How does the Finder know the right app to open a file with? Or QuickLook how to preview its contents? Or other services like Spotlight know how to index and handle files? UTIs.
MIME
Many think that a file’s type is determined by its extension. Although partly true, that’s indirect: it’s the UTI which sets the type, as explained here.
Source code workthrough of one method of checking for and automatically downloading updates to an app, in Swift 5 for macOS 10.11-10.14.
What’s a UUID, and a UTI? What can you learn from each, and where can you look them up? Important info about these, and a new release of a tool to help.
The Desktop and Finder illusions are held together by Launch Services, which associates file types with apps. This and more now hinge on the UTI.
Each time I try to update an old article about network intrusion detection systems, it gets tougher.
Much of the content of messages I receive in Mail is missing, and attachments seem muddled. What is wrong?
The Eclectic Light Company 