sub indexex
{
   my ($str, $substr, $position) = @_;
   
   my $start = $position || 0;
   my $len = length $str;
   my $sublen = length $substr;
   my @retval = ();

   return @retval unless $sublen;
   while($start + $sublen < $len)
   {
      if(substr($str, $start, $sublen))
      {
         push @retval, $start;
      } 
      $start++;
   }

   return @retval;
}