python-rsrcfork/README.rst

``rsrcfork``
============

A pure Python library for reading Macintosh Toolbox or Carbon resource manager data, as found in resource forks or ``.rsrc`` files even on current Mac OS X/macOS systems.

Requirements
------------

Python 3.6 or later. No other libraries are required.

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

``rsrcfork`` is available `on PyPI`__ and can be installed using ``pip``: 

.. code-block:: sh

	python3 -m pip install rsrcfork

Alternatively you can run the ``setup.py`` script manually:

.. code-block:: sh

	python3 setup.py install

__ https://pypi.python.org/pypi/rsrcfork

Features
--------

* Reading resources from data or resource forks (the latter only work on macOS of course)
* Reading data lazily with seeking, or sequentially without seeking
* Accessing resource data and attributes by their type code and ID, using a mapping-like interface
* REPL-friendly ``repr``\s that truncate long resource data so it doesn't fill the entire screen

Examples
--------

Simple example
^^^^^^^^^^^^^^

.. code-block:: python

	>>> import rsrcfork
	>>> rf = rsrcfork.open("/Users/Shared/Test.textClipping")
	>>> rf
	<rsrcfork.ResourceFile at 0x1046e6048, attributes ResourceFileAttrs.0, containing 4 resource types: [b'utxt', b'utf8', b'TEXT', b'drag']>
	>>> rf[b"TEXT"]
	<rsrcfork.ResourceFile._LazyResourceMap at 0x10470ed30 containing one resource: rsrcfork.Resource(resource_type=b'TEXT', resource_id=256, name=None, attributes=ResourceAttrs.0, data=b'Here is some text')>

Automatic selection of data/resource fork
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: python

	>>> import rsrcfork
	>>> datarf = rsrcfork.open("/System/Library/Fonts/Monaco.dfont") # Resources in data fork
	>>> datarf._stream
	<_io.BufferedReader name='/System/Library/Fonts/Monaco.dfont'>
	>>> resourcerf = rsrcfork.open("/Users/Shared/Test.textClipping") # Resources in resource fork
	>>> resourcerf._stream
	<_io.BufferedReader name='/Users/Shared/Test.textClipping/..namedfork/rsrc'>

Command-line interface
^^^^^^^^^^^^^^^^^^^^^^

.. code-block:: sh

	$ python3 -m rsrcfork /Users/Shared/Test.textClipping
	No header system data
	No header application data
	No file attributes
	4 resource types:
	'utxt': 1 resources:
	(256), unnamed, no attributes, 34 bytes
	
	'utf8': 1 resources:
	(256), unnamed, no attributes, 17 bytes
	
	'TEXT': 1 resources:
	(256), unnamed, no attributes, 17 bytes
	
	'drag': 1 resources:
	(128), unnamed, no attributes, 64 bytes
	
	$ python3 -m rsrcfork /Users/Shared/Test.textClipping "'TEXT' (256)"
	Resource 'TEXT' (256), unnamed, no attributes, 17 bytes:
	00000000 48 65 72 65 20 69 73 20 73 6f 6d 65 20 74 65 78 |Here is some tex|
	00000010 74                                              |t|
	00000011
	

Limitations
-----------

This library only understands the resource file's general structure, i. e. the type codes, IDs, attributes, and data of the resources stored in the file. The data of individual resources is provided in raw bytes form and is not processed further - the format of this data is specific to each resource type.

Definitions of common resource types can be found inside Carbon and related frameworks in Apple's macOS SDKs as ``.r`` files, a format roughly similar to C struct definitions, which is used by the ``Rez`` and ``DeRez`` command-line tools to de/compile resource data. There doesn't seem to be an exact specification of this format, and most documentation on it is only available inside old manuals for MPW (Macintosh Programmer's Workshop) or similar development tools for old Mac systems. Some macOS text editors, such as BBEdit/TextWrangler and TextMate support syntax highlighting for ``.r`` files.

Writing resource data is not supported at all.

