How to lock files in macOS Big Sur's Finder

File locking has a long tradition in computing: you or independently running software wants to make sure that a file isn’t modified or deleted when it’s needed or in use. Because macOS is Unix based, it offers file-level permissions flags that control how a file can be manipulated and by whom.But macOS has long had a separate way to lock a file from the Finder that also prevents it from being modified, deleted, or rename from the Terminal or other apps. Lock, unlock, and status comm