exsilium / xmodem.js

XMODEM implementation in JavaScript

xmodem.js

XMODEM is a simple file transfer protocol. This project implements the protocol in JavaScript. Please see the API docs for more details.

Installation

npm install xmodem.js

Usage

Sending

var xmodem = require('xmodem.js');
xmodem.send(socket, buffer);

Receiving

var xmodem = require('xmodem.js');
xmodem.receive(socket, receiveFile);

xmodem.js's Issues

If EOT block is not acknowledged, xmodem.js doesn't resend the EOT block again

I had the following situation while using this package:

1. After the file was sent, xmodem.js sends EOT.
2. Receiver responds with NAK.
3. xmodem.js sends the last sent xmodem block again.

I think that this is not correct. Instead of sending the last block again, it should send the EOT command again.

When the uploader sends an EOT byte instead of an SOH byte, the downloader
sends a NAK byte. If the uploader sends another EOT immediately after that,
the downloader sends an ACK byte and the transfer is complete.

Or am I wrong?

I would be very happy to submit a PR for this, as I already fixed this problem on my local machine.

SerialPort doesn't function as a socket

I'm attempting to use xmodem to send data to a serial port. The API and code comments suggest this is possible. However if a SerialPort is given to the send function:

serialPort = new SerialPort(port, {baudRate: 9600}, false);
xmodem.send(port, buffer);

The following error occurs:

.\node_modules\xmodem.js\lib\index.js:221 Uncaught (in promise) TypeError: socket.on is not a function
    at Xmodem.send (.\node_modules\xmodem.js\lib\index.js:221)
    at ReadLineParser.<anonymous> (app.js:490)
    at ReadLineParser.emit (events.js:200)
    at addChunk (_stream_readable.js:294)
    at readableAddChunk (_stream_readable.js:271)
    at ReadLineParser.Readable.push (_stream_readable.js:210)
    at ReadLineParser.Transform.push (_stream_transform.js:150)
    at ReadLineParser._transform (.\node_modules\@serialport\parser-delimiter\delimiter.js:35)
    at ReadLineParser.Transform._read (_stream_transform.js:189)
    at ReadLineParser.Transform._write (_stream_transform.js:177)

Does this package not support SerialPort?

CRC failure on ZIP File

Hey @exsilium, first off... thank you for the library.

I am using this library to serve up a ZIP file for download from SyncTERM.
When I do that, I get a CRC failure. A standard TXT files seems to work fine however.
Am I missing something? The first chuck seems to be getting sent over perfectly, just a failing CRC.

Code:

xmodem.send(socket, fs.readFileSync('zines/LOD-4.ZIP'));