<?xml version='1.0'?> <!--*-nxml-*--> <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> <!-- This file is part of systemd. Copyright 2014 Zbigniew Jędrzejewski-Szmek systemd is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. --> <refentry id="sd_bus_new"> <refentryinfo> <title>sd_bus_new</title> <productname>systemd</productname> <authorgroup> <author> <contrib>A monkey with a typewriter</contrib> <firstname>Zbigniew</firstname> <surname>Jędrzejewski-Szmek</surname> <email>zbyszek@in.waw.pl</email> </author> </authorgroup> </refentryinfo> <refmeta> <refentrytitle>sd_bus_new</refentrytitle> <manvolnum>3</manvolnum> </refmeta> <refnamediv> <refname>sd_bus_new</refname> <refname>sd_bus_ref</refname> <refname>sd_bus_unref</refname> <refpurpose>Create a new bus object and create or destroy references to it</refpurpose> </refnamediv> <refsynopsisdiv> <funcsynopsis> <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> <funcprototype> <funcdef>int <function>sd_bus_new</function></funcdef> <paramdef>sd_bus** <parameter>bus</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>sd_bus* <function>sd_bus_ref</function></funcdef> <paramdef>sd_bus* <parameter>bus</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>sd_bus* <function>sd_bus_unref</function></funcdef> <paramdef>sd_bus* <parameter>bus</parameter></paramdef> </funcprototype> </funcsynopsis> </refsynopsisdiv> <refsect1> <title>Description</title> <para><function>sd_bus_new()</function> creates a new bus object. This object is reference counted, and will be destroyed when all references are gone. Initially, the caller of this function owns the sole reference.</para> <para><function>sd_bus_ref()</function> creates a new reference to <parameter>bus</parameter>. This bus object will not be destroyed until <function>sd_bus_unref()</function> has been called as many times plus once more. Once the reference count has dropped to zero, <parameter>bus</parameter> cannot be used anymore, so further calls to <function>sd_bus_ref()</function> or <function>sd_bus_unref()</function> are illegal.</para> <para><function>sd_bus_unref()</function> destroys a reference to <parameter>bus</parameter>.</para> </refsect1> <refsect1> <title>Return Value</title> <para>On success, <function>sd_bus_new()</function> returns 0 or a positive integer. On failure, it returns a negative errno-style error code.</para> <para><function>sd_bus_ref</function> always returns the argument. </para> <para><function>sd_bus_unref</function> always returns <constant>NULL</constant>.</para> </refsect1> <refsect1> <title>Errors</title> <para>Returned errors may indicate the following problems:</para> <variablelist> <varlistentry> <term><varname>-ENOMEM</varname></term> <listitem><para>Memory allocation failed.</para></listitem> </varlistentry> </variablelist> </refsect1> <refsect1> <title>Notes</title> <para><function>sd_bus_new()</function> and other functions described here are available as a shared library, which can be compiled and linked to with the <constant>libsystemd-bus</constant> <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> file.</para> </refsect1> <refsect1> <title>See Also</title> <para> <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_bus_open_user</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_bus_open_system</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_bus_default_user</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_bus_default_system</refentrytitle><manvolnum>3</manvolnum></citerefentry> </para> </refsect1> </refentry>