For the last 10 years, macOS has relied on Uniform Type Identifiers to recognise different types of files, for opening in apps, QuickLook, Spotlight and in other features.
Precize
First Aid in Disk Utility, or fsck_apfs in Terminal, have given warnings or errors with id numbers. How do you work out which file or folder that refers to?
How APFS is the first Mac native file system to have true inodes and inode numbers. What they are, and how you can use them in volume groups and different types of file link.
When the numbers simply don’t add up. How some extended attributes may be included in quoted file sizes, but others are ignored, and Sequoia hasn’t really changed this since Classic Mac OS of 25 years ago.
Three different ways to link to files, and two for folders. Which should you use, and how well do they cope with changes in that volume?
How can you assure yourself that important files retain their data intact? Here’s a simple strategy for doing that, which works better on a file system that doesn’t check integrity.
A full toolset for working with extended attributes, everything you might want to know about files, and a text-only Rich Text editor, all ready for Tahoe.
The only disk images of varying size used to be sparse bundles and sparse disk images. Now plain read-write disk images can also vary in the disk space they take, as explained here.
If you’re running any version of SilentKnight before 2.10, you need to update it now for compatibility with Catalina and later, particularly for Sequoia. And there are more essential updates too.
Update adds two new datestamp fields, and gives decimal seconds in times. Use this app to explore how macOS sets those on files, as shown.
The Eclectic Light Company 