This is a library for creating and inspecting [HFS](https://en.wikipedia.org/wiki/Hierarchical_File_System)-format disk images. Mac-specific concepts like [resource forks](https://en.wikipedia.org/wiki/Resource_fork) and [type](https://en.wikipedia.org/wiki/Type_code)/[creator codes](https://en.wikipedia.org/wiki/Creator_code) are first-class citizens. Python interface ---------------- The Python API is simple. The contents of a `Volume` or a `Folder` are accessed using the index operator `[]`. While working on a filesystem, its entire high-level contents are stored in memory as a Python object. ``` from machfs import Volume, Folder, File v = Volume() v['Folder'] = Folder() v['Folder']['File'] = File() v['Folder']['File'].data = b'Hello from Python!\r' v['Folder']['File'].rsrc = b'' # Use the macresources library to work with resource forks v['Folder']['File'].type = b'TEXT' v['Folder']['File'].creator = b'TTXT' # Teach Text/SimpleText with open('FloppyImage.dsk', 'wb') as f: flat = v.write( size=1440*1024, # "High Density" floppy align=512, # Allocation block alignment modulus (2048 for CDs) desktopdb=True, # Create a dummy Desktop Database to prevent a rebuild on boot bootable=True, # This requires a folder with a ZSYS and a FNDR file startapp=('Folder','File'), # Path (as tuple) to an app to open at boot ) f.write(flat) with open('FloppyImage.dsk', 'rb') as f: flat = f.read() v = Volume() v.read(flat) # And you can read an image back! ``` Command-line interface ---------------------- This package also installs the `MakeHFS` and `DumpHFS` utilities, for working with folders on your native filesystem. Briefly, resource forks are stored in Rez-formatted `.rdump` files, and type and creator codes are stored in 8-byte `.idump` files. Admittedly this method of storage is not pretty, but it exposes changes to resource files without requiring Mac-specific software. For example, Git can track the addition and removal of resources. Files with a `TEXT` type are assumed to be UTF-8 encoded with Unix-style (LF) line endings, and are converted to Mac OS Roman encoding with Mac-style (CR) line endings. Both commands have a `--help` argument to display their options. Why? ---- I want an automated, reproducible way to compile legacy MacOS software. Without any current operating system fully supporting HFS, [libhfs/hfsutils](https://www.mars.org/home/rob/proj/hfs/) (a C library and command-line wrapper) is the most capable implementation. The implementor chose to emulate POSIX I/O on a fake "mounted" filesystem. While this is important for machines with very limited RAM, the maintenance of consistent HFS data structures across incremental operations is a complicated task requiring a large amount of low-level code. Frequent I/O to the real filesystem also occurs. Current machines have memory and cycles to burn, so an in-memory implementation in a high-level programming language seemed like a reasonable tradeoff. As a result, `machfs` has nearly an order of magnitude fewer lines than `libhfs`, and is more maintainable, at a nearly negligible cost in performance.