def separate_files_and_options(args):
    """
    Take a list of arguments and separate out files and options. An option is
    any string starting with a '-'. File arguments are relative to the current
    working directory and they can be incomplete.
    Returns:
        a tuple (file_list, option_list)
    """
    file_args = []
    opt_args = []

    for arg in args:
        if arg and arg[0] != "-":
            file_args.append(arg)
        else:
            opt_args.append(arg)
    return file_args, opt_args