private static void clearAll(LFCServer lfcServer, String dir) {
   try {
     ArrayList<FileDesc> l = lfcServer.listDirectory(dir);
     if (l == null) {
       return;
     }
     for (FileDesc fd : l) {
       String name = fd.getFileName();
       String path = dir + "/" + name;
       String perm = fd.getPermissions();
       if (perm == null) {
         clear(lfcServer, path);
       } else if (perm.charAt(0) == 'd') {
         clearAll(lfcServer, path);
         System.out.println("rmdir: path=" + path);
         lfcServer.rmdir(path);
       } else {
         clear(lfcServer, path);
       }
     }
     lfcServer.rmdir(dir);
   } catch (LFCException e) {
     e.printStackTrace();
   }
 }