|
NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | SEE ALSO | COLOPHON |
SD_JOURNAL_SEEK_HEAD(3) sd_journal_seek_head SD_JOURNAL_SEEK_HEAD(3)
sd_journal_seek_head, sd_journal_seek_tail,
sd_journal_seek_monotonic_usec, sd_journal_seek_realtime_usec,
sd_journal_seek_cursor - Seek to a position in the journal
#include <systemd/sd-journal.h>
int sd_journal_seek_head(sd_journal *j);
int sd_journal_seek_tail(sd_journal *j);
int sd_journal_seek_monotonic_usec(sd_journal *j, sd_id128_t boot_id,
uint64_t usec);
int sd_journal_seek_realtime_usec(sd_journal *j, uint64_t usec);
int sd_journal_seek_cursor(sd_journal *j, const char *cursor);
sd_journal_seek_head() seeks to the beginning of the journal, i.e. to
the position before the oldest available entry.
Similarly, sd_journal_seek_tail() may be used to seek to the end of
the journal, i.e. the position after the most recent available entry.
sd_journal_seek_monotonic_usec() seeks to a position with the
specified monotonic timestamp, i.e. CLOCK_MONOTONIC. Since monotonic
time restarts on every reboot a boot ID needs to be specified as
well.
sd_journal_seek_realtime_usec() seeks to a position with the
specified realtime (wallclock) timestamp, i.e. CLOCK_REALTIME. Note
that the realtime clock is not necessarily monotonic. If a realtime
timestamp is ambiguous, it is not defined which position is sought
to.
sd_journal_seek_cursor() seeks to the position at the specified
cursor string. For details on cursors, see sd_journal_get_cursor(3).
If no entry matching the specified cursor is found the call will seek
to the next closest entry (in terms of time) instead. To verify
whether the newly selected entry actually matches the cursor, use
sd_journal_test_cursor(3).
Note that these calls do not actually make any entry the new current
entry, this needs to be done in a separate step with a subsequent
sd_journal_next(3) invocation (or a similar call). Only then, entry
data may be retrieved via sd_journal_get_data(3) or an entry cursor
be retrieved via sd_journal_get_cursor(3). If no entry exists that
matches exactly the specified seek address, the next closest is
sought to. If sd_journal_next(3) is used, the closest following entry
will be sought to, if sd_journal_previous(3) is used the closest
preceding entry is sought to.
The functions return 0 on success or a negative errno-style error
code.
All functions listed here are thread-agnostic and only a single
specific thread may operate on a given object during its entire
lifetime. It's safe to allocate multiple independent objects and use
each from a specific thread in parallel. However, it's not safe to
allocate such an object in one thread, and operate or free it from
any other, even if locking is used to ensure these threads don't
operate on it at the very same time.
These APIs are implemented as a shared library, which can be compiled
and linked to with the libsystemd pkg-config(1) file.
systemd(1), sd-journal(3), sd_journal_open(3), sd_journal_next(3),
sd_journal_get_data(3), sd_journal_get_cursor(3),
sd_journal_get_realtime_usec(3)
This page is part of the systemd (systemd system and service manager)
project. Information about the project can be found at
⟨http://www.freedesktop.org/wiki/Software/systemd⟩. If you have a bug
report for this manual page, see
⟨http://www.freedesktop.org/wiki/Software/systemd/#bugreports⟩. This
page was obtained from the project's upstream Git repository
⟨https://github.com/systemd/systemd.git⟩ on 2020-08-13. (At that
time, the date of the most recent commit that was found in the repos‐
itory was 2020-08-11.) If you discover any rendering problems in
this HTML version of the page, or you believe there is a better or
more up-to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not part
of the original manual page), send a mail to man-pages@man7.org
systemd 246 SD_JOURNAL_SEEK_HEAD(3)
Pages that refer to this page: 30-systemd-environment-d-generator(7) , systemd.index(7)