求解select函数为啥一直返回值为0

面包加火腿

[C++] 纯文本查看 复制代码

int CConnectScan::scan(const char *IP,int start,int stop)
{
	WORD wVersion;
	WSADATA WsaData;
	int time;
	struct timeval timeout;
	struct fd_set fdset;
	wVersion = MAKEWORD(2, 2);
	if (WSAStartup(wVersion, &WsaData) != 0)    //初始化Winsock DLL
	{
		printf("未找到可用winsock.dll！ \n");
		return -1;
	}
	SOCKET PortScanSock = socket(AF_INET, SOCK_STREAM, 0);
	unsigned long ul = 1;
	if (ioctlsocket(PortScanSock, FIONBIO, (unsigned long*)&ul) == SOCKET_ERROR)
		return 0;
	SOCKADDR_IN ADDR;
	ADDR.sin_family = AF_INET;
	ADDR.sin_addr.S_un.S_addr = inet_addr(IP);
	for (int Port = start; Port <= stop; Port++)
	{
		if (PortScanSock == NULL)
			PortScanSock = socket(AF_INET, SOCK_STREAM, 0);
		ADDR.sin_port = (Port);
		connect(PortScanSock, (sockaddr*)&ADDR, sizeof(ADDR));
		FD_ZERO(&fdset);
		FD_SET(PortScanSock, &fdset);
		timeout.tv_sec = 0;
		timeout.tv_usec = 500 * 1000;
		time = select(PortScanSock + 1, 0, &fdset, 0, &timeout);
		PortDetil result;
		result.PortNum = Port;
		if (time <= 0)
		{
			result.OpenFlag = 0;
			list.push_back(result);
		}
		else
		{
			result.OpenFlag = 1;
			list.push_back(result);
			closesocket(PortScanSock);
			PortScanSock = NULL;
		}
	}
}

刚学网络编程不是很懂，select返回值一直为0，百度了一下没改过来==！好悲剧

昊情·

刚学得有必要学的那么深吗？99乘法表那些算法懂了没？

面包加火腿

昊情· 发表于 2016-1-27 11:20
刚学得有必要学的那么深吗？99乘法表那些算法懂了没？

初学网络编程，不是初学编程，动态规划，贪婪这些算法也都学过了，虽然不精通懂得少，但至少会用可以做OJ的算法题。我问的不够谦虚？有必要提算法么？

perble

学习学习技术，加油！

ruguoruo

学习学习技术，加油！

perble

还是不错的哦，顶了

ljy07

学习学习技术，加油！

fireworld

感谢楼主的分享~

Lucifer

还是不错的哦，顶了

HUC-参谋长

还是不错的哦，顶了