This utility program is designed as a HFS+ format disk recovery program. Rather than following the file system b-trees, it instead walks the disk looking for anything that might be a file, directory, or extent record. After compiling an index of the contained information, it recreates all the files and directories found into an output folder.

Assuming a standard disk sector size of 512:

hffs <input-image>

This will look for the disk header and footer, and spit out some info including the block size used for the HFS+ format. We can then kick off the recovery using the block size.

hffs --block-size <block-size> -o <output-directory> <input-image>

Additional options allow fine tuning of various other settings, and can dramatically speed up the process. Of particular interest is the --stop-block option which will stop searching for file system information after a particular block number. Since HFS+ stores the file system catalog info in duplicate once at the start of the disk, and once at the end of the disk, stopping the search after the initial catalog entries have been found will often yield good results.

I worked on this until it fullfilled my needs and recovered data off of a corrupted disk I had. Your mileage may vary. Of particular importance is to only run this on an image of your corrupted disk, not the disk itself. Use a program to safely copy the contents off of the disk minimizing the chance for additional damage. Again HFFS makes no effort to minimize disk seeks, or reads. Running it on a damaged disk may cause further harm. Use a program like ddrescue to create a copy of the data.