pyxterm.js

A fully functional terminal in your browser.

How does this work?

On the backend:

• A Flask server is running
• The Flask server uses flask-socketio, a websocket library for Flask and socketio
• A pty ("pseudo-terminal") is spawned that runs bash.
  • You can think of a pty as a way to serialize/deserialize a terminal session. The Python docs describe it as "starting another process and being able to write to and read from its controlling terminal programmatically".

On the frontend:

• Xterm.js is used to render Xterm output data in the browser.
  • This means escape codes used by terminals to control the cursor location, color, and other options can be passed directly to Xterm.js and Xterm.js will faithfully render them as a terminal would.
  • Output from the pty process on the backend is fed into it.
  • Input from the browser is passed via websocket to the pty's input

Why?

The real purpose of this is to show a basic proof of concept on how to bring Xterm.js, Python, Flask, and Websockets together to run a pty in the browser.

This is a

• starting point to build your own web app with a terminal
• learning tool to understand what a pty is, and how to use one in Python
• way to see Flask and Flask-SocketIO in action
• way to play around with Xterm.js in a meaningful environment

Installation

Option 1

Run pyxtermjs with no commitment in an ephemeral environment with pipx

pipx run pyxtermjs  # install and run in ephemeral environment

Option 2

Clone this repository, enter the pyxtermjs directory, create a virtual environment (python3 -m venv venv), activate it (source venv/bin/activate) then run

pip install -r requirements.txt
python -m pyxtermjs

Documentation

>> pyxtermjs --help
usage: pyxtermjs [-h] [-p PORT] [--debug] [--version] [--command COMMAND]
                 [--cmd-args CMD_ARGS]

A fully functional terminal in your browser.
https://github.com/cs01/pyxterm.js

optional arguments:
  -h, --help            show this help message and exit
  -p PORT, --port PORT  port to run server on (default: 5000)
  --debug               debug the server (default: False)
  --version             print version and exit (default: False)
  --command COMMAND     Command to run in the terminal (default: bash)
  --cmd-args CMD_ARGS   arguments to pass to command (i.e. --cmd-args='arg1
                        arg2 --flag') (default: )