How to convert encodingName to codePage identifier?

Question

Given the name of an encoding, how can i get the corresponding codePage identifier?

For example:

• "iso-8859-1": 28591
• "windows-1252": 1252
• "IBM500": 500
• "utf-16le": 1200
• "utf-8": 65001

Hypothetical use case: the Windows function MultiByteToWideChar only takes a CodePage, and i only have an encodingName.

And EnumSystemCodePages returns a list of strings, not code page identifiers (so you can't pass them to GetCPInfo).

Bonus Reading

• MSDN: List of code page identifiers

Answer 1

IMultiLanguage::GetCharsetInfo will convert strings like "shift_jis" and "gb2312" to codepage 932 and 936 but it does not know about all names so you must also provide your own lookup table. I suspect this uses the same registry keys as suggested in one of the other answers.

Charset	CodePage
"windows-1252"	1252
"utf-8"	1200
"utf-16"	Unspecified error
"iso-8859-1"	1252 (wrong)
"ibm850"	Unspecified error

Answer 2

There is no Win32 API for what you ask.

If you can use .NET, you can create an object instance of the System.Text.Encoding class from an encoding name using the Encoding.GetEncoding(String) method, and then you can read its CodePage property.

Otherwise, you can look in the following Registry keys:

HKEY_CLASSES_ROOT\MIME\Database\Codepage
HKEY_CLASSES_ROOT\Mime\Database\Charset

But, do note that there are some inaccuracies in the Registry. For example, iso-8859-1 gets mapped to codepage 1252 instead of the more preferred 28591.

Otherwise, you will just have to create your own lookup table in your code as needed.

Answer 3

Since there is no way in Windows to do it, you have to create your own (always wrong, always incomplete) version:

