String readFile(String path, Directory currentDirectory, User currentUser)
      throws FileUnknownException, IsNotPlainFileException, AccessDeniedException {

    Directory directory = absolutePath(path, currentUser, currentDirectory);
    String filename = getLastPathToken(path);
    File f = directory.getFileByName(filename);
    f.checkAccessRead(currentUser);
    return f.printContent(currentUser);
  }