($key, $val) = each($process)) {
        foreach ($val as $k => $v) {
            unset($process[$key][$k]);
            if (is_array($v)) {
                $process[$key][str_replace(array('\\'), '', $k)] = $v;
                $process[] = &$process[$key][str_replace(array('\\'), '', $k)];
            } else {
                $process[$key][str_replace(array('\\'), '', $k)] = str_replace(array('\\'), '', $v);
            }
        }
    }
    unset($process);

?>