← Back to branch summary

~ubuntu-branches/ubuntu/trusty/systemd/trusty

« back to all changes in this revision

Viewing changes to man/sd_journal_previous.html

  • Committer: Package Import Robot
  • Author(s): Michael Biebl, Michael Biebl, Michael Stapelberg, Daniel Schaal, Ondrej Balaz
  • Date: 2013-09-12 00:13:11 UTC
  • mfrom: (1.1.11) (9.1.2 experimental)
  • mto: This revision was merged to the branch mainline in revision 53.
  • Revision ID: package-import@ubuntu.com-20130912001311-dz35it34wr2lbday
Tags: 204-3
http://bugs.debian.org/719444
http://bugs.debian.org/721347
http://bugs.debian.org/722180
http://bugs.debian.org/709780
http://bugs.debian.org/711245
[ Michael Biebl ]
* Upload to unstable.
* Use /bin/bash in debug-shell.service as Debian doesn't have /sbin/sushell.
* Only import net.ifaces cmdline property for network devices.
* Generate strict dependencies between the binary packages using a
  shlibs.local file and add an explicit versioned dependency on
  libsystemd-login0 to systemd to ensure packages are upgraded in sync.
  Closes: #719444
* Drop obsolete Replaces: libudev0 from udev package.
* Use correct paths for various binaries, like /sbin/quotaon, which are
  installed in / and not /usr in Debian.  Closes: #721347
* Don't install kernel-install(8) man page since we don't install the
  corresponding binary either.  Closes: #722180
* Cherry-pick upstream fixes to make switching runlevels and starting
  reboot via ctrl-alt-del more robust.
* Cherry-pick upstream fix to properly apply ACLs to Journal files.

[ Michael Stapelberg ]
* Make systemctl enable|disable call update-rc.d for SysV init scripts.
  Closes: #709780
* Don't mount /tmp as tmpfs by default and make it possible to enable this
  feature via "systemctl enable tmp.mount".

[ Daniel Schaal ]
* Add bug-script to systemd and udev.  Closes: #711245

[ Ondrej Balaz ]
* Recognize discard option in /etc/crypttab.

Show diffs side-by-side

added added

removed removed

Lines of Context:
man/sd_journal_previous.html
 
1
<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>sd_journal_next</title><meta name="generator" content="DocBook XSL Stylesheets V1.78.1"></head><body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"><style>
 
2
    a.headerlink {
 
3
      color: #c60f0f;
 
4
      font-size: 0.8em;
 
5
      padding: 0 4px 0 4px;
 
6
      text-decoration: none;
 
7
      visibility: hidden;
 
8
    }
 
9
 
 
10
    a.headerlink:hover {
 
11
      background-color: #c60f0f;
 
12
      color: white;
 
13
    }
 
14
 
 
15
    h1:hover > a.headerlink, h2:hover > a.headerlink, h3:hover > a.headerlink, dt:hover > a.headerlink {
 
16
      visibility: visible;
 
17
    }
 
18
  </style><a href="index.html">Index </a>·
 
19
  <a href="systemd.directives.html">Directives </a>·
 
20
  <a href="../python-systemd/index.html">Python </a>·
 
21
  <a href="../libudev/index.html">libudev </a>·
 
22
  <a href="../libudev/index.html">gudev </a><span style="float:right">systemd 204</span><hr><div class="refentry"><a name="sd_journal_next"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>sd_journal_next, sd_journal_previous, sd_journal_next_skip, sd_journal_previous_skip, SD_JOURNAL_FOREACH, SD_JOURNAL_FOREACH_BACKWARDS — Advance or set back the read pointer in the 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_next</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_previous</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_next_skip</b>(</code></td><td>sd_journal* <var class="pdparam">j</var>, </td></tr><tr><td> </td><td>uint64_t <var class="pdparam">skip</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_previous_skip</b>(</code></td><td>sd_journal* <var class="pdparam">j</var>, </td></tr><tr><td> </td><td>uint64_t <var class="pdparam">skip</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"><b class="fsfunc">SD_JOURNAL_FOREACH</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"><b class="fsfunc">SD_JOURNAL_FOREACH_BACKWARDS</b>(</code></td><td>sd_journal* <var class="pdparam">j</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a name="idm259772947248"></a><h2 id="Description">Description<a class="headerlink" title="Permalink to this headline" href="#Description">¶</a></h2><p><code class="function">sd_journal_next()</code> advances
 
23
                the read pointer into the journal by one entry. The
 
24
                only argument taken is a journal context object as
 
25
                allocated via
 
26
                <a href="sd_journal_open.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_open</span>(3)</span></a>. After
 
27
                successful invocation the entry may be read with
 
28
                functions such as
 
29
                <a href="sd_journal_get_data.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_get_data</span>(3)</span></a>.</p><p>Similar, <code class="function">sd_journal_previous()</code> sets
 
30
                the read pointer back one entry.</p><p><code class="function">sd_journal_next_skip()</code> and
 
