lush

A shell. Written as a toy demo for my terminal line editor ledit, using the reference C implementation.

Demo

Features

• Syntax highlighting (a la fish or oh-my-zsh)
• Command and filename onion skin/ghosting (a la fish -- provides autofill suggestions based on programs in $PATH and files in current directory)
• Case-insensitive tab completion
  • Optionally, install fzf for fuzzy file finding support.
• Functional line editor (arrow keys, Control+arrow keys for moving between words, home/end keys, backspace/delete)
• Aliases (see config.h)
• Persistent command history (saved to disk)
• ~8x faster than fish, and on par with bash and zsh speed-wise (see benchmarks)
• 500 lines of pure -pedantic C

In its current state, lush works so long as you don't try to break it. Not recommended for use as a daily driver, but still fun and satisfying to use.

My focus with this project has been less on creating the guts of a robust shell, and more on making the user interface as user-friendly and "bells-and-whistly" as possible. As a result, features like builtins or aliases are somewhat hastily implemented and leave a good amount to be desired from a technical standpoint. However, work to properly implement these features can be done without fear of causing the rest of the shell to implode, based on the way the properly-written parts of the codebase have been written.

Compiling and Running

lush has no dependencies other than the C standard library, meaning it can be compiled and run with:

 $ make
 $ ./lush

Configuration

Configuration of lush is done entirely at compile-time through the header file config.h. Here are the options provided:

• Text colors
• PS1 (prompt)
• History file
• Aliases
• Builtins

To-Do

• Environment variables (+ runtime PS1 customization)
• Fix escaping/quoted strings
• Fix onion skin not applying to builtins/aliases
• Multi-line editing
• Investigate and fix autocomplete occasionally not working
• Remove printfs where they aren't strictly necessary