#include <iostream>
#include <boost/array.hpp>
#include <boost/asio.hpp>

using boost::asio::ip::tcp;

int main(int argc, char* argv[])
{
      try
      {
          if (argc != 2)
          {
              std::cerr << "Usage: client <host>"<<argv[1] << std::endl;
              return 1;
          }
          boost::asio::io_service io_service;
          tcp::resolver resolver(io_service);
          tcp::resolver::query query(argv[1],  "daytime");
          tcp::resolver::iterator endpoint_iterator = resolver.resolve(query);
          tcp::socket socket(io_service);
          boost::asio::connect(socket, endpoint_iterator);
          for (;;)
          {
              boost::array<char, 128> buf;
              boost::system::error_code error;
              size_t len = socket.read_some(boost::asio::buffer(buf), error);
              if (error == boost::asio::error::eof)
                  break; // Connection closed cleanly by peer.      else if (error)
              throw boost::system::system_error(error); // Some other error.
              std::cout.write(buf.data(), len);
          }
      }
      catch (std::exception& e)
      {
          std::cerr << e.what() << std::endl;
      }
      return 0;
}

#include <ctime>
#include <iostream>
#include <string>
#include <boost/asio.hpp>

using boost::asio::ip::tcp;

std::string make_daytime_string()
{
    using namespace std; // For time_t, time and ctime;
    time_t now = time(0);
    return "Hello world!";
}

int main()
{
    try
    {
      boost::asio::io_service io_service;

      tcp::acceptor acceptor(io_service, tcp::endpoint(tcp::v4(), 13));

      for (;;)
      {
        tcp::socket socket(io_service);
        acceptor.accept(socket);

        std::string message = make_daytime_string();

        boost::system::error_code ignored_error;
        boost::asio::write(socket, boost::asio::buffer(message), ignored_error);
      }
    }
    catch (std::exception& e)
    {
      std::cerr << e.what() << std::endl;
    }

    return 0;
}