bencode

node-bencode

A node library for encoding and decoding bencoded data,
according to the BitTorrent specification.

Index

• About BEncoding
• Installation
• Usage
• API

About BEncoding

from Wikipedia:

Bencode (pronounced like B encode) is the encoding used by the peer-to-peer file sharing system BitTorrent for storing and transmitting loosely structured data.

It supports four different types of values:

• byte strings
• integers
• lists
• dictionaries

Bencoding is most commonly used in torrent files. These metadata files are simply bencoded dictionaries.

Install with npm

npm install bencode

Usage

var bencode = require( 'bencode' )

Encoding

var data = {
  string: 'Hello World',
  integer: 12345,
  dict: {
    key: 'This is a string within a dictionary'
  },
  list: [ 1, 2, 3, 4, 'string', 5, {} ]
}

var result = bencode.encode( data )

Output

d6:string11:Hello World7:integeri12345e4:dictd3:key36:This is a string within a dictionarye4:litli1ei2ei3ei4e6:stringi5edeee

Decoding

var data   = new Buffer( 'd6:string11:Hello World7:integeri12345e4:dictd3:key36:This is a string within a dictionarye4:litli1ei2ei3ei4e6:stringi5edeee' )
var result = bencode.decode( data )

Output

{
  string: <Buffer 48 65 6c 6c 6f 20 57 6f 72 6c 64>,
  integer: 12345,
  dict: {
    key: <Buffer 54 68 69 73 20 69 73 20 61 20 73 74 72 69 6e 67 20 77 69 74 68 69 6e 20 61 20 64 69 63 74 69 6f 6e 61 72 79>
  },
  list: [ 1, 2, 3, 4, <Buffer 73 74 72 69 6e 67>, 5, {} ]
}

Automagically convert bytestrings to strings:

var result = bencode.decode( data, 'utf8' )

Output

{
  string: 'Hello World',
  integer: 12345,
  dict: {
    key: 'This is a string within a dictionary'
  },
  list: [ 1, 2, 3, 4, 'string', 5, {} ]
}

API

bencode.encode( data )

Buffer | Array | String | Object | Number data

Returns String

bencode.decode( data, encoding )

Buffer data
String encoding

If encoding is set, bytestrings are automatically converted to strings.

Returns Object | Array | Buffer | String | Number

Changelog

0.3.0

• #decode() accepts a encoding as its second paramtere