$ perl -MData::Dumper -E' $Data::Dumper::Useqq = 1; $_ = "e\x{301}"; $h{$_} = 1; say $h{$_} || 0; ' 1 #### $ perl -E' $Data::Dumper::Useqq = 1; $a = "e\x{301}"; $b = "\xE9"; $h{$a} = 1; say $h{$b} || 0; ' 0 #### $ perl -MUnicode::Normalize=NFC -E' $Data::Dumper::Useqq = 1; $a = NFC("e\x{301}"); $b = NFC("\xE9"); $h{$a} = 1; say $h{$b} || 0; ' 1