获取嵌入式开发板的MAC地址，并将其转换为字符串-MAC address for embedded development board, and convert it to a string

嵌入式linux下网口状态检测工具。检测网口是否连接，获取网口ip、子网掩码和mac地址。-a small tool for net port detection based on linux.it can get ip address, mac address , net mask and connection state for each net port.