92 lines
2.7 KiB
Markdown
92 lines
2.7 KiB
Markdown
|
# dns-txt
|
||
|
|
|
||
|
|
Encode or decode the RDATA field in multicast DNS TXT records. For use
|
||
|
|
with DNS-Based Service Discovery. For details see [RFC
|
||
|
|
6763](https://tools.ietf.org/html/rfc6763).
|
||
|
|
|
||
|
|
[](https://travis-ci.org/watson/dns-txt)
|
||
|
|
[](https://github.com/feross/standard)
|
||
|
|
[](https://github.com/mafintosh/abstract-encoding)
|
||
|
|
|
||
|
|
## Installation
|
||
|
|
|
||
|
|
```
|
||
|
|
npm install dns-txt
|
||
|
|
```
|
||
|
|
|
||
|
|
## Usage
|
||
|
|
|
||
|
|
```js
|
||
|
|
var txt = require('dns-txt')()
|
||
|
|
|
||
|
|
var obj = {
|
||
|
|
foo: 1,
|
||
|
|
bar: 2
|
||
|
|
}
|
||
|
|
|
||
|
|
var enc = txt.encode(obj) // <Buffer 05 66 6f 6f 3d 31 05 62 61 72 3d 32>
|
||
|
|
|
||
|
|
txt.decode(enc) // { foo: '1', bar: '2' }
|
||
|
|
```
|
||
|
|
|
||
|
|
## API
|
||
|
|
|
||
|
|
The encoder and decoder conforms to [RFC 6763](https://tools.ietf.org/html/rfc6763).
|
||
|
|
|
||
|
|
### Initialize
|
||
|
|
|
||
|
|
The module exposes a constructor function which can be called with an
|
||
|
|
optional options object:
|
||
|
|
|
||
|
|
```js
|
||
|
|
var txt = require('dns-txt')({ binary: true })
|
||
|
|
```
|
||
|
|
|
||
|
|
The options are:
|
||
|
|
|
||
|
|
- `binary` - If set to `true` all values will be returned as `Buffer`
|
||
|
|
objects. The default behavior is to turn all values into strings. But
|
||
|
|
according to the RFC the values can be any binary data. If you expect
|
||
|
|
binary data, use this option.
|
||
|
|
|
||
|
|
#### `txt.encode(obj, [buffer], [offset])`
|
||
|
|
|
||
|
|
Takes a key/value object and returns a buffer with the encoded TXT
|
||
|
|
record. If a buffer is passed as the second argument the object should
|
||
|
|
be encoded into that buffer. Otherwise a new buffer should be allocated
|
||
|
|
If an offset is passed as the third argument the object should be
|
||
|
|
encoded at that byte offset. The byte offset defaults to `0`.
|
||
|
|
|
||
|
|
This module does not actively validate the key/value pairs, but keep the
|
||
|
|
following in rules in mind:
|
||
|
|
|
||
|
|
- To be RFC compliant, each key should conform with the rules as
|
||
|
|
specified in [section
|
||
|
|
6.4](https://tools.ietf.org/html/rfc6763#section-6.4).
|
||
|
|
|
||
|
|
- To be RFC compliant, each value should conform with the rules as
|
||
|
|
specified in [section
|
||
|
|
6.5](https://tools.ietf.org/html/rfc6763#section-6.5).
|
||
|
|
|
||
|
|
After encoding `txt.encode.bytes` is set to the amount of bytes used to
|
||
|
|
encode the object.
|
||
|
|
|
||
|
|
#### `txt.decode(buffer, [offset], [length])`
|
||
|
|
|
||
|
|
Takes a buffer and returns a decoded key/value object. If an offset is
|
||
|
|
passed as the second argument the object should be decoded from that
|
||
|
|
byte offset. The byte offset defaults to `0`. Note that all keys will be
|
||
|
|
lowercased and all values will be Buffer objects.
|
||
|
|
|
||
|
|
After decoding `txt.decode.bytes` is set to the amount of bytes used to
|
||
|
|
decode the object.
|
||
|
|
|
||
|
|
#### `txt.encodingLength(obj)`
|
||
|
|
|
||
|
|
Takes a single key/value object and returns the number of bytes that the given
|
||
|
|
object would require if encoded.
|
||
|
|
|
||
|
|
## License
|
||
|
|
|
||
|
|
MIT
|