Encode::Supported -- Supported encodings by Encode
Encoding names are case insensitive. White space in names is ignored. In addition an encoding may have aliases. Each encoding has one "canonical" name. The "canonical" name is chosen from the names of the encoding by picking the first in the following sequence (with a few exceptions).
The name used by the Perl community. That includes 'utf8' and 'ascii'. Unlike aliases, canonical names directly reach the method so such frequently used words like 'utf8' don't need to do alias lookups.
The MIME name as defined in IETF RFCs This includes all "iso-"'s.
The name in the IANA registry.
The name used by the organization that defined it.
In case de jure canonical names differ from that of the Encode module, they are always aliased if it ever be implemented. So you can safely tell if a given encoding is implemented or not just by passing the canonical name.
Because of all the alias issues, and because in the general case encodings have state, "Encode" uses an encoding object internally once an operation is in progress.
As of Perl 5.8.0, at least the following encodings are recognized. Note that unless otherwise specified, they are all case insensitive (via alias) and all occurrence of spaces are replaced with '-'. In other words, "ISO 8859 1" and "iso-8859-1" are identical.
Encodings are categorized and implemented in several different modules but you don't have to use Encode::XX to make them available for most cases. Encode.pm will automatically load those modules on demand.
use Encode::XX
The following encodings are always available.
Canonical Aliases Comments & References ---------------------------------------------------------------- ascii US-ascii [ECMA] iso-8859-1 latin1 [ISO] utf8 UTF-8 [RFC2279] ----------------------------------------------------------------
Unicode coding schemes other than native utf8 are supported by Encode::Unicode which will be autoloaded on demand.
---------------------------------------------------------------- UCS-2BE UCS-2, iso-10646-1 [IANA, UC] UCS-2LE [UC] UTF-16 [UC] UTF-16BE [UC] UTF-16LE [UC] UTF-32 [UC] UTF-32BE [UC] UTF-32LE [UC] ----------------------------------------------------------------
To find how those (UCS-2|UTF-(16|32))(LE|BE)? differ to one another, see Encode::Unicode.
Encode::Byte implements most of single-byte encodings except for Symbols and EBCDIC. The following encodings are based single-byte encoding implemented as extended ASCII. For most cases it uses \x80-\xff (upper half) to map non-ASCII characters.
Since there are so many, they are presented in table format with languages and corresponding encoding names by vendors. Note the table is sorted in order of ISO-8859 and the corresponding vendor mappings are slightly different from that of ISO. See http://czyborra.com/charsets/iso8859.html for details.
Lang/Regions ISO/Other Std. DOS Windows Macintosh Others ---------------------------------------------------------------- N. America (ASCII) cp437 AdobeStandardEncoding cp863 (DOSCanadaF) W. Europe iso-8859-1 cp850 cp1252 MacRoman nextstep hp-roman8 cp860 (DOSPortuguese) Cntrl. Europe iso-8859-2 cp852 cp1250 MacCentralEurRoman MacCroatian MacRomanian MacRumanian Latin3 [1] iso-8859-3 Latin4 [2] iso-8859-4 Cyrillics iso-8859-5 cp855 cp1251 MacCyrillic (Also see next section) cp866 MacUkrainian Arabic iso-8859-6 cp864 cp1256 MacArabic cp1006 MacFarsi Greek iso-8859-7 cp737 cp1253 MacGreek cp869 (DOSGreek2) Hebrew iso-8859-8 cp862 cp1255 MacHebrew Turkish iso-8859-9 cp857 cp1254 MacTurkish Nordics iso-8859-10 cp865 cp861 MacIcelandic MacSami Thai iso-8859-11 [3] cp874 MacThai (iso-8859-12 is nonexistent. Reserved for Indics?) Baltics iso-8859-13 cp775 cp1257 Celtics iso-8859-14 Latin9 [4] iso-8859-15 Latin10 iso-8859-16 Vietnamese viscii cp1258 MacVietnamese ---------------------------------------------------------------- [1] Esperanto, Maltese, and Turkish. Turkish is now on 8859-5. [2] Baltics. Now on 8859-10. [3] Also know as TIS 620. [4] Nicknamed Latin0; Euro sign as well as French and Finnish letters that are missing from 8859-1 are added.
