"Network programming Notes" Simple TCP protocol Socket programming (C language Edition Server and client)

is a generic socket programming diagram .

Establishment of the server:

Gets the native name used to parse the IP address of the machine, then the IP address is successfully bound, then the server is listening, waiting for the client to connect. That is, the next step is the TCP/IP three handshake operation, the operation succeeds the server and the client can communicate. Here is the comment code:

1 voidSocketconnect ()2 {3     Charserver_name[ -];4 wsadata wsadata;5     structHostent *HP;6     structsockaddr_in addrserver;7     8WSAStartup (0x202, &wsadata);9     TenSOCKFD = socket (af_inet, Sock_stream,0);//Socket OneGetHostName (server_name, -); AHP = gethostbyname (server_name);//get the native name -printf"machine Name:%s\n", server_name); -  thememset (&addrserver,0,sizeof(Addrserver));//Initialize -memcpy (& (ADDRSERVER.SIN_ADDR), hp->h_addr, hp->h_length);//set the IP address of the server -addrserver.sin_family = af_inet;//Set Version -Addrserver.sin_port = htons ((unsigned Short) server_port);//set the port number +     //bind .... Bind IP address and port number -     if(Socket_error = = Bind (SOCKFD, (LPSOCKADDR) &addrserver,sizeof(Addrserver))) +     { Aprintf"Bind Socket error!\n"); at         //exit (1); -     } -     Else -     { -printf"bind socket success...\n"); -     } inListen (SOCKFD,5);//listening ... Monitor -printf"Server listening status ... \ n"); to  +ZeroMemory ((void*) &addrtemp,sizeof(addrtemp)); -Nlen =sizeof(addrtemp); theCONNFD = Accept (SOCKFD, &addrtemp, &nlen);//Accept ... Three-time handshake *printf"Accept Client success...\n\n"); $}

Client-side creation:

In fact, the client and server code are similar, but the most behind a connect () function, is to send a request link to the server, because the server in the Accept () function block waiting for the client link, and then after three handshake, after success, the server and the client can communicate.

1WSAStartup (0x202, &wsadata);2 if(SOCKFD = socket (af_inet, Sock_stream,0)) <0)//socket ...3 {4printf"Socket error!\n");5Exit1);6 }    7GetHostName (server_name, -);8Host = gethostbyname (server_name);//get the native name9printf"machine Name:%s\n", server_name);Ten  Onememset (&addrserver,0,sizeof(Addrserver));//Initialize Amemcpy (& (ADDRSERVER.SIN_ADDR), host->h_addr, host->h_length);//Set IP -addrserver.sin_family = af_inet;//Set the version number -Addrserver.sin_port = htons ((unsigned Short) server_port);//set the port number the  - //connect .... Initiating a link to the server - if(Connect (SOCKFD,structSOCKADDR *) &addrserver,sizeof(structsockaddr ))) - { +printf"Connect error!\n"); -Exit1); + } Aprintf"Connection Server succeeded Connec success...\n\n");

Next is the Send () and recv () functions:

1 //send ... Send Message2scanf"%s", sendbuf);3 GetChar ();4 5 if(sendbytes = Send (CONNFD, SendBuf, strlen (SENDBUF),0)) <=0)6 {7printf"Send Error!\n");8     Continue;9 }Tenmemset (SendBuf,0,sizeof(SENDBUF));

1 //recv ... Receiving Messages2memset (Recvbuf,0,sizeof(RECVBUF));3 if(Recvbytes = recv (CONNFD, Recvbuf,sizeof(RECVBUF),0)) <=0)4 {5printf"recv error!\n");6Exit1);7 }8printf"recvbytes =%d\n", recvbytes);9printf"recv from client:%s\n", RECVBUF);

Reference Original: http://blog.csdn.net/shiren_bod/article/details/6647022

"Network programming Notes" Simple TCP protocol Socket programming (C language Edition Server and client)