-d $s and $s = abs_path($s) or return -1 ; 
  -d $d and $d = abs_path($d) or return -1 ; 

##</code><code>##

  -d $_ and $_ = abs_path($_) or return -1 for $s, $d;

##</code><code>##

 (-d $_) ? ($_ = abs_path($_)) : (return -1) for $s, $d;