IO.println() in Elixir

println.ex

defmodule Koni do
  @moduledoc """
  Create a file with the following content:

  IO.println("Your-text-here")

  Then run the following command:
  Koni.println("path/to/file") 
  """
  def read_file(file_path) do
    {:ok, contents} = File.read(file_path)

    String.split(contents, "\n")
  end

  def println(file_path) do
    file_lines = read_file(file_path)
    regex = ~r/IO\.println\(["'](.*?)["']\)/
    matches = Enum.filter(file_lines, fn line -> Regex.match?(regex, line) end)

    if Enum.empty?(matches) do
      {:error, "The file doesn't contain any \"IO.println\" function calls."}
    else
      Enum.each(matches, fn match ->
        [_, text] = Regex.run(regex, match)

        IO.puts(text)
      end)
    end
  end
end