1 //
2 // blocking_udp_echo_client.cpp
3 // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4 //
5 // Copyright (c) 2003-2016 Christopher M. Kohlhoff (chris at kohlhoff dot com)
6 //
7 // Distributed under the Boost Software License, Version 1.0. (See accompanying
8 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
9 //
10 
11 #include <cstdlib>
12 #include <cstring>
13 #include <iostream>
14 #include "asio.hpp"
15 
16 using asio::ip::udp;
17 
18 enum { max_length = 1024 };
19 
main(int argc,char * argv[])20 int main(int argc, char* argv[])
21 {
22   try
23   {
24     if (argc != 3)
25     {
26       std::cerr << "Usage: blocking_udp_echo_client <host> <port>\n";
27       return 1;
28     }
29 
30     asio::io_context io_context;
31 
32     udp::socket s(io_context, udp::endpoint(udp::v4(), 0));
33 
34     udp::resolver resolver(io_context);
35     udp::resolver::results_type endpoints =
36       resolver.resolve(udp::v4(), argv[1], argv[2]);
37 
38     std::cout << "Enter message: ";
39     char request[max_length];
40     std::cin.getline(request, max_length);
41     size_t request_length = std::strlen(request);
42     s.send_to(asio::buffer(request, request_length), *endpoints.begin());
43 
44     char reply[max_length];
45     udp::endpoint sender_endpoint;
46     size_t reply_length = s.receive_from(
47         asio::buffer(reply, max_length), sender_endpoint);
48     std::cout << "Reply is: ";
49     std::cout.write(reply, reply_length);
50     std::cout << "\n";
51   }
52   catch (std::exception& e)
53   {
54     std::cerr << "Exception: " << e.what() << "\n";
55   }
56 
57   return 0;
58 }
59