function EncodingNameToCodePage(EncodingName: string): Cardinal;
const
    cp: array[0..151] of record CodePage: Cardinal; Name: string end = //Thank you John Herbster
        (
            (CodePage: 037;         Name: 'IBM037'),                //IBM EBCDIC US-Canada
            (CodePage: 437;         Name: 'IBM437'),                //OEM United States
            (CodePage: 500;         Name: 'IBM500'),                //IBM EBCDIC International
            (CodePage: 708;         Name: 'ASMO-708'),          //Arabic (ASMO 708)
            (CodePage: 709;         Name: ''),                      //Arabic (ASMO-449+, BCON V4)
            (CodePage: 710;         Name: ''),                      //Arabic - Transparent Arabic
            (CodePage: 720;         Name: 'DOS-720'),               //Arabic (Transparent ASMO); Arabic (DOS)
            (CodePage: 737;         Name: 'ibm737'),                //OEM Greek (formerly 437G); Greek (DOS)
            (CodePage: 775;         Name: 'ibm775'),                //OEM Baltic; Baltic (DOS)
            (CodePage: 850;         Name: 'ibm850'),                //OEM Multilingual Latin 1; Western European (DOS)
            (CodePage: 852;         Name: 'ibm852'),                //OEM Latin 2; Central European (DOS)
            (CodePage: 855;         Name: 'IBM855'),                //OEM Cyrillic (primarily Russian)
            (CodePage: 857;         Name: 'ibm857'),                //OEM Turkish; Turkish (DOS)
            (CodePage: 858;         Name: 'IBM00858'),          //OEM Multilingual Latin 1 + Euro symbol
            (CodePage: 860;         Name: 'IBM860'),                //OEM Portuguese; Portuguese (DOS)
            (CodePage: 861;         Name: 'ibm861'),                //OEM Icelandic; Icelandic (DOS)
            (CodePage: 862;         Name: 'DOS-862'),               //OEM Hebrew; Hebrew (DOS)
            (CodePage: 863;         Name: 'IBM863'),                //OEM French Canadian; French Canadian (DOS)
            (CodePage: 864;         Name: 'IBM864'),                //OEM Arabic; Arabic (864)
            (CodePage: 865;         Name: 'IBM865'),                //OEM Nordic; Nordic (DOS)
            (CodePage: 866;         Name: 'cp866'),             //OEM Russian; Cyrillic (DOS)
            (CodePage: 869;         Name: 'ibm869'),                //OEM Modern Greek; Greek, Modern (DOS)
            (CodePage: 870;         Name: 'IBM870'),                //IBM EBCDIC Multilingual/ROECE (Latin 2); IBM EBCDIC Multilingual Latin 2
            (CodePage: 874;         Name: 'windows-874'),       //ANSI/OEM Thai (ISO 8859-11); Thai (Windows)
            (CodePage: 875;         Name: 'cp875'),             //IBM EBCDIC Greek Modern
            (CodePage: 932;         Name: 'shift_jis'),         //ANSI/OEM Japanese; Japanese (Shift-JIS)
            (CodePage: 936;         Name: 'gb2312'),                //ANSI/OEM Simplified Chinese (PRC, Singapore); Chinese Simplified (GB2312)
            (CodePage: 949;         Name: 'ks_c_5601-1987'),    //ANSI/OEM Korean (Unified Hangul Code)
            (CodePage: 950;         Name: 'big5'),                  //ANSI/OEM Traditional Chinese (Taiwan; Hong Kong SAR, PRC); Chinese Traditional (Big5)
            (CodePage: 1026;        Name: 'IBM1026'),               //IBM EBCDIC Turkish (Latin 5)
            (CodePage: 1047;        Name: 'IBM01047'),          //IBM EBCDIC Latin 1/Open System
            (CodePage: 1140;        Name: 'IBM01140'),          //IBM EBCDIC US-Canada (037 + Euro symbol); IBM EBCDIC (US-Canada-Euro)
            (CodePage: 1141;        Name: 'IBM01141'),          //IBM EBCDIC Germany (20273 + Euro symbol); IBM EBCDIC (Germany-Euro)
            (CodePage: 1142;        Name: 'IBM01142'),          //IBM EBCDIC Denmark-Norway (20277 + Euro symbol); IBM EBCDIC (Denmark-Norway-Euro)
            (CodePage: 1143;        Name: 'IBM01143'),          //IBM EBCDIC Finland-Sweden (20278 + Euro symbol); IBM EBCDIC (Finland-Sweden-Euro)
            (CodePage: 1144;        Name: 'IBM01144'),          //IBM EBCDIC Italy (20280 + Euro symbol); IBM EBCDIC (Italy-Euro)
