1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
|
<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>sd_journal_seek_head</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><style>
a.headerlink {
color: #c60f0f;
font-size: 0.8em;
padding: 0 4px 0 4px;
text-decoration: none;
visibility: hidden;
}
a.headerlink:hover {
background-color: #c60f0f;
color: white;
}
h1:hover > a.headerlink, h2:hover > a.headerlink, h3:hover > a.headerlink, dt:hover > a.headerlink {
visibility: visible;
}
</style><a href="index.html">Index </a>·
<a href="systemd.directives.html">Directives </a>·
<a href="../python-systemd/index.html">Python </a>·
<a href="../libudev/index.html">libudev </a>·
<a href="../libudev/index.html">gudev </a><span style="float:right">systemd 204</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
journal</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><pre class="funcsynopsisinfo">#include <systemd/sd-journal.h></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="idm259772866880"></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>
seeks to the beginning of the journal, i.e. the oldest
available entry.</p><p>Similar,
<code class="function">sd_journal_seek_tail()</code> may be
used to seek to the end of the journal, i.e. the most
recent available entry.</p><p><code class="function">sd_journal_seek_monotonic_usec()</code>
seeks to the entry with the specified monotonic
timestamp, i.e. CLOCK_MONOTONIC. Since monotonic time
restarts on every reboot a boot ID needs to be
specified as well.</p><p><code class="function">sd_journal_seek_realtime_usec()</code>
seeks to the entry with the specified realtime
(wallclock) timestamp, i.e. CLOCK_REALTIME. Note that
the realtime clock is not necessarily monotonic. If a
realtime timestamp is ambiguous it is not defined
which position is sought to.</p><p><code class="function">sd_journal_seek_cursor()</code>
seeks to the entry located at the specified cursor
string. For details on cursors see
<a href="sd_journal_get_cursor.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_get_cursor</span>(3)</span></a>. If
no entry matching the specified cursor is found the
call will seek to the next closest entry (in terms of
time) instead. To verify whether the newly selected
entry actually matches the cursor use
<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
entry the new current entry, this needs to be done in
a separate step with a subsequent
<a href="sd_journal_next.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_next</span>(3)</span></a>
invocation (or a similar call). Only then entry data
may be retrieved via
<a href="sd_journal_get_data.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_get_data</span>(3)</span></a>. If
no entry exists that matches exactly the specified
seek address the next closest is sought to. If
<a href="sd_journal_next.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_next</span>(3)</span></a>
is used the closest following entry will be sought to,
if
<a href="sd_journal_previous.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_previous</span>(3)</span></a>
is used the closest preceding entry is sought
to.</p></div><div class="refsect1"><a name="idm259772854032"></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
errno-style error code.</p></div><div class="refsect1"><a name="idm259772852848"></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>,
<code class="function">sd_journal_seek_tail()</code>,
<code class="function">sd_journal_seek_monotonic_usec()</code>,
<code class="function">sd_journal_seek_realtime_usec()</code>,
and <code class="function">sd_journal_seek_cursor()</code>
interfaces are available as shared library, which can
be compiled and linked to with the
<code class="literal">libsystemd-journal</code>
<a href="pkg-config.html"><span class="citerefentry"><span class="refentrytitle">pkg-config</span>(1)</span></a>
file.</p></div><div class="refsect1"><a name="idm259772838944"></a><h2 id="See Also">See Also<a class="headerlink" title="Permalink to this headline" href="#See%20Also">¶</a></h2><p>
<a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>,
<a href="sd-journal.html"><span class="citerefentry"><span class="refentrytitle">sd-journal</span>(3)</span></a>,
<a href="sd_journal_open.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_open</span>(3)</span></a>,
<a href="sd_journal_next.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_next</span>(3)</span></a>,
<a href="sd_journal_get_data.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_get_data</span>(3)</span></a>,
<a href="sd_journal_get_cursor.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_get_cursor</span>(3)</span></a>,
<a href="sd_journal_get_realtime_usec.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_get_realtime_usec</span>(3)</span></a>
</p></div></div></body></html>
|
