基于套接字的编程

基于TCP的套接字编程流程：

服务器端程序：

#include <Winsock2.h>
#include <stdio.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[100];
		sprintf(sendBuf,"Welcome %s to http://www.sunxin.org",
			inet_ntoa(addrClient.sin_addr));
		send(sockConn,sendBuf,strlen(sendBuf)+1,0);
		char recvBuf[100];
		recv(sockConn,recvBuf,100,0);
		printf("%s\n",recvBuf);
		closesocket(sockConn);
	}
}

客户端程序：

#include <Winsock2.h>
#include <stdio.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));

	char recvBuf[100];
	recv(sockClient,recvBuf,100,0);
	printf("%s\n",recvBuf);
	send(sockClient,"This is lisi",strlen("This is lisi")+1,0);

	closesocket(sockClient);
	WSACleanup();
	system("pause");
}

效果图：

基于UDP的套接字编程流程：