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8474b70c3a
We were inconsistent, but marking them up as constants makes more sense then as variables.
229 lines
9.9 KiB
XML
229 lines
9.9 KiB
XML
<?xml version='1.0'?> <!--*-nxml-*-->
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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
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<!--
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This file is part of systemd.
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Copyright 2013 Lennart Poettering
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU Lesser General Public License as published by
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the Free Software Foundation; either version 2.1 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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-->
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<refentry id="sd_bus_request_name" conditional="ENABLE_KDBUS">
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<refentryinfo>
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<title>sd_bus_request_name</title>
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<productname>systemd</productname>
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<authorgroup>
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<author>
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<contrib>Developer</contrib>
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<firstname>Lennart</firstname>
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<surname>Poettering</surname>
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<email>lennart@poettering.net</email>
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</author>
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</authorgroup>
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</refentryinfo>
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<refmeta>
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<refentrytitle>sd_bus_request_name</refentrytitle>
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<manvolnum>3</manvolnum>
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</refmeta>
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<refnamediv>
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<refname>sd_bus_request_name</refname>
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<refname>sd_bus_release_name</refname>
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<refpurpose>Request or release a well-known name on a bus</refpurpose>
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</refnamediv>
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<refsynopsisdiv>
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<funcsynopsis>
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<funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo>
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<funcprototype>
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<funcdef>int <function>sd_bus_request_name</function></funcdef>
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<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
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<paramdef>const char *<parameter>name</parameter></paramdef>
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<paramdef>uint64_t <parameter>flags</parameter></paramdef>
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</funcprototype>
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<funcprototype>
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<funcdef>int <function>sd_bus_release_name</function></funcdef>
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<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
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<paramdef>const char *<parameter>name</parameter></paramdef>
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</funcprototype>
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</funcsynopsis>
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</refsynopsisdiv>
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<refsect1>
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<title>Description</title>
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<para><function>sd_bus_request_name()</function> requests
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a well-known name on a bus. It takes a bus connection,
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a valid bus name and a flags parameter. The flags
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parameter is a combination of the following
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flags:</para>
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<variablelist>
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<varlistentry>
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<term><varname>SD_BUS_NAME_ALLOW_REPLACEMENT</varname></term>
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<listitem><para>After acquiring the
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name successfully, permit other peers
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to take over the name when they try to
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acquire it with the
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<varname>SD_BUS_NAME_REPLACE_EXISTING</varname>
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flag set. If
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<varname>SD_BUS_NAME_ALLOW_REPLACEMENT</varname>
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is not set on the original request,
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such a request by other peers will be
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denied.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>SD_BUS_NAME_REPLACE_EXISTING</varname></term>
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<listitem><para>Take over the name
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if it is already acquired by another
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peer, and that other peer has permitted
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takeover by setting
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<varname>SD_BUS_NAME_ALLOW_REPLACEMENT</varname>
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while acquiring it.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><varname>SD_BUS_NAME_QUEUE</varname></term>
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<listitem><para>Queue the acquisition
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of the name when the name is already
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taken.</para></listitem>
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</varlistentry>
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</variablelist>
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<para><function>sd_bus_release_name()</function> releases
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an acquired well-known name. It takes a bus connection
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and a valid bus name as parameters.</para>
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</refsect1>
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<refsect1>
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<title>Return Value</title>
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<para>On success, these calls return 0 or a positive
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integer. On failure, these calls return a negative
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errno-style error code.</para>
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<para>If <varname>SD_BUS_NAME_QUEUE</varname> is
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specified, <function>sd_bus_request_name()</function>
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will return 0 when the name is already taken by
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another peer and the client has been added to the
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queue for the name. In that case, the caller can
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subscribe to <literal>NameOwnerChanged</literal>
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signals to be notified when the name is successfully
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acquired. <function>sd_bus_request_name()</function>
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returns > 0 when the name has immediately been
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acquired successfully.</para>
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</refsect1>
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<refsect1>
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<title>Errors</title>
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<para>Returned errors may indicate the following problems:</para>
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<variablelist>
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<varlistentry>
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<term><constant>-EALREADY</constant></term>
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<listitem><para>The caller already is
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the owner of the specified
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name.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>-EEXIST</constant></term>
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<listitem><para>The name has already
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been acquired by a different peer, and
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SD_BUS_NAME_REPLACE_EXISTING was not
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specified or the other peer did not
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specify SD_BUS_NAME_ALLOW_REPLACEMENT
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while acquiring the
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name.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>-ESRCH</constant></term>
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<listitem><para>It was attempted to
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release a name that is currently not
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registered on the
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bus.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>-EADDRINUSE</constant></term>
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<listitem><para>It was attempted to
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release a name that is owned by a
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different peer on the
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bus.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>-EINVAL</constant></term>
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<listitem><para>A specified parameter
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is invalid.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>-ENOTCONN</constant></term>
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<listitem><para>The bus connection has
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been disconnected.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><constant>-ECHILD</constant></term>
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<listitem><para>The bus connection has
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been created in a different process
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than the current one.</para></listitem>
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</varlistentry>
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</variablelist>
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</refsect1>
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<refsect1>
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<title>Notes</title>
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<para>The <function>sd_bus_acquire_name()</function>
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and <function>sd_bus_release_name()</function>
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interfaces are available as a shared library, which can
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be compiled and linked to with the
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<constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
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file.</para>
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</refsect1>
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<refsect1>
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<title>See Also</title>
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<para>
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<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
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<citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
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<citerefentry><refentrytitle>sd_bus_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>
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</para>
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</refsect1>
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</refentry>
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