Hi, here is a related "bug" report: https://bugs.freedesktop.org/show_bug.cgi?id=64614
Doing a "next" after "seek_tail" ends up in some unexpected behaviour. Just do a "previous" after seeking the tail and everything works fine. The problem is symmetrical: Same goes for "previous" after "seek_head". You need to do a "next" immediately after "seek_head". I hope that will help, Sascha ----- Original Message ----- From: "Daurnimator" <q...@daurnimator.com> To: "systemd Mailing List" <systemd-devel@lists.freedesktop.org> Sent: Monday, October 13, 2014 7:27:22 AM Subject: [systemd-devel] odd seek_tail behaviour Hi All, I was trying to write a program that tailed the journal, but found that sd_journal_seek_tail() didn't work as expected. That is: that it would seek to the last/most recent thing in the journal, and I could tail things from there. I whipped up a quick demonstration program, that shows that messages I 'next' through, are before the 'cutoff': #include <stdio.h> #include <assert.h> #include "systemd/sd-journal.h" int main() { sd_journal* j; assert(sd_journal_open(&j, 0)==0); uint64_t from, to; assert(sd_journal_get_cutoff_realtime_usec(j, &from, &to)==1); printf("CUTOFF = %llu\n", to); printf("TAIL = %d\n", sd_journal_seek_tail(j)); for (int i=0; i<10; i++) { printf("NEXT = %lld\n", sd_journal_next(j)); assert(sd_journal_get_realtime_usec(j, &from)==0); printf("FOUND from %llu\n", from); } return 0; } Compiled with: gcc -std=c99 tail_logs.c -l systemd Example output: CUTOFF = 1413177397982789 TAIL = 0 NEXT = 1 FOUND from 1400437372012374 NEXT = 1 FOUND from 1400438753925868 NEXT = 1 FOUND from 1400438753926192 NEXT = 1 FOUND from 1400438753926257 NEXT = 1 FOUND from 1400438753926289 NEXT = 1 FOUND from 1400438753926309 NEXT = 1 FOUND from 1400438753926330 NEXT = 1 FOUND from 1400438753926353 NEXT = 1 FOUND from 1400438753926373 NEXT = 1 FOUND from 1400438753926395 Is this behaviour expected? I'm using systemd 216. Regards, Daurn. _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel