gistfile1.cpp

#include <stdexcept>
#include <iostream>
#include <string>
#include <boost/thread.hpp>
#include <boost/asio.hpp>
#include <boost/chrono.hpp>

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

boost::asio::io_service io;
tcp::socket sock(io);
boost::asio::streambuf buf;

void cln_handle_read(const boost::system::error_code& e, std::size_t) {
  if (e) {
    throw std::runtime_error(e.message());
  }
  
  std::istream is(&buf);
  std::string line;
  std::getline(is, line);
  std::cout << "Answer: " << line << std::endl;
}

int client() {
  try {
    std::string data("Henrich Herz");
    
    tcp::resolver resolver(io);
    tcp::resolver::query query(tcp::v4(), "localhost", "12345");
    tcp::resolver::iterator iterator = resolver.resolve(query);

    tcp::socket s(io);
    boost::asio::connect(sock, iterator);

    boost::asio::write(sock, boost::asio::buffer(data));
    boost::asio::write(sock, boost::asio::buffer("\n"));
    
    boost::this_thread::sleep_for(boost::chrono::seconds(1));
    
    boost::asio::async_read_until(sock, buf, '\n', &cln_handle_read);
    io.run();
    return 0;
  } catch (const std::exception &e) {
    std::cout << "client fail: " << e.what() << std::endl;
    return 1;
  }
}

int server() {
  try {
    tcp::acceptor acc(io, tcp::endpoint(tcp::v4(), 12345));
    acc.accept(sock);
    boost::asio::read_until(sock, buf, '\n');
    std::istream is(&buf);
    std::string line;
    std::getline(is, line);
    boost::asio::write(sock, boost::asio::buffer(line));
    boost::asio::write(sock, boost::asio::buffer("\n"));
    return 0;
  } catch (const std::exception &e) {
    std::cout << "server fail: " << e.what() << std::endl;
    return 1;
  }
}

int main(int argc, char **argv) {
  if (argc == 2 && std::string("client") == argv[1]) {
    return client();
  } else if (argc == 2 && std::string("server") == argv[1]) {
    return server();
  } else {
    std::cout << "wrong usage\n";
    return 1;
  }
}