mirror of
https://github.com/systemd/systemd.git
synced 2024-12-19 15:13:36 +08:00
148 lines
7.1 KiB
XML
148 lines
7.1 KiB
XML
<?xml version='1.0'?> <!--*-nxml-*-->
|
|
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
|
|
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
|
|
|
|
<!--
|
|
This file is part of systemd.
|
|
|
|
Copyright 2012 Lennart Poettering
|
|
|
|
systemd is free software; you can redistribute it and/or modify it
|
|
under the terms of the GNU Lesser General Public License as published by
|
|
the Free Software Foundation; either version 2.1 of the License, or
|
|
(at your option) any later version.
|
|
|
|
systemd is distributed in the hope that it will be useful, but
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public License
|
|
along with systemd; If not, see <http://www.gnu.org/licenses/>.
|
|
-->
|
|
|
|
<refentry id="sd_journal_get_realtime_usec">
|
|
|
|
<refentryinfo>
|
|
<title>sd_journal_get_realtime_usec</title>
|
|
<productname>systemd</productname>
|
|
|
|
<authorgroup>
|
|
<author>
|
|
<contrib>Developer</contrib>
|
|
<firstname>Lennart</firstname>
|
|
<surname>Poettering</surname>
|
|
<email>lennart@poettering.net</email>
|
|
</author>
|
|
</authorgroup>
|
|
</refentryinfo>
|
|
|
|
<refmeta>
|
|
<refentrytitle>sd_journal_get_realtime_usec</refentrytitle>
|
|
<manvolnum>3</manvolnum>
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>sd_journal_get_realtime_usec</refname>
|
|
<refname>sd_journal_get_monotonic_usec</refname>
|
|
<refpurpose>Read timestamps from the current journal entry</refpurpose>
|
|
</refnamediv>
|
|
|
|
<refsynopsisdiv>
|
|
<funcsynopsis>
|
|
<funcsynopsisinfo>#include <systemd/sd-journal.h></funcsynopsisinfo>
|
|
|
|
<funcprototype>
|
|
<funcdef>int <function>sd_journal_get_realtime_usec</function></funcdef>
|
|
<paramdef>sd_journal* <parameter>j</parameter></paramdef>
|
|
<paramdef>uint64_t* <parameter>usec</parameter></paramdef>
|
|
</funcprototype>
|
|
|
|
<funcprototype>
|
|
<funcdef>int <function>sd_journal_get_monotonic_usec</function></funcdef>
|
|
<paramdef>sd_journal* <parameter>j</parameter></paramdef>
|
|
<paramdef>uint64_t* <parameter>usec</parameter></paramdef>
|
|
<paramdef>sd_id128_t* <parameter>boot_id</parameter></paramdef>
|
|
</funcprototype>
|
|
|
|
</funcsynopsis>
|
|
</refsynopsisdiv>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<para><function>sd_journal_get_realtime_usec()</function>
|
|
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. <constant>CLOCK_REALTIME</constant>.</para>
|
|
|
|
<para><function>sd_journal_get_monotonic_usec()</function>
|
|
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. <constant>CLOCK_MONOTONIC</constant>. 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
|
|
<citerefentry><refentrytitle>sd_id128_get_boot</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
|
for more information. If the boot ID parameter is
|
|
passed <constant>NULL</constant> the function will
|
|
fail if the monotonic timestamp of the current entry
|
|
is not of the current system boot.</para>
|
|
|
|
<para>Note that these functions will not work before
|
|
<citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
|
(or related call) has been called at least
|
|
once, in order to position the read pointer at a valid entry.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Return Value</title>
|
|
|
|
<para><function>sd_journal_get_realtime_usec()</function>
|
|
and
|
|
<function>sd_journal_get_monotonic_usec()</function>
|
|
returns 0 on success or a negative errno-style error
|
|
code. If the boot ID parameter was passed <constant>NULL</constant> and the
|
|
monotonic timestamp of the current journal entry is
|
|
not of the current system boot, -ESTALE is returned by <function>sd_journal_get_monotonic_usec()</function>.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Notes</title>
|
|
|
|
<para>The
|
|
<function>sd_journal_get_realtime_usec()</function>
|
|
and
|
|
<function>sd_journal_get_monotonic_usec()</function>
|
|
interfaces are available as shared library, which can
|
|
be compiled and linked to with the
|
|
<constant>libsystemd-journal</constant>
|
|
<citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
|
file.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>See Also</title>
|
|
|
|
<para>
|
|
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_journal_open</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_journal_get_data</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_id128_get_boot</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_journal_get_cutoff_realtime_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
|
</para>
|
|
</refsect1>
|
|
|
|
</refentry>
|