How to set access permissions to protect a database file?

[Markos <markos@c2o.pro.br>]

Hi,

I made a program (reading_room.tcl), with Sqlite running on Debian 9, to control the books of a reading room.

I implemented an authentication system for common users and administrator users in the reading_room program.

Now I want that any user logged in the Linux be able to run the program reading_room.tcl, which will access the database (books.db)

But I want to protect the file books.db so that only the the program reading_room.tcl can access the books.db file. But that no user could delete or write to the file books.db (only the program reading_room.tcl)

Please, how can I configure the system to do that?

How to define the permissions?

Thanks,

Markos