Further info on resource files
------------------------------

Sources of information about the resource fork data format, and the structure of common resource types:

* Inside Macintosh, Volume I, Chapter 5 "The Resource Manager". This book can probably be obtained in physical form somewhere, but the relevant chapter/book is also available in a few places online:
	- `Apple's legacy documentation <https://developer.apple.com/legacy/library/documentation/mac/pdf/MoreMacintoshToolbox.pdf>`_
	- pagetable.com, a site that happened to have a copy of the book: `info blog post <http://www.pagetable.com/?p=50>`_, `direct download <http://www.weihenstephan.org/~michaste/pagetable/mac/Inside_Macintosh.pdf>`_
* `Wikipedia <https://en.wikipedia.org/wiki/Resource_fork>`_, of course
* The `Resource Fork <http://fileformats.archiveteam.org/wiki/Resource_Fork>`_ article on "Just Solve the File Format Problem" (despite the title, this is a decent site and not clickbait)
* The `KSFL <https://github.com/kreativekorp/ksfl>`_ library (and `its wiki <https://github.com/kreativekorp/ksfl/wiki/Macintosh-Resource-File-Format>`_), written in Java, which supports reading and writing resource files
* Alysis Software Corporation's article on resource compression (found on `the company's website <http://www.alysis.us/arctechnology.htm>`_ and in `MacTech Magazine's online archive <http://preserve.mactech.com/articles/mactech/Vol.09/09.01/ResCompression/index.html>`_) has some information on the structure of certain kinds of compressed resources.
* Apple's macOS SDK, which is distributed with Xcode. The latest version of Xcode is available for free from the Mac App Store. Current and previous versions can be downloaded from `the Apple Developer download page <https://developer.apple.com/download/more/>`_. Accessing these downloads requires an Apple ID with (at least) a free developer program membership.
* Apple's MPW (Macintosh Programmer's Workshop) and related developer tools. These were previously available from Apple's FTP server at ftp://ftp.apple.com/, which is no longer functional. Because of this, these downloads are only available on mirror sites, such as http://staticky.com/mirrors/ftp.apple.com/.

If these links are no longer functional, some are archived in the `Internet Archive Wayback Machine <https://archive.org/web/>`_ or `archive.is <http://archive.is/>`_ aka `archive.fo <https://archive.fo/>`_.

Changelog
---------

Version 1.2.0 (next version)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

* Added support for compressed resources.
	* Compressed resource data is automatically decompressed, both in the Python API and on the command line.
	* This is technically a breaking change, since in previous versions the compressed resource data was returned directly. However, this change will not affect end users negatively, unless one has already implemented custom handling for compressed resources.
	* Currently, only the three standard System 7.0 compression formats (``'dcmp'`` IDs 0, 1, 2) are supported. Attempting to access a resource compressed in an unsupported format results in a ``DecompressError``.
	* To access the raw resource data as stored in the file, without automatic decompression, use the ``res.data_raw`` attribute (for the Python API), or the ``--no-decompress`` option (for the command-line interface). This can be used to read the resource data in its compressed form, even if the compression format is not supported.

Version 1.1.3.post1
^^^^^^^^^^^^^^^^^^^

* Fixed a formatting error in the README.rst to allow upload to PyPI.

Version 1.1.3
^^^^^^^^^^^^^

**Note: This version is not available on PyPI, see version 1.1.3.post1 changelog for details.**

* Added a setuptools entry point for the command-line interface. This allows calling it using just ``rsrcfork`` instead of ``python3 -m rsrcfork``.
* Changed the default value of ``ResourceFork.__init__``'s ``close`` keyword argument from ``True`` to ``False``. This matches the behavior of classes like ``zipfile.ZipFile`` and ``tarfile.TarFile``.
* Fixed ``ResourceFork.open`` and ``ResourceFork.__init__`` not closing their streams in some cases.
* Refactored the single ``rsrcfork.py`` file into a package. This is an internal change and should have no effect on how the ``rsrcfork`` module is used.

Version 1.1.2
^^^^^^^^^^^^^

* Added support for the resource file attributes "Resources Locked" and "Printer Driver MultiFinder Compatible" from ResEdit.
* Added more dummy constants for resource attributes with unknown meaning, so that resource files containing such attributes can be loaded without errors.

Version 1.1.1
^^^^^^^^^^^^^

* Fixed overflow issue with empty resource files or empty resource type entries
* Changed ``_hexdump`` to behave more like ``hexdump -C``

Version 1.1.0
^^^^^^^^^^^^^

* Added a command-line interface - run ``python3 -m rsrcfork --help`` for more info

Version 1.0.0
^^^^^^^^^^^^^

* Initial version