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PHP determines file upload type and filters unsafe data_PHP tutorial
- WBOYOriginal
- 2016-07-20 11:06:541678browse
php tutorial to determine file upload type and filter unsafe data
This function filters unsafe characters
function s_addslashes($string, $force = 0) {
if(! get_magic_quotes_gpc()) {
if(is_array($string)) {
foreach($string as $key => $val) {
$string[$key] = s_addslashes($val, $ force);
}
} else {
$string=str_replace("","& # x",$string); //
Filter some unsafe characters
$string = addslashes($string);
}
}
return $string;
}
Example:
$_COOKIE = c_addslashes($_COOKIE) ;
$_POST = c_addslashes($_POST);
$_GET = c_addslashes($_GET);
Add
if($_FILES){
foreach( $_FILES as $key => $_value )
{
$_FILES[$key]['type'] =$_value['type'];
}
if( substr($_FILES[$key]['type'],0,6) !='image/')
{
exit;
}
}
Upload prohibited For files other than image files,
Tip:
Do not get the file extension to determine the type. This is the most unsafe. We use $_FIlES['form']
['type' ]
This can read the file content to identify the file type, but its recognition is limited, but if you use pictures, it is enough
to understand it.
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