            (CodePage: 1145;        Name: 'IBM01145'),          //IBM EBCDIC Latin America-Spain (20284 + Euro symbol); IBM EBCDIC (Spain-Euro)
            (CodePage: 1146;        Name: 'IBM01146'),          //IBM EBCDIC United Kingdom (20285 + Euro symbol); IBM EBCDIC (UK-Euro)
            (CodePage: 1147;        Name: 'IBM01147'),          //IBM EBCDIC France (20297 + Euro symbol); IBM EBCDIC (France-Euro)
            (CodePage: 1148;        Name: 'IBM01148'),          //IBM EBCDIC International (500 + Euro symbol); IBM EBCDIC (International-Euro)
            (CodePage: 1149;        Name: 'IBM01149'),          //IBM EBCDIC Icelandic (20871 + Euro symbol); IBM EBCDIC (Icelandic-Euro)
            (CodePage: 1200;        Name: 'utf-16'),                //Unicode UTF-16, little endian byte order (BMP of ISO 10646); available only to managed applications
            (CodePage: 1201;        Name: 'unicodeFFFE'),       //Unicode UTF-16, big endian byte order; available only to managed applications
            (CodePage: 1250;        Name: 'windows-1250'),      //ANSI Central European; Central European (Windows)
            (CodePage: 1251;        Name: 'windows-1251'),      //ANSI Cyrillic; Cyrillic (Windows)
            (CodePage: 1252;        Name: 'windows-1252'),      //ANSI Latin 1; Western European (Windows)
            (CodePage: 1253;        Name: 'windows-1253'),      //ANSI Greek; Greek (Windows)
            (CodePage: 1254;        Name: 'windows-1254'),      //ANSI Turkish; Turkish (Windows)
            (CodePage: 1255;        Name: 'windows-1255'),      //ANSI Hebrew; Hebrew (Windows)
            (CodePage: 1256;        Name: 'windows-1256'),      //ANSI Arabic; Arabic (Windows)
            (CodePage: 1257;        Name: 'windows-1257'),      //ANSI Baltic; Baltic (Windows)
            (CodePage: 1258;        Name: 'windows-1258'),      //ANSI/OEM Vietnamese; Vietnamese (Windows)
            (CodePage: 1361;        Name: 'Johab'),             //Korean (Johab)
            (CodePage: 10000;   Name: 'macintosh'),         //MAC Roman; Western European (Mac)
            (CodePage: 10001;   Name: 'x-mac-japanese'),        //Japanese (Mac)
            (CodePage: 10002;   Name: 'x-mac-chinesetrad'), //MAC Traditional Chinese (Big5); Chinese Traditional (Mac)
            (CodePage: 10003;   Name: 'x-mac-korean'),          //Korean (Mac)
            (CodePage: 10004;   Name: 'x-mac-arabic'),          //Arabic (Mac)
            (CodePage: 10005;   Name: 'x-mac-hebrew'),          //Hebrew (Mac)
            (CodePage: 10006;   Name: 'x-mac-greek'),           //Greek (Mac)
            (CodePage: 10007;   Name: 'x-mac-cyrillic'),        //Cyrillic (Mac)
            (CodePage: 10008;   Name: 'x-mac-chinesesimp'), //MAC Simplified Chinese (GB 2312); Chinese Simplified (Mac)
            (CodePage: 10010;   Name: 'x-mac-romanian'),        //Romanian (Mac)
            (CodePage: 10017;   Name: 'x-mac-ukrainian'),       //Ukrainian (Mac)
            (CodePage: 10021;   Name: 'x-mac-thai'),                //Thai (Mac)
            (CodePage: 10029;   Name: 'x-mac-ce'),              //MAC Latin 2; Central European (Mac)
            (CodePage: 10079;   Name: 'x-mac-icelandic'),       //Icelandic (Mac)
            (CodePage: 10081;   Name: 'x-mac-turkish'),         //Turkish (Mac)
            (CodePage: 10082;   Name: 'x-mac-croatian'),        //Croatian (Mac)
            (CodePage: 12000;   Name: 'utf-32'),                    //Unicode UTF-32, little endian byte order; available only to managed applications
            (CodePage: 12001;   Name: 'utf-32BE'),              //Unicode UTF-32, big endian byte order; available only to managed applications
            (CodePage: 20000;   Name: 'x-Chinese_CNS'),         //CNS Taiwan; Chinese Traditional (CNS)
            (CodePage: 20001;   Name: 'x-cp20001'),             //TCA Taiwan
            (CodePage: 20002;   Name: 'x_Chinese-Eten'),        //Eten Taiwan; Chinese Traditional (Eten)
