gistfile1.cpp

#include <cstdlib>
#include <cstring>
#include <iostream>
#include <boost/array.hpp>
#include <boost/bind.hpp>
#include <boost/asio.hpp>

namespace posix = boost::asio::posix;

class echo_client
{
public:
  echo_client(boost::asio::io_service& io_service)
    : input_(io_service, STDIN_FILENO),
      output_(io_service, STDOUT_FILENO),
      input_buffer_(1024)
  {
      // Read a line of input entered by the user.
      boost::asio::async_read_until(input_, input_buffer_, '\n',
          boost::bind(&echo_client::handle_read, this,
            boost::asio::placeholders::error,
            boost::asio::placeholders::bytes_transferred));
  }

private:

  void handle_read(const boost::system::error_code& error,
      std::size_t length)
  {
    if (!error)
    {
      // Write the message to the output
      boost::asio::async_write(output_, input_buffer_,
          boost::bind(&echo_client::handle_write, this,
            boost::asio::placeholders::error));
    }
    else
    {
      close();
    }
  }

  void handle_write(const boost::system::error_code& error)
  {
    if (!error)
    {
      // Read a line of input entered by the user.
      boost::asio::async_read_until(input_, input_buffer_, '\n',
          boost::bind(&echo_client::handle_read, this,
            boost::asio::placeholders::error,
            boost::asio::placeholders::bytes_transferred));
    }
    else
    {
      close();
    }
  }

  void close()
  {
    // Cancel all outstanding asynchronous operations.
    input_.close();
    output_.close();
  }

private:
  posix::stream_descriptor input_;
  posix::stream_descriptor output_;
  boost::asio::streambuf input_buffer_;
};

int main(int argc, char* argv[])
{
  try
  {
    boost::asio::io_service io_service;

    echo_client c(io_service);

    io_service.run();
  }
  catch (std::exception& e)
  {
    std::cerr << "Exception: " << e.what() << "\n";
  }

  return 0;
}