A sample of synchronous TCP client using boost::asio.

asio_client.cpp

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

namespace asio = boost::asio;

int main() {
  asio::io_service io_service;
  asio::ip::tcp::socket socket(io_service);

  socket.connect( asio::ip::tcp::endpoint( asio::ip::address::from_string("127.0.0.1"), 31400 ) );

  const std::string msg = "ping\n";
  boost::system::error_code error;
  asio::write( socket, asio::buffer(msg), error );

  if( error ) {
    std::cout << "send failed: " << error.message() << std::endl;
  }
  else {
    std::cout << "send correct!" << std::endl;
  }

  asio::streambuf receive_buffer;
  asio::read( socket, receive_buffer, asio::transfer_all(), error );

  if( error && error != asio::error::eof ) {
    std::cout << "receive failed: " << error.message() << std::endl;
  }
  else {
    const char* data = asio::buffer_cast<const char*>(receive_buffer.data());
    std::cout << data << std::endl;
  }

  return 0;
}

同样出现到read这里就一直循环等待的情况，无解…………