            (CodePage: 20003;   Name: 'x-cp20003'),             //IBM5550 Taiwan
            (CodePage: 20004;   Name: 'x-cp20004'),             //TeleText Taiwan
            (CodePage: 20005;   Name: 'x-cp20005'),             //Wang Taiwan
            (CodePage: 20105;   Name: 'x-IA5'),                 //IA5 (IRV International Alphabet No. 5, 7-bit); Western European (IA5)
            (CodePage: 20106;   Name: 'x-IA5-German'),          //IA5 German (7-bit)
            (CodePage: 20107;   Name: 'x-IA5-Swedish'),         //IA5 Swedish (7-bit)
            (CodePage: 20108;   Name: 'x-IA5-Norwegian'),       //IA5 Norwegian (7-bit)
            (CodePage: 20127;   Name: 'us-ascii'),              //US-ASCII (7-bit)
            (CodePage: 20261;   Name: 'x-cp20261'),             //T.61
            (CodePage: 20269;   Name: 'x-cp20269'),             //ISO 6937 Non-Spacing Accent
            (CodePage: 20273;   Name: 'IBM273'),                    //IBM EBCDIC Germany
            (CodePage: 20277;   Name: 'IBM277'),                    //IBM EBCDIC Denmark-Norway
            (CodePage: 20278;   Name: 'IBM278'),                    //IBM EBCDIC Finland-Sweden
            (CodePage: 20280;   Name: 'IBM280'),                    //IBM EBCDIC Italy
            (CodePage: 20284;   Name: 'IBM284'),                    //IBM EBCDIC Latin America-Spain
            (CodePage: 20285;   Name: 'IBM285'),                    //IBM EBCDIC United Kingdom
            (CodePage: 20290;   Name: 'IBM290'),                    //IBM EBCDIC Japanese Katakana Extended
            (CodePage: 20297;   Name: 'IBM297'),                    //IBM EBCDIC France
            (CodePage: 20420;   Name: 'IBM420'),                    //IBM EBCDIC Arabic
            (CodePage: 20423;   Name: 'IBM423'),                    //IBM EBCDIC Greek
            (CodePage: 20424;   Name: 'IBM424'),                    //IBM EBCDIC Hebrew
            (CodePage: 20833;   Name: 'x-EBCDIC-KoreanExtended'),           //IBM EBCDIC Korean Extended
            (CodePage: 20838;   Name: 'IBM-Thai'),              //IBM EBCDIC Thai
            (CodePage: 20866;   Name: 'koi8-r'),                    //Russian (KOI8-R); Cyrillic (KOI8-R)
            (CodePage: 20871;   Name: 'IBM871'),                    //IBM EBCDIC Icelandic
            (CodePage: 20880;   Name: 'IBM880'),                    //IBM EBCDIC Cyrillic Russian
            (CodePage: 20905;   Name: 'IBM905'),                    //IBM EBCDIC Turkish
            (CodePage: 20924;   Name: 'IBM00924'),              //IBM EBCDIC Latin 1/Open System (1047 + Euro symbol)
            (CodePage: 20932;   Name: 'EUC-JP'),                    //Japanese (JIS 0208-1990 and 0212-1990)
            (CodePage: 20936;   Name: 'x-cp20936'),             //Simplified Chinese (GB2312); Chinese Simplified (GB2312-80)
            (CodePage: 20949;   Name: 'x-cp20949'),             //Korean Wansung
            (CodePage: 21025;   Name: 'cp1025'),                    //IBM EBCDIC Cyrillic Serbian-Bulgarian
            (CodePage: 21027;   Name: ''),                          //(deprecated)
            (CodePage: 21866;   Name: 'koi8-u'),                    //Ukrainian (KOI8-U); Cyrillic (KOI8-U)
            (CodePage: 28591;   Name: 'iso-8859-1'),                //ISO 8859-1 Latin 1; Western European (ISO)
            (CodePage: 28592;   Name: 'iso-8859-2'),                //ISO 8859-2 Central European; Central European (ISO)
            (CodePage: 28593;   Name: 'iso-8859-3'),                //ISO 8859-3 Latin 3
            (CodePage: 28594;   Name: 'iso-8859-4'),                //ISO 8859-4 Baltic
            (CodePage: 28595;   Name: 'iso-8859-5'),                //ISO 8859-5 Cyrillic
            (CodePage: 28596;   Name: 'iso-8859-6'),                //ISO 8859-6 Arabic
            (CodePage: 28597;   Name: 'iso-8859-7'),                //ISO 8859-7 Greek
            (CodePage: 28598;   Name: 'iso-8859-8'),                //ISO 8859-8 Hebrew; Hebrew (ISO-Visual)
            (CodePage: 28599;   Name: 'iso-8859-9'),                //ISO 8859-9 Turkish
