In case compile errors like "cannot include <unistd.h>" in win_flex generated file try add --wincompat invoke option.
This new option changes <unistd.h> unix header with windows analog <io.h> and replaces isatty/fileno functions to
"safe" windows analogs _isatty/_fileno as well. If you have compile issues with it afterwards please open ticket
at http://sourceforge.net/p/winflexbison/tickets .