threatfender/tux

Write well-structured command line interfaces with ease.

Tux

Official Site – Docs – Examples

Terminal User Experience

Tux is a modular, dependency-free Elixir library designed for the speedy creation of elegant command line interfaces which subscribe to the philosophy "One module per command".

Its modular structure ensures its core functionalities can be overwritten and composed to fulfill custom needs, and having no dependencies means it can achieve a higher level of security by minimizing trusted parties.

Installation

Add tux to your list of dependencies in mix.exs and optionally update your .formatter.exs:

# mix.exs
{:tux, "~> 0.4.0"}

# .formatter.exs
import_deps: [:tux]

Example

Here's a very short example to illustrate the mechanics of the library, although keep in mind that tux has more features, among which: command preloads, nested commands, command alerts, help messages, command testing and more.

1. A command module implements a command:

defmodule Demo.HelloCmd do
  use Tux.Command

  @impl true
  def about(), do: "Greet current user"

  @impl true
  def main(env, args), do: {:ok, "Hello #{env.pre.user}!"}
end

2. A dispatcher module groups commands together:

defmodule Demo do
  use Tux.Dispatcher

  # Command registration
  cmd "hello", Demo.HelloCmd, preloads: [:user]
  cmd "adios", Demo.AdiosCmd
  cmd "group", Demo.AnotherDispatcher

  # Preloads can be executed before each command that registers them
  def user(_), do: System.fetch_env!("USER")
end

3. Test your escript with the supplied testing macros:

defmodule DemoTest do
  use Tux.Case

  scenario "check greet command",
    using: Demo,
    invoke: "hello",
    expect: [approx: "Hello"]
end

4. Build your elixir app as an escript, just make sure to add the escript: [main_module: Demo] to the :project section of your mix.exs. See mix escript.build for more details.

$ mix escript.build
Generated escript demo

$ ./demo hello
Hello tuxuser!

Next Steps

• Visit the official site
• Read the docs on HexDocs
• Look into the examples folder for complete escripts

License

Tux is open source software licensed under the Apache 2.0 License.