man/sd_journal_get_cutoff_realtime_usec.xml

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   5 <!--
   6   SPDX-License-Identifier: LGPL-2.1+
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   8
   9 <refentry id="sd_journal_get_cutoff_realtime_usec" xmlns:xi="http://www.w3.org/2001/XInclude">
  10
  11   <refentryinfo>
  12     <title>sd_journal_get_cutoff_realtime_usec</title>
  13     <productname>systemd</productname>
  14
  15     <authorgroup>
  16       <author>
  17         <contrib>Developer</contrib>
  18         <firstname>Lennart</firstname>
  19         <surname>Poettering</surname>
  20         <email>lennart@poettering.net</email>
  21       </author>
  22     </authorgroup>
  23   </refentryinfo>
  24
  25   <refmeta>
  26     <refentrytitle>sd_journal_get_cutoff_realtime_usec</refentrytitle>
  27     <manvolnum>3</manvolnum>
  28   </refmeta>
  29
  30   <refnamediv>
  31     <refname>sd_journal_get_cutoff_realtime_usec</refname>
  32     <refname>sd_journal_get_cutoff_monotonic_usec</refname>
  33     <refpurpose>Read cut-off timestamps from the current journal entry</refpurpose>
  34   </refnamediv>
  35
  36   <refsynopsisdiv>
  37     <funcsynopsis>
  38       <funcsynopsisinfo>#include &lt;systemd/sd-journal.h&gt;</funcsynopsisinfo>
  39
  40       <funcprototype>
  41         <funcdef>int <function>sd_journal_get_cutoff_realtime_usec</function></funcdef>
  42         <paramdef>sd_journal *<parameter>j</parameter></paramdef>
  43         <paramdef>uint64_t *<parameter>from</parameter></paramdef>
  44         <paramdef>uint64_t *<parameter>to</parameter></paramdef>
  45       </funcprototype>
  46
  47       <funcprototype>
  48         <funcdef>int <function>sd_journal_get_cutoff_monotonic_usec</function></funcdef>
  49         <paramdef>sd_journal *<parameter>j</parameter></paramdef>
  50         <paramdef>sd_id128_t <parameter>boot_id</parameter></paramdef>
  51         <paramdef>uint64_t *<parameter>from</parameter></paramdef>
  52         <paramdef>uint64_t *<parameter>to</parameter></paramdef>
  53       </funcprototype>
  54
  55     </funcsynopsis>
  56   </refsynopsisdiv>
  57
  58   <refsect1>
  59     <title>Description</title>
  60
  61     <para><function>sd_journal_get_cutoff_realtime_usec()</function>
  62     retrieves the realtime (wallclock) timestamps of the first and
  63     last entries accessible in the journal. It takes three arguments:
  64     the journal context object <parameter>j</parameter> and two
  65     pointers <parameter>from</parameter> and <parameter>to</parameter>
  66     pointing at 64-bit unsigned integers to store the timestamps in.
  67     The timestamps are in microseconds since the epoch, i.e.
  68     <constant>CLOCK_REALTIME</constant>. Either one of the two
  69     timestamp arguments may be passed as <constant>NULL</constant> in
  70     case the timestamp is not needed, but not both.</para>
  71
  72     <para><function>sd_journal_get_cutoff_monotonic_usec()</function>
  73     retrieves the monotonic timestamps of the first and last entries
  74     accessible in the journal. It takes three arguments: the journal
  75     context object <parameter>j</parameter>, a 128-bit identifier for
  76     the boot <parameter>boot_id</parameter>, and two pointers to
  77     64-bit unsigned integers to store the timestamps,
  78     <parameter>from</parameter> and <parameter>to</parameter>. The
  79     timestamps are in microseconds since boot-up of the specific boot,
  80     i.e. <constant>CLOCK_MONOTONIC</constant>. Since the monotonic
  81     clock begins new with every reboot it only defines a well-defined
  82     point in time when used together with an identifier identifying
  83     the boot, see
  84     <citerefentry><refentrytitle>sd_id128_get_boot</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  85     for more information. The function will return the timestamps for
  86     the boot identified by the passed boot ID. Either one of the two
  87     timestamp arguments may be passed as <constant>NULL</constant> in
  88     case the timestamp is not needed, but not both.</para>
  89   </refsect1>
  90
  91   <refsect1>
  92     <title>Return Value</title>
  93
  94     <para><function>sd_journal_get_cutoff_realtime_usec()</function>
  95     and <function>sd_journal_get_cutoff_monotonic_usec()</function>
  96     return 1 on success, 0 if not suitable entries are in the journal
  97     or a negative errno-style error code.</para>
  98
  99     <para>Locations pointed to by parameters
 100     <parameter>from</parameter> and <parameter>to</parameter> will be
 101     set only if the return value is positive, and obviously, the
 102     parameters are non-null.</para>
 103   </refsect1>
 104
 105   <refsect1>
 106     <title>Notes</title>
 107
 108     <para>All functions listed here are thread-agnostic and only a single thread may operate
 109     on a given <structname>sd_journal</structname> object.</para>
 110
 111     <xi:include href="libsystemd-pkgconfig.xml" xpointer="pkgconfig-text"/>
 112   </refsect1>
 113
 114   <refsect1>
 115     <title>See Also</title>
 116
 117     <para>
 118       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 119       <citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 120       <citerefentry><refentrytitle>sd_journal_open</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 121       <citerefentry><refentrytitle>sd_journal_get_realtime_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 122       <citerefentry><refentrytitle>sd_id128_get_boot</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 123       <citerefentry><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry>
 124     </para>
 125   </refsect1>
 126
 127 </refentry>