POSIX: "Filesystems should behave like this."
APFS & ZFS: "Hold my non-case-sensitive, transactional, snapshot-capable beer."

@fribbledom POSIX-compliant filesystems should behave like that; not all filesystems have to match the specification, and there are a bunch of the options you need to query at run-time to figure out which features are present.

(I was at Apple when it had to pass the conformance test, and I worked on HFS+, which could not pass the tests without some weiiiiiiiiiiiiiiiiiirrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrd hacks put into place.)

@kithrup

I totally understand and even applaud the advancements made over the past few years and decades.

That said, from a tool author's perspective, it's becoming increasingly frustrating to even just retrieve and display the current available disk space without resorting to a bunch of filesystem- and platform-specific hacks and workarounds.

@fribbledom @kithrup df does not work well for that?

@fribbledom your forgot NTFS which has more hacks like shortening paths with ~

@sandro @kithrup

Depends. How confusing or not do you find this output, for example:

Size: 228Gi
Used: 10Gi
Avail: 19Gi
Capacity: 36%

@fribbledom

Yeah, I love ZFS, but everything with its size needs ... acclimatization

@sandro @kithrup

@fribbledom You can generally get the available space easily enough -- finding out how much space is *used* is a lot harder. And you can't necessarily count on "if I remove this large file, I will get that much space back."

@kazriko @fribbledom Yes, I am very familiar with ZFS. 😄

For example, instead of adding drives, you can replace drives one at a time with larger ones, and when you're all done, *poof* you have more storage! It's one of my favorite features with ZFS.