A couple of points:

• You should omit the ampersand (&) from your subroutine call.
• You should check for the success or otherwise of the mkdir commands by looking at the return code from system. A non-zero return code would mean something went a bit wonky. It's nice to have faith but your print statement might be a bit optimistic.

I hope this is of interest.

Cheers,

JohnGG