The `check` option performs two tasks through the configuration processing functions available at `src/configuration.sh`

1. Traversing the configuration directory to assemble a file list containing full paths for both the `base` and `bkp` directories
2. Comparing the installed packages with the `packages` file at the root of the configuration directory

The first task is currently accomplished by resorting to `find`. While this allows for cleaner code, it relies on a utility with variable behavior across operating systems. Given the simplicity of the query, a better option might be using a POSIX-compliant wildcard such as `.[!.]* ..?* *` to match the files directly (e.g., in a for loop). Another option that may provide both readability and portability is repeating the match, once for hidden file and once for non-hidden files.

The second task is accomplished by resorting to the package management functions available at `src/package.sh`. The `package_manager` function abstracts the actual package manager in the underlying system and provides an OS-independent way to query manually installed packages.

Through the parsed `packages` configuration file at the root of the configuration directory (`~/.config/tori/packages` by default), both package lists are sorted and deduplicated before they can be filtered by each other using `grep` inverted matching.

This allows obtaining both differences and displaying them to the user. If no resolution strategy has been configured or passed through the command line interface, several options are displayed:

1. Install/uninstall all
2. Enter packages to install/uninstall 
3. Add all to/remove all from configuration
4. Enter packages to add to/remove from configuration
5. Decide in editor

Not all of these options are implemented and some require significant more effort than others. The last option, in particular, requires defining and parsing a syntax that allows users to interface with the possible options.