/node-iconv

node.js iconv bindings - text recoding for fun and profit!

Primary LanguageJavaScriptOtherNOASSERTION

node-iconv

Fork from the lib bnoordhuis/node-iconv. It adds the third parameter for setting the transliteration locale. This allow to transform ß in ss instead to the most simplistic s automatically. Good if you want to normalize text for comparing later in a more linguistically "correct" way.

For transliterate you can just:

var iconvDE = new Iconv('UTF-8', 'ASCII//TRANSLIT//IGNORE', 'de_DE.UTF-8');
iconvDE.convert(TEST_STRING).toString()

Note: This library needs to be installed with env GYP_DEFINES="node_iconv_use_system_libiconv=1" npm install. Make sure the correct env is set when installing this library. Otherwise it will use the static iconv library that can't transliterate correctly.

The third argument is the name of the transliteration definition file for iconv. Make sure to have it installed in your unix system. For example, for installing German you can:

apt-get -y install locales
sed -i -e 's/# de_DE.UTF-8 UTF-8/de_DE.UTF-8 UTF-8/' /etc/locale.gen
dpkg-reconfigure --frontend=noninteractive locales
update-locale

The rest of the library should work as described in the original Readme.

The original Readme is left here for documentation purposes:

Text recoding in JavaScript for fun and profit!

Supported encodings

European languages
    ASCII, ISO-8859-{1,2,3,4,5,7,9,10,13,14,15,16},
    KOI8-R, KOI8-U, KOI8-RU,
    CP{437,737,775,850,852,853,855,857,858,860,861,863,865,866,869}
    CP{1125,1250,1251,1252,1253,1254,1257}
    Mac{Roman,CentralEurope,Iceland,Croatian,Romania},
    Mac{Cyrillic,Ukraine,Greek,Turkish},
    Macintosh
Semitic languages
    ISO-8859-{6,8}, CP{1255,1256}, CP862, CP864, Mac{Hebrew,Arabic}
Japanese
    EUC-JP, SHIFT_JIS, CP932, ISO-2022-JP, ISO-2022-JP-2, ISO-2022-JP-1
    EUC-JISX0213, Shift_JISX0213, ISO-2022-JP-3
Chinese
    EUC-CN, HZ, GBK, CP936, GB18030, EUC-TW, BIG5, CP950, BIG5-HKSCS,
    BIG5-HKSCS:2004, BIG5-HKSCS:2001, BIG5-HKSCS:1999, ISO-2022-CN,
    ISO-2022-CN-EXT, BIG5-2003 (experimental)
Korean
    EUC-KR, CP949, ISO-2022-KR, JOHAB
Turkmen
    TDS565
Armenian
    ARMSCII-8
Georgian
    Georgian-Academy, Georgian-PS
Tajik
    KOI8-T
Kazakh
    PT154, RK1048
Thai
    ISO-8859-11, TIS-620, CP874, MacThai
Laotian
    MuleLao-1, CP1133
Vietnamese
    VISCII, TCVN, CP1258
Platform specifics
    HP-ROMAN8, NEXTSTEP, ATARIST, RISCOS-LATIN1
Full Unicode
    UTF-8
    UCS-2, UCS-2BE, UCS-2LE
    UCS-4, UCS-4BE, UCS-4LE
    UTF-16, UTF-16BE, UTF-16LE
    UTF-32, UTF-32BE, UTF-32LE
    UTF-7
    C99, JAVA
Full Unicode, in terms of `uint16_t` or `uint32_t`
    (with machine dependent endianness and alignment)
    UCS-2-INTERNAL, UCS-4-INTERNAL
Locale dependent, in terms of `char` or `wchar_t`
    (with machine dependent endianness and alignment, and with OS and
    locale dependent semantics)
    char, wchar_t
    The empty encoding name "" is equivalent to "char": it denotes the
    locale dependent character encoding.

If you don't need the full gamut of encodings, consider using iconv-lite. It supports most common encodings and doesn't require a compiler to install.

Installing with npm

$ npm install iconv

Note that you do not need to have a copy of libiconv installed to use this module.

Compiling from source

$ git clone git://github.com/bnoordhuis/node-iconv.git
$ cd node-iconv
$ npm install

If you have a specific node.js source checkout that you want to build against, replace the last command with:

$ npm install --nodedir=/path/to/node

Usage

Encode from one character encoding to another:

// convert from UTF-8 to ISO-8859-1
var Buffer = require('buffer').Buffer;
var Iconv  = require('iconv').Iconv;
var assert = require('assert');

var iconv = new Iconv('UTF-8', 'ISO-8859-1');
var buffer = iconv.convert('Hello, world!');
var buffer2 = iconv.convert(Buffer.from('Hello, world!'));
assert.equals(buffer.inspect(), buffer2.inspect());
// do something useful with the buffers

A simple ISO-8859-1 to UTF-8 conversion TCP service:

var net = require('net');
var Iconv = require('iconv').Iconv;
var server = net.createServer(function(conn) {
  var iconv = new Iconv('latin1', 'utf-8');
  conn.pipe(iconv).pipe(conn);
});
server.listen(8000);
console.log('Listening on tcp://0.0.0.0:8000/');

Look at test/test-basic.js and test/test-stream.js for more examples and node-iconv's behaviour under error conditions.

Notes

Things to keep in mind when you work with node-iconv.

Chunked data

Say you are reading data in chunks from a HTTP stream. The logical input is a single document (the full POST request data) but the physical input will be spread over several buffers (the request chunks).

You must accumulate the small buffers into a single large buffer before performing the conversion. If you don't, you will get unexpected results with multi-byte and stateful character sets like UTF-8 and ISO-2022-JP.

The above only applies when you are calling Iconv#convert() yourself. If you use the streaming interface, node-iconv takes care of stitching partial character sequences together again.

Dealing with untranslatable characters

Characters are not always translatable to another encoding. The UTF-8 string "ça va が", for example, cannot be represented in plain 7-bits ASCII without some loss of fidelity.

By default, node-iconv throws EILSEQ when untranslatabe characters are encountered but this can be customized. Quoting the iconv_open(3) man page:

//TRANSLIT
When  the  string  "//TRANSLIT"  is appended to tocode, transliteration is
activated. This means that when a character cannot be represented in the
target character set, it can be approximated through one or several
similarly looking characters.

//IGNORE
When the string "//IGNORE" is appended to tocode, characters that cannot be
represented in the target character set will be silently discarded.

Example usage:

var iconv = new Iconv('UTF-8', 'ASCII');
iconv.convert('ça va'); // throws EILSEQ

var iconv = new Iconv('UTF-8', 'ASCII//IGNORE');
iconv.convert('ça va'); // returns "a va"

var iconv = new Iconv('UTF-8', 'ASCII//TRANSLIT');
iconv.convert('ça va'); // "ca va"

var iconv = new Iconv('UTF-8', 'ASCII//TRANSLIT//IGNORE');
iconv.convert('ça va が'); // "ca va "

EINVAL

EINVAL is raised when the input ends in a partial character sequence. This is a feature, not a bug.