First, please read below contents aloud:

Not all Perl programs have to be portable There is no reason you should not use Perl as a language to glue Unix tools together, or to prototype a Macintosh application, or to manage the Windows registry. If it makes no sense to aim for portability for one reason or another in a given program, then don't bother.

Secondly, run perldoc perlport, and read carefully. it explains clearly (I think) why perl and perl standard modules are also possible not usable in all support platforms....