This library is a modern, pure Go readline shell implementation, with full .inputrc and legacy readline command/option support, and extended with various commands, options and tools commonly found in modern shells. Its architecture and completion system is heavily inspired from Z-Shell. It is used, between others, to power the console library.

Features

Core

• Pure Go, almost-only standard library
• Cross-platform (Linux / MacOS / Windows)
• Full .inputrc support (all commands/options)
• Extensive test suite and almost full coverage of core code
• Extended list of additional commands/options (edition/completion/history)
• Complete multiline edition/movement support
• Command-line edition in $EDITOR/$VISUAL support
• Programmable API, with failure-safe access to core components
• Support for an arbitrary number of history sources

Emacs / Standard

• Native Emacs commands
• Emacs-style macro engine (not working across multiple calls)
• Keywords switching (operators, booleans, hex/binary/digit) with iterations
• Command/mode cursor status indicator
• Complete undo/redo history
• Command status/arg/iterations hint display

Vim

• Near-native Vim mode
• Vim text objects (code blocks, words/blank/shellwords)
• Extended surround select/change/add functionality, with highlighting
• Vim Visual/Operator pending mode & cursor styles indications
• Vim Insert and Replace (once/many)
• All Vim registers, with completion support
• Vim-style macro recording (q<a>) and invocation (@<a>)

Interface

• Support for PS1/PS2/RPROMPT/transient/tooltip prompts (compatible with oh-my-posh)
• Extended completion system, keymap-based and configurable, easy to populate & use
• Multiple completion display styles, with color support.
• Completion & History incremental search system & highlighting (fuzzy-search).
• Automatic & context-aware suffix removal for efficient flags/path/list completion.
• Optional asynchronous autocomplete
• Builtin & programmable syntax highlighting

Documentation

Readline is used by the console library and its example binary. To get a grasp of the functionality provided by readline and its default configuration, install and start the binary.

The documentation is available on the repository wiki, for both users and developers.

Showcases

- Emacs edition

(This extract is quite a pity, because its author is not using Emacs and does not know many of its shortcuts)

- Vim edition

- Undo/redo line history

- Keyword switching & selection

Switching various keywords

Using regexp-based selection to grab parts of words (here, URL components)

- Vim selection & movements (basic)

- Vim surround (selection and change)

Selecting/adding/changing surround regions

Surround and change in shellwords, matching brackets, etc.

- Vim registers (with completion)

- History movements/completion/use/search

History movement, completion and some other other widgets

- Completion

Classic mode & incremental search mode

Suffix-autoremoval

- Prompts

- Logging

- Inputrc init file reload

- Multiline edition

- Macros

Emacs

Vim

Status

This library is now in a release status, as it has underwent several major rewrites and is now considered mostly feature-complete, with a solid testing suite to ensure safe and smooth operation to the best extent possible. New releases will be regularly pushed when bugs are found and corrected.

Additionally:

• Key dispatch/flushing, meta-key enable, etc might still contain some bugs/wrong behavior: 30 years of legacy support for 3000 different terminal emulators cannot be done right by me alone.
• Please open a PR or an issue if you face any bug, and it will be promptly resolved.
• Don't hesitate proposing a new feature or a PR if you deem it to be useful to most users.

Credits

• @kenshaw for his .inputrc parsing package, which brings much wider compatibility to this library.
• chzyer/readline for the Windows I/O code and everything related.
• Some of the Vim code is inspired or translated from zsh-vi-mode.
• lmorg/readline, for the line tokenizers.