sd_journal_get_cutoff_realtime_usec, sd_journal_get_cutoff_monotonic_usec — Read cut-off timestamps from the current journal entry
#include <systemd/sd-journal.h>
| int sd_journal_get_cutoff_realtime_usec( | sd_journal *j, | 
| uint64_t *from, | |
| uint64_t *to ); | 
| int sd_journal_get_cutoff_monotonic_usec( | sd_journal *j, | 
| sd_id128_t boot_id, | |
| uint64_t *from, | |
| uint64_t *to ); | 
sd_journal_get_cutoff_realtime_usec()
    retrieves the realtime (wallclock) timestamps of the first and
    last entries accessible in the journal. It takes three arguments:
    the journal context object j and two
    pointers from and to
    pointing at 64-bit unsigned integers to store the timestamps in.
    The timestamps are in microseconds since the epoch, i.e.
    CLOCK_REALTIME. Either one of the two
    timestamp arguments may be passed as NULL in
    case the timestamp is not needed, but not both.
sd_journal_get_cutoff_monotonic_usec()
    retrieves the monotonic timestamps of the first and last entries
    accessible in the journal. It takes three arguments: the journal
    context object j, a 128-bit identifier for
    the boot boot_id, and two pointers to
    64-bit unsigned integers to store the timestamps,
    from and to. The
    timestamps are 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. The function will return the timestamps for
    the boot identified by the passed boot ID. Either one of the two
    timestamp arguments may be passed as NULL in
    case the timestamp is not needed, but not both.
sd_journal_get_cutoff_realtime_usec()
    and sd_journal_get_cutoff_monotonic_usec()
    return 1 on success, 0 if not suitable entries are in the journal
    or a negative errno-style error code.
Locations pointed to by parameters
    from and to will be
    set only if the return value is positive, and obviously, the
    parameters are non-null.
The
    sd_journal_get_cutoff_realtime_usec() and
    sd_journal_get_cutoff_monotonic_usec()
    interfaces are available as a shared library, which can be
    compiled and linked to with the
    libsystemd pkg-config(1)
    file.