C + + uses sockets for TCP,UDP network communication

Learning Xinxin Sun Teacher's VC + +, there is a period of time, the first contact socket to tell the truth a bit do not understand, the first is basically to see him say a sentence I write a complete, the second time in the look at the socket a little bit feel, Next I use the socket to complete the TCP and UDP two communication mode of the process and code to share, I hope to be a little bit of help to everyone, what is wrong to welcome you to the great God.

TCP

TCP is a point-to-point communication mode, high quality data transmission, for the transmission of high data integrity requirements of the general use of TCP, specific to VC + +, the general choice is server/client mode, socket TCP communication in the server side generally divided into the following steps:

Server-side

1. Load socket font, load socket library code is generally fixed each copy below OK.

      WORD wversionrequested;
      wsadata wsadata;
      int err;
      Wversionrequested=makeword ();
      Err=wsastartup (Wversionrequested,&wsadata) ;
      if (err!=0)
    {
    return;
   }
      if (Lobyte (wsadata.wversion)!=1| | Hibyte (wsadata.wversion)!=1)
   {

WSACleanup ();
Return
}

2. Creating sockets

SOCKET Socksrv=socket (af_inet,sock_stream,0);
Sockaddr_in sockaddr;//Create an address structure, set its variables
Sockaddr.sin_addr. S_un. S_addr=htonl (Inaddr_any);
Sockaddr.sin_family=af_inet;
Sockaddr.sin_port=htons (6000);

3. Connect sockets and IP addresses and ports

Bind (Socksrv, (sockaddr*) &sockaddr,sizeof (sockaddr));//Binding

4. Set the socket to listen mode

Listen (socksrv,5);//set to listening mode

5. Create a linked socket

Sockaddr_in sockclient;
int len=sizeof (SOCKADDR);
Socket Sockcon=accept (SOCKSRV, (sockaddr*) &sockclient,&len);//create a linked socket

6. Sending and receiving data to the client

Char sendbuf[100];

Send (Sockcon,sendbuf,strlen (SENDBUF) +1,0);
Char recvbuf[100];
Recv (sockcon,recvbuf,100,0);//send \ receive function

7. Close the socket

Closesocket (Sockcon);//Close socket

Client

1. Loading socket font

As with server-side code, direct replication can

2. Creating sockets

SOCKET Sockclient=socket (af_inet,sock_stream,0);
Sockaddr_in sockaddr;
Sockaddr.sin_addr. S_un. S_ADDR=INET_ADDR ("127.0.0.1");
Sockaddr.sin_family=af_inet;
Sockaddr.sin_port=htons (6000);

3. Sockets and IP addresses and port connections

Connect (sockclient, (sockaddr*) &sockaddr,sizeof (sockaddr));

4. Send and receive data to the server

Char recvbuf[100];
Recv (sockclient,recvbuf,100,0);
printf ("%s\n", recvbuf);
Send (sockclient, "Hello Server", strlen ("Server Hello") +1,0);

5. Close the socket

Closesocket (sockclient);
WSACleanup ();

Don't forget to add the header file #include<winsock2.h> at the same time to link ws2_32.lib. And then it's OK.

Udp

UDP is a non-connected, broadcast-based data transmission mechanism, its real-time high, the integrity of the output transmission can not be guaranteed, for some real-time requirements high, the integrity of the situation is not high use of UDP.

Server-side

1. Loading socket font

Don't say anything, just copy it.

2. Create a UDP socket

SOCKET Socksrv=socket (af_inet,sock_dgram, 0);//The difference between this parameter in the main and TCP mode
Sockaddr_in sockaddr;//Create an address structure, set its variables
Sockaddr.sin_addr. S_un. S_addr=htonl (Inaddr_any);
Sockaddr.sin_family=af_inet;
Sockaddr.sin_port=htons (6000);

3. Bind sockets and IP addresses and ports

Bind (Socksrv, (sockaddr*) &sockaddr,sizeof (sockaddr));//Binding

4. Receiving data

The reception function here is recvfrom ();

5. Close the socket

Closesocket (sock);

Client

1. Loading socket font

Don't say anything, just copy it.

2. Create a UDP socket

SOCKET Sockclient=socket (af_inet,sock_dgram, 0);
Sockaddr_in sockaddr;
Sockaddr.sin_addr. S_un. S_ADDR=INET_ADDR ("127.0.0.1");
Sockaddr.sin_family=af_inet;
Sockaddr.sin_port=htons (6000);

3. Send data

SendTo ();//The Sending function is also different

4. Close the socket

Closesocket (sockclient);
WSACleanup ();

Don't forget to add the header file #include<winsock2.h> at the same time to link ws2_32.lib. And then it's OK.

C + + uses sockets for TCP,UDP network communication