I'm tinkering with my first module. Well, really tweaking the old sso module to suit my purposes and will likely eventually release it.
The existing module uses the _init() hook to run code every time a Drupal page gets loaded, regardless of the path. In general, newer modules use the _menu() hook to designate what to do depending on the path provided.
But I didn't see any documentation for the menu hook saying how to do two things:
1) Designate an action that should be taken regardless of the path.
2) Designate an action that should be take if no other paths in this module's menu are satisfied.
Of course, what I'm asking may not be possible at the present time.
In addition, I'm wondering if there are plans to eventually deprecate _init() hooks.