alt.hn

12/11/2025 at 3:36:31 AM

Using extended attributes to tag files

 https://alexlance.blog/tagging.html

by alance

12/11/2025 at 9:56:05 PM

So you're telling me my size 0 file may unknowingly be a large key/value db? Neat.

The system call to read these attributes is getxattr(), for anyone curious.

by sureglymop

12/11/2025 at 10:48:37 PM

Ha, it suddenly sounds like trouble.

Eg: one could piggy-back an entirely new file onto an existing file (it might have to be text encoded?).

It looks like the kernel might impose a limit of 64KiB on a file's metadata, but that's still quite a lot of room for data smuggling...

by alance

12/11/2025 at 3:36:31 AM

My recent journey sorting through years of files and categorizing/tagging them with the built-in Extended File Attribute functionality.

by alance

12/11/2025 at 3:33:58 PM

I've lost extended attributes of files on a number of systems because they aren't always included by default in file operations. I don't trust everything that could possibly write/update a file to preserve them--common 'safe' pattern is to rename as .bak and write new file contents without EA to original name. Nor do I trust myself from archiving without using the right options in a hurry.

by karmakaze

12/11/2025 at 10:38:45 PM

Yes concerning. The possibility of losing them between filesystems is worrying too.

One rule of thumb is `mv` will keep the attributes by default (given similar filesystem) and everything else needs tweaking/extra args. There's a section on it over here:

https://wiki.archlinux.org/title/Extended_attributes#Preserv...

by alance