sockets(套接字)編程有三種,流式套接字(SOCK_STREAM),數據報套接字(SOCK_DGRAM),原始套接字(SOCK_RAW);基于TCP的socket編程是采用的流式套接字。在這個程序中,將兩個工程添加到一個工作區。要鏈接一個ws2_32.lib的庫文件。

服務器端編程的步驟:

1:加載套接字庫,創建套接字(WSAStartup()/socket());

2:綁定套接字到一個IP地址和一個端口上(bind());

3:將套接字設置為監聽模式等待連接請求(listen());

4:請求到來后,接受連接請求,返回一個新的對應于此次連接的套接字(accept());

5:用返回的套接字和客戶端進行通信(send()/recv());

6:返回,等待另一連接請求;

7:關閉套接字,關閉加載的套接字庫(closesocket()/WSACleanup())。

服務器端代碼如下:
#include?<stdio.h>
#include?
<Winsock2.h>
void?main()
{
?WORD?wVersionRequested;
?WSADATA?wsaData;
?
int?err;
?
?wVersionRequested?
=?MAKEWORD(?1,?1?);
?
?err?
=?WSAStartup(?wVersionRequested,?&wsaData?);
?
if?(?err?!=?0?)?{
??
return;
?}

?
?
if?(?LOBYTE(?wsaData.wVersion?)?!=?1?||
????????HIBYTE(?wsaData.wVersion?)?
!=?1?)?{
??WSACleanup(?);
??
return;
?}

?SOCKET?sockSrv
=socket(AF_INET,SOCK_STREAM,0);

?SOCKADDR_IN?addrSrv;
?addrSrv.sin_addr.S_un.S_addr
=htonl(INADDR_ANY);
?addrSrv.sin_family
=AF_INET;
?addrSrv.sin_port
=htons(6000);
?
?bind(sockSrv,(SOCKADDR
*)&addrSrv,sizeof(SOCKADDR));

?listen(sockSrv,
5);

?SOCKADDR_IN?addrClient;
?
int?len=sizeof(SOCKADDR);
?
while(1)
?
{
??SOCKET?sockConn
=accept(sockSrv,(SOCKADDR*)&addrClient,&len);
??
char?sendBuf[50];
??sprintf(sendBuf,
"Welcome?%s?to?here!",inet_ntoa(addrClient.sin_addr));
??send(sockConn,sendBuf,strlen(sendBuf)
+1,0);
??
char?recvBuf[50];
??recv(sockConn,recvBuf,
50,0);
??printf(
"%s\n",recvBuf);
??closesocket(sockConn);
?}


}
客戶端編程的步驟:

1:加載套接字庫,創建套接字(WSAStartup()/socket());

2:向服務器發出連接請求(connect());

3:和服務器端進行通信(send()/recv());

4:關閉套接字,關閉加載的套接字庫(closesocket()/WSACleanup())。

客戶端的代碼如下:
#include?<stdio.h>
#include?
<Winsock2.h>
void?main()
{
?WORD?wVersionRequested;
?WSADATA?wsaData;
?
int?err;
?
?wVersionRequested?
=?MAKEWORD(?1,?1?);
?
?err?
=?WSAStartup(?wVersionRequested,?&wsaData?);
?
if?(?err?!=?0?)?{
??
return;
?}

?
?
if?(?LOBYTE(?wsaData.wVersion?)?!=?1?||
????????HIBYTE(?wsaData.wVersion?)?
!=?1?)?{
??WSACleanup(?);
??
return;
?}

?SOCKET?sockClient
=socket(AF_INET,SOCK_STREAM,0);
?
?SOCKADDR_IN?addrSrv;
?addrSrv.sin_addr.S_un.S_addr
=inet_addr("127.0.0.1");
?addrSrv.sin_family
=AF_INET;
?addrSrv.sin_port
=htons(6000);
?connect(sockClient,(SOCKADDR
*)&addrSrv,sizeof(SOCKADDR));
?send(sockClient,
"hello",strlen("hello")+1,0);
?
char?recvBuf[50];
?recv(sockClient,recvBuf,
50,0);
?printf(
"%s\n",recvBuf);
?
?closesocket(sockClient);
?WSACleanup();
}