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.
forks
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.
A simple and concise example of a page from the documentation which we, as a community, could readily produce for macOS. Fancy giving us a hand?
They’re responsible for determining Gatekeeper’s checks, contain Finder information, and much more. With a new free tool too.
If you wanted to mess someone’s Mac up, you could go into their system files and change things around when they were out at lunch.
