def _parse_line(sep, line):
    """
    Parse a grub commands/config with format: cmd{sep}opts
    Returns: (name, value): value can be None
    """
    strs = line.split(sep, 1)
    return (strs[0].strip(), None) if len(strs) == 1 else (strs[0].strip(), strs[1].strip())