*xy problem. A/B is a user testing thing.

I found this: https://wiki.archlinux.org/title/Getty

That’s for Arch, but it’s pretty standard, unless Ubuntu/Mint have deviated from tradition. Getty is what manages the TTYs. I assume running under X or Wayland is not what you’re looking for.

If my grandmother had wheels, she’d be a bicycle. Don’t try to force a hierarchical filesystem into other applications. Asking “what it if was different” doesn’t make sense, because if ext4 was a tagging filesystem, it would be tagfs! Tagfs and others already exist, you can use them today! Go crazy, use object or document stores! Embed everything in xml! But for operating systems or actual human interface, those are terrible ideas, which is why we don’t do that.

I brought up hard links to say “yes, you can do that, but it doesn’t mean you should”. There are few cases for hard links. The only one I’ve seen in actual use is in media downloaders, where a file gets downloaded to one folder, then hardlinked from a library folder, so that you don’t have two copies of that video. The library (jellyfin) can do whatever it wants to the link (move, rename) while the downloader (qbittorrent) can still keepit for seeding, and either side can happily delete its copy without affecting the other.

No, in nearly every case, you never want a hard link. You want one file, and symlinks to it. (Technically every file is a hard link to an inode, and subsequent ones are just additional links to the same inode.) In ext4, you can’t easily get a list of links to an inode, you have to scan the filesystem and look for duplicates. Other filesystems might make this easier.

You shouldn’t try to use a tree filesystem to approximate a tagged database. Use the appropriate tool for the job.

This fortnight in plasma?

Why can’t I have a file in two folders? Why does one have to be a “reference”?

All files are references. But you have always been able to put a reference to one file in multiple folders by using hard links.

Why can’t I filter for files that exist in 3 folders with X extension?

find dir1 dir2 dir3 -name '*.x' -type f