Well, I think I finally figured our a problem that’s been bugging me for quite a while.
Every once in a while, especially if I’m using an external drive that’s acting weird or even the now defunct Lima, I’d occasionally see files that appeared grey in directory listings. You couldn’t rename them, you couldn’t display their contents (regardless of having size), etc.
Doing a ls -@Oaeln filename, showed nothing special.
Except… the date, which was always Jan 24, 1984, 3:00AM.
Ok, yes, that’s the Mac’s birthday — and some even call it an Easter Egg. But it’s likely an Easter Egg with a purpose.
The date appears as kind of a place holder, such as momentarily when a file is downloaded. And during that time, the system knows the file is incomplete, and this is just as good as any other way to mark it as such.
Turns out this also appears to be the way that corrupted files appear too.
For example, I synchronized some files with my Lima (which stores it on a USB disk somewhere), and if the synchronization process fails it’s supposed to pick up and try later. However, if that doesn’t happen, then partially transmitted data can reside there. And Lima’s going out of business was what led me to go try to pull all data, complete or not.
Attempting to inspect the contents of such files, such as on a Lima mount, appears to confirm this, resulting in a message of read error.
So. Grey files. It’s not a Happy Birthday to Us from Mac, but a date long past being used as a magic number.