PHP: stripslashes - Manual (2024)

72

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.

5

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!

<?phpfunction add_slashes_recursive( $variable )
{
if ( is_string( $variable ) )
return addslashes( $variable ) ;

elseif (

3

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;
}

1

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

1

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().

2

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

function

1

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

1

Rather use str_replace than explode/implode for your purpose.

2

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

1

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.

1

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

<?phpfunction 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

1

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;
}
}
?>

1

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

1

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.

1

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;
}

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

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

1

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!

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

as in example:

<?phpif (!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

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

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 (

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;
}

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.

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;
}
?>

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);

-1

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.

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

}

return

-1

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;
}
}

-3

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

-4

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) ""

-3

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;
}
?>

-5

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 ...

-10

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 ;
}
}