CShell

CShell is an extensible, in-development, POSIX-compliant shell made with Python.

Found a bug? Want a new feature? Create an issue! (Please check for an existing one first to avoid duplicates.)

Want to contribute? You can find good first issues here.

Table of Contents

• Installation Guide
• Features
• ShellExtension and the CShell Extension Framework

Installation Guide

CShell ony supports Linux at this time. Support for macOS and Windows may come soon.

To install CShell, execute this command:

git clone https://github.com/CragglesG/cshell cshell-install && cd cshell-install && ./install.sh

The above command clones the CShell repo, enters the cloned directory, and runs the install script. To update your user PATH, run:

source ~/.bashrc

You can now run CShell with the cshell command.

Features

CShell is currently under heavy development, and is not yet complete. Here's a list of features that are available now:

• exit, echo, type, pwd, cd, builtins, reload, and history built-ins
• History and .inputrc support
• Extensions framework through ShellExtension
• Environment variables support
• Built-in PATH support
• Fallback to default system shell

ShellExtension and the CShell Extension Framework

The CShell Extension Framework allows developers to extend CShell using the ShellExtension class. Extensions are provided with the user input, path files, and built-ins available in the current session, along with a function to display output to the user. Below is an example of a simple CShell extension:

from shell_extensions import ShellExtension

class TestExtension(ShellExtension):
    def __init__(self):
        super().__init__("test-extension", self.test)
    
    def test(self, msg, pathfiles, builtins, send):
        send("This is a test extension\n")

The above extension displays the output This is a test extension to the user, followed by a newline. The newline is necessary to move the prompt to the next line. The super().__init__ function takes two arguments, the extension command and the function to call.

All extensions should be located in ~/.cshell/extensions/. CShell will scan this folder for extensions and register them upon starting.

Important: CShell first searches for commands in the built-ins dictionary, followed by the extensions dictionary, and finally the path files dictionary. Extensions can therefore override path files, but not built-ins.