Integrated console application library, using Go structs as commands, with menus, completions, hints, history, Vim mode, $EDITOR usage, and more ...

pushedAt 6 months ago


Gonsole - Integrated Console Application library

This package rests on a readline console library, (giving advanced completion, hint, input and history system), and the go-flags commands library. Also added, a bit of optional boilerplate for better user experience.


The purpose of this library is to offer a complete off-the-shelf console application, with some key aspects:

  • Better overall features than what is seen in most projects, including those not written in Go.
  • A simple but powerful way of transforming code (structs and anything they might embed), into commands.
  • Easily provide completions for any command/subcommand, any arguments, or any option arguments.
  • If you get how to declare a go-flags compatible command, you can declare commands for this console.

Simple Usage

The library is made to work with sane but powerful defaults. Paste the following, run it, and take a look around to get a feel, without your commands. Default editing mode is Vim. THis example doesn't have an exit command: you'll need to close your terminal.

func main() {

	// Instantiate a new console, with a single, default menu.
	// All defaults are set, and nothing is needed to make it work
	console := gonsole.NewConsole()

	// By default the shell as created a single menu and
	// made it current, so you can access it and set it up.
	menu := console.CurrentMenu()

	// Set the prompt (config, for usability purposes). Each menu has its own.
	// See the documentation for more prompt setup possibilities.
	prompt := menu.PromptConfig()
	prompt.Left = "application-name"
	prompt.Multiline = false

	// Add a default help command, that can be used with any command, however nested:
	// 'help <command> <subcommand> <subcommand'
	// The console creates it and attaches it to all existing contexts.
	// "core" is the name of the group in which we will put this command.

	// Add a configuration command if you want your users to be able
	// to modify it on the fly, export it as files or as JSON.
	// Please see the documentation and/or use this example to
	// see what can be done with this.
	console.AddConfigCommand("config", "core")

	// Everything is ready for a tour.
	// Run the console and take a look around.

If you're still here, at least you want to declare and bind commands. Just as everything else possible with this library, it is explained in the Wiki, although with more pictures than text (I like pictures), because the code is heavily documented (I don't like to repeat myself). Using the library, as usual:

go get -u github.com/maxlandon/gonsole

Documentation Contents




The list of features supported or provided by this library can fall into 2 different categories: the shell/console interface part, and the commands/parsing logic part. Some of the features below are simply extrated from my readline library (everything below Shell Details).

Menus & Commands

  • Declare different "menus" to which you can bind commands, prompt and shell settings.
  • The library is fundamentally a wrapper around the go-flags commands/options, etc.
  • This go-flag library allows you to create commands out of structs (however populated), and gonsole asks you to pass these structs to it.
  • This works for any level of command nesting.
  • Also allows you to declare as many option groups you want, all of that will work.
  • All commands have methods for adding completions either to their arguments, or to their options.

Shell details

  • Vim / Emacs input and editing modes.
  • Vim modes (Insert, Normal, Replace, Delete) with visual prompt Vim status indicator
  • Line editing using $EDITOR (vi in the example - enabled by pressing [ESC] followed by [v])
  • Vim registers (one default, 10 numbered, and 26 lettered) and Vim iterations

Completion engine

  • Rather easy declaration of completion generators, which some level of customization.
  • 3 types of completion categories (Grid, List and Map)
  • In List completion groups, ability to have alternative candidates (used for displaying --long and -s (short) options, with descriptions)
  • Completions working anywhere in the input line (your cursor can be anywhere)
  • Completions are searchable with Ctrl-F,


  • You can pass special completers that will be triggered if the rune (like $ or @) is detected, anywhere in the line. These variables are expanded at command execution time, and work in completions as well.
  • You can export the configuration for your application, its menus, and add some custom subcommands to the root one, for specialized actions over it.
  • Also, an optional help command can be bound to the console, in additional to default -h/--help flags for every command.
  • History sources can also be bound per menu/menu.

Prompt system & Colors

  • 1-line and 2-line prompts, both being customizable.
  • Function for refreshing the prompt, with optional behavior settings.

Hints & Syntax highlighting

  • A hint line can be printed below the input line, with any type of information. See utilities for a default one.
  • The Hint system is now refreshed depending on the cursor position as well, like completions.
  • A syntax highlighting system.

Command history

  • Ability to have 2 different history sources (I used this for clients connected to a server, used by a single user).
  • History is searchable like completions.
  • Default history is an in-memory list.
  • Quick history navigation with Up/Down arrow keys in Emacs mode, and j/k keys in Vim mode.

Status & Support


  • Support for any issue opened.
  • Answering any questions related.
  • Taking blames if things are done wrong.


  • Recursive option completion (-sP, -oL, etc)
  • config load command
  • Analyse args and pull out from comps if in line
  • Add color for strings in input line (this will need a good part of murex parser code)
  • Add token parsing code from murex (this must be well thought out, like the quotes stuff, because it must also not interfere with other commands in special menus, the command parsing code, etc...)
  • Let the user pass keypresses and their associated behavior, like we could do in readline.

Version Information

  • The version string will be based on Semantic Versioning. ie version numbers will be formatted (major).(minor).(patch) - for example 2.0.1

  • major releases will have breaking changes. Be sure to read CHANGES.md for upgrade instructions

  • minor releases will contain new APIs or introduce new user facing features which may affect useability from an end user perspective. However minor releases will not break backwards compatibility at the source code level and nor will it break existing expected user-facing behavior. These changes will be documented in CHANGES.md too

  • patch releases will be bug fixes and such like. Where the code has changed but both API endpoints and user experience will remain the same (except where expected user experience was broken due to a bug, then that would be bumped to either a minor or major depending on the significance of the bug and the significance of the change to the user experience)

  • Any updates to documentation, comments within code or the example code will not result in a version bump because they will not affect the output of the go compiler. However if this concerns you then I recommend pinning your project to the git commit hash rather than a patch release


The gonsole library is distributed under the Apache License (Version 2.0, January 2004) (http://www.apache.org/licenses/). All the example code and documentation in /examples, /completers is public domain.

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