snake-pipe-rust

Not just yet another snake game in the terminal 😉.

https://github.com/topheman/snake-pipe-rust/assets/985982/76161595-1c3a-4252-9cbd-25e144bf185c

This one follows the unix philosophy as:

• snakepipe gamestate accepts user inputs, calculates the state of the game and writes it to stdout
• snakepipe render reads the state of the game from stdin and renders it on the terminal
• snakepipe throttle reads a pre-recorded game from stdin and writes to stdout each tick so that snakepipe render can pick it up
• snakepipe render-browser spawns a server and sends stdin via server-sent events to a JavaScript renderer in your browser
• snakepipe stream-sse connects to the server spawned by render-browser and streams server-sent events back to the terminal
• snakepipe socket-play accepts gamestate from stdin and pushes it to a unix socket
• snakepipe socket-watch reads gamestate from a unix socket
• snakepipe tcp-play accepts gamestate from stdin and pushes it to a tcp socket
• snakepipe tcp-watch reads gamestate from a tcp socket
• snakepipe pipeline <command> prints out the most common pipelines (combinations of commands), so that you could directly pbcopy/paste them

That way:

• you could write your own version of the gamestate or render command in any programming language and make it work with mine
• it's a great exercise to handle stream serialization/deserialization in rust

Motivation

I've already done a few rust projects (with WebAssembly or bevy), however, I wanted something that needs to deal directly with:

• I/O
• parsing
• parallelism
• async programming
• handling piping/stdin/stdout/signaling ...
• inter-process communication

Install

Any OS - if you have Rust >= 1.75.0 - How to install Rust (if you don't have it yet)

cargo install snakepipe

On MacOS, with Homebrew (ships with its own shell completions for zsh, bash and fish)

brew install topheman/tap/snakepipe

Other OS: see releases.

Usage

Piping

🎮 Play in terminal

# basic usage
snakepipe gamestate|snakepipe render

# change the defaults
snakepipe gamestate --frame-duration 80 --width 70 --height 20 --snakepipe-length 15|snakepipe render

# call help on any of the commands
snakepipe --help

📼 You can even record and replay using basic piping

# record a game into a file using the builtin `tee` command utility
snakepipe gamestate|tee /tmp/snakepipe-output|snakepipe render

# replay the game you recorded
cat /tmp/snakepipe-output|snakepipe throttle|snakepipe render

🖥 You can mirror your playing terminal into a server you can open in a browser

snakepipe gamestate|snakepipe render-browser|snakepipe render

Then open http://localhost:8080. You'll be able to switch between renderers in your browser as you are playing in your terminal (thanks to server-sent events).

🖼 You can mirror your playing terminal into another one, through http

Open two terminals:

# main terminal:
# - accepts user inputs
# - spawns an http server that streams stdin to server-sent events
# - renders the game to the terminal so you can play
snakepipe gamestate|snakepipe render-browser|snakepipe render

# mirroring terminal (not necessary the same device, only need to be on the same network):
# - connects to the http server and streams server-sent events to sdout
# - render the gamestate retrieved from the server
snakepipe stream-sse|snakepipe render

You could share your game accross your LAN!

IPC (Inter-process communication)

TCP

Open two terminals. snakepipe tcp-play will expose a process that accepts tcp connections (on port 8050 by default). You can connect to it via netcat (the nc command), that will pipe the tcp stream output to stdout.

# main terminal
snakepipe gamestate|snakepipe tcp-play|snakepipe render

# mirroring terminal
nc localhost 8050|snakepipe render # with netcat
snakepipe tcp-watch|snakepipe render # or with snakepipe itself

Unix domain sockets

Open two terminals. snakepipe socket-play will expose a unix domain socket (by default on /tmp/snakepipe.sock). You can connect to it via netcat (the nc command), that will pipe the socket stream to stdout.

# main terminal
snakepipe gamestate|snakepipe socket-play|snakepipe render

# mirroring terminal
nc -U /tmp/snakepipe.sock|snakepipe render # with netcat
snakepipe socket-watch|snakepipe render # or with snakepipe itself

Others

📺 You can also mirror your playing terminal into another one

You should prefer using IPC.

Open two terminals that will communicate via a file that will be tailed and piped to snakepipe render

# mirroring terminal
cat /dev/null > /tmp/snakepipe-output && tail -f /tmp/snakepipe-output|snakepipe render

# main terminal
snakepipe gamestate|tee /tmp/snakepipe-output|snakepipe render

😉 And maybe you'll find other ways?...

Shell completions

If you install snakepipe with Homebrew, it ships with its own completions for zsh, bash and fish and they will be installed without you having to do anything.

