(out, err)`` namedtuple.
``out`` and ``err`` will be ``text`` objects.

Returns an instance of :class:`CaptureFixture[str] <pytest.CaptureFixture>`.

Example:

.. code-block:: python

    def test_system_echo(capfd):
        os.system('echo "hello"')
        captured = capfd.readouterr()
        assert captured.out == "hello\n"
rw