Fix list of files.

    Optionally fix files recursively.

def fix_multiple_files(filenames, options, output=None):
    """Fix list of files.

    Optionally fix files recursively.

    """
    results = []
    filenames = find_files(filenames, options.recursive, options.exclude)
    if options.jobs > 1:
        import multiprocessing
        pool = multiprocessing.Pool(options.jobs)
        ret = pool.map(_fix_file, [(name, options) for name in filenames])
        results.extend([x for x in ret if x is not None])
    else:
        for name in filenames:
            ret = _fix_file((name, options, output))
            if ret is None:
                continue
            if options.diff:
                if ret != '':
                    results.append(ret)
            elif options.in_place:
                results.append(ret)
            else:
                original_source = readlines_from_file(name)
                if "".join(original_source).splitlines() != ret.splitlines():
                    results.append(ret)
    return results