man/sd-journal.xml

   1 <?xml version='1.0'?> <!--*-nxml-*-->
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4
   5 <!--
   6   SPDX-License-Identifier: LGPL-2.1+
   7
   8   This file is part of systemd.
   9
  10   Copyright 2012 Lennart Poettering
  11 -->
  12
  13 <refentry id="sd-journal"
  14   xmlns:xi="http://www.w3.org/2001/XInclude">
  15
  16   <refentryinfo>
  17     <title>sd-journal</title>
  18     <productname>systemd</productname>
  19
  20     <authorgroup>
  21       <author>
  22         <contrib>Developer</contrib>
  23         <firstname>Lennart</firstname>
  24         <surname>Poettering</surname>
  25         <email>lennart@poettering.net</email>
  26       </author>
  27     </authorgroup>
  28   </refentryinfo>
  29
  30   <refmeta>
  31     <refentrytitle>sd-journal</refentrytitle>
  32     <manvolnum>3</manvolnum>
  33   </refmeta>
  34
  35   <refnamediv>
  36     <refname>sd-journal</refname>
  37     <refpurpose>APIs for submitting and querying log entries to and
  38     from the journal</refpurpose>
  39   </refnamediv>
  40
  41   <refsynopsisdiv>
  42     <funcsynopsis>
  43       <funcsynopsisinfo>#include &lt;systemd/sd-journal.h&gt;</funcsynopsisinfo>
  44     </funcsynopsis>
  45
  46     <cmdsynopsis>
  47       <command>pkg-config --cflags --libs libsystemd</command>
  48     </cmdsynopsis>
  49
  50   </refsynopsisdiv>
  51
  52   <refsect1>
  53     <title>Description</title>
  54
  55     <para><filename>sd-journal.h</filename> provides APIs to submit
  56     and query log entries. The APIs exposed act both as client for the
  57     <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
  58     journal service and as parser for the journal files on disk.
  59     </para>
  60
  61     <para>See
  62     <citerefentry><refentrytitle>sd_journal_print</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
  63     <citerefentry><refentrytitle>sd_journal_stream_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
  64     <citerefentry><refentrytitle>sd_journal_open</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
  65     <citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
  66     <citerefentry><refentrytitle>sd_journal_get_realtime_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
  67     <citerefentry><refentrytitle>sd_journal_add_match</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
  68     <citerefentry><refentrytitle>sd_journal_seek_head</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
  69     <citerefentry><refentrytitle>sd_journal_enumerate_fields</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
  70     <citerefentry><refentrytitle>sd_journal_get_cursor</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
  71     <citerefentry><refentrytitle>sd_journal_get_cutoff_realtime_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
  72     <citerefentry><refentrytitle>sd_journal_get_cutoff_monotonic_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
  73     <citerefentry><refentrytitle>sd_journal_get_usage</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
  74     <citerefentry><refentrytitle>sd_journal_get_catalog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
  75     <citerefentry><refentrytitle>sd_journal_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
  76     <citerefentry><refentrytitle>sd_journal_has_runtime_files</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  77     and
  78     <citerefentry><refentrytitle>sd_journal_has_persistent_files</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  79     for more information about the functions implemented.</para>
  80
  81     <para>Command line access for submitting entries to the journal is
  82     available with the
  83     <citerefentry><refentrytitle>systemd-cat</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  84     tool. Command line access for querying entries from the journal is
  85     available with the
  86     <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  87     tool.</para>
  88   </refsect1>
  89
  90   <refsect1>
  91     <title>Thread safety</title>
  92
  93     <para>Functions that operate on the <structname>sd_journal</structname> object are thread
  94     agnostic — given <structname>sd_journal</structname> pointer may only be used from one thread at
  95     a time, but multiple threads may use multiple such objects safely. Other functions —
  96     those that are used to send entries to the journal, like
  97     <citerefentry><refentrytitle>sd_journal_print</refentrytitle><manvolnum>3</manvolnum></citerefentry>
  98     and similar, or those that are used to retrieve global information like
  99     <citerefentry><refentrytitle>sd_journal_stream_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 100     and
 101     <citerefentry><refentrytitle>sd_journal_get_catalog_for_message_id</refentrytitle><manvolnum>3</manvolnum></citerefentry>
 102     — are thread-safe and may be called from multiple threads in parallel.</para>
 103   </refsect1>
 104
 105   <xi:include href="libsystemd-pkgconfig.xml" />
 106
 107   <refsect1>
 108     <title>See Also</title>
 109     <para>
 110       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 111       <citerefentry><refentrytitle>sd_journal_print</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 112       <citerefentry><refentrytitle>sd_journal_stream_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 113       <citerefentry><refentrytitle>sd_journal_open</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 114       <citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 115       <citerefentry><refentrytitle>sd_journal_get_data</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 116       <citerefentry><refentrytitle>sd_journal_get_realtime_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 117       <citerefentry><refentrytitle>sd_journal_add_match</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 118       <citerefentry><refentrytitle>sd_journal_seek_head</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 119       <citerefentry><refentrytitle>sd_journal_enumerate_fields</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 120       <citerefentry><refentrytitle>sd_journal_get_cursor</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 121       <citerefentry><refentrytitle>sd_journal_get_cutoff_realtime_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 122       <citerefentry><refentrytitle>sd_journal_get_cutoff_monotonic_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 123       <citerefentry><refentrytitle>sd_journal_get_usage</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 124       <citerefentry><refentrytitle>sd_journal_get_fd</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 125       <citerefentry><refentrytitle>sd_journal_query_unique</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 126       <citerefentry><refentrytitle>sd_journal_get_catalog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 127       <citerefentry><refentrytitle>sd_journal_has_runtime_files</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 128       <citerefentry><refentrytitle>sd_journal_has_persistent_files</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 129       <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 130       <citerefentry><refentrytitle>sd-id128</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 131       <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 132     </para>
 133   </refsect1>
 134
 135 </refentry>