PERL UTF-8

encode variable to bytes

    Encode::_utf8_off $buf;

decode 100% valid utf8 data

    Encode::_utf8_on $str;

If we are sure, that input data is valid utf8 string.

decode possible utf8 data

    my $success = utf8::decode $buf;

The UTF-8 flag is turned on only if the source string contains multiple-byte UTF-8 characters.