要获得nmap结果，必须等待扫描结束。
如何强制nmap逐渐显示新find的主机，并在运行时打开端口？
添加这个命令行开关：
-v (Increase verbosity level) . Increases the verbosity level, causing Nmap to print more information about the scan in progress. Open ports are shown as they are found and completion time estimates are provided when Nmap thinks a scan will take more than a few minutes. Use it twice or more for even greater verbosity: -vv, or give a verbosity level directly, for example -v3..
来源： https ： //nmap.org/book/man-output.html