Last modified: 2011-04-14 15:14:36 UTC
A previous attempt to list and count all books was abandoned: http://www.mediawiki.org/wiki/Extension:AllBooks
Using a regex to list and count books is fragile, and doesn't further the primary goal here of /searching/ books. This includes both searching within a single book and searching for some term among all books (and getting results back which are /books/ not pages).
This is a very specialised feature request. I think that without some additional effort/outreach, there will not ever be a response to this issue. I suggest to close this yourself with 'WONTFIX' and find alternative ways to get this feature request filled.