Pure JS character encoding conversion

- Doesn't need native code compilation. Works on Windows and in sandboxed environments like Cloud9.
- Used in popular projects like Express.js (body_parser), Grunt, Nodemailer, Yeoman and others.
- Faster than node-iconv (see below for performance comparison).
- Intuitive encode/decode API
- Streaming support for Node v0.10+
- [Deprecated] Can extend Node.js primitives (buffers, streams) to support all iconv-lite encodings.
- In-browser usage via Browserify (~180k gzip compressed with Buffer shim included).
- Typescript type definition file included.
- React Native is supported (need to explicitly `npm install` two more modules: `buffer` and `stream`).
- License: MIT.

# Usage

## Basic API

var iconv = require('iconv-lite');
// Convert from an encoded buffer to js string.
str = iconv.decode(Buffer.from([0x68, 0x65, 0x6c, 0x6c, 0x6f]), 'win1251');
// Convert from js string to an encoded buffer.
buf = iconv.encode("Sample input string", 'win1251');
// Check if encoding is supported
iconv.encodingExists("us-ascii")

## Streaming API (Node v0.10+)

// Decode stream (from binary stream to js strings)
http.createServer(function(req, res) {
var converterStream = iconv.decodeStream('win1251');
req.pipe(converterStream);
converterStream.on('data', function(str) {
console.log(str); // Do something with decoded strings, chunk-by-chunk.
});
});
// Convert encoding streaming example
fs.createReadStream('file-in-win1251.txt')
.pipe(iconv.decodeStream('win1251'))
.pipe(iconv.encodeStream('ucs2'))
.pipe(fs.createWriteStream('file-in-ucs2.txt'));
// Sugar: all encode/decode streams have .collect(cb) method to accumulate data.
http.createServer(function(req, res) {
req.pipe(iconv.decodeStream('win1251')).collect(function(err, body) {
assert(typeof body == 'string');
console.log(body); // full request body string
});
});

## [Deprecated] Extend Node.js own encodings

> NOTE: This doesn't work on latest Node versions. See details.

// After this call all Node basic primitives will understand iconv-lite encodings.
iconv.extendNodeEncodings();
// Examples:
buf = new Buffer(str, 'win1251');
buf.write(str, 'gbk');
str = buf.toString('latin1');
assert(Buffer.isEncoding('iso-8859-15'));
Buffer.byteLength(str, 'us-ascii');
http.createServer(function(req, res) {
req.setEncoding('big5');
req.collect(function(err, body) {
console.log(body);
});
});
fs.createReadStream("file.txt", "shift_jis");
// External modules are also supported (if they use Node primitives, which they probably do).
request = require('request');
request({
url: "http://github.com/",
encoding: "cp932"
});
// To remove extensions
iconv.undoExtendNodeEncodings();

# Supported encodings

- All node.js native encodings: utf8, ucs2 / utf16-le, ascii, binary, base64, hex.
- Additional unicode encodings: utf16, utf16-be, utf-7, utf-7-imap.
- All widespread singlebyte encodings: Windows 125x family, ISO-8859 family, IBM/DOS codepages, Macintosh family, KOI8 family, all others supported by iconv library. Aliases like 'latin1', 'us-ascii' also supported.
- All widespread multibyte encodings: CP932, CP936, CP949, CP950, GB2312, GBK, GB18030, Big5, Shift_JIS, EUC-JP.

See all supported encodings on wiki.

Most singlebyte encodings are generated automatically from node-iconv. Thank you Ben Noordhuis and libiconv authors!

Multibyte encodings are generated from Unicode.org mappings and WHATWG Encoding Standard mappings. Thank you, respective authors!

# Encoding/decoding speed

Comparison with node-iconv module (1000x256kb, on MacBook Pro, Core i5/2.6 GHz, Node v0.12.0). Note: your results may vary, so please always check on your hardware.

    operation             iconv@2.1.4   iconv-lite@0.4.7
    ----------------------------------------------------------
    encode('win1251')     ~96 Mb/s      ~320 Mb/s
    decode('win1251')     ~95 Mb/s      ~246 Mb/s

# BOM handling

- Decoding: BOM is stripped by default, unless overridden by passing `stripBOM: false` in options (f.ex. `iconv.decode(buf, enc, {stripBOM: false})`). A callback might also be given as a `stripBOM` parameter - it'll be called if BOM character was actually found.
- If you want to detect UTF-8 BOM when decoding other encodings, use node-autodetect-decoder-stream module.
- Encoding: No BOM added, unless overridden by `addBOM: true` option.

# UTF-16 Encodings

This library supports UTF-16LE, UTF-16BE and UTF-16 encodings. First two are straightforward, but UTF-16 is trying to be smart about endianness in the following ways:

- Decoding: uses BOM and 'spaces heuristic' to determine input endianness. Default is UTF-16LE, but can be overridden with ‘defaultEncoding: 'utf-16be’`option. Strips BOM unless`stripBOM: false`.`
- `Encoding: uses UTF-16LE and writes BOM by default. Use`addBOM: false` to override.

# Other notes

When decoding, be sure to supply a Buffer to decode() method, otherwise bad things usually happen.
Untranslatable characters are set to � or ?. No transliteration is currently supported.
Node versions 0.10.31 and 0.11.13 are buggy, don't use them (see #65, #77).

# Testing

$ git clone git@github.com:ashtuchkin/iconv-lite.git
$ cd iconv-lite
$ npm install
$ npm test
$ # To view performance:
$ node test/performance.js
$ # To view test coverage:
$ npm run coverage
$ open coverage/lcov-report/index.html