Codice PHP:
<html>
<head></head>
<body>
<?PHP
    
if (isset($_GET['user']))
    {
        
$data=file($_GET['user'].'.txt');
        
$pass=rtrim($data[3]);
        
var_dump($_GET['pass']); var_dump($pass);

        if (
$_GET['pass']==$pass) echo "ok passw giusta ".$_GET['pass'];
    }
?>