mnoGoSearch supports almost all known 8 bit character sets (later called charsets) as well as some multi-byte charsets including Korean EUC-Kr, Chinese big5 and GB2312, Japanese shift-JIS, EUC-JP and ISO-2022-JP, as well as UTF8. Some multi-byte charsets are not supported by default, because the conversion tables for them are rather large and that leads to a considerable increase of the executable files size. See configure parameters to enable support for these charsets.
mnoGoSearch also supports the following Macintosh character sets: MacCE, MacCroatian, MacGreek, MacRoman, MacTurkish, MacIceland, MacRomania, MacThai, MacArabic, MacHebrew, MacCyrillic, MacGujarati.
It is often necessary to deal with several languages simultaneously. The number of supported languages depends on the choice of charset that mnoGoSearch will use to store data. The charset is specified by the LocalCharset command.
When UTF-8 is specified in the LocalCharset command, you may work with any languages supported in Unicode. That means you may use any number of over 650 languages. However, using UTF-8 may consume a large amount of disk space (up to twice for some languages), leading to slower indexation and search.
Since every character set includes Latin characters, any character set supports at least two languages - English and one or more other languages. US-ASCII is an exception - it supports only Latin characters.
Note: When using mnoGoSearch in standard (non-UTF-8) mode, you may use as many languages as you like if they all belong to same language group.
Table 7-1. Language groups
Language group | Languages | Character sets |
Group 1 | Western Europe: Albanian, Catalan, Danish, Dutch, English, Faeroese, Finnish, French, Galician, German, Icelandic, Italian, Norwegian, Portuguese, Spanish, Swedish | ASCII 8, CP437, CP850, CP860, CP1252, ISO 8859-1, ISO 8859-15, MacRoman, MacIceland |
Group 2 | Eastern Europe: Croatian, Czech, Estonian, Hungarian, Latvian, Lithuanian, Polish, Romanian, Slovak, Slovene | CP852, CP1250, ISO 8859-2, MacCentralEurope, MacRomania, MacCroatian |
Group 4 | Baltic | CP1257, ISO-8859-4, ISO-8859-13 |
Group 5 | Cyrillic: Bulgarian, Belorussian, Macedonian, Russian, Serbian, Ukrainian | CP855, CP866, CP1251, ISO 8859-5, Koi8-r, Koi8-u, MacCyrillic |
Group 6 | Arabic | CP864, CP1256, ISO 8859-6, MacArabic |
Group 7 | Greek | CP869, CP1253, ISO 8859-7, MacGreek |
Group 8 | Hebrew | CP1255, ISO 8859-8, MacHebrew |
Group 9 | Turkish | CP857, CP1254, ISO 8859-9, MacTurkish |
Group 101 | Japanese | Shift-JIS, EUC-JP, ISO-2022-JP |
Group 102 | Simplified Chinese (PRC) | GB2312 |
Group 103 | Traditional Chinese (ROC) | Big5 |
Group 104 | Korean | EUC-KR |
Group 105 | Thai | CP874, TIS 620, MacThai |
Group 106 | Vietnamese | CP1258 |
Group 107 | Indian | MacGujarati, TSCII |
Group 108 | Georgian | geostd8 |
Unicode | Over 650 languages | UTF-8 (Unicode) |
E.g. in case your search engine was configured to use LocalCharset from the 5th group (Cyrillic), you may index servers containing documents in Bulgarian, Belorussian, Macedonian, Russian, Serbian and Ukrainian. Indexing a multi-language document in UTF-8 is possible as well; however, the indexer will extract and save only Cyrillic content from the page. To provide support for over 650 languages, please use LocalCharset UTF-8.
The indexer recodes all documents to the character set specified in the indexer.conf LocalCharset command. Internal recoding is implemented using Unicode. Please note that some recoding procedures may loose some data. For example, recoding between any Greek and Russian charsets looses all national characters. This does not matter for a single language sites. If you want to build multi-lingual search engine use the UTF8 character set as LocalCharset.
You may use the BrowserCharset command to choose a charset which will be used to display search results. BrowserCharset may differ from LocalCharset.
