sub to_dotquad {
   # Given a binary int IP, returns dotted-quad (Reverse of ip2num)
   my $bin = shift;
   my $result = ''; # Empty string
   
   for (24,16,8,0){
       $result .= ($bin >> $_  & 255)  . '.';
   }
   chop $result; # Delete extra trailing dot
   return $result;
}