All cp* are also available as ibm-*, ms-*, and windows-* . See also http://czyborra.com/charsets/codepages.html.
Macintosh encodings don't seem to be registered in such entities as IANA. "Canonical" names in Encode are based upon Apple's Tech Note 1150. See http://developer.apple.com/technotes/tn/tn1150.html for details
Though ISO-8859 does have ISO-8859, KOI8 series is far more popular in the Net. Encode comes with the following KOI charsets. For gory details, see http://czyborra.com/charsets/cyrillic.html
---------------------------------------------------------------- koi8-f koi8-r cp878 [RFC1489] koi8-u [RFC2319] ----------------------------------------------------------------
GSM0338 is for GSM handsets. Though it shares alphanumerals with ASCII, control character ranges and other parts are mapped very differently, presumably to store Greek and Cyrillic alphabets. This is also covered in Encode::Byte even though it does not comply to extended ASCII.
Note that Vietnamese is listed above. Also read "Encoding vs Charset" below. Also note these are implemented in distinct module by languages, due the the size concerns. Please refer to their respective document pages.
Standard DOS/Win Macintosh Comment/Reference ---------------------------------------------------------------- euc-cn [1] MacChineseSimp (gbk) cp936 [2] gb12345-raw { GB12345 without CES } gb2312-raw { GB2312 without CES } hz iso-ir-165 ---------------------------------------------------------------- [1] GB2312 is aliased to this. see L<Microsoft-related naming mess> [2] gbk is aliased to this. see L<Microsoft-related naming mess>
Standard DOS/Win Macintosh Comment/Reference ---------------------------------------------------------------- euc-jp shiftjis cp932 macJapanese 7bit-jis euc-jp iso-2022-jp [RFC1468] iso-2022-jp-1 [RFC2237] jis0201-raw { JIS X 0201 (roman + halfwidth kana) without CES } jis0208-raw { JIS X 0208 (Kanji + fullwidth kana) without CES } jis0212-raw { JIS X 0212 (Extended Kanji) without CES } ----------------------------------------------------------------
Standard DOS/Win Macintosh Comment/Reference ---------------------------------------------------------------- euc-kr MacKorean [RFC1557] cp949 [1] iso-2022-kr [RFC1557] johab [KS X 1001:1998, Annex 3] ksc5601-raw { KSC5601 without CES } ---------------------------------------------------------------- [1] ks_c_5601-1987, (x-)?windows-949, and uhc are aliased to this. See below.
Standard DOS/Win Macintosh Comment/Reference ---------------------------------------------------------------- big5 cp950 MacChineseTrad big5-hkscs ----------------------------------------------------------------
Due to size concerns, additional Chinese encodings below are distributed separately on CPAN, under the name Encode::HanExtra.
Standard DOS/Win Macintosh Comment/Reference ---------------------------------------------------------------- gb18030 euc-tw big5plus ----------------------------------------------------------------
See perlebcdic for details.
---------------------------------------------------------------- cp37 cp500 cp875 cp1026 cp1047 posix-bc ----------------------------------------------------------------
For symbols and dingbats.
---------------------------------------------------------------- symbol dingbats MacDingbats AdobeZdingbat AdobeSymbol ----------------------------------------------------------------
The following are not supported as yet. Some because they are rarely used, some because of technical difficulties. They may be supported by external modules via CPAN in future, however.
Not very popular yet. Needs Unicode Database or equivalent to implement encode() (Because it includes JIS X 0208/0212, KSC5601, and GB2312 simultaneously, which code points in Unicode overlap. So you need to lookup the database to determine what character set a given Unicode character should belong).
Not very popular. Needs CNS 11643-1 and 2 which are not available in this module. CNS 11643 is supported (via euc-tw) in Encode::HanExtra. Autrijus may add support for this encoding in his module in future.
