I just released ex_cli 0.1.0, a library to build user friendly CLI applications.

It provides a nice DSL to define a CLI app, takes care of parsing arguments, displaying meaningful error messages and formatting usage. More cool stuff, such as per-command help and man page generation, is coming. See the roadmap for more info.

Here is a small screencast of the generated CLI app.

which is generated by writing a module like this:

defmodule MyApp.xCLI do
  use ExCLI.DSL, escript: true

  name "mycli"

  command :hello do
    description "Greets the user"
    argument :name
    option :from
    run context do
      if from = context[:from] do
        IO.write("#{from} says")
      end
      IO.puts("Hello #{context.name}!")
    end
  end
end

For more info, checkout the repository:

https://github.com/tuvistavie/ex_cli