--- /dev/null
+<?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_open_user">
+
+ <refentryinfo>
+ <title>sd_bus_open_user</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_open_user</refentrytitle>
+ <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+ <refname>sd_bus_open_user</refname>
+ <refname>sd_bus_open_system</refname>
+ <refname>sd_bus_open_system_remote</refname>
+ <refname>sd_bus_open_system_container</refname>
+
+ <refname>sd_bus_default_user</refname>
+ <refname>sd_bus_default_system</refname>
+
+ <refpurpose>Open a connection to the system or user bus</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <funcsynopsis>
+ <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_open_user</function></funcdef>
+ <paramdef>sd_bus** <parameter>bus</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_open_system</function></funcdef>
+ <paramdef>sd_bus** <parameter>bus</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_open_system_remote</function></funcdef>
+ <paramdef>const char *<parameter>host</parameter></paramdef>
+ <paramdef>sd_bus** <parameter>bus</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_open_system_container</function></funcdef>
+ <paramdef>const char *<parameter>machine</parameter></paramdef>
+ <paramdef>sd_bus** <parameter>bus</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_default_user</function></funcdef>
+ <paramdef>sd_bus** <parameter>bus</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_default_system</function></funcdef>
+ <paramdef>sd_bus** <parameter>bus</parameter></paramdef>
+ </funcprototype>
+ </funcsynopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para><function>sd_bus_open_user()</function> creates a new bus
+ object and opens a connection to the the user bus.
+ <function>sd_bus_open_system()</function> does the same, but
+ connects to the system bus.</para>
+
+ <para>If <varname>$DBUS_SESSION_BUS_ADDRESS</varname> environment
+ variable is set
+ (c.f. <citerefentry><refentrytitle>environ</refentrytitle><manvolnum>7</manvolnum></citerefentry>),
+ it will be used as the address of the user bus. This variable can
+ contain multiple addresses separated by <literal>;</literal>. If
+ this variable is not set, a suitable default for the default user
+ D-Bus instance will be used.</para>
+
+ <para>If <varname>$DBUS_SYSTEM_BUS_ADDRESS</varname> environment
+ variable is set, it will be used as the address of the system
+ bus. This variable uses the same syntax as
+ <varname>$DBUS_SESSION_BUS_ADDRESS</varname>/. If this variable is
+ not set, a suitable default for the default system D-Bus instance
+ will be used.</para>
+
+ <para><function>sd_bus_open_system_remote()</function> connects to
+ the system bus on the specified <parameter>host</parameter> using
+ SSH. <parameter>host</parameter> consists of an optional user name
+ followed by the <literal>@</literal> symbol, and the hostname.
+ </para>
+
+ <para><function>sd_bus_open_system_remote()</function> connects to
+ the system bus in the specified <parameter>machine</parameter>,
+ where <parameter>machine</parameter> is the name of a container.
+ See
+ <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ for more information about "machines".</para>
+
+ <para><function>sd_bus_default_user()</function> returns a bus
+ object connected to the user bus. This bus object is shared
+ per-thread. It is created on the first invocation of
+ <function>sd_bus_default_user()</function>, and subsequent
+ invocations returns a reference to the same object.</para>
+
+ <para><function>sd_bus_default_system()</function> is similar to
+ <function>sd_bus_default_user()</function>, but connects to the
+ system bus.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Return Value</title>
+
+ <para>On success, these calls return 0 or a positive
+ integer. On failure, these calls return a negative
+ errno-style error code.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Reference ownership</title>
+ <para>Functions <function>sd_bus_open_user()</function>,
+ <function>sd_bus_open_system()</function>,
+ <function>sd_bus_open_system_remote()</function>, and
+ <function>sd_bus_open_system_machine()</function> return a new
+ object and the caller owns the sole reference. When not needed
+ anymore, this reference should be destroyed with
+ <citerefentry><refentrytitle>sd_bus_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
+ </para>
+
+ <para>Functions <function>sd_bus_default_user()</function> and
+ <function>sd_bus_default_system()</function> do not create a new
+ reference.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Errors</title>
+
+ <para>Returned errors may indicate the following problems:</para>
+
+ <variablelist>
+
+ <varlistentry>
+ <term><varname>-EINVAL</varname></term>
+
+ <listitem><para>Specified parameter is invalid
+ (<constant>NULL</constant> in case of output
+ parameters).</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>-ENOMEM</varname></term>
+
+ <listitem><para>Memory allocation failed.</para></listitem>
+ </varlistentry>
+
+ <para>In addition, any further connection-related errors may be
+ by returned. See <citerefentry><refentrytitle>sd_bus_send</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Notes</title>
+
+ <para><function>sd_bus_open_user()</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_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_bus_ref</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_bus_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>ssh</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd-machined.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ </para>
+ </refsect1>
+
+</refentry>
~ianmdlvl / elogind.git / blobdiff