added htmlspecialchars() to the ouput

Author: artyuum

index.php

@@ -51,7 +51,7 @@
  <h2> Output </h2>
  </div>
  <pre>
-<?= $cmd ?>
+<?= htmlspecialchars($cmd, ENT_QUOTES, 'UTF-8') ?>
  </pre>
 <?php endif; ?>