All right, very interesting, thank you.   Now, as a follow-on question:   is there anything out there (e.g. “elsewhere on CPAN”) that would enable people who are intending to write “portable” Perl routines ... and to write them but once ... to (“easily??”) circumvent these differences?   For example, if a Perl program that was originally written with Unix in mind, now needs to be moved to Windows, is there (for instance) some kind of translation-function that could massage a Windows return-code into what a Unix-eyed program would expect?   Something that would let the programmer elegantly ignore the differences, if they chose?