kashav/rdrp

rdrp

A cross-platform command line tool for sending and receiving files over your local network, inspired by AirDrop.

Contents

• Demo
• Design
• Installation
• Usage
  • Send
  • Broadcast
  • Monitor
• Docker
• Contribute
• Related
• License

Demo

Design

rdrp uses Multicast DNS to enable peer-to-peer discovery between clients. This means that rdrp will likely not work in most cloud/virtual environments.

When a client first connects, they're registered as a new instance on the _rdrp._tcp service. Each sender continuously browses this service for newly connected broadcasters with whom they'll establish a connection and attempt to send their respective file.

This program implements mDNS with grandcat/zeroconf.

Read more about mDNS: RFC 6762 and DNS-SD: RFC 6763.

Installation / setup

Go should be installed and configured.

Install with Go:

$ go get -v github.com/kashav/rdrp/...
$ which rdrp
$GOPATH/bin/rdrp

Or, install directly via source:

$ git clone https://github.com/kashav/rdrp.git $GOPATH/src/github.com/kashav/rdrp
$ cd $_ # $GOPATH/src/github.com/kashav/rdrp
$ make install all
$ ./rdrp

Usage

Run rdrp with the --help flag to view the usage dialogue.

$ rdrp --help
usage: rdrp [<flags>] <command> [<args> ...]

Send and receive files over your local network.

Flags:
      --help       Show context-sensitive help (also try --help-long and --help-man).
  -n, --name=NAME  Set your connection name.
  -d, --debug      Enable debug mode.
      --version    Show application version.

Commands:
  help [<command>...]
    Show help.

  broadcast
    Receive a file.

  list [<flags>]
    View active clients.

  send [<flags>]
    Send a file.

There's two parties involved in a single transaction: the sender and the receiver.

Send

To send a file, use the send command. Provide the file path with the --file flag or pass the file's contents via stdin.

Every broadcaster will receive a request to transfer the file (unless names are specified with the --to flag). This process continues until aborted (Ctrl+C).

$ rdrp help send
usage: rdrp send [<flags>]

Send a file.

Flags:
      --help       Show context-sensitive help (also try --help-long and --help-man).
  -n, --name=NAME  Set your connection name.
  -d, --debug      Enable debug mode.
      --version    Show application version.
  -f, --file=FILE  Specify the transfer file (you may optionally pass your file via stdin).
      --to=TO ...  Comma-separated list of client names.

Examples

$ rdrp send --file=README.md

$ rdrp send --name sender < README.md

$ tar -cvzf archive.tar.gz /path/to/directory/
$ rdrp send --file=archive.tar.gz --to=a

$ echo "hello" | rdrp send --to=b,c

Broadcast

To broadcast yourself as a receiver (i.e. someone receiving a file), use the broadcast command.

You'll be listening for incoming send requests. Upon a new connection, you'll be prompted on whether you'd like to accept the file or not, just like AirDrop. The incoming file is copied to stdout.

$ rdrp broadcast -help
usage: rdrp broadcast

Receive a file.

Flags:
      --help       Show context-sensitive help (also try --help-long and --help-man).
  -n, --name=NAME  Set your connection name.
  -d, --debug      Enable debug mode.
      --version    Show application version.

Examples

$ rdrp broadcast # output is copied to stdout
...

$ rdrp broadcast --name b > archive.tar.gz

Note that each of the above roles has an optional name flag, a name is chosen at random if not provided (which is what happened in the demo above).

List

You can view all connected clients with list. Use --type to specify the type of clients to list and --watch to listen for new connections.

$ rdrp list -help

View active clients.

Flags:
      --help        Show context-sensitive help (also try --help-long and --help-man).
  -n, --name=NAME   Set your connection name.
  -d, --debug       Enable debug mode.
      --version     Show application version.
  -w, --watch       Watch for new connections.
  -t, --type="all"  Specify which type of client to listen for.

Use with Docker

Start off by cloning the repository (if you've already cloned, navigate to the project root):

$ git clone https://github.com/kashav/rdrp
$ cd rdrp

Build the Docker image:

$ docker build -t kashav/rdrp .

And run it! The --rm flag automatically removes the container when the program exits.

$ docker run --rm kashav/rdrp [broadcast|list|send] ...

Contribute

This project is completely open source, feel free to open an issue or submit a pull request.

Before submitting a PR, please ensure that tests are passing and that the linter is happy. The following commands may be of use.

$ make install \
       get-tools
$ make fmt \
       vet \
       lint
$ make test \
       coverage

The demo GIF was generated with asciinema, with tmux.

Related

• taku-k/airdrop
• tlehman/zerocat

License

rdrp source code is released under the MIT License.