use SuperSplit;

if ( $^O =~ /linux/){  
  $dir = `ls -l`;       $col = 4;
}else{         #sorry, no macs ;-)
  $dir = `dir -w`; $col = 2;
}

@$sortedref = 
 sort{ $a->[$col] <=> $b->[$col] } @{supersplit('\s+','\n',$dir)};
print superjoin( $sortedref );