If you installed snakepipe manually, you can generate the completions files with the snakepipe generate-completions command.

Manual of commands

A snake game based on stdin/stdout following unix philosophy
Usage: snakepipe <COMMAND>
Commands:
gamestate       Accepts user inputs (arrow keys to control the snake) and outputs the state of the game to stdout
render          Reads gamestate from stdin and renders the game on your terminal
throttle        Reads stdin line by line and outputs each line on stdout each frame_duration ms (usefull for replaying a file)
render-browser  Let's you render the game in your browser at http://localhost:8080 by spawning a server and sending stdin via server-sent events to a JavaScript renderer
stream-sse      Connects to the server spawned by render-browser and streams server-sent events back to the terminal
help            Print this message or the help of the given subcommand(s)
Options:
-h, --help     Print help
-V, --version  Print version

Accepts user inputs (arrow keys to control the snake) and outputs the state of the game to stdout
Usage: snakepipe gamestate [OPTIONS]
Options:
--frame-duration <FRAME_DURATION>  in ms [default: 120]
--width <WIDTH>                    default 25
--height <HEIGHT>                  default 25
--snake-length <SNAKE_LENGTH>      [default: 2]
--fit-terminal

Reads gamestate from stdin and renders the game on your terminal
Usage: snakepipe render

Reads stdin line by line and outputs each line on stdout each `frame_duration` ms (usefull for replaying a file)
Usage: snakepipe throttle [OPTIONS]
Options:
--frame-duration <FRAME_DURATION>  in ms [default: 120]
--loop-infinite

Let's you render the game in your browser at http://localhost:8080 by spawning a server and sending stdin via server-sent events to a JavaScript renderer
Usage: snakepipe render-browser [OPTIONS]
Options:
--port   [default: 8080]

Connects to the server spawned by `render-browser` and streams server-sent events back to the terminal
Usage: snakepipe stream-sse [OPTIONS]
Options:
--address <ADDRESS>  [default: http://localhost:8080]

Accepts gamestate from stdin and pushes it to a unix socket
Usage: snakepipe socket-play [OPTIONS]
Options:
--path <PATH>  Unix socket file path [default: /tmp/snakepipe.sock]

Reads gamestate from a unix socket
Usage: snakepipe socket-watch [OPTIONS]
Options:
--path <PATH>  Unix socket file path [default: /tmp/snakepipe.sock]

Accepts gamestate from stdin and pushes it to a tcp socket
Usage: snakepipe tcp-play [OPTIONS]
Options:
--port <PORT>  Port number [default: 8050]
--host <HOST>  Tcp host [default: 127.0.0.1]

Reads gamestate from a tcp socket
Usage: snakepipe tcp-watch [OPTIONS]
Options:
--port <PORT>  Port number [default: 8050]
--host <HOST>  Tcp host [default: 127.0.0.1]

Prints out some common pipelines, so that you can copy/paste them to execute (you can pipe to `pbcopy`)
Usage: snakepipe pipeline [OPTIONS] [COMMAND]
Commands:
play        Play in the terminal
record      Record a party in the terminal
replay      Replay a party you recorded in the terminal
file-play   Play and share a party via a shared file in realtime
file-watch  Render the party you are sharing through a file in realtime
http-play   Play and share a party through an http server
http-watch  Render the party you shared through the http server, in the terminal

Using as a library

cargo add snakepipe # add it to your project

This crate is a cli, but it also exports a lib from where you can import a few utilities, such as snakepipe::stream::parse_gamestate - direct link to docs.rs:

use snakepipe::stream::{parse_gamestate, Game};

fn main() -> () {
    match parse_gamestate() {
        Ok(stream) => {
            println!(
                "Frame duration {}, Snake length {}, Level {}x{}",
                stream.options.frame_duration,
                stream.options.snake_length,
                stream.options.size.width,
                stream.options.size.height
            );
            for parsed_line in stream.lines {
                do_something(parsed_line);
            }
        }
        Err(e) => {
            eprintln!("Error occurred while parsing stdin: \"{}\"", e);
        }
    }
}

fn do_something(parsed_line: Game) {
    println!("Snake head position {:?}", parsed_line.snake.head)
}

Contributing

You can:

• Make an implementation of the actual snakepipe render command for the terminal in an other language than rust
• Make your own JavaScript renderer for the snakepipe render-browser command and ask for a PR to integrate it to the project

An Experimental/Partial nodejs implementation of this crate available at topheman/snake-pipe-node.

More infos in CONTRIBUTING.md.