fstream output(argv[1], ios::out | ios::trunc | ios::binary);

    if (!address_book.SerializeToOstream(&output)) {

      cerr << "Failed to write address book." << endl;

      return -1;

    }

 // Read the existing address book.

    fstream input(argv[1], ios::in | ios::binary);

    if (!input) {

      cout << argv[1] << ": File not found.  Creating a new file." << endl;

    } else if (!address_book.ParseFromIstream(&input)) {

      cerr << "Failed to parse address book." << endl;

      return -1;

    }

void *buffer = malloc(size);

address_book.SerializeToArray(buffer, size);

std::ostringstream stream;

address_book.SerializeToOstream(&stream);

string text = stream.str();

char* ctext = string.c_str();