How to give apps, folders and files custom icons, and how that still uses resource forks, just as it did back in 1984.
forks
ResEdit changed what was in the resource fork. With Mac OS X, Apple moved away from forks to extended attributes, now used for quarantine flags and more.
Thirty years ago, many Macs were hit by the Wdef virus, which exploited a vulnerability which remains today: it travelled in an extended attribute. Should we be worried now?
All about xattrs: their origin, where they’re stored, how they’re named and typed, how to find and work with them, and their common problems.
Classic resource forks passed into Mac OS X, but were deprecated by Apple in 10.8. Now in Catalina they can stop working: is this a new security measure?
I claimed (from a guess) that there might be 0.8 GB of xattrs in my Home folder. I was wildly wrong: there are actually over 3.8 GB. Here’s how xattrs are distributed.
Many files in macOS are more than just their data, and contain metadata in extended attributes. Does macOS know the true size of any file, taking into account those attributes?
A traditional ‘resource fork’ containing resource structures, lumped into a binary xattr. Still commonly used for image previews, and found in many older files.
General account of xattrs, their storage, types, tools for working with them, and common problems.
One of the great hidden features in macOS, xattrs are rarely used by anyone outside Apple, largely because they are so poorly supported by functions calls and tools.
The Eclectic Light Company 