Bug#563270: grepmail: options to parse mbox in reverse order and to stop after a while

[Josip Rodin <joy@debbugs.entuzijast.net>]

Package: grepmail
Version: 5.3033-4
Severity: wishlist

Hi,

For date-based searches, if there was an option to search the input from
bottom to top, and/or to stop after reaching a specified number of hits,
it would be significantly faster than what we get now. For example:

% ls -l randommbox                                         
-rw------- 1 joy joy 29640019 2010-01-01 12:32 randommbox

% time grepmail -d 'since 5 days ago' randommbox | grep -c ^Date:
23
grepmail -d 'since 5 days ago' randommbox  14,88s user 0,31s system 99% cpu 15,201 total
grep -c ^Date:  0,00s user 0,00s system 0% cpu 15,200 total

% time tail -10000 randommbox | grepmail -d 'since 5 days ago' | grep -c Date:
23
tail -10000 randommbox  0,00s user 0,00s system 0% cpu 0,946 total
grepmail -d 'since 5 days ago'  0,92s user 0,07s system 98% cpu 1,007 total
grep -c Date:  0,00s user 0,00s system 0% cpu 1,005 total

The trouble with the tail(1) above is that it's just a guess.

-- 
     2. That which causes joy or happiness.