| <?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"> |
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| Copyright 2013 Lennart Poettering |
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| |
| <refentry id="sd_bus_request_name"> |
| |
| <refentryinfo> |
| <title>sd_bus_request_name</title> |
| <productname>systemd</productname> |
| |
| <authorgroup> |
| <author> |
| <contrib>Developer</contrib> |
| <firstname>Lennart</firstname> |
| <surname>Poettering</surname> |
| <email>lennart@poettering.net</email> |
| </author> |
| </authorgroup> |
| </refentryinfo> |
| |
| <refmeta> |
| <refentrytitle>sd_bus_request_name</refentrytitle> |
| <manvolnum>3</manvolnum> |
| </refmeta> |
| |
| <refnamediv> |
| <refname>sd_bus_request_name</refname> |
| <refname>sd_bus_release_name</refname> |
| <refpurpose>Request or release a well-known name on a bus</refpurpose> |
| </refnamediv> |
| |
| <refsynopsisdiv> |
| <funcsynopsis> |
| <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> |
| |
| <funcprototype> |
| <funcdef>int <function>sd_bus_request_name</function></funcdef> |
| <paramdef>sd_bus* <parameter>bus</parameter></paramdef> |
| <paramdef>const char *<parameter>name</parameter></paramdef> |
| <paramdef>uint64_t <parameter>flags</parameter></paramdef> |
| </funcprototype> |
| |
| <funcprototype> |
| <funcdef>int <function>sd_bus_release_name</function></funcdef> |
| <paramdef>sd_bus* <parameter>bus</parameter></paramdef> |
| <paramdef>const char *<parameter>name</parameter></paramdef> |
| </funcprototype> |
| </funcsynopsis> |
| </refsynopsisdiv> |
| |
| <refsect1> |
| <title>Description</title> |
| |
| <para><function>sd_bus_request_name()</function> requests |
| a well-known name on a bus. It takes a bus connection, |
| a valid bus name and a flags parameter. The flags |
| parameter is a combination of the following |
| flags:</para> |
| |
| <variablelist> |
| <varlistentry> |
| <term><varname>SD_BUS_NAME_ALLOW_REPLACEMENT</varname></term> |
| |
| <listitem><para>After acquiring the |
| name successfully, permit other peers |
| to take over the name when they try to |
| acquire it with the |
| <varname>SD_BUS_NAME_REPLACE_EXISTING</varname> |
| flag set. If |
| <varname>SD_BUS_NAME_ALLOW_REPLACEMENT</varname> |
| is not set on the original request, |
| such a request by other peers will be |
| denied.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>SD_BUS_NAME_REPLACE_EXISTING</varname></term> |
| |
| <listitem><para>Take over the name |
| if it is already acquired by another |
| peer, and that other peer has permitted |
| takeover by setting |
| <varname>SD_BUS_NAME_ALLOW_REPLACEMENT</varname> |
| while acquiring it.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>SD_BUS_NAME_QUEUE</varname></term> |
| |
| <listitem><para>Queue the acquisition |
| of the name when the name is already |
| taken.</para></listitem> |
| </varlistentry> |
| </variablelist> |
| |
| <para><function>sd_bus_release_name()</function> releases |
| an acquired well-known name. It takes a bus connection |
| and a valid bus name as parameters.</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> |
| |
| <para>If <varname>SD_BUS_NAME_QUEUE</varname> is |
| specified, <function>sd_bus_request_name()</function> |
| will return 0 when the name is already taken by |
| another peer and the client has been added to the |
| queue for the name. In that case, the caller can |
| subscribe to <literal>NameOwnerChanged</literal> |
| signals to be notified when the name is successfully |
| acquired. <function>sd_bus_request_name()</function> |
| returns > 0 when the name has immediately been |
| acquired successfully.</para> |
| </refsect1> |
| |
| <refsect1> |
| <title>Errors</title> |
| |
| <para>Returned errors may indicate the following problems:</para> |
| |
| <variablelist> |
| <varlistentry> |
| <term><varname>-EALREADY</varname></term> |
| |
| <listitem><para>The caller already is |
| the owner of the specified |
| name.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>-EEXIST</varname></term> |
| |
| <listitem><para>The name has already |
| been acquired by a different peer, and |
| SD_BUS_NAME_REPLACE_EXISTING was not |
| specified or the other peer did not |
| specify SD_BUS_NAME_ALLOW_REPLACEMENT |
| while acquiring the |
| name.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>-ESRCH</varname></term> |
| |
| <listitem><para>It was attempted to |
| release a name that is currently not |
| registered on the |
| bus.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>-EADDRINUSE</varname></term> |
| |
| <listitem><para>It was attempted to |
| release a name that is owned by a |
| different peer on the |
| bus.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>-EINVAL</varname></term> |
| |
| <listitem><para>A specified parameter |
| is invalid.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>-ENOTCONN</varname></term> |
| |
| <listitem><para>The bus connection has |
| been disconnected.</para></listitem> |
| </varlistentry> |
| |
| <varlistentry> |
| <term><varname>-ECHILD</varname></term> |
| |
| <listitem><para>The bus connection has |
| been created in a different process |
| than the current one.</para></listitem> |
| </varlistentry> |
| </variablelist> |
| </refsect1> |
| |
| <refsect1> |
| <title>Notes</title> |
| |
| <para>The <function>sd_bus_acquire_name()</function> |
| and <function>sd_bus_release_name()</function> |
| interfaces are available as a shared library, which can |
| be compiled and linked to with the |
| <constant>libsystemd</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> |
| </para> |
| </refsect1> |
| |
| </refentry> |