Run an Elixir function on Module load

If you want to run a function on Module load, you can turn to Modules @on_load hook.

#hello_world.ex
defmodule Example do
  @on_load :hello_world

  def hello_world do
    IO.puts("Hello World!")
    :ok
  end
end

$ elixir hello_world.ex
Hello World!

Your function must return :ok otherwise the module load will be aborted.

Using @on_load can be an efficient way to run examples, quick scripts, setup requirements, benchmarking or load in libraries from other languages.