|
NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | SEE ALSO | COLOPHON |
SD_JOURNAL_GET_REALTIME_USEC(3)nal_get_realtime_usecNAL_GET_REALTIME_USEC(3)
sd_journal_get_realtime_usec, sd_journal_get_monotonic_usec - Read
timestamps from the current journal entry
#include <systemd/sd-journal.h>
int sd_journal_get_realtime_usec(sd_journal *j, uint64_t *usec);
int sd_journal_get_monotonic_usec(sd_journal *j, uint64_t *usec,
sd_id128_t *boot_id);
sd_journal_get_realtime_usec() gets the realtime (wallclock)
timestamp of the current journal entry. It takes two arguments: the
journal context object and a pointer to a 64-bit unsigned integer to
store the timestamp in. The timestamp is in microseconds since the
epoch, i.e. CLOCK_REALTIME.
sd_journal_get_monotonic_usec() gets the monotonic timestamp of the
current journal entry. It takes three arguments: the journal context
object, a pointer to a 64-bit unsigned integer to store the timestamp
in, as well as a 128-bit ID buffer to store the boot ID of the
monotonic timestamp. The timestamp is in microseconds since boot-up
of the specific boot, i.e. CLOCK_MONOTONIC. Since the monotonic
clock begins new with every reboot, it only defines a well-defined
point in time when used together with an identifier identifying the
boot. See sd_id128_get_boot(3) for more information. If the boot ID
parameter is passed NULL, the function will fail if the monotonic
timestamp of the current entry is not of the current system boot.
Note that these functions will not work before sd_journal_next(3) (or
related call) has been called at least once, in order to position the
read pointer at a valid entry.
sd_journal_get_realtime_usec() and sd_journal_get_monotonic_usec()
returns 0 on success or a negative errno-style error code. If the
boot ID parameter was passed NULL and the monotonic timestamp of the
current journal entry is not of the current system boot, -ESTALE is
returned by sd_journal_get_monotonic_usec().
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_id128_get_boot(3), clock_gettime(2),
sd_journal_get_cutoff_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_GET_REALTIME_USEC(3)
Pages that refer to this page: sd-journal(3) , sd_journal_enumerate_available_data(3) , sd_journal_enumerate_data(3) , sd_journal_foreach(3) , SD_JOURNAL_FOREACH(3) , sd_journal_foreach_backwards(3) , SD_JOURNAL_FOREACH_BACKWARDS(3) , sd_journal_foreach_data(3) , SD_JOURNAL_FOREACH_DATA(3) , sd_journal_get_cutoff_monotonic_usec(3) , sd_journal_get_cutoff_realtime_usec(3) , sd_journal_get_data(3) , sd_journal_get_data_threshold(3) , sd_journal_next(3) , sd_journal_next_skip(3) , sd_journal_previous(3) , sd_journal_previous_skip(3) , sd_journal_restart_data(3) , sd_journal_seek_cursor(3) , sd_journal_seek_head(3) , sd_journal_seek_monotonic_usec(3) , sd_journal_seek_realtime_usec(3) , sd_journal_seek_tail(3) , sd_journal_set_data_threshold(3) , 30-systemd-environment-d-generator(7) , systemd.directives(7) , systemd.index(7)