If you would be willing, what's your opinion on using SQLite as an image format like this? The "When to Use" page specifically sites application file formats as a good use, but would your header byte allocation be done begrudgingly or contentedly?
There's no reason `file` couldn't be made to recognize special cases of SQLite databases. It certainly handles far uglier cases already.
And SQLite already provides a place to store meta-data about a table: http://www.sqlite.org/pragma.html#pragma_user_version Though the bummer is user_version is only 32 bits.
If the format catches on, they wont. For one, it would have it's own fixed file extension, and second, file(1) will be updated to perform and extra check even if something initially looks like a common SQLite database file.
Since SQLite aims to be a generic way for applications to store data, it'd be nice if its "open database" and "create database" functions allowed you to supply, say, a 4- or 8-byte magic value that would be stored at a fixed location in the file's header so tools could distinguish your SQLite-based file-format from everybody else's, without having to load the thing up and examine the schema.