            (CodePage: 28603;   Name: 'iso-8859-13'),           //ISO 8859-13 Estonian
            (CodePage: 28605;   Name: 'iso-8859-15'),           //ISO 8859-15 Latin 9
            (CodePage: 29001;   Name: 'x-Europa'),              //Europa 3
            (CodePage: 38598;   Name: 'iso-8859-8-i'),          //ISO 8859-8 Hebrew; Hebrew (ISO-Logical)
            (CodePage: 50220;   Name: 'iso-2022-jp'),           //ISO 2022 Japanese with no halfwidth Katakana; Japanese (JIS)
            (CodePage: 50221;   Name: 'csISO2022JP'),           //ISO 2022 Japanese with halfwidth Katakana; Japanese (JIS-Allow 1 byte Kana)
            (CodePage: 50222;   Name: 'iso-2022-jp'),           //ISO 2022 Japanese JIS X 0201-1989; Japanese (JIS-Allow 1 byte Kana - SO/SI)
            (CodePage: 50225;   Name: 'iso-2022-kr'),           //ISO 2022 Korean
            (CodePage: 50227;   Name: 'x-cp50227'),             //ISO 2022 Simplified Chinese; Chinese Simplified (ISO 2022)
            (CodePage: 50229;   Name: ''),                          //ISO 2022 Traditional Chinese
            (CodePage: 50930;   Name: ''),                          //EBCDIC Japanese (Katakana) Extended
            (CodePage: 50931;   Name: ''),                          //EBCDIC US-Canada and Japanese
            (CodePage: 50933;   Name: ''),                          //EBCDIC Korean Extended and Korean
            (CodePage: 50935;   Name: ''),                          //EBCDIC Simplified Chinese Extended and Simplified Chinese
            (CodePage: 50936;   Name: ''),                          //EBCDIC Simplified Chinese
            (CodePage: 50937;   Name: ''),                          //EBCDIC US-Canada and Traditional Chinese
            (CodePage: 50939;   Name: ''),                          //EBCDIC Japanese (Latin) Extended and Japanese
            (CodePage: 51932;   Name: 'euc-jp'),                    //EUC Japanese
            (CodePage: 51936;   Name: 'EUC-CN'),                    //EUC Simplified Chinese; Chinese Simplified (EUC)
            (CodePage: 51949;   Name: 'euc-kr'),                    //EUC Korean
            (CodePage: 51950;   Name: ''),                          //EUC Traditional Chinese
            (CodePage: 52936;   Name: 'hz-gb-2312'),                //HZ-GB2312 Simplified Chinese; Chinese Simplified (HZ)
            (CodePage: 54936;   Name: 'GB18030'),                   //Windows XP and later: GB18030 Simplified Chinese (4 byte); Chinese Simplified (GB18030)
            (CodePage: 57002;   Name: 'x-iscii-de'),                //ISCII Devanagari
            (CodePage: 57003;   Name: 'x-iscii-be'),                //ISCII Bangla
            (CodePage: 57004;   Name: 'x-iscii-ta'),                //ISCII Tamil
            (CodePage: 57005;   Name: 'x-iscii-te'),                //ISCII Telugu
            (CodePage: 57006;   Name: 'x-iscii-as'),                //ISCII Assamese
            (CodePage: 57007;   Name: 'x-iscii-or'),                //ISCII Odia
            (CodePage: 57008;   Name: 'x-iscii-ka'),                //ISCII Kannada
            (CodePage: 57009;   Name: 'x-iscii-ma'),                //ISCII Malayalam
            (CodePage: 57010;   Name: 'x-iscii-gu'),                //ISCII Gujarati
            (CodePage: 57011;   Name: 'x-iscii-pa'),                //ISCII Punjabi
            (CodePage: 65000;   Name: 'utf-7'),                 //Unicode (UTF-7)
            (CodePage: 65001;   Name: 'utf-8')                      //Unicode (UTF-8)
    );
var
    i: Integer;
begin
    Result := 0;
    if EncodingName = '' then
        Exit;

    for i := Low(cp) to High(cp) do
    begin
        if cp[i].Name = '' then
            Continue;
        if SameText(EncodingName, cp[i].Name) then
        begin
            Result := cp[i].CodePage;
            Exit;
        end;
    end;
end;

Answer 4

ICU has functionality that can be used for this purpose though it is a bit clumsy (if you are going to use ICU at all you might as well go ahead and use its conversion facility rather than use it to obtain the code page then use MultiByteToWideChar).