'\" t .TH "SD_JOURNAL_GET_REALTIME_USEC" "3" "" "systemd 256.8" "sd_journal_get_realtime_usec" .\" ----------------------------------------------------------------- .\" * Define some portability stuff .\" ----------------------------------------------------------------- .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .\" http://bugs.debian.org/507673 .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html .\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" ----------------------------------------------------------------- .\" * set default formatting .\" ----------------------------------------------------------------- .\" disable hyphenation .nh .\" disable justification (adjust text to left margin only) .ad l .\" ----------------------------------------------------------------- .\" * MAIN CONTENT STARTS HERE * .\" ----------------------------------------------------------------- .SH "NAME" sd_journal_get_realtime_usec, sd_journal_get_monotonic_usec \- Read timestamps from the current journal entry .SH "SYNOPSIS" .sp .ft B .nf #include .fi .ft .HP \w'int\ sd_journal_get_realtime_usec('u .BI "int sd_journal_get_realtime_usec(sd_journal\ *" "j" ", uint64_t\ *" "usec" ");" .HP \w'int\ sd_journal_get_monotonic_usec('u .BI "int sd_journal_get_monotonic_usec(sd_journal\ *" "j" ", uint64_t\ *" "usec" ", sd_id128_t\ *" "boot_id" ");" .SH "DESCRIPTION" .PP \fBsd_journal_get_realtime_usec()\fR 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\&. \fBCLOCK_REALTIME\fR\&. .PP \fBsd_journal_get_monotonic_usec()\fR 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\&. \fBCLOCK_MONOTONIC\fR\&. 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 \fBsd_id128_get_boot\fR(3) for more information\&. If the boot ID parameter is passed \fBNULL\fR, the function will fail if the monotonic timestamp of the current entry is not of the current system boot\&. .PP Note that these functions will not work before \fBsd_journal_next\fR(3) (or related call) has been called at least once, in order to position the read pointer at a valid entry\&. .SH "RETURN VALUE" .PP \fBsd_journal_get_realtime_usec()\fR and \fBsd_journal_get_monotonic_usec()\fR returns 0 on success or a negative errno\-style error code\&. If the boot ID parameter was passed \fBNULL\fR and the monotonic timestamp of the current journal entry is not of the current system boot, \fB\-ESTALE\fR is returned by \fBsd_journal_get_monotonic_usec()\fR\&. .SH "NOTES" .PP All functions listed here are thread\-agnostic and only a single specific thread may operate on a given object during its entire lifetime\&. It\*(Aqs safe to allocate multiple independent objects and use each from a specific thread in parallel\&. However, it\*(Aqs 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\*(Aqt operate on it at the very same time\&. .PP Functions described here are available as a shared library, which can be compiled against and linked to with the \fBlibsystemd\fR\ \&\fBpkg-config\fR(1) file\&. .SH "HISTORY" .PP \fBsd_journal_get_realtime_usec()\fR and \fBsd_journal_get_monotonic_usec()\fR were added in version 187\&. .SH "SEE ALSO" .PP \fBsystemd\fR(1), \fBsd-journal\fR(3), \fBsd_journal_open\fR(3), \fBsd_journal_next\fR(3), \fBsd_journal_get_data\fR(3), \fBsd_journal_get_seqnum\fR(3), \fBsd_id128_get_boot\fR(3), \fBclock_gettime\fR(2), \fBsd_journal_get_cutoff_realtime_usec\fR(3)