Parse and check the command line arguments.

def main(argv=sys.argv):
    """Parse and check the command line arguments."""
    parser = setup_parser()

    (opts, args) = parser.parse_args(argv[1:])

    if not args:
        parser.error('A package path is required.')

    rootpath, excludes = args[0], args[1:]
    if not opts.destdir:
        parser.error('An output directory is required.')
    if opts.header is None:
        opts.header = path.normpath(rootpath).split(path.sep)[-1]
    if opts.suffix.startswith('.'):
        opts.suffix = opts.suffix[1:]
    if not path.isdir(rootpath):
        print >>sys.stderr, '%s is not a directory.' % rootpath
        sys.exit(1)
    if not path.isdir(opts.destdir):
        if not opts.dryrun:
            os.makedirs(opts.destdir)
    rootpath = path.normpath(path.abspath(rootpath))
    excludes = normalize_excludes(rootpath, excludes)
    modules = recurse_tree(rootpath, excludes, opts)
    if opts.full:
        from sphinx import quickstart as qs
        modules.sort()
        prev_module = ''
        text = ''
        for module in modules:
            if module.startswith(prev_module + '.'):
                continue
            prev_module = module
            text += '   %s\n' % module
        d = dict(
            path = opts.destdir,
            sep  = False,
            dot  = '_',
            project = opts.header,
            author = opts.author or 'Author',
            version = opts.version or '',
            release = opts.release or opts.version or '',
            suffix = '.' + opts.suffix,
            master = 'index',
            epub = True,
            ext_autodoc = True,
            ext_viewcode = True,
            makefile = True,
            batchfile = True,
            mastertocmaxdepth = opts.maxdepth,
            mastertoctree = text,
        )
        if not opts.dryrun:
            qs.generate(d, silent=True, overwrite=opts.force)
    elif not opts.notoc:
        create_modules_toc_file(modules, opts)