@a = map unpack('N', $_),
     sort
     map pack('N', $_),
     65, 66, 67, 97, 98, 99;

  => 97, 65, 98, 66, 99, 67  using "use locale" on your system.
     a   A   b   B   c   C

  => 65, 66, 67, 97, 98, 99  using "no locale".
     A   B   C   a   b   c