Here's a quick proposal for a new "notmuch search-messages" command, from which one can generate a list of Message IDs matching a search string.
Beyond this, I'd like to add some --format options to both "search" and "search-messages" so that users can get out the information they want, (such as thread-id only from a thread search, filenames only from a message search, etc.). Any thoughts from others on this kind of thing? I know people have been talking about doing thing like modifying message files based on tags, and this seems like the beginnings of support for doing scripted operations like that. -Carl