1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Source listing for Daytime.6</title> 5<link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../../boost_asio.html" title="Boost.Asio"> 8<link rel="up" href="../tutdaytime6.html" title="Daytime.6 - An asynchronous UDP daytime server"> 9<link rel="prev" href="../tutdaytime6.html" title="Daytime.6 - An asynchronous UDP daytime server"> 10<link rel="next" href="../tutdaytime7.html" title="Daytime.7 - A combined TCP/UDP asynchronous server"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="../tutdaytime6.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../tutdaytime6.html"><img src="../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../boost_asio.html"><img src="../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../tutdaytime7.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h4 class="title"> 27<a name="boost_asio.tutorial.tutdaytime6.src"></a><a class="link" href="src.html" title="Source listing for Daytime.6">Source listing 28 for Daytime.6</a> 29</h4></div></div></div> 30<pre class="programlisting">// 31// server.cpp 32// ~~~~~~~~~~ 33// 34// Copyright (c) 2003-2020 Christopher M. Kohlhoff (chris at kohlhoff dot com) 35// 36// Distributed under the Boost Software License, Version 1.0. (See accompanying 37// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 38// 39 40#include <ctime> 41#include <iostream> 42#include <string> 43#include <boost/array.hpp> 44#include <boost/bind/bind.hpp> 45#include <boost/shared_ptr.hpp> 46#include <boost/asio.hpp> 47 48using boost::asio::ip::udp; 49 50std::string make_daytime_string() 51{ 52 using namespace std; // For time_t, time and ctime; 53 time_t now = time(0); 54 return ctime(&now); 55} 56 57class udp_server 58{ 59public: 60 udp_server(boost::asio::io_context& io_context) 61 : socket_(io_context, udp::endpoint(udp::v4(), 13)) 62 { 63 start_receive(); 64 } 65 66private: 67 void start_receive() 68 { 69 socket_.async_receive_from( 70 boost::asio::buffer(recv_buffer_), remote_endpoint_, 71 boost::bind(&udp_server::handle_receive, this, 72 boost::asio::placeholders::error, 73 boost::asio::placeholders::bytes_transferred)); 74 } 75 76 void handle_receive(const boost::system::error_code& error, 77 std::size_t /*bytes_transferred*/) 78 { 79 if (!error) 80 { 81 boost::shared_ptr<std::string> message( 82 new std::string(make_daytime_string())); 83 84 socket_.async_send_to(boost::asio::buffer(*message), remote_endpoint_, 85 boost::bind(&udp_server::handle_send, this, message, 86 boost::asio::placeholders::error, 87 boost::asio::placeholders::bytes_transferred)); 88 89 start_receive(); 90 } 91 } 92 93 void handle_send(boost::shared_ptr<std::string> /*message*/, 94 const boost::system::error_code& /*error*/, 95 std::size_t /*bytes_transferred*/) 96 { 97 } 98 99 udp::socket socket_; 100 udp::endpoint remote_endpoint_; 101 boost::array<char, 1> recv_buffer_; 102}; 103 104int main() 105{ 106 try 107 { 108 boost::asio::io_context io_context; 109 udp_server server(io_context); 110 io_context.run(); 111 } 112 catch (std::exception& e) 113 { 114 std::cerr << e.what() << std::endl; 115 } 116 117 return 0; 118} 119</pre> 120<p> 121 Return to <a class="link" href="../tutdaytime6.html" title="Daytime.6 - An asynchronous UDP daytime server">Daytime.6 - An 122 asynchronous UDP daytime server</a> 123 </p> 124</div> 125<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 126<td align="left"></td> 127<td align="right"><div class="copyright-footer">Copyright © 2003-2020 Christopher M. 128 Kohlhoff<p> 129 Distributed under the Boost Software License, Version 1.0. 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