closh - Bash-like shell based on Clojure

Closh combines the best of traditional unix shells with the power of Clojure. It aims to be a modern alternative to bash.

Demo showing how to execute commands and using Clojure to manipulate outputs in shell:

Why try to reinvent bash?

• Bash has obscure syntax for non-trivial operations and lots of WTF moments.
• It treats everything as text while we mostly need to manipulate structured information.
• It is a large codebase which makes it difficult to hack on it and try innovative ideas. Which is one of the reasons why the shell did not improve much in recent decades.
• Traditional shells are limited in terms of presentation and discoverability, what if we could bring back richer environment as imagined by lisp machines?

Why shell based on Clojure(Script)?

• Clojure's has a simple syntax and well-thought design which makes it pleasurable to work with.
• Its extensive collection of powerful functions for data manipulation is suitable to provide solutions for daily tasks.
• Write shell scripts in a language you use daily for development so you don't have to google arcane shell constructs every time you need to do anything but simplest tasks.
• Less amount and more composable code allows to experiment with new features and ideas.

Warning: Closh is still in a early stage and under a heavy development, has many rough edges and is subject to change a lot. Closh is tested on Linux, should run on macOS too.

Community and Contribution

If you have feedback about a specific feature or found a bug please open an issue.
Use reddit for general discussion and to share scripts and workflows. Chat room is on gitter.

If you would like to contribute take look at open issues. Leave a comment if you find anything interesting and we can improve the project together.

Install

Windows is currently NOT supported! If you know your way around with Windows, we need your help (see #54).

ClojureScript/Lumo version

Install closh (requires Node.js version 9.x, support for version 10 is in progress, see #113):

npm install -g closh

If you get a permission error then try:

npm install -g closh --unsafe-perm

To install development version from master branch:

npm i -g dundalek/closh

Clojure/JVM version

Run with clojure CLI:

clojure -Sdeps '{:deps {closh {:git/url "https://github.com/dundalek/closh.git" :tag "v0.3.3" :sha "093c8a55c9c3d2a326435d6943a92e5b8090cda1"}}}' -m closh.zero.frontend.rebel

Alternatively for a faster startup you can download AOT compiled uberjar file and run it with:

java -jar closh-zero.jar

The jar file also contains a special header, so once you make it executable you can run it directly:

chmod +x closh-zero.jar
./closh-zero.jar

Quick Start

Start the shell:

closh

Run simple commands like you are used to:

$ echo hi

$ git status

$ ls -l *.json

Commands starting with a parenthesis are evaluated as Clojure code:

$ (+ 1 2)
; => 3

The power comes from combining shell commands and Clojure:

$ echo hi | (clojure.string/upper-case)
; => HI

$ ls *.json |> (reverse)

; Count number of files grouped by first letter sorted by highest count first
$ ls |> (group-by first) | (map #(update % 1 count)) | (sort-by second) | (reverse)

If you like closh you can set it as your default shell.

Be careful and first test closh from other shell to make sure it works on your machine so you don't get locked out of shell (after chsh you need to log out and log back in for changes to take effect):

which closh | sudo tee -a /etc/shells
chsh -s $(which closh)

For the JVM version you can make it the default shell similarly like:

closh=/path/to/closh-zero.jar
chmod +x $closh
echo $closh | sudo tee -a /etc/shells
chsh -s $closh

Documentation

• Guide and Reference - Introduction to closh and basic configuration
• Cookbook - Recipes for integration of other tools like NVM, Autojump, etc.
• Design Principles - Learn about the philosophy and what guides design decisions
• Tech notes - Read about internals and architecture
• Notes on Existing Shells
• Changelog

Roadmap

Next release

• Script mode

Terminal UI improvements and ideas

Explore innovate UI ideas, explore what a shell could become and all possibilities within an ASCII terminal. The goal is to reimagine what people think a command line interface is without having to lose its core power.

• Explore launcher functionality similar to Alfred and others
• Readline improvements
• Interactive command-line interfaces
• Key bindings
• Syntax highlighting in CLJS
• Automatic abbreviation suggestion
• Data helpers that automatically parse command output into data structures

More UI exploration

Explore if we could take shell power and functionality and lift it from the boundaries set by ASCII terminals.

• Structured graphical output ala TermKit or lisp machines
• Explore possibilty of a web interface

Stabilization and performance

I hope that new UI ideas above will get people excited and interested. After that we should work on stabilization and adding all the remaining features people are used to from traditional shells.

• Explore possibility to run via Planck
• Distribute closh and lumo as a single binary
• Explore possibility to compile JVM version with Graal and distribute as a single binary
• Implement a low-level native pipeline library to improve performance
• Make it more robust and better error handling
• Job control

Limitations

Lumo version (CLJS)

• No syntax highlighting
• Prompt quirks
• Synchronous execution hacks (via deasync library)

JVM version (CLJ)

• Aliases and abbreviations do not work
• Cannot redirect STDIO >= 3 (Java ProcessBuilder limitation)

Development

Clone the repo and install dependencies

git clone git@github.com:dundalek/closh.git
cd closh
npm install

Run the cljs app

npm start

Run in dev mode reloading on changes

npm run dev

Run the clj app

clojure -m closh.zero.frontend.rebel

Run tests once

npm run test

Re-run tests on change

npm run test-auto

Sponsors

Thank you for the support:

• AdGoji

Copyright & License

Copyright (c) Jakub Dundalek and contributors

Distributed under the Eclipse Public License 1.0 (same as Clojure).

Logo created by @batarian71 under CC BY 4.0.