|
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().
The sd_journal_get_realtime_usec() and
sd_journal_get_monotonic_usec() interfaces are available 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)
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systemd 234 SD_JOURNAL_GET_REALTIME_USEC(3)
Pages that refer to this page: sd-journal(3), sd_journal_get_cutoff_realtime_usec(3), sd_journal_get_data(3), sd_journal_next(3), sd_journal_seek_head(3), systemd.directives(7), systemd.index(7)