1<?xml version='1.0'?>
2<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" >
4<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
5
6<refentry id="org.freedesktop.LogControl1"
7    xmlns:xi="http://www.w3.org/2001/XInclude">
8  <refentryinfo>
9    <title>org.freedesktop.LogControl1</title>
10    <productname>systemd</productname>
11  </refentryinfo>
12
13  <refmeta>
14    <refentrytitle>org.freedesktop.LogControl1</refentrytitle>
15    <manvolnum>5</manvolnum>
16  </refmeta>
17
18  <refnamediv>
19    <refname>org.freedesktop.LogControl1</refname>
20    <refpurpose>D-Bus interface to query and set logging configuration</refpurpose>
21  </refnamediv>
22
23  <refsect1>
24    <title>Introduction</title>
25
26    <para><interfacename>org.freedesktop.LogControl1</interfacename> is a generic interface that is intended
27    to be used by any daemon which allows the log level and target to be set over D-Bus. It is implemented by
28    various daemons that are part of the
29    <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry> suite.</para>
30
31    <para>It is assumed that those settings are global for the whole program, so a fixed object path is
32    used. The interface should always be available under the path
33    <filename>/org/freedesktop/LogControl1</filename>.</para>
34  </refsect1>
35
36  <refsect1>
37    <title>Description</title>
38
39    <para>The following interface is exposed:</para>
40
41    <programlisting executable="systemd" node="/org/freedesktop/LogControl1" interface="org.freedesktop.LogControl1">
42node /org/freedesktop/LogControl1 {
43  interface org.freedesktop.LogControl1 {
44    properties:
45      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
46      @org.freedesktop.systemd1.Privileged("true")
47      readwrite s LogLevel = '...';
48      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
49      @org.freedesktop.systemd1.Privileged("true")
50      readwrite s LogTarget = '...';
51      @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
52      readonly s SyslogIdentifier = '...';
53  };
54  interface org.freedesktop.DBus.Peer { ... };
55  interface org.freedesktop.DBus.Introspectable { ... };
56  interface org.freedesktop.DBus.Properties { ... };
57};
58    </programlisting>
59
60    <!--Autogenerated cross-references for systemd.directives, do not edit-->
61
62    <variablelist class="dbus-interface" generated="True" extra-ref="org.freedesktop.LogControl1"/>
63
64    <variablelist class="dbus-interface" generated="True" extra-ref="org.freedesktop.LogControl1"/>
65
66    <variablelist class="dbus-property" generated="True" extra-ref="LogLevel"/>
67
68    <variablelist class="dbus-property" generated="True" extra-ref="LogTarget"/>
69
70    <variablelist class="dbus-property" generated="True" extra-ref="SyslogIdentifier"/>
71
72    <!--End of Autogenerated section-->
73
74    <refsect2>
75      <title>Properties</title>
76
77      <para><varname>LogLevel</varname> describes the
78      <citerefentry project="man-pages"><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>-style
79      log-level, and should be one of <literal>emerg</literal>, <literal>alert</literal>,
80      <literal>crit</literal>, <literal>err</literal>, <literal>warning</literal>, <literal>notice</literal>,
81      <literal>info</literal>, <literal>debug</literal>, in order of increasing verbosity.</para>
82
83      <para><varname>LogTarget</varname> describes the log target (mechanism). It should be one of
84      <literal>console</literal> (log to the console or standard output),
85      <literal>kmsg</literal> (log to the kernel ring buffer),
86      <literal>journal</literal> (log to the journal natively, see
87      <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>),
88      <literal>syslog</literal> (log using the
89      <citerefentry project="man-pages"><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry> call).
90      </para>
91
92      <para>Those two properties are writable, so they may be set by sufficiently privileged users.</para>
93
94      <para><varname>SyslogIdentifier</varname> is a read-only property that shows the "syslog identifier".
95      It is a short string that identifies the program that is the source of log messages that is passed to
96      the <citerefentry project="man-pages"><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry> call.
97      </para>
98    </refsect2>
99  </refsect1>
100
101  <refsect1>
102    <title>Tools</title>
103
104    <para><command>journalctl</command> option <option>-p</option>/<option>--priority=</option> may be used
105    to filter log messages by log level, option <option>-t</option>/<option>--identifier=</option> may be
106    used to by the syslog identifier, and filters like <literal>_TRANSPORT=syslog</literal>,
107    <literal>_TRANSPORT=journal</literal>, and <literal>_TRANSPORT=kernel</literal> may be used to filter
108    messages by the mechanism through which they reached <command>systemd-journald</command>.</para>
109
110    <para><command>systemctl log-level</command> and <command>systemctl log-target</command> verbs may be
111    used to query and set the <varname>LogLevel</varname> and <varname>LogTarget</varname> properties of the
112    service manager. <command>systemctl service-log-level</command> and <command>systemctl
113    service-log-target</command> may similarly be used for individual services. (Services must have the
114    <varname>BusName=</varname> property set and must implement the interface described here. See
115    <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>
116    for details about <varname>BusName=</varname>.)</para>
117  </refsect1>
118
119  <refsect1>
120    <title>See Also</title>
121    <para>
122      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
123      <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
124      <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
125      <citerefentry><refentrytitle>systemd.service</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
126      <citerefentry project="man-pages"><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>
127    </para>
128  </refsect1>
129</refentry>
130