用 mingw rebuild linux network ap, 找不到 netdn.h, inet.h, socket.h

google 到是 在 win32 改用 winsock2.h, 但我還沒有用看看, 我乾脆用 cygwin 

#ifdef WIN32
# include  < winsock2.h >
#else
# include  < netdn.h >
# include  < inet.h >
# include  < socket.h>
# include
# indlude
#endif