> What are you going to do with that file you "identified" if not read it to get something out of it
Anything where there's a decision based on the file format but not its contents. This happens all the time.
* Telling the user what file type it is.
* Choosing a parser to load a file with.
* Restricting file types on upload forms.
* Identifying files for linters.
* Associating files with programs.
Ok some of those use file extensions because it's a lot easier and text based formats often don't have a magic number, but it's still a valid use case.
Anything where there's a decision based on the file format but not its contents. This happens all the time.
* Telling the user what file type it is.
* Choosing a parser to load a file with.
* Restricting file types on upload forms.
* Identifying files for linters.
* Associating files with programs.
Ok some of those use file extensions because it's a lot easier and text based formats often don't have a magic number, but it's still a valid use case.