I wrote the first reply in about 10 minutes and had to leave. Let me be more clear about the is_utf8 flag check. Don't use is_utf8. is_utf8 checks if a string is internally encoded in utf8. Deep inside the angry bowels of perl! Using is_utf8 is fraught with peril, which is unfortunate for such a seemingly easy function, right? It doesn't do what you think it does.
You didn't read the unicode docs did you? Here is a great link: http://perldoc.perl.org/perlunifaq.html#What-is-%22the-UTF8-flag%22%3f. There is also perluniintro, perlunicode, utf8 etc. Feel free to continue screwing yourself by not reading these. Don't forget to not read the link I gave in my first reply.
Now I have time to reply to your bullets:
- use utf8 is necessary for writing your source code in utf8. This is only useful for writing string literals in utf8, since there is not yet a snowman operator (perl6?). Your output is probably garbled because your string literal ($umbreon) is written in utf8 and perl has no way to know this without the use utf8.
- Your terminal/shell is utf8 compatible. It translates everything as utf8. You can print each byte of a utf8 character separately and your terminal would decode it as utf8.
- The UTF8 is not corrupted. The UTF8 is just fine. You are encoding it twice.
- You are encoding, decoding, and encoding again.
- With utf8 turned on, JSON will decode the byte string you provide it from utf8 to perl's internal string representation.
In response to your latest reply: Stop worrying about the utf8 flag and just worry about encoding once and decoding once. Don't encode with JSON if you are encoding to utf8 before writing to the file. Vice-versa with decode. That's all you need to worry about. Remember, this also applies to STDOUT.
The wide characters are probably mangled because you are using a utf8 string constant.