The following are unsupported due to the lack of mapping data.
'8' - arabic8, greek8, hebrew8, kana8, thai8, and turkish8 '15' - japanese15, korean15, and roi15
Anton doubts its usefulness.
None of the Encode team knows Hebrew enough (ISO-8859-8, cp1255 and MacHebrew are supported because and just because there were mappings available at http://www.unicode.org/). Contributions welcome.
Ditto.
Though Jungshik has reported that Mozilla supports this encoding it was too late before 5.8.0 for us to add one. In future via a separate module. See http://lxr.mozilla.org/seamonkey/source/intl/uconv/ucvlatin/vps.uf and http://lxr.mozilla.org/seamonkey/source/intl/uconv/ucvlatin/vps.ut if you are interested in helping us.
MacArmenian, MacBengali, MacBurmese, MacEthiopic MacExtArabic, MacGeorgian, MacKannada, MacKhmer MacLaotian, MacMalayalam, MacMongolian, MacOriya MacSinhalese, MacTamil, MacTelugu, MacTibetan MacVietnamese
The rest of which already available are based upon the vendor mappings at http://www.unicode.org/Public/MAPPINGS/VENDORS/APPLE/ .
The maps for the following is available at http://www.unicode.org/ but remains unsupport because those encodings need algorithmical approach, currently unsupported by enc2xs
MacDevanagari MacGurmukhi MacGujarati
For details, please see Unicode mapping issues and notes: at http://www.unicode.org/Public/MAPPINGS/VENDORS/APPLE/DEVANAGA.TXT .
Unicode mapping issues and notes:
I believe this issue is prevalent not only for Mac Indics but also in other Indic encodings, but the above were the only Indic encodings maps that I could find at http://www.unicode.org/ .
We are used to using the term (character) encoding and character set interchangeably. But just as using the term byte and character is dangerous and should be differentiated when needed, we need to differentiate encoding and character set.
To understand that, it's follow how we make computers grok our characters.
First we start with which characters to include. We call this collection of characters character repertoire.
Then we have to give each character a unique ID so your computer can tell the difference from 'a' to 'A'. This itemized character repertoire is now a character set.
If your computer can grow the character set without further processing, you can go ahead use it. This is called a coded character set (CCS) or raw character encoding. ASCII is used this way for most cases.
But in many cases especially multi-byte CJK encodings, you have to tweak a little more. Your network connection may not accept any data with the Most Significant Bit set, Your computer may not be able to tell if a given byte is a whole character or just half of it. So you have to encode the character set to use it.
A character encoding scheme (CES) determines how to encode a given character set, or a set of multiple character sets. 7bit ISO-2022 is an example of CES. You switch between character sets via escape sequence.
Technically, or Mathematically speaking, a character set encoded in such a CES that maps character by character may form a CCS. EUC is such an example. CES of EUC is as follows;
Map ASCII unchanged.
Map such a character set that consists of 94 or 96 powered by N members by adding 0x80 to each byte.
You can also use 0x8e and 0x8f to tell the following sequence of characters belong to yet another character set. each following byte is added by 0x80
By carefully looking at at the encoded byte sequence, you may find the byte sequence conforms a unique number. In that sense EUC is a CCS generated by a CES above from up to four CCS (complicated?). UTF-8 falls into this category. See "UTF-8" in perlUnicode to find how UTF-8 maps Unicode to a byte sequence.
You may also find by now why 7bit ISO-2022 cannot conform a CCS. If you look at a byte sequence \x21\x21, you can't tell if it is two !'s or IDEOGRAPHIC SPACE. EUC maps the latter to \xA1\xA1 so you have no trouble between "!!". and " "
This section tries to classify the supported encodings by their applicability for information exchange over the Internet and to choose the most suitable aliases to name them in the context of such communication.
To (en|de) code Encodings marked as (**), You need Encode::HanExtra, available from CPAN.
(**)
Encode::HanExtra
Encoding names
US-ASCII UTF-8 ISO-8859-* KOI8-R Shift_JIS EUC-JP ISO-2022-JP ISO-2022-JP-1 EUC-KR Big5 GB2312
are registered to IANA as preferred MIME names and may probably be used over the Internet.
