Concussion Shell

It's kinda like Bash except it causes severe brain damage because it's actually a Python REPL.

Usage

$ pip install concussion
$ concussion
>>> cat + README.md | head + -n + 4
# Concussion Shell

It's kinda like Bash except it causes severe brain damage because it's actually
a Python REPL.

How it works

Everything is implemented using horrific operator overloads.

Since the commands can't be executed while they're being constructed, commands are instead executed when stringified using repr(), which works nicely with Python's interactive console.

Python doesn't support building commands from adjacent identifiers, so Concussion uses the + operator to join arguments for a command.

>>> echo + hello + world
hello world

Notice that none of these variables were never defined. Concussion uses a custom dictionary for the local variable scope such that any undefined variables create a new string-like object, which helps to improve readability.

You can pipe commands using the standard | pipe operator.

>>> ls + -l | less
# less is broken because I can't be bothered to make my shell look like a TTY
# so the output is incorrect

To create shell aliases, you simply use Python variable assignments

>>> # This makes for an epic prank
>>> bash = concussion
>>> bash
Concussion shell...

Because && and || are not supported in Python, use the and and or keywords instead.

>>> false or echo + hi
>>> false and echo + hi
hi
>>> true or echo + hi
hi
>>> true and echo + hi

You can also do file redirection like in Bash

>>> echo + hi > hi.txt
>>> cat < hi.txt
hi
>>> echo + "hi again" >> hi.txt  # append
>>> cat < hi.txt
hi
hi again

Because working with regular strings or pathlib's Path objects is tedious in a shell-like environment, Concussion provides its own CursedPath object, which simplifies many aspects of string manipulation.

>>> str(path/to/some-file.txt)
"['path/to/some-file.txt']"

Note that the /, - and . operators all result in string joining.

in order to path to files from the root of the file system, a _ can be used before the leading /, since a leading / in Python produces a SyntaxError.

>>> _/usr/bin/sl
# [epic train ASCII art]

Setting concussion as your default shell

This will almost definitely break your system.

$ sudo chsh --shell $(which concussion)
...

Known issues

Currently all stderr goes directly to this process's stderr, and it cannot be redirected. Maybe I'll implement this at some point.
Currently no support for executing tasks asynchronously. Perhaps I could use β to signify this since it looks kinda like an & but is a valid identifier.
Many programs don't work nicely because they think they're not running in a terminal.