import os
import pickle
import bz2


def main():
    dir_names = sorted(os.listdir('/usr/bin'))
    with bz2.open('name_cache.bz2', 'wb') as name_cache_file:
        cached_bytes = pickle.dumps(dir_names, protocol=4)
        name_cache_file.write(cached_bytes)


if __name__ == '__main__':
    main()