From: Greg Hurrell <greg.hurrell@...>
Date: 2007-02-25T23:20:05+09:00
Subject: Re: Using unpack on a UTF-8 string

On 24 feb, 23:47, Carlos <a...@quovadis.com.ar> wrote:
>
> The UNICODE codepoint for the euro sign is 8364. In your string you have
> that number encoded as a sequence of bytes [226, 130, 172]. That encoding is
> known as UTF-8. #unpack decodifies that sequence of bytes and gives you the
> number.
>
> For analogy, think as if you had the string "\272!\000\000" and did an
> #unpack("I"). The sequence of bytes [186, 33, 0, 0] also represent the
> number 8364, but this time encoded in the internal format my computer uses.
> #unpack retrieves that number. The fact that UTF-8 is used for encoding
> UNICODE codepoints is incidental to this.
>
> To unpack the bytes from a string use #unpack("C*").

Thanks a million, Carlos. I never would have figured that out for
myself. I misunderstood the documentation for String#unpack:

C    | Fixnum  | extract a character as an unsigned integer
U    | Integer | UTF-8 characters as unsigned integers

unpack('C*') does indeed give me what I want...

Cheers,
Greg