Current File : //usr/lib/node_modules/npm/node_modules/iconv-lite/README.md
## Pure JS character encoding conversion [](https://travis-ci.org/ashtuchkin/iconv-lite)
* Doesn't need native code compilation. Works on Windows and in sandboxed environments like [Cloud9](http://c9.io).
* Used in popular projects like [Express.js (body_parser)](https://github.com/expressjs/body-parser),
[Grunt](http://gruntjs.com/), [Nodemailer](http://www.nodemailer.com/), [Yeoman](http://yeoman.io/) and others.
* Faster than [node-iconv](https://github.com/bnoordhuis/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](https://github.com/substack/node-browserify) (~180k gzip compressed with Buffer shim included).
* Typescript [type definition file](https://github.com/ashtuchkin/iconv-lite/blob/master/lib/index.d.ts) included.
* React Native is supported (need to explicitly `npm install` two more modules: `buffer` and `stream`).
* License: MIT.
[](https://npmjs.org/packages/iconv-lite/)
## Usage
### Basic API
```javascript
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+)
```javascript
// 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](https://github.com/ashtuchkin/iconv-lite/wiki/Node-v4-compatibility).
```javascript
// 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](https://github.com/ashtuchkin/iconv-lite/wiki/Supported-Encodings).
Most singlebyte encodings are generated automatically from [node-iconv](https://github.com/bnoordhuis/node-iconv). Thank you Ben Noordhuis and libiconv authors!
Multibyte encodings are generated from [Unicode.org mappings](http://www.unicode.org/Public/MAPPINGS/) and [WHATWG Encoding Standard mappings](http://encoding.spec.whatwg.org/). 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](https://github.com/danielgindi/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](https://github.com/ashtuchkin/iconv-lite/wiki/Use-Buffers-when-decoding).
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
```bash
$ 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
```
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