Each charset is recognized by a number of its aliases. Different web servers could return the same charset in different notations. For example, ISO-8859-2, ISO8859-2, latin2 are the same charsets. The search engine understands the following charsets names aliases:
Table 7-2. Charsets aliases
ISO-2022-JP: | ISO-2022-JP |
ISO-8859-1: | CP819, CSISOLATIN, IBM819, ISO-8859-1, ISO-IR-100, ISO_8859-1, ISO_8859-1:1987, L1, LATIN1 |
ISO-8859-10: | CSISOLATIN6, ISO-8859-10, ISO-IR-157, ISO_8859-10, ISO_8859-10:1992, L6, LATIN6 |
ISO-8859-11: | ISO-8859-11, TIS-620, TIS620, TACTIS |
ISO-8869-13: | ISO-8859-13, ISO-IR-179, ISO_8859-13, L7, LATIN7 |
ISO-8859-14: | ISO-8859-14, ISO-IR-199, ISO_8859-14, ISO_8859-14:1998, L8, LATIN8 |
ISO-8859-15: | ISO-8859-15, ISO-IR-203, ISO_8859-15, ISO_8859-15:1998 |
ISO-8859-16: | ISO-8859-16, ISO-IR-226, ISO_8859-16, ISO_8859-16:2000 |
ISO-8859-2: | CSISOLATIN2, ISO-8859-2, ISO-IR-101, ISO_8859-2, ISO_8859-2:1987, L2, LATIN2 |
ISO-8859-3: | CSISOLATIN3, ISO-8859-3, ISO-IR-109, ISO_8859-3, ISO_8859-3:1988, L3, LATIN3 |
ISO-8859-4: | CSISOLATIN4, ISO-8859-4, ISO-IR-110, ISO_8859-4, ISO_8859-4:1988, L4, LATIN4 |
ISO-8859-5: | CSISOLATINCYRILLIC, CYRILLIC, ISO-8859-5, ISO-IR-144, ISO_8859-5, ISO_8859-5:1988 |
ISO-8859-6: | ARABIC, ASMO-708, CSISOLATINARABIC, ECMA-114, ISO-8859-6, ISO-IR-127, ISO_8859-6, ISO_8859-6:1987 |
ISO-8859-7: | CSISOLATINGREEK, ECMA-118, ELOT_928, GREEK, GREEK8, ISO-8859-7, ISO-IR-126, ISO_8859-7, ISO_8859-7:1987 |
ISO-8859-8: | CSISOLATINHEBREW, HEBREW, ISO-8859-8, ISO-IR-138, ISO_8859-8, ISO_8859-8:1988 |
ISO-8859-9: | CSISOLATIN5, ISO-8859-9, ISO-IR-148, ISO_8859-9, ISO_8859-9:1989, L5, LATIN5 |
armscii-8: | ARMSCII-8, ARMSCII8 |
big5: | BIG-5, BIG-FIVE, BIG5, BIGFIVE, CN-BIG5, CSBIG5 |
cp1250: | CP1250, MS-EE, WINDOWS-1250 |
cp1251: | CP1251, MS-CYRL, WINDOWS-1251 |
cp1252: | CP1252, MS-ANSI, WINDOWS-1252 |
cp1253: | CP1253, MS-GREEK, WINDOWS-1253 |
cp1254: | CP1254, MS-TURK, WINDOWS-1254 |
cp1255: | CP1255, MS-HEBR, WINDOWS-1255 |
cp1256: | CP1256, MS-ARAB, WINDOWS-1256 |
cp1257: | CP1257, WINBALTRIM, WINDOWS-1257 |
cp1258: | CP1258, WINDOWS-1258 |
cp437: | 437, CP437, IBM437 |
cp850: | 850, CP850, CSPC850MULTILINGUAL, IBM850 |
cp852: | 852, CP852, IBM852 |
cp855: | 855, CP855, IBM855 |
cp857: | 857, CP857, IBM857 |
cp860: | 860, CP860, IBM860 |
cp861: | 861, CP861, IBM861 |
cp862: | 862, CP862, IBM862 |
cp863: | 863, CP863, IBM863 |
cp864: | 864, CP864, IBM864 |
cp865: | 865, CP865, IBM865 |
cp866: | 866, CP866, CSIBM866, IBM866 |
cp869: | 869, CP869, IBM869, CP874, WINDOWS-874 |
EUC-JP: | CSEUCJP, EUC-JP, EUCJP, UJIS, X-EUC-JP |
EUC-KR: | CSEUCKR, EUC-KR, EUCKR |
GB2312: | CHINESE, CSGB2312, CSISO58GB231280, GB2312, GB_2312-80, ISO-IR-58 |
koi8-r: | CSKOI8R, KOI8-R, KOI8R |
KOI8-u | KOI8-U, KOI8U |
shift-JIS: | CSSHIFTJIS, MS_KANJI, S-JIS, SHIFT-JIS, SHIFT_JIS, SJIS |
cp367: | ANSI_X3.4-1968, ASCII, CP367, CSASCII, IBM367, ISO-IR-6, ISO646-US, ISO_646.IRV:1991, US, US-ASCII |
UTF8: | UTF-8, UTF8 |
viscii: | CSVISCII, VISCII, VISCII1.1-1 |
MacCyrillic: | MACCYRILLIC, X-MAC-CYRILLIC |
MacRoman: | MACROMAN, MACINTOSH, CSMACINTOSH, MAC |
MacCentralEurope: | MACCENTRALEUROPE, MACCE |
The indexer detects document charsets in this order:
"Content-type: text/html; charset=xxx"
<META NAME="Content-Type" CONTENT="text/html; charset=xxx"> (for HTML documents) or
<?xml version="1.0" encoding="xxx"?> (for XML documents)
The selection of this variant may be switched off by using the: GuesserUseMeta no command in your indexer.conf.
The defaults to "Charset" settings of the corresponding Server or Realm command.
Since 3.2.0, mnoGoSearch has an automatic charset and language guesser. It currently recognizes more than 100 various charsets and languages. Charset and language detection is implemented using the "N-Gram-Based Text Categorization" technique. There is a number of so called "language map" files, one for each language-charset pair. They are installed under /usr/local/mnogosearch/etc/langmap/ directory by default. Take a look there to check the list of currently provided charset-language pairs. Guesser works fine for texts bigger than 500 characters. Shorter texts may not be guessed well.
To build your own language map use mguesser utility. In addition, your need to collect files with language samples in the desired charset. For new language maps creation, use the following command:
mguesser -p -c charset -l language < FILENAME > language.charset.lm
You can also use mguesser utility to guess document's language and charset by using existing language maps. To do this, use following command:
mguesser [-n maxhits] < FILENAME
For some languages, you may use several different charsets. To convert from one charset supported by mnoGoSearch to another, use mconv utility.
mconv [OPTIONS] -f charset_from -t charset_to [configfile] < infile > outfile
By default, both mguesser and mconv utilities are installed into the /usr/local/mnogosearch/sbin/ directory.
Since version 3.2.14, mnoGoSearch has an ability to update language and charset maps automatically while indexing, if the remote server supplies pages with exactly specified language and charset. To enable this function, specify command
LangMapUpdate yesin your indexer.conf file.
Use the RemoteCharset indexer.conf command to choose the default charset of indexed servers.
You can set the default language for Servers by using the DefaultLang indexer.conf command. This is useful for further restricting search results language.