Note on ISO−2022−JP(−1)?


Encode::JP − Japanese Encodings


    use Encode qw/encode decode/;
    $euc_jp = encode("euc−jp", $utf8);   # loads Encode::JP implicitly
    $utf8   = decode("euc−jp", $euc_jp); # ditto


This module implements Japanese charset encodings. Encodings supported are as follows.

  Canonical   Alias             Description
  euc−jp      / euc.*jp$/i     EUC (Extended Unix Character)
              / jp.*euc/i
          / ujis$/i
  shiftjis    / shift.*jis$/i  Shift JIS (aka MS Kanji)
          / sjis$/i
  7bit−jis    / jis$/i         7bit JIS
  iso−2022−jp                   ISO−2022−JP                  [RFC1468]
                = 7bit JIS with all Halfwidth Kana
                  converted to Fullwidth
  iso−2022−jp−1                 ISO−2022−JP−1                [RFC2237]
                                = ISO−2022−JP with JIS X 0212−1990
                  support.  See below
  MacJapanese                   Shift JIS + Apple vendor mappings
  cp932       / windows−31j$/i Code Page 932
                                = Shift JIS + MS/IBM vendor mappings
  jis0201−raw                   JIS0201, raw format
  jis0208−raw                   JIS0201, raw format
  jis0212−raw                   JIS0201, raw format


To find out how to use this module in detail, see Encode.

Note on ISO−2022−JP(−1)?

ISO−2022−JP−1 ( RFC2237 ) is a superset of ISO−2022−JP ( RFC1468 ) which adds support for JIS X 0212−1990. That means you can use the same code to decode to utf8 but not vice versa.

  $utf8 = decode('iso−2022−jp−1', $stream);


  $utf8 = decode('iso−2022−jp',   $stream);

yield the same result but

  $with_0212 = encode('iso−2022−jp−1', $utf8);

is now different from

  $without_0212 = encode('iso−2022−jp', $utf8 );

In the latter case, characters that map to 0212 are first converted to U+3013 (0xA2AE in EUC-JP; a white square also known as ’Tofu’ or ’geta mark’) then fed to the decoding engine. U+FFFD is not used, in order to preserve text layout as much as possible.


The ASCII region (0x00−0x7f) is preserved for all encodings, even though this conflicts with mappings by the Unicode Consortium.




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