socket通信

前提包含<WinSock2.h>文件，项目的编译链接库包含动态库ws2_32.lib,与其他库之间以空格分开，每个项目都要设置。

运行时，先运行服务器端程序，再运行客户端程序。

1、（1）TCP服务器程序

#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);
	}
}

 （2）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();
}

 2、基于UDP的聊天程序

（1）服务器端程序

#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_DGRAM,0);
	SOCKADDR_IN addrSrv;
	addrSrv.sin_addr.S_un.S_addr=htonl(INADDR_ANY);
	addrSrv.sin_family=AF_INET;
	addrSrv.sin_port=htons(600);

	bind(sockSrv,(SOCKADDR*)&addrSrv,sizeof(SOCKADDR));

	char recvBuf[100];
	char sendBuf[100];
	char tempBuf[200];

	SOCKADDR_IN addrClient;
	int len=sizeof(SOCKADDR);

	while(1)
	{
		recvfrom(sockSrv,recvBuf,100,0,(SOCKADDR*)&addrClient,&len);
		if('q'==recvBuf[0])
		{
			sendto(sockSrv,"q",strlen("q")+1,0,(SOCKADDR*)&addrClient,len);
			printf("Chat end!\n");
			break;
		}
		sprintf(tempBuf,"%s say : %s",inet_ntoa(addrClient.sin_addr),recvBuf);
		printf("%s\n",tempBuf);

		printf("Please input data:\n");
		gets(sendBuf);
		sendto(sockSrv,sendBuf,strlen(sendBuf)+1,0,(SOCKADDR*)&addrClient,len);
	}
	closesocket(sockSrv);
	WSACleanup();
}

 （2）客户端程序

#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_DGRAM,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(600);

	char recvBuf[100];
	char sendBuf[100];
	char tempBuf[200];

	int len=sizeof(SOCKADDR);

	while(1)
	{
		printf("Please input data:\n");
		gets(sendBuf);
		sendto(sockClient,sendBuf,strlen(sendBuf)+1,0,(SOCKADDR*)&addrSrv,len);

		recvfrom(sockClient,recvBuf,100,0,(SOCKADDR*)&addrSrv,&len);
		if('q'==recvBuf[0])
		{
			sendto(sockClient,"q",strlen("q")+1,0,(SOCKADDR*)&addrSrv,len);
			printf("Chat end!\n");
			break;
		}
		sprintf(tempBuf,"%s say : %s",inet_ntoa(addrSrv.sin_addr),recvBuf);
		printf("%s\n",tempBuf);
	}

	closesocket(sockClient);
	WSACleanup();
}