private void user_kick(String[] cmd) throws IOException {
   if (cmd.length == 2 && logged) {
     String username = cmd[1];
     boolean b = GestionePartite.getInstance().kickUser(username);
     if (b) OutputWrite("user_kick=OK");
     else OutputWrite("user_kick=error");
   } else OutputWrite("user_kick=error");
 }
 private void user_list_online(String[] cmd) throws IOException {
   if (cmd.length == 1) {
     if (!logged) {
       OutputWrite("user_list_online=error;message=Non sei loggato");
     } else {
       ArrayList<String> list = GestionePartite.getInstance().listUsers();
       StringBuilder resp =
           new StringBuilder(
               "user_list_online=OK;client_attivi="
                   + ConnectionsCount.getConnectionsAlive()
                   + ";loggati="
                   + list.size());
       for (int i = 0; i < list.size(); i++) {
         resp.append(";utente=" + list.get(i));
       }
       OutputWrite(resp.toString());
     }
   } else OutputWrite("user_list_online=error;message=Usage: list_users");
 }