Already you know from where you are running the perl script and what relative path you give as argument, you can easily make out the original path from that.
IMO the resolved filename is the best that you can expect. because the original filename you can form very easily.
Vivek
-- In accordance with the prarabdha of each, the One whose function it is to ordain makes each to act. What will not happen will never happen, whatever effort one may put forth. And what will happen will not fail to happen, however much one may seek to prevent it. This is certain. The part of wisdom therefore is to stay quiet.