README.md 6.38 KB
Newer Older
Rosanny Sihombing's avatar
Rosanny Sihombing committed
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
## Pure JS character encoding conversion [![Build Status](https://travis-ci.org/ashtuchkin/iconv-lite.svg?branch=master)](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.

[![NPM Stats](https://nodei.co/npm/iconv-lite.png?downloads=true&downloadRank=true)](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
```