unix网络编程 chapter4.11代码改写

sever显示client的IP地址和端口：

#include"WinSock2.h"
#include "time.h"
#include "stdio.h"

#include <iostream>

#pragma comment(lib,"WS2_32")

using namespace std;

const int MaxLine = 1024;

int main()
{
	int lRet = 0;
	WSADATA lWsaData;
	if ((lRet = WSAStartup(MAKEWORD(2,2), &lWsaData)) != 0)
	{
		cout << "Error " << lRet << endl;
		return 0;
	}

	int lListen = 0, lConnfd = 0;
	SOCKADDR_IN lServAddr;
	char lBuf[MaxLine];
	time_t lTicks;

	lServAddr.sin_family = AF_INET;
	lServAddr.sin_addr.s_addr = htonl(INADDR_ANY);
	lServAddr.sin_port = htons(9999);

	SOCKET lSocket = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
	if (INVALID_SOCKET == lSocket)
	{
		cout << "INVALID_SOCKET" << endl;
		return 0;
	}
	bind(lSocket,(sockaddr*)(&lServAddr),sizeof(lServAddr));
	listen(lSocket,5);

	while(true)
	{
		SOCKADDR_IN lClientAddr;
		int lLen = sizeof(lClientAddr);
		SOCKET lAcceptedSocket = accept(lSocket,(sockaddr*)&lClientAddr,&lLen);
		printf("Connection from %s, port %d\n",inet_ntoa(lClientAddr.sin_addr),ntohs(lClientAddr.sin_port));
		lTicks = time(NULL);
		sprintf(lBuf, "%.24s\r\n", ctime(&lTicks));
		char *lTempStr = lBuf;
		int lSize = strlen(lBuf);
		for (int i = 0; i < lSize; ++i)
		{
			send(lAcceptedSocket,lBuf+i,1,0);
		}
		closesocket(lAcceptedSocket);
	}
}

　　

重点是这句：

SOCKET lAcceptedSocket = accept(lSocket,(sockaddr*)&lClientAddr,&lLen);

lAcceptedSocket是sever监听到来自客户端的connection并接受链接后创建的已连接socket，当完成本次client服务时，lAcceptedSocket就会关闭。accept不仅返回了已连接套接字，而且更新了lClientAddr和lLen，这就是书中提到的“值-结果参数”方法，也就是C++里面的引用形参，嗯，这个示例就这些了！