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[elogind.git] / man / sd_bus_new.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 <!--
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8 Copyright 2014 Zbigniew Jędrzejewski-Szmek
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10 systemd is free software; you can redistribute it and/or modify it
11 under the terms of the GNU Lesser General Public License as published by
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23
24 <refentry id="sd_bus_new" conditional="ENABLE_KDBUS">
25
26   <refentryinfo>
27     <title>sd_bus_new</title>
28     <productname>systemd</productname>
29
30     <authorgroup>
31       <author>
32         <contrib>A monkey with a typewriter</contrib>
33         <firstname>Zbigniew</firstname>
34         <surname>Jędrzejewski-Szmek</surname>
35         <email>zbyszek@in.waw.pl</email>
36       </author>
37     </authorgroup>
38   </refentryinfo>
39
40   <refmeta>
41     <refentrytitle>sd_bus_new</refentrytitle>
42     <manvolnum>3</manvolnum>
43   </refmeta>
44
45   <refnamediv>
46     <refname>sd_bus_new</refname>
47     <refname>sd_bus_ref</refname>
48     <refname>sd_bus_unref</refname>
49
50     <refpurpose>Create a new bus object and create or destroy references to it</refpurpose>
51   </refnamediv>
52
53   <refsynopsisdiv>
54     <funcsynopsis>
55       <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
56
57       <funcprototype>
58         <funcdef>int <function>sd_bus_new</function></funcdef>
59         <paramdef>sd_bus **<parameter>bus</parameter></paramdef>
60       </funcprototype>
61
62       <funcprototype>
63         <funcdef>sd_bus *<function>sd_bus_ref</function></funcdef>
64         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
65       </funcprototype>
66
67       <funcprototype>
68         <funcdef>sd_bus *<function>sd_bus_unref</function></funcdef>
69         <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
70       </funcprototype>
71     </funcsynopsis>
72   </refsynopsisdiv>
73
74   <refsect1>
75     <title>Description</title>
76
77     <para><function>sd_bus_new()</function> creates a new bus
78     object. This object is reference-counted, and will be destroyed
79     when all references are gone. Initially, the caller of this
80     function owns the sole reference.</para>
81
82     <para><function>sd_bus_ref()</function> creates a new reference to
83     <parameter>bus</parameter>. This bus object will not be destroyed
84     until <function>sd_bus_unref()</function> has been called as many
85     times plus once more. Once the reference count has dropped to
86     zero, <parameter>bus</parameter> cannot be used anymore, so
87     further calls to <function>sd_bus_ref()</function> or
88     <function>sd_bus_unref()</function> are illegal.</para>
89
90     <para><function>sd_bus_unref()</function> destroys a reference to
91     <parameter>bus</parameter>.</para>
92   </refsect1>
93
94   <refsect1>
95     <title>Return Value</title>
96
97     <para>On success, <function>sd_bus_new()</function> returns 0 or a
98     positive integer. On failure, it returns a negative errno-style
99     error code.</para>
100
101     <para><function>sd_bus_ref</function> always returns the argument.
102     </para>
103
104     <para><function>sd_bus_unref</function> always returns
105     <constant>NULL</constant>.</para>
106   </refsect1>
107
108   <refsect1>
109     <title>Errors</title>
110
111     <para>Returned errors may indicate the following problems:</para>
112
113     <variablelist>
114       <varlistentry>
115         <term><varname>-ENOMEM</varname></term>
116
117         <listitem><para>Memory allocation failed.</para></listitem>
118       </varlistentry>
119     </variablelist>
120   </refsect1>
121
122   <refsect1>
123     <title>Notes</title>
124
125     <para><function>sd_bus_new()</function> and other functions
126     described here are available as a shared library, which can be
127     compiled and linked to with the
128     <constant>libsystemd</constant> <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
129     file.</para>
130   </refsect1>
131
132   <refsect1>
133     <title>See Also</title>
134
135     <para>
136       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
137       <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
138       <citerefentry><refentrytitle>sd_bus_open_user</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
139       <citerefentry><refentrytitle>sd_bus_open_system</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
140       <citerefentry><refentrytitle>sd_bus_default_user</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
141       <citerefentry><refentrytitle>sd_bus_default_system</refentrytitle><manvolnum>3</manvolnum></citerefentry>
142     </para>
143   </refsect1>
144
145 </refentry>