Daytime.4 - A synchronous UDP daytime client
一个同步的UDP daytime客户端
This tutorial program shows how to use asio to implement a client application with UDP.
本例示范如何使用Asio实现一个UDP客户端程序。
#include
<
iostream
>
#include
<
boost
/
array.hpp
>
#include
<
boost
/
asio.hpp
>
using
boost::asio::ip::udp;
The start of the application is essentially the same as for the TCP daytime client.
应用程序的开始部分同TCP daytime客户端在本质上是相同的。
int
main(
int
argc,
char
*
argv[])
{
try
{
if
(argc
!=
2
)
{
std::cerr
<<
"
Usage: client <host>
"
<<
std::endl;
return
1
;
}
boost::asio::io_service io_service;
We use an boost::asio::ip::udp::resolver object to find the correct remote endpoint to use based on the host and service names. The query is restricted to return only IPv4 endpoints by the boost::asio::ip::udp::v4() argument.
我们使用boost::asio::ip::udp::resolver对象来找到正确的基于主机和服务器名称的远程终端。使用boost::asio::ip::udp::v4()参数来限制query 仅仅返回IPv4的节点。
The boost::asio::ip::udp::resolver::resolve() function is guaranteed to return at least one endpoint in the list if it does not fail. This means it is safe to dereference the return value directly.
如果函数没有失败，boost::asio::ip::udp::resolver::resolve() 保证至少返回列表中一个节点。这意味着直接解引用（提领）返回值是安全的。
Since UDP is datagram-oriented, we will not be using a stream socket. Create an boost::asio::ip::udp::socket and initiate contact with the remote endpoint.
udp::socket socket(io_service);
socket.open(udp::v4());
boost::array < char , 1 > send_buf = { 0 };
socket.send_to(boost::asio::buffer(send_buf), receiver_endpoint);
Now we need to be ready to accept whatever the server sends back to us. The endpoint on our side that receives the server's response will be initialised by boost::asio::ip::udp::socket::receive_from().
boost::array < char , 128 > recv_buf;
udp::endpoint sender_endpoint;
size_t len = socket.receive_from(
boost::asio::buffer(recv_buf), sender_endpoint);
std::cout.write(recv_buf.data(), len);
}
Finally, handle any exceptions that may have been thrown.
最后，处理可能抛出的任何异常。
catch (std::exception & e)
{
std::cerr << e.what() << std::endl;
}
return 0 ;
}
See the full source listing
全部源码：
// client.cpp
// ~~~~~~~~~~
//
// Copyright (c) 2003-2008 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt )
//
#include < iostream >
#include < boost / array.hpp >
#include < boost / asio.hpp >
using boost::asio::ip::udp;
int main( int argc, char * argv[])
{
try
{
if (argc != 2 )
{
std::cerr << " Usage: client <host> " << std::endl;
return 1 ;
}
boost::asio::io_service io_service;
udp::resolver resolver(io_service);
udp::resolver::query query(udp::v4(), argv[ 1 ], " daytime " );
udp::endpoint receiver_endpoint = * resolver.resolve(query);
udp::socket socket(io_service);
socket.open(udp::v4());
boost::array < char , 1 > send_buf = { 0 };
socket.send_to(boost::asio::buffer(send_buf), receiver_endpoint);
boost::array < char , 128 > recv_buf;
udp::endpoint sender_endpoint;
size_t len = socket.receive_from(
boost::asio::buffer(recv_buf), sender_endpoint);
std::cout.write(recv_buf.data(), len);
}
catch (std::exception & e)
{
std::cerr << e.what() << std::endl;
}
return 0 ;
}
Daytime.5 - A synchronous UDP daytime server
一个同步的UDP daytime服务器
This tutorial program shows how to use asio to implement a server application with UDP.
本例示范如何使用Asio实现一个UDP服务器应用程序。
int
main()
{
try
{
boost::asio::io_service io_service;
Create an boost::asio::ip::udp::socket object to receive requests on UDP port 13.
创建一个boost::asio::ip::udp::socket对象用来接收来自UDP端口13的请求。
udp::socket socket(io_service, udp::endpoint(udp::v4(),
13
));
Wait for a client to initiate contact with us. The remote_endpoint object will be populated by boost::asio::ip::udp::socket::receive_from().
服务器一直等待直到客户端发起同它的连接。remote_endpoint 对象将被boost::asio::ip::udp::socket::receive_from()初始化。
for
(;;)
{
boost::array
<
char
,
1
>
recv_buf;
udp::endpoint remote_endpoint;
boost::system::error_code error;
socket.receive_from(boost::asio::buffer(recv_buf),
remote_endpoint,
0
, error);
if
(error
&&
error
!=
boost::asio::error::message_size)
throw
boost::system::system_error(error);
Determine what we are going to send back to the client.
