They’re XML, structured into dictionaries and arrays containing key-value pairs. Preference plists are managed, and need special treatment.
cfprefsd
UserDefaults and cfprefsd manage the preference system, an amorphous database spread across hundreds of files which can only be controlled in Terminal. It’s time for a change.
Something wrong with the Finder or an app, and you want to trash its preferences? Don’t: macOS will defeat you. Here’s how to do that so it works.
When nothing seems able to get that preference setting right, don’t abandon hope – follow this instead.
Preference files are involved in many Mac problems, and are often their solution. Using them now isn’t simple: here is some guidance.
Helpful info and advice for all those using recent versions of my more popular free apps and utilities, about security and auto-updates.
The current macOS implementation of preferences is appalling design in every respect, and is essentially undocumented even for developers. Is this the way that macOS is heading?
Have you ever tried removing or editing a preference file, to no effect? This explains why that happens, and how to get changes to work properly.
The Eclectic Light Company 