Boost ASIO learning note [1]-synchronous communication

This article uses a sample code to illustrate how to use the boost ASIO for synchronous communication.

#include  <iostream> #include  <boost/asio.hpp>using namespace std;using  Boost::asio::ip::tcp; int main () {    boost::asio::io_service    IOSERVICE;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;&NBSP;//&NBSP;I/O Event model encapsulation, such as win under the IOCP , Unix under the Poll, linux under the Epoll and so on     tcp::socket                socket (Ioservice);       tcp:: endpoint             endpoint;   &NBSP;&NBSP;&NBSP;//&NBSP;TCP endpoint, including address and Port     boost::system::error_code errcode;     tcp::resolver resolver (ioservice);      //  address name Resolver     tcp::resolver::iterator iter_endpoint;           // reSolver can return multiple addresses at once, using iterators to access     tcp::resolver::query query ("mail.163.com",  "POP3");           //  Host address Query condition class, the first parameter is the hostname, and the next one is the service name of the desired connection.         //  Specify the service name to enable the returned endpoint to include the host address, and also set the default port for the service (for example, POP3 default port is 110         //  If you only need to query the host address, the service name can be an empty string (the Returned Endpoint.port () ==0)          iter_endpoint = resolver.resolve (Query, errcode);   //  resolve the required service address     if  ( errcode.value ()  != 0)  {         cout<< "error code: " <<errcode.value () << ", " << "error message: " <<errcode.message () <<endl;         return 1;    }         //  Gets the target service endpoint address and port foundstored in endpoint instances)     endpoint = iter_endpoint->endpoint ();      cout<<endpoint.address () << ":" <<endpoint.port () <<endl;    &NBSP;&NBSP;&NBSP;&NBSP;&NBSP;//&NBSP;POP3 Command     const char *cmd_user =   "user myuser\n";    const char *cmd_pass =  "pass  mypass\n ";    const char *cmd_list = " list\n ";     const char *cmd_quit =  "quit\n";    char result[256];    //  server returns message Cache         try {         //  connect the POP3 server and get the server welcome message. The         // boost::asio::buffer function creates a cache wrapper object with an internal address pointing to the result variable          socket.connect (endpoint);            size_t len = socket.read_some (Boost::asio::buffer (result,  256));        if  ( len > 0 )  {             result[len] =  ';  '            cout<< "received: " <<result <<endl;        }                 //  Send user command,  and receive reply          socket.send (Boost::asio::buffer (Cmd_user, strlen (Cmd_user)));         len = socket.read_some (Boost::asio::buffer (result, 256));         if  ( len > 0 )  {             result[len] =  ';             cout<< "received: " <<result<<endl;         }        //  Send Password command,  and receive reply          socket.send (Boost::asio::buffer (Cmd_pass, strlen (Cmd_pass)));         len = socket.read_some (Boost::asio::buffer (result, 256));         if  ( len > 0 )  {             result[len] =  ';     '         cout<< "received: " <<result<<endl;         }        //  Send Exit command,   Receive reply   &nbsP;     socket.send (Boost::asio::buffer (Cmd_quit, strlen (cmd_quit)));         len = socket.read_some (Boost::asio::buffer (result, 256));         if  ( len > 0 )  {             result[len] =  ';    '          cout<< "received: " <<result<<endl;         }        socket.close ( );    } catch  (const boost::system::system_error& e)  {         cout<< "connect error: " <<e.what () <<endl;     }    return 0;}

Boost ASIO learning note [1]-synchronous communication