确定服务器将要传回给客户端的信息。
std::
string
message
=
make_daytime_string();
Send the response to the remote_endpoint.
给信息发送给远程终端。
boost::system::error_code ignored_error;
socket.send_to(boost::asio::buffer(message),
remote_endpoint,
0
, ignored_error);
}
}
Finally, handle any exceptions.
最后，处理任何异常。
catch
(std::exception
&
e)
{
std::cerr
<<
e.what()
<<
std::endl;
}
return
0
;
}
See the full source listing
// server.cpp
// ~~~~~~~~~~
//
// Copyright (c) 2003-2008 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt )
//
#include < ctime >
#include < iostream >
#include < string >
#include < boost / array.hpp >
#include < boost / asio.hpp >
using boost::asio::ip::udp;
std:: string make_daytime_string()
{
using namespace std; // For time_t, time and ctime;
time_t now = time( 0 );
return ctime( & now);
}
int main()
{
try
{
boost::asio::io_service io_service;
udp::socket socket(io_service, udp::endpoint(udp::v4(), 13 ));
for (;;)
{
boost::array < char , 1 > recv_buf;
udp::endpoint remote_endpoint;
boost::system::error_code error;
socket.receive_from(boost::asio::buffer(recv_buf),
remote_endpoint, 0 , error);
if (error && error != boost::asio::error::message_size)
throw boost::system::system_error(error);
std:: string message = make_daytime_string();
boost::system::error_code ignored_error;
socket.send_to(boost::asio::buffer(message),
remote_endpoint, 0 , ignored_error);
}
}
catch (std::exception & e)
{
std::cerr << e.what() << std::endl;
}
return 0 ;
}
Daytime.5 - A synchronous UDP daytime server
一个同步的UDP daytime服务器
This tutorial program shows how to use asio to implement a server application with UDP.
本例示范如何使用Asio实现一个UDP服务器应用程序。
int
main()
{
try
{
boost::asio::io_service io_service;
Create an boost::asio::ip::udp::socket object to receive requests on UDP port 13.
创建一个boost::asio::ip::udp::socket对象用来接收来自UDP端口13的请求。
udp::socket socket(io_service, udp::endpoint(udp::v4(),
13
));
Wait for a client to initiate contact with us. The remote_endpoint object will be populated by boost::asio::ip::udp::socket::receive_from().
服务器一直等待直到客户端发起同它的连接。remote_endpoint 对象将被boost::asio::ip::udp::socket::receive_from()初始化。
for
(;;)
{
boost::array
<
char
,
1
>
recv_buf;
udp::endpoint remote_endpoint;
boost::system::error_code error;
socket.receive_from(boost::asio::buffer(recv_buf),
remote_endpoint,
0
, error);
if
(error
&&
error
!=
boost::asio::error::message_size)
throw
boost::system::system_error(error);
Determine what we are going to send back to the client.
确定服务器将要传回给客户端的信息。
std::
string
message
=
make_daytime_string();
Send the response to the remote_endpoint.
给信息发送给远程终端。
boost::system::error_code ignored_error;
socket.send_to(boost::asio::buffer(message),
remote_endpoint,
0
, ignored_error);
}
}
Finally, handle any exceptions.
最后，处理任何异常。
catch
(std::exception
&
e)
{
std::cerr
<<
e.what()
<<
std::endl;
}
return
0
;
}
See the full source listing
// server.cpp
// ~~~~~~~~~~
//
// Copyright (c) 2003-2008 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt )
//
#include < ctime >
#include < iostream >
#include < string >
#include < boost / array.hpp >
#include < boost / asio.hpp >
using boost::asio::ip::udp;
std:: string make_daytime_string()
{
using namespace std; // For time_t, time and ctime;
time_t now = time( 0 );
return ctime( & now);
}
int main()
{
try
{
boost::asio::io_service io_service;
udp::socket socket(io_service, udp::endpoint(udp::v4(), 13 ));
for (;;)
{
boost::array < char , 1 > recv_buf;
udp::endpoint remote_endpoint;
boost::system::error_code error;
socket.receive_from(boost::asio::buffer(recv_buf),
remote_endpoint, 0 , error);
if (error && error != boost::asio::error::message_size)
throw boost::system::system_error(error);
std:: string message = make_daytime_string();
boost::system::error_code ignored_error;
socket.send_to(boost::asio::buffer(message),
remote_endpoint, 0 , ignored_error);
}
}
catch (std::exception & e)
{
std::cerr << e.what() << std::endl;
}
return 0 ;
}