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);

DESCRIPTION

       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 in. 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 VALUE

       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().

NOTES

       The sd_journal_get_realtime_usec() and sd_journal_get_monotonic_usec() interfaces are available as shared
       library, which can be compiled and linked to with the libsystemd-journalpkg-config(1) file.

SEE ALSO

       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)