31
                <code class="function">sd_journal_previous_skip()</code>
 
32
                advance/set back the read pointer by multiple entries
 
33
                at once, as specified in the <code class="varname">skip</code>
 
34
                parameter.</p><p>The journal is strictly ordered by reception
 
35
                time, and hence advancing to the next entry guarantees
 
36
                that the entry then pointing to is later in time than
 
37
                then previous one, or has the same timestamp.</p><p>Note that
 
38
                <a href="sd_journal_get_data.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_get_data</span>(3)</span></a>
 
39
                and related calls will fail unless
 
40
                <code class="function">sd_journal_next()</code> has been
 
41
                invoked at least once in order to position the read
 
42
                pointer on a journal entry.</p><p>Note that the
 
43
                <code class="function">SD_JOURNAL_FOREACH()</code> macro may be used
 
44
                as a wrapper around
 
45
                <a href="sd_journal_seek_head.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_seek_head</span>(3)</span></a>
 
46
                and <code class="function">sd_journal_next()</code> in order to
 
47
                make iterating through the journal easier. See below
 
48
                for an example. Similar,
 
49
                <code class="function">SD_JOURNAL_FOREACH_BACKWARDS()</code>
 
50
                may be used for iterating the journal in reverse
 
51
                order.</p></div><div class="refsect1"><a name="idm259772933856"></a><h2 id="Return Value">Return Value<a class="headerlink" title="Permalink to this headline" href="#Return%20Value">¶</a></h2><p>The four calls return the number of entries
 
52
                advanced/set back on success or a negative errno-style
 
53
                error code. When the end or beginning of the journal
 
54
                is reached, a number smaller than requested is
 
55
                returned. More specifically, if
 
56
                <code class="function">sd_journal_next()</code> or
 
57
                <code class="function">sd_journal_previous()</code> reach the
 
58
                end/beginning of the journal they will return 0,
 
59
                instead of 1 when they are successful. This should be
 
60
                considered an EOF marker.</p></div><div class="refsect1"><a name="idm259772923184"></a><h2 id="Notes">Notes<a class="headerlink" title="Permalink to this headline" href="#Notes">¶</a></h2><p>The <code class="function">sd_journal_next()</code>, <code class="function">sd_journal_previous()</code>,
 
61
                <code class="function">sd_journal_next_skip()</code> and
 
62
                <code class="function">sd_journal_previous_skip()</code> interfaces are
 
63
                available as shared library, which can be compiled and
 
64
                linked to with the
 
65
                <code class="literal">libsystemd-journal</code>
 
66
                <a href="pkg-config.html"><span class="citerefentry"><span class="refentrytitle">pkg-config</span>(1)</span></a>
 
67
                file.</p></div><div class="refsect1"><a name="idm259772917408"></a><h2 id="Examples">Examples<a class="headerlink" title="Permalink to this headline" href="#Examples">¶</a></h2><p>Iterating through the journal:</p><pre class="programlisting">#include &lt;stdio.h&gt;
 
68
#include &lt;string.h&gt;
 
69
#include &lt;systemd/sd-journal.h&gt;
 
70
 
 
71
int main(int argc, char *argv[]) {
 
72
        int r;
 
73
        sd_journal *j;
 
74
        r = sd_journal_open(&amp;j, SD_JOURNAL_LOCAL_ONLY);
 
75
        if (r &lt; 0) {
 
76
                fprintf(stderr, "Failed to open journal: %s\n", strerror(-r));
 
77
                return 1;
 
78
        }
 
79
        SD_JOURNAL_FOREACH(j) {
 
80
                const char *d;
 
81
                size_t l;
 
82
 
 
83
                r = sd_journal_get_data(j, "MESSAGE", &amp;d, &amp;l);
 
84
                if (r &lt; 0) {
 
85
                        fprintf(stderr, "Failed to read message field: %s\n", strerror(-r));
 
86
                        continue;
 
87
                }
 
88
 
 
89
                printf("%.*s\n", (int) l, d);
 
90
        }
 
91
        sd_journal_close(j);
 
92
        return 0;
 
93
}</pre></div><div class="refsect1"><a name="idm259772914160"></a><h2 id="See Also">See Also<a class="headerlink" title="Permalink to this headline" href="#See%20Also">¶</a></h2><p>
 
94
                        <a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>,
 
95
                        <a href="sd-journal.html"><span class="citerefentry"><span class="refentrytitle">sd-journal</span>(3)</span></a>,
 
96
                        <a href="sd_journal_open.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_open</span>(3)</span></a>,
 
97
                        <a href="sd_journal_get_data.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_get_data</span>(3)</span></a>,
 
98
                        <a href="sd_journal_get_realtime_usec.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_get_realtime_usec</span>(3)</span></a>,
 
99
                        <a href="sd_journal_get_cursor.html"><span class="citerefentry"><span class="refentrytitle">sd_journal_get_cursor</span>(3)</span></a>
 
100
                </p></div></div></body></html>