Share discuz's php to prevent sql injection function

Share the sql anti-injection function in discuz forum, it is well written.

$magic_quotes_gpc = get_magic_quotes_gpc();
@extract(daddslashes($_COOKIE));
@extract(daddslashes($_POST));
@extract(daddslashes($_GET));
if(! $magic_quotes_gpc) {
$_FILES = daddslashes($_FILES);
}

function daddslashes($string, $force = 0) {
if(!$GLOBALS['magic_quotes_gpc'] || $force) {
if( is_array($string)) {
foreach($string as $key => $val) {
$string[$key] = daddslashes($val, $force);
}
} else {
$string = addslashes ($string);
}
}
return $string;
}