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.
file types
Explaining inodes, names, dates, permissions, file types, and specialised attributes used for iCloud.
You’re checking through old files. How can you tell which file type they are when you don’t recognise the extension, or they don’t even have that to help?
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.
Icons are a fundamental part of a graphical interface, and convey valuable information. Although QuickLook thumbnails can enhance, they can also conflict unless carefully thought out.
An old bug in UTIs can cause problems for apps, and may even crash them. The issue is that macOS can’t always tell what type of object certain ‘files’ are.
Last of 3 articles explains how macOS selects and starts the app with which to open a document which you double-clicked/tapped.
Second of 3 articles explains how macOS puts documents through its security checks before opening them.
How does macOS open the document that you double-click/tap? First of 3 parts explaining what should happen and where it can go wrong.
Additional information is now shown for UTIs, it has its own custom app icon, and works wonderfully in Dark Mode.
The Eclectic Light Company 