from __future__ import print_function
# A Linux-only demo
#
import sys

if not sys.platform.startswith('linux'):
    raise Exception("Linux-only demo")

from _readdir import ffi
lib = ffi.dlopen(None)


def walk(basefd, path):
    print('{', path)
    dirfd = lib.openat(basefd, path, 0)
    if dirfd < 0:
        # error in openat()
        return
    dir = lib.fdopendir(dirfd)
    dirent = ffi.new("struct dirent *")
    result = ffi.new("struct dirent **")
    while True:
        if lib.readdir_r(dir, dirent, result):
            # error in readdir_r()
            break
        if result[0] == ffi.NULL:
            break
        name = ffi.string(dirent.d_name)
        print('%3d %s' % (dirent.d_type, name))
        if dirent.d_type == 4 and name != '.' and name != '..':
            walk(dirfd, name)
    lib.closedir(dir)
    print('}')


walk(-1, "/tmp")