node-buffer-peek-stream


Take a peek at the start of a stream and get back a new stream rewound from the start without
buffering the entire stream. Useful when you need to inspect the start of the stream before
deciding what to do with the stream.

``
npm install buffer-peek-stream
`

Useful if you want to inspect the start of a stream before deciding what to do with it.

This works with buffers and does no string decoding. If you know you have a string and already
know its encoding then checkout peek-stream.




Usage


As a promise (with await)...
`
const peek = require('buffer-peek-stream').promise;
const readstream = fs.createReadStream('package.json');

const [data, outputStream] = await peek(readstream, 65536);

// outputStream is ready to be piped somewhere else
outputStream.pipe(somewhere_else);
`

As a callback...
`
var peek = require('buffer-peek-stream');
var readstream = fs.createReadStream('package.json');

peek(readstream, 65536, function (err, data, outputStream) {
if (err) throw err;

// outputStream is ready to be piped somewhere else
outputStream.pipe(somewhere_else);
});
`

As a stream...
`
var PeekStream = require('buffer-peek-stream').BufferPeekStream;

var peek = new PeekStream(65536);
var readstream = fs.createReadStream('package.json');

// peek will only emit the peek event once
peek.once('peek', function (buf) {

// readstream is ready to be piped somewhere else
peek.pipe(somewhere_else);
});

readstream.pipe(peek);

// alternatively pipe peek here instead of in data callback
``

Licence

MIT