def add_common_options(parser):
    """These command line options are used by both smdparse.py and ismd.py.
    """
    parser.add_argument('-f', '--filename', required=True, help='the file that you want to parse')

    parser.add_argument('-c', '--cssfile', nargs='*', dest="cssfilelist", help='the CSS file you want used for the styling. Default is smd.css')

    parser.add_argument('-d', '--path', nargs='?', const='./html', default='./html', help='the directory that you want the HTML file written to. Default is ./html')

    parser.add_argument('-i', '--import', nargs='*', dest="importfilelist", help='list of file(s) to import after builtins.md loaded. Default is None')

    parser.add_argument('-sph', '--smdparse-head-name', dest="head_file_name", default="smdparse_head.md", help='the filename to use for the head HTML markdown. Default is smdparse_head.md')

    return parser