   * If `:abort`, the runtime system aborts producing a core dump, if that is
     enabled in the operating system;
 
-  * If a char list, an erlang crash dump is produced with status as slogan,
+  * If a string, an erlang crash dump is produced with status as slogan,
     and then the runtime system exits with status code 1;
 
   Note that on many platforms, only the status codes 0-255 are supported

  the result as a binary.

  If `command` is a char list, a char list is returned.
  Returns a binary otherwise.
  """
  @spec cmd(binary) :: binary
  @spec cmd(char_list) :: char_list

  def cmd(command) when is_list(command) do

  end

  def find_executable(program) when is_binary(program) do
    case :os.find_executable(List.from_char_data!(program)) do
      false -> nil
      other -> String.from_char_data!(other)
    end
  end

