SD_JOURNAL_GET_REALTIME_Usd_journal_get_realtimSD_JOURNAL_GET_REALTIME_USEC(3)NAME
sd_journal_get_realtime_usec, sd_journal_get_monotonic_usec - Read
timestamps from the current journal entry
SYNOPSIS
#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);
DESCRIPTIONsd_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.
RETURN VALUEsd_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().
NOTES
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.
SEE ALSOsystemd(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)systemd 212SD_JOURNAL_GET_REALTIME_USEC(3)