Shift_JIS has been officialized by JIS X 0208:1997. "Microsoft-related naming mess" gives details.
Shift_JIS
GB2312 is the IANA name for EUC-CN. See "Microsoft-related naming mess" for details.
GB2312
EUC-CN
GB_2312-80 raw encoding is available as gb2312-raw with Encode. See Encode::CN for details.
GB_2312-80
gb2312-raw
EUC-CN KOI8-U [RFC2319]
have not been registered with IANA (as of March 2002) but seem to be supported by major web browsers. IANA name for EUC-CN is GB2312.
KS_C_5601-1987
is heavily misused. See "Microsoft-related naming mess" for details.
KS_C_5601-1987 raw encoding is available as kcs5601-raw with Encode. See Encode::KR for details.
kcs5601-raw
UTF-16 UTF-16BE UTF-16LE
are IANA-registered charsets. See [RFC 2781] for details. Jungshik Shin reports that UTF-16 with a BOM is well accepted by MS IE 5/6 and NS 4/6. Beware however that
charset
UTF-16 support in any software you're going to be using/interoperating with has probably been less tested then UTF-8 support
UTF-16
UTF-8
UTF-8 coded data seamlessly passes traditional command piping (cat, more, etc.) while UTF-16 coded data is likely to cause confusion (with it's zero bytes, for example)
cat
more
it is beyond the power of words to describe the way HTML browsers encode non-ASCII form data. To get a general impression visit http://ppewww.ph.gla.ac.uk/~flavell/charset/form-i18n.html. While encoding of form data has stabilized for UTF-8 coded pages (at least IE 5/6, NS 6, Opera 6 behave consistently), be sure to expect fun (and cross-browser discrepancies) with UTF-16 coded pages!
ASCII
The rule of thumb is to use UTF-8 unless you know what you're doing and unless you really benefit from using UTF-16.
ISO-IR-165 [RFC1345] VISCII GB 12345 GB 18030 (**) (see links bellow) EUC-TW (**)
are totally valid encodings but not registered at IANA. The names under which they are listed here are probably the most widely-known names for these encodings and are recommended names.
BIG5PLUS (**)
is a bit proprietary name.
Microsoft products misuse the following names:
Microsoft extension to EUC-KR.
EUC-KR
Proper names: CP949, UHC, x-windows-949 (as used by Mozilla).
CP949
UHC
x-windows-949
See http://lists.w3.org/Archives/Public/ietf-charsets/2001AprJun/0033.html for details.
Encode aliases KS_C_5601-1987 to cp949 to reflect this common misusage. Raw KS_C_5601-1987 encoding is available as kcs5601-raw.
cp949
See Encode::KR for details.
Microsoft extension to EUC-CN.
Proper names: CP936, GBK.
CP936
GBK
GB2312 has been registered in the EUC-CN meaning at IANA. This has partially repaired the situation: Microsoft's GB2312 has become a superset of the official GB2312.
Encode aliases GB2312 to euc-cn in full agreement with IANA registration. cp936 is supported separately. Raw GB_2312-80 encoding is available as gb2312-raw.
euc-cn
cp936
See Encode::CN for details.
Microsoft extension to Big5.
Big5
Proper name: CP950.
CP950
Encode separately supports Big5 and cp950.
cp950
Microsoft's understanding of Shift_JIS.
JIS has not endorsed the full Microsoft standard however. The official Shift_JIS includes only JIS X 0201 and JIS X 0208 character sets, while Microsoft has always been meaning Shift_JIS to encode a wider character repertoire. See IANA registration for Windows-31J.
IANA
Windows-31J
As a historical predecessor Microsoft's variant probably has more rights for the name, albeit it may be objected that Microsoft shouldn't have used JIS as part of the name in the first place.
Unambiguous name: CP932. IANA name (not used?): Windows-31J.
