Winsock Service Program

# Include <winsock2.h>
# Include <stdio. h>

Int main (INT argc, char ** argv)
{
Wsadata;
Char hostname [256];
Hostent * hostent;
Protoent * protoent;
In_addr ** ADDR;
Char * ipaddr;
Socket socket;
Sockaddr_in sin;
Socket acceptsocket;
 
// Initialize Winsock
If (wsastartup (makeword (2, 2), & wsadata ))
{
Printf ("init Winsock failed! \ N ");
Return 1;
}

// Obtain the Host Name
Gethostname (hostname, 256 );
Printf ("% s \ n", hostname );

// Obtain host information
Hostent = gethostbyname (hostname );
Printf ("% s \ n", hostent-> h_name );
 
// List Host IP addresses
ADDR = (in_addr **) hostent-> h_addr_list;
While (* ADDR)
{
Ipaddr = inet_ntoa (** ADDR );
Printf ("% s \ n", ipaddr );
ADDR ++;
}

 
// Create a socket
 
Protoent = getprotobyname ("TCP ");
 
Socket = socket (af_inet, sock_stream, protoent-> p_proto );

If (socket <0)
{
Printf ("socket error! ");
Return 2;
}

 
// Bind a socket
Sin. sin_port = htons (23 );
Sin. sin_family = af_inet;
Sin. sin_addr.s_addr = 0;

If (BIND (socket, (sockaddr *) & sin, sizeof (SIN )))
{
Printf ("% s \ n", "socket error! ");
Return 3;
}

// Listen for requests
If (Listen (socket, 1 ))
{
Printf ("% s", "socket error! ");
Return 4;
}
 
//
While (1)
{
Acceptsocket = socket_error;
While (acceptsocket = socket_error)
{
Acceptsocket = accept (socket, (sockaddr *) & sin, null );
}
Printf ("Client Connected. \ n ");
Break;
}

Char MSG [] = "\ r \ n = connected! = \ R \ n ";

Printf ("% d \ n", send (acceptsocket, MSG, strlen (MSG), 0 ));

// Disable the socket sending and receiving function
Shutdown (acceptsocket, 0 );

Closesocket (acceptsocket );
Closesocket (socket );

// Cancel the blocked socket
If (wsaisblocking () wsacancelblockingcall ();
 
// Release Winsock Resources
Wsacleanup ();
 
Return 0;
}