asyncinotify
============

An async python inotify package.  Kept as simple and easy-to-understand as
possible, while still being flexible and powerful.  This is built on no external
dependencies, and works through ctypes in a very obvious fashion.

This works without any other external dependencies.

The code is available on GitHub_ and the documentation is available on
ReadTheDocs_. The package itself is available on PyPi_.

Installation
------------

You know the drill::

  pip install asyncinotify

Usage
-----

The core of this package is ``asyncinotify.Inotify``.  Most important
Classes may be imported directly from the ``asyncinotify`` package.

.. code-block:: python

  from pathlib import Path
  from asyncinotify import Inotify, Mask
  import asyncio

  async def main():
      # Context manager to close the inotify handle after use
      with Inotify() as inotify:
          # Adding the watch can also be done outside of the context manager.
          # __enter__ doesn't actually do anything except return self.
          # This returns an asyncinotify.inotify.Watch instance
          inotify.add_watch('/tmp', Mask.ACCESS | Mask.MODIFY | Mask.OPEN | Mask.CREATE | Mask.DELETE | Mask.ATTRIB | Mask.CLOSE | Mask.MOVE | Mask.ONLYDIR)
          # Iterate events forever, yielding them one at a time
          async for event in inotify:
              # Events have a helpful __repr__.  They also have a reference to
              # their Watch instance.
              print(event)

              # the contained path may or may not be valid UTF-8.  See the note
              # below
              print(repr(event.path))

  asyncio.run(main())

This will asynchronously watch the /tmp directory and report events it
encounters.

This library also supports synchronous operation, using the
`asyncinotify.inotify.Inotify.sync_get`` method, or simply using
synchronous iteration.

Support
-------

You can examine `our testing matrix <https://github.com/ProCern/asyncinotify/blob/master/.github/workflows/test.yaml>`_ to see all the hosts that we actively test on.

Additionally, there is consideration and code for the following platforms, though they are not tested by the maintainer of this project:

* FreeBSD 15+
* z/OS 2.5 or newer (needs `asyncinotify_zos helper package <https://github.com/ocurero/asyncinotify_zos>`_)

We regularly remove out-of-support OSes from the tests and add new releases.

We support back to Python 3.6 as long as it remains easy to do so.  We may, in
some future version, restrict Python support to non-EOL versions, if supporting
the older versions becomes inconvenient.

Motivation
----------

There are a few different python inotify packages.  Most of them either have odd
conventions, expose too much of the underlying C API in a way that I personally
don't like, are badly documented, they work with paths in a non-idiomatic way,
are not asynchronous, or are overengineered compared to the API they are
wrapping.  I find that the last one is true for the majority of them.

I encourage everybody to read the `sources <GitHub_>`_ of this package.  They are
quite simple and easy to understand.

This library

* Works in a very simple way.  It does not have many add-ons or extra features beyond
  presenting a very Python interface to the raw inotify functionality.  Any extra
  features (such as recursive watching) are presented as completely separate classes.
  The core inotify functionality is as pure as it can reasonably be.

* Grabs events in bulk and caches them for minor performance gains.

* Leverages IntFlag for all masks and flags, allowing the user to use the
  features of IntFlag, such as seeing individual applied flags in the ``repr``,
  checking for flag set bits with ``in``.

* Exposes all paths via python's pathlib_

* Exposes all the functionality of inotify without depending on the user having
  to interact with any of the underlying mechanics of Inotify.  You should never
  have to touch the inotify or watch descriptors for any reason.

The primary motivation is that this is written to be a Python inotify module
that I would feel comfortable using.

.. _ospackage: https://docs.python.org/3/library/os.html#file-names-command-line-arguments-and-environment-variables
.. _surrogateescape: https://docs.python.org/3/library/codecs.html#surrogateescape
.. _GitHub: https://github.com/ProCern/asyncinotify
.. _pathlib: https://docs.python.org/3/library/pathlib.html
.. _ReadTheDocs: https://asyncinotify.readthedocs.io/en/latest/
.. _PyPi: https://pypi.org/project/asyncinotify/


License
-------

This code is Copyright 2019 - 2023 Absolute Performance, Inc, and 2024 - 2026
ProCern Technology Solutions.

It is written and maintained by `Taylor C. Richberger <mailto:taylor.richberger@procern.com>`_.

This Source Code Form is subject to the terms of the Mozilla Public License, v.
2.0. If a copy of the MPL was not distributed with this file, You can obtain one
at https://mozilla.org/MPL/2.0/.

Note that this does **not** have the Exhibit B - “Incompatible With Secondary
Licenses” Notice.  This software is explicitly **compatible** with secondary
licenses.  It is MPL 2.0 to ensure that any improvements and other changes are
distributed.  We do not want to inhibit nor prohibit its use with other FOSS or
proprietary software, regardless of the license.  In other words, if you aren't
changing asyncinotify, you can pretty much just use it as a library without
worrying, unless your other license is explicitly or implicitly incompatible
with it (which should be incredibly uncommon).

