man/sd_journal_seek_monotonic_usec.html

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  22   <a href="../libudev/index.html">gudev </a><span style="float:right">systemd 208</span><hr><div class="refentry"><a name="sd_journal_seek_head"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>sd_journal_seek_head, sd_journal_seek_tail, sd_journal_seek_monotonic_usec, sd_journal_seek_realtime_usec, sd_journal_seek_cursor — Seek to a position in the
  23                 journal</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><pre class="funcsynopsisinfo">#include &lt;systemd/sd-journal.h&gt;</pre><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">int <b class="fsfunc">sd_journal_seek_head</b>(</code></td><td>sd_journal* <var class="pdparam">j</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">int <b class="fsfunc">sd_journal_seek_tail</b>(</code></td><td>sd_journal* <var class="pdparam">j</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">int <b class="fsfunc">sd_journal_seek_monotonic_usec</b>(</code></td><td>sd_journal* <var class="pdparam">j</var>, </td></tr><tr><td> </td><td>sd_id128_t <var class="pdparam">boot_id</var>, </td></tr><tr><td> </td><td>uint64_t <var class="pdparam">usec</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">int <b class="fsfunc">sd_journal_seek_realtime_usec</b>(</code></td><td>sd_journal* <var class="pdparam">j</var>, </td></tr><tr><td> </td><td>uint64_t <var class="pdparam">usec</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div><table border="0" class="funcprototype-table" summary="Function synopsis" style="cellspacing: 0; cellpadding: 0;"><tr><td><code class="funcdef">int <b class="fsfunc">sd_journal_seek_cursor</b>(</code></td><td>sd_journal* <var class="pdparam">j</var>, </td></tr><tr><td> </td><td>const char * <var class="pdparam">cursor</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a name="idm274696451184"></a><h2 id="Description">Description<a class="headerlink" title="Permalink to this headline" href="#Description">¶</a></h2><p><code class="function">sd_journal_seek_head()</code>
  24                 seeks to the beginning of the journal, i.e. the oldest
  25                 available entry.</p><p>Similar,
  26                 <code class="function">sd_journal_seek_tail()</code> may be
  27                 used to seek to the end of the journal, i.e. the most
  28                 recent available entry.</p><p><code class="function">sd_journal_seek_monotonic_usec()</code>
  29                 seeks to the entry with the specified monotonic
  30                 timestamp,
  31                 i.e. <code class="constant">CLOCK_MONOTONIC</code>. Since
  32                 monotonic time restarts on every reboot a boot ID
  33                 needs to be specified as well.</p><p><code class="function">sd_journal_seek_realtime_usec()</code>
  34                 seeks to the entry with the specified realtime
  35                 (wallclock) timestamp,
  36                 i.e. <code class="constant">CLOCK_REALTIME</code>. Note that
  37                 the realtime clock is not necessarily monotonic. If a
  38                 realtime timestamp is ambiguous, it is not defined
  39                 which position is sought to.</p><p><code class="function">sd_journal_seek_cursor()</code>
  40                 seeks to the entry located at the specified cursor
  41                 string. For details on cursors, see
  42                 <a href="sd_journal_get_cursor.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_get_cursor</span>(3)</span></a>. If
  43                 no entry matching the specified cursor is found the
  44                 call will seek to the next closest entry (in terms of
  45                 time) instead. To verify whether the newly selected
  46                 entry actually matches the cursor, use
  47                 <a href="sd_journal_test_cursor.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_test_cursor</span>(3)</span></a>.</p><p>Note that these calls do not actually make any
  48                 entry the new current entry, this needs to be done in
  49                 a separate step with a subsequent
  50                 <a href="sd_journal_next.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_next</span>(3)</span></a>
  51                 invocation (or a similar call). Only then, entry data
  52                 may be retrieved via
  53                 <a href="sd_journal_get_data.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_get_data</span>(3)</span></a>. If
  54                 no entry exists that matches exactly the specified
  55                 seek address, the next closest is sought to. If
  56                 <a href="sd_journal_next.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_next</span>(3)</span></a>
  57                 is used, the closest following entry will be sought to,
  58                 if
  59                 <a href="sd_journal_previous.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_previous</span>(3)</span></a>
  60                 is used the closest preceding entry is sought
  61                 to.</p></div><div class="refsect1"><a name="idm274696437440"></a><h2 id="Return Value">Return Value<a class="headerlink" title="Permalink to this headline" href="#Return%20Value">¶</a></h2><p>The functions return 0 on success or a negative
  62                 errno-style error code.</p></div><div class="refsect1"><a name="idm274696428912"></a><h2 id="Notes">Notes<a class="headerlink" title="Permalink to this headline" href="#Notes">¶</a></h2><p>The <code class="function">sd_journal_seek_head()</code>,
  63                 <code class="function">sd_journal_seek_tail()</code>,
  64                 <code class="function">sd_journal_seek_monotonic_usec()</code>,
  65                 <code class="function">sd_journal_seek_realtime_usec()</code>,
  66                 and <code class="function">sd_journal_seek_cursor()</code>
  67                 interfaces are available as shared library, which can
  68                 be compiled and linked to with the
  69                 <code class="constant">libsystemd-journal</code> <a href="pkg-config.html"><span class="citerefentry"><span class="refentrytitle">pkg-config</span>(1)</span></a>
  70                 file.</p></div><div class="refsect1"><a name="idm274696422592"></a><h2 id="See Also">See Also<a class="headerlink" title="Permalink to this headline" href="#See%20Also">¶</a></h2><p>
  71                         <a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>,
  72                         <a href="sd-journal.html"><span class="citerefentry"><span class="refentrytitle">sd-journal</span>(3)</span></a>,
  73                         <a href="sd_journal_open.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_open</span>(3)</span></a>,
  74                         <a href="sd_journal_next.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_next</span>(3)</span></a>,
  75                         <a href="sd_journal_get_data.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_get_data</span>(3)</span></a>,
  76                         <a href="sd_journal_get_cursor.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_get_cursor</span>(3)</span></a>,
  77                         <a href="sd_journal_get_realtime_usec.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_get_realtime_usec</span>(3)</span></a>
  78                 </p></div></div></body></html>