systemd/man/sd_journal_get_cutoff_realtime_usec.xml
2023-12-25 15:51:47 +01:00

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<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
<refentry id="sd_journal_get_cutoff_realtime_usec" xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sd_journal_get_cutoff_realtime_usec</title>
<productname>systemd</productname>
</refentryinfo>
<refmeta>
<refentrytitle>sd_journal_get_cutoff_realtime_usec</refentrytitle>
<manvolnum>3</manvolnum>
</refmeta>
<refnamediv>
<refname>sd_journal_get_cutoff_realtime_usec</refname>
<refname>sd_journal_get_cutoff_monotonic_usec</refname>
<refpurpose>Read cut-off timestamps from the current journal entry</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include &lt;systemd/sd-journal.h&gt;</funcsynopsisinfo>
<funcprototype>
<funcdef>int <function>sd_journal_get_cutoff_realtime_usec</function></funcdef>
<paramdef>sd_journal *<parameter>j</parameter></paramdef>
<paramdef>uint64_t *<parameter>from</parameter></paramdef>
<paramdef>uint64_t *<parameter>to</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_journal_get_cutoff_monotonic_usec</function></funcdef>
<paramdef>sd_journal *<parameter>j</parameter></paramdef>
<paramdef>sd_id128_t <parameter>boot_id</parameter></paramdef>
<paramdef>uint64_t *<parameter>from</parameter></paramdef>
<paramdef>uint64_t *<parameter>to</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><function>sd_journal_get_cutoff_realtime_usec()</function>
retrieves the realtime (wallclock) timestamps of the first and
last entries accessible in the journal. It takes three arguments:
the journal context object <parameter>j</parameter> and two
pointers <parameter>from</parameter> and <parameter>to</parameter>
pointing at 64-bit unsigned integers to store the timestamps in.
The timestamps are in microseconds since the epoch, i.e.
<constant>CLOCK_REALTIME</constant>. Either one of the two
timestamp arguments may be passed as <constant>NULL</constant> in
case the timestamp is not needed, but not both.</para>
<para><function>sd_journal_get_cutoff_monotonic_usec()</function>
retrieves the monotonic timestamps of the first and last entries
accessible in the journal. It takes three arguments: the journal
context object <parameter>j</parameter>, a 128-bit identifier for
the boot <parameter>boot_id</parameter>, and two pointers to
64-bit unsigned integers to store the timestamps,
<parameter>from</parameter> and <parameter>to</parameter>. The
timestamps are 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. 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 <constant>NULL</constant> in
case the timestamp is not needed, but not both.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
<para><function>sd_journal_get_cutoff_realtime_usec()</function>
and <function>sd_journal_get_cutoff_monotonic_usec()</function>
return 1 on success, 0 if not suitable entries are in the journal
or a negative errno-style error code.</para>
<para>Locations pointed to by parameters
<parameter>from</parameter> and <parameter>to</parameter> will be
set only if the return value is positive, and obviously, the
parameters are non-null.</para>
</refsect1>
<refsect1>
<title>Notes</title>
<xi:include href="threads-aware.xml" xpointer="strict" />
<xi:include href="libsystemd-pkgconfig.xml" xpointer="pkgconfig-text"/>
</refsect1>
<refsect1>
<title>History</title>
<para><function>sd_journal_get_cutoff_realtime_usec()</function> and
<function>sd_journal_get_cutoff_monotonic_usec()</function> were added in version 187.</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para><simplelist type="inline">
<member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
<member><citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
<member><citerefentry><refentrytitle>sd_journal_open</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
<member><citerefentry><refentrytitle>sd_journal_get_realtime_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
<member><citerefentry><refentrytitle>sd_id128_get_boot</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
<member><citerefentry><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry></member>
</simplelist></para>
</refsect1>
</refentry>