perl -e '
  my $str = { map { $_ => "\x{A9}" } qw(byte char) };
  utf8::upgrade($str->{char});
  for (keys %$str) {
    open (my $fh, "<", \do{$str->{$_}});
    printf( "$_ is read as %s\n", unpack "H*", <$fh>);
  }
  printf "Strings are: %s\n",
    ($str->{byte} eq $str->{char} ? "equal" : "different")
  ;
'