依赖函数:
if_nametoindex IF名字 to IF索引
if_indextoname IF索引 to IF名字
MACOS 10.7 版本支援(就是2011年发不OSX的第一个面向用的系统版本)
int GetInterfaceIndex(const ppp::string& ifrName) noexcept{if (ifrName.empty()){return -1;}int interface_index = (int)if_nametoindex(ifrName.data());if (interface_index == 0 || interface_index == -1){return -1;}return interface_index;}bool GetInterfaceName(int interface_index, ppp::string& ifrName) noexcept{ifrName.clear();if (interface_index == 0 || interface_index == -1){return false;}char buf[255];if (if_indextoname((unsigned int)interface_index, buf)){char ch = *buf;if (ch == '\x0'){return false;}ifrName = buf;return true;}else{return false;}}