man/sd_journal_get_cutoff_realtime_usec.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1+ -->
   5
   6 <refentry id="sd_journal_get_cutoff_realtime_usec" xmlns:xi="http://www.w3.org/2001/XInclude">
   7
   8   <refentryinfo>
   9     <title>sd_journal_get_cutoff_realtime_usec</title>
  10     <productname>systemd</productname>
  11   </refentryinfo>
  12
  13   <refmeta>
  14     <refentrytitle>sd_journal_get_cutoff_realtime_usec</refentrytitle>
  15     <manvolnum>3</manvolnum>
  16   </refmeta>
  17
  18   <refnamediv>
  19     <refname>sd_journal_get_cutoff_realtime_usec</refname>
  20     <refname>sd_journal_get_cutoff_monotonic_usec</refname>
  21     <refpurpose>Read cut-off timestamps from the current journal entry</refpurpose>
  22   </refnamediv>
  23
  24   <refsynopsisdiv>
  25     <funcsynopsis>
  26       <funcsynopsisinfo>#include &lt;systemd/sd-journal.h&gt;</funcsynopsisinfo>
  27
  28       <funcprototype>
  29         <funcdef>int <function>sd_journal_get_cutoff_realtime_usec</function></funcdef>
  30         <paramdef>sd_journal *<parameter>j</parameter></paramdef>
  31         <paramdef>uint64_t *<parameter>from</parameter></paramdef>
  32         <paramdef>uint64_t *<parameter>to</parameter></paramdef>
  33       </funcprototype>
  34
  35       <funcprototype>
  36         <funcdef>int <function>sd_journal_get_cutoff_monotonic_usec</function></funcdef>
  37         <paramdef>sd_journal *<parameter>j</parameter></paramdef>
  38         <paramdef>sd_id128_t <parameter>boot_id</parameter></paramdef>
  39         <paramdef>uint64_t *<parameter>from</parameter></paramdef>
  40         <paramdef>uint64_t *<parameter>to</parameter></paramdef>
  41       </funcprototype>
  42
  43     </funcsynopsis>
  44   </refsynopsisdiv>
  45
  46   <refsect1>
  47     <title>Description</title>
  48
  49     <para><function>sd_journal_get_cutoff_realtime_usec()</function>
  50     retrieves the realtime (wallclock) timestamps of the first and
  51     last entries accessible in the journal. It takes three arguments:
  52     the journal context object <parameter>j</parameter> and two
  53     pointers <parameter>from</parameter> and <parameter>to</parameter>
  54     pointing at 64-bit unsigned integers to store the timestamps in.
  55     The timestamps are in microseconds since the epoch, i.e.
  56     <constant>CLOCK_REALTIME</constant>. Either one of the two
  57     timestamp arguments may be passed as <constant>NULL</constant> in
  58     case the timestamp is not needed, but not both.</para>
  59
  60     <para><function>sd_journal_get_cutoff_monotonic_usec()</function>
  61     retrieves the monotonic timestamps of the first and last entries
  62     accessible in the journal. It takes three arguments: the journal
  63     context object <parameter>j</parameter>, a 128-bit identifier for
  64     the boot <parameter>boot_id</parameter>, and two pointers to
  65     64-bit unsigned integers to store the timestamps,
  66     <parameter>from</parameter> and <parameter>to</parameter>. The
  67     timestamps are in microseconds since boot-up of the specific boot,
  68     i.e. <constant>CLOCK_MONOTONIC</constant>. Since the monotonic
  69     clock begins new with every reboot it only defines a well-defined
  70     point in time when used together with an identifier identifying
  71     the boot, see
  72     <citerefentry><refentrytitle>sd_id128_get_boot</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  73     for more information. The function will return the timestamps for
  74     the boot identified by the passed boot ID. Either one of the two
  75     timestamp arguments may be passed as <constant>NULL</constant> in
  76     case the timestamp is not needed, but not both.</para>
  77   </refsect1>
  78
  79   <refsect1>
  80     <title>Return Value</title>
  81
  82     <para><function>sd_journal_get_cutoff_realtime_usec()</function>
  83     and <function>sd_journal_get_cutoff_monotonic_usec()</function>
  84     return 1 on success, 0 if not suitable entries are in the journal
  85     or a negative errno-style error code.</para>
  86
  87     <para>Locations pointed to by parameters
  88     <parameter>from</parameter> and <parameter>to</parameter> will be
  89     set only if the return value is positive, and obviously, the
  90     parameters are non-null.</para>
  91   </refsect1>
  92
  93   <refsect1>
  94     <title>Notes</title>
  95
  96     <xi:include href="threads-aware.xml" xpointer="strict" />
  97
  98     <xi:include href="libsystemd-pkgconfig.xml" xpointer="pkgconfig-text"/>
  99   </refsect1>
 100
 101   <refsect1>
 102     <title>See Also</title>
 103
 104     <para>
 105       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 106       <citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 107       <citerefentry><refentrytitle>sd_journal_open</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 108       <citerefentry><refentrytitle>sd_journal_get_realtime_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 109       <citerefentry><refentrytitle>sd_id128_get_boot</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 110       <citerefentry><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 111     </para>
 112   </refsect1>
 113
 114 </refentry>