Unix, pre 5.10: 42
-nle'@_=();@_[unpack"C*",$_]=/./g;print@_'

Windows, pre 5.10: 40
-nle@_=();@_[unpack'C*',$_]=/./g;print@_

Unix, 5.10+: 40:
-nlE'@_=();@_[unpack"C*",$_]=/./g;say@_'

Windows, 5.10+: 38:
-nlE@_=();@_[unpack'C*',$_]=/./g;say@_