software estimation

I have a piece of code written to copy files, and a lot more, to a mainframe. I have to write another piece of code, from scratch, to do the same of actions to the same set to a UNIX box. I have to estimate how long it will take to write the second piece using the first piece as my starting block. Does anyone know of any methodologies which I can say, given x lines of code, it may take me n hours? The target language is PERL, but I could substitute C/C++ at a pinch.

>>1
If you have no idea how long it'll take you, tell whoever that you need time to assess how much time it'll take. Then stop and fucking think about the problem. Once you've got an estimate of how long it'll take you either double or triple it (depending on the scope of the problem and your domain knowledge) and give that to them.

That's the trick to being a miracle worker.