use strict;
use Carp;

my ($l, $r, @err) = split /\./, $test;

carp "oops, more than 2 \.'s.\n" if @err;

if ($l) {
   if ($r) {
      #handle case of rational dollars
   } else {
      #handle case of integer dollars
   }
} else {
   carp "oops, we don't even have a dollar!\n";
}