def read_input_h5(h5):
    """
    h5 should have:
        .attrs['lines'] = list of lines
       group 'variables' with .attrs that are the variables

    See: write_input_h5
    """
    gpt_input = {}
    gpt_input['lines'] = list(h5.attrs['lines'])
    gpt_input['variables'] = dict(h5['variables'].attrs)

    return gpt_input