Transform stream that lets you inspect the start of a readable stream before deciding what to do with it
npm install 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.
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
``