On Mon, Sep 28, 2015 at 10:00 PM, Carl Worth <cwo...@cworth.org> wrote: > On Mon, Sep 28 2015, Xu Wang wrote: >> I would look to look for all emails from a colleague jongho. I tried: >> >> from:jongho attachment:pdf >> >> which seems to do as I wanted. > > Good. That should work. > >> To understand more, what does the following search for? >> >> from:jongho attachment:.*pdf > > Uhm, probably only strange things. There are some mechanisms for getting > notmuch to emit some debugging information on what the final search > terms end up being, (but I don't recall if they still require > recompilation or not). > > I'm not testing now, but I wouldn't be surprised if that ended up doing > something like searching for a phrase like "attachment pdf" anywhere > within a message. (The Xapian parser can be somewhat unpredictable when > you give it unexpected input.) > >> Also, how does the first one above know that I want only PDF >> attachments and not an attachment called "pdformula.txt" ? > > It doesn't know that you want only PDF attachments. The key part is that > the indexing is performed by breaking text up into individual terms, (at > punctuation boundaries usually). So a search specification like > "attachment:pdf" is searching for things that were indexed with the > "pdf" term within the attachment prefix. So that won't match a filename > like pdformula.txt, (which would be indexed as two terms, "pdformula" > and "txt"), but it would match pdf.ormula.txt, (which would be indexed > as three terms, "pdf", "ormula" and "txt"). > > The Xapian documentation can be examined if you want more details.
This is highly useful. Thank for such an explanation!! Thank you, Carl. Kind regards, Xu _______________________________________________ notmuch mailing list notmuch@notmuchmail.org http://notmuchmail.org/mailman/listinfo/notmuch