CP932
Encode separately supports Shift_JIS and cp932.
cp932
A collection of unique characters. A character set in the most strict sense. At this stage characters are not numbered.
A character set that is mapped in a way computers can use directly. Many character encodings including EUC falls in this category.
An algorithm to map a character set to a byte sequence. You don't have to be able to tell which character set a given byte sequence belongs. 7-bit ISO-2022 is a CES but it cannot be a CCS. EUC is an example of being both a CCS and CES.
has long been used in the meaning of encoding, CES.
encoding
While character set word combination has lost this meaning in MIME context since [RFC 2130], charset abbreviation has retained it. This is how [RFC 2277], [RFC 2278] bless charset:
character set
This document uses the term "charset" to mean a set of rules for mapping from a sequence of octets to a sequence of characters, such as the combination of a coded character set and a character encoding scheme; this is also what is used as an identifier in MIME "charset=" parameters, and registered in the IANA charset registry ... (Note that this is NOT a term used by other standards bodies, such as ISO). [RFC 2277]
Extended Unix Character. See ISO-2022
A CES that was carefully designed to coexist with ASCII. There are 7 bit version and 8 bit version.
7 bit version switches character set via escape sequence so this cannot form a CCS. Since this is more difficult to handle in programs than the 8 bit version, 7 bit version is not very popular except for iso-2022-jp, the de facto standard CES for e-mails.
8 bit version can conform a CCS. EUC and ISO-8859 are two examples thereof. Pre-5.6 perl could use them as string literals.
Short for Universal Character Set. When you say just UCS, it means Unicode
ISO/IEC 10646 encoding form: Universal Character Set coded in two octets.
A Character Set that aims to include all character repertoire of the world. Many character sets in various national as well as industrial standards have become, in a way, just subsets of Unicode.
Short for Unicode Transformation Format. Determines how to map a Unicode character into byte sequence.
A UTF in 16-bit encoding. Can either be in big endian or little endian. Big endian version is called UTF-16BE (equals to UCS-2 + Surrogate Support) and little endian version is UTF-16LE.
Encode, Encode::Byte, Encode::CN, Encode::JP, Encode::KR, Encode::TW, Encode::EBCDIC, Encode::Symbol
European Computer Manufacturers Association http://www.ecma.ch
ISO-2022
http://www.ecma.ch/ecma1/STAND/ECMA-035.HTM
The very specification of ISO-2022 is available from the link above.
Internet Assigned Numbers Authority http://www.iana.org/
http://www.iana.org/assignments/character-sets
Most of the canonical names in Encode derive from this list so you can directly apply the string you have extracted from MIME header of mails and web pages.
canonical names
International Organization for Standardization http://www.iso.ch/
Request For Comments -- need I say more? http://www.rfc.net/, http://www.faqs.org/rfcs/
Unicode Consortium http://www.unicode.org/
http://www.unicode.org/glossary/
The glossary of this document is based upon this site.
http://czyborra.com/
Contains a a lot of useful information, especially gory details of ISO vs. vendor mappings.
http://www.oreilly.com/people/authors/lunde/cjk_inf.html
Somewhat obsolete (last update in 1996), but still useful. Also try
ftp://ftp.oreilly.com/pub/examples/nutshell/cjkv/pdf/GB18030_Summary.pdf
You will find brief info on EUC-CN, GBK and mostly on GB 18030
GB 18030
http://jshin.net/faq
And especially it's subject 8.
http://jshin.net/faq/qa8.html
A comprehensive overview of the Korean (KS *) standards.
KS *
CJKV Information Processing
CJKV Information Processing 1999 O'Reilly & Associates, ISBN : 1-56592-224-7
The modern successor of the CJK.inf.
CJK.inf
Features a comprehensive coverage on CJKV character sets and encodings along with many other issues faced by anyone trying to better support CJKV languages/scripts in all the areas of information processing.
To purchase this book visit http://www.oreilly.com/catalog/cjkvinfo/
To install Encode, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Encode
CPAN shell
perl -MCPAN -e shell install Encode
For more information on module installation, please visit the detailed CPAN module installation guide.