Play around with the inotify C-API in Python

inotify.py

import ctypes
import select
import pathlib

from ctypes import c_char_p, c_int, c_uint32
import os


class EventStruct(ctypes.Structure):

    _fields_ = (
        ("wd", c_int),
        ("mask", c_uint32),
        ("cookie", c_uint32),
        ("len", c_uint32),
    )

IN_MODIFY = 0x00000002
IN_CREATE = 0x00000100

path = pathlib.Path('.').absolute()

libc = ctypes.CDLL(None)

inotify_add_watch = ctypes.CFUNCTYPE(c_int, c_int, c_char_p, c_uint32, use_errno=True)(("inotify_add_watch", libc))

inotify_init = ctypes.CFUNCTYPE(c_int, use_errno=True)(("inotify_init", libc))

inotify_fd = inotify_init()
print(f'Created FD: {inotify_fd}')

poller = select.poll()

poller.register(inotify_fd, select.POLLIN)

wd = inotify_add_watch(inotify_fd, str(path).encode(), IN_MODIFY | IN_CREATE )

while True:
    print('Polling')
    fd, _ = poller.poll()[0]
    if fd == inotify_fd:
        data = os.read(inotify_fd, 0xfff)
        print(data)

        struct = EventStruct.from_buffer_copy(data)
        print(struct.wd)
        print(struct.mask)
        print(struct.cookie)
        print(struct.len)

        name = data[16 : 16 + struct.len].rstrip(b"\0")
        print(name)