mirror of
https://github.com/systemd/systemd.git
synced 2024-11-23 18:23:32 +08:00
144 lines
6.2 KiB
XML
144 lines
6.2 KiB
XML
<?xml version='1.0'?> <!--*-nxml-*-->
|
|
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
|
|
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
|
|
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
|
|
|
|
<refentry id="sd_bus_add_node_enumerator"
|
|
xmlns:xi="http://www.w3.org/2001/XInclude">
|
|
|
|
<refentryinfo>
|
|
<title>sd_bus_add_node_enumerator</title>
|
|
<productname>systemd</productname>
|
|
</refentryinfo>
|
|
|
|
<refmeta>
|
|
<refentrytitle>sd_bus_add_node_enumerator</refentrytitle>
|
|
<manvolnum>3</manvolnum>
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>sd_bus_add_node_enumerator</refname>
|
|
|
|
<refpurpose>Add a node enumerator for a D-Bus object path prefix</refpurpose>
|
|
</refnamediv>
|
|
|
|
<refsynopsisdiv>
|
|
<funcsynopsis>
|
|
<funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo>
|
|
|
|
<funcprototype>
|
|
<funcdef>typedef int (*<function>sd_bus_node_enumerator_t</function>)</funcdef>
|
|
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
|
|
<paramdef>const char *<parameter>prefix</parameter></paramdef>
|
|
<paramdef>void *<parameter>userdata</parameter></paramdef>
|
|
<paramdef>char ***<parameter>ret_nodes</parameter></paramdef>
|
|
<paramdef>sd_bus_error *<parameter>ret_error</parameter></paramdef>
|
|
</funcprototype>
|
|
|
|
<funcprototype>
|
|
<funcdef>int <function>sd_bus_add_node_enumerator</function></funcdef>
|
|
<paramdef>sd_bus *<parameter>bus</parameter></paramdef>
|
|
<paramdef>sd_bus_slot **<parameter>slot</parameter></paramdef>
|
|
<paramdef>const char *<parameter>path</parameter></paramdef>
|
|
<paramdef>sd_bus_node_enumerator_t <parameter>callback</parameter></paramdef>
|
|
<paramdef>void *<parameter>userdata</parameter></paramdef>
|
|
</funcprototype>
|
|
</funcsynopsis>
|
|
</refsynopsisdiv>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<para><function>sd_bus_add_node_enumerator()</function> adds a D-Bus node enumerator for the
|
|
given path prefix. The given callback is called to enumerate all the available objects with
|
|
the given path prefix when required (e.g. when
|
|
<constant>org.freedesktop.DBus.Introspectable.Introspect</constant> or
|
|
<constant>org.freedesktop.DBus.ObjectManager.GetManagedObjects</constant> are called on a
|
|
D-Bus service managed by sd-bus).</para>
|
|
|
|
<para><parameter>callback</parameter> is called with the path and userdata pointer registered
|
|
with <function>sd_bus_add_node_enumerator()</function>. When called, it should store all the
|
|
child object paths of the given path prefix in <parameter>ret_nodes</parameter> with a NULL
|
|
terminator item. The callback should return a non-negative value on success.
|
|
If an error occurs, it can either return a
|
|
negative integer, set <parameter>ret_error</parameter> to a non-empty error or do both. Any
|
|
errors returned by the callback are encoded as D-Bus errors and sent back to the caller. Errors
|
|
in <parameter>ret_error</parameter> take priority over negative return values.</para>
|
|
|
|
<para>Note that a node enumerator callback will only ever be called for a single path prefix
|
|
and hence, for normal operation, <parameter>prefix</parameter> can be ignored. Also, a node
|
|
enumerator is only used to enumerate the available child objects under a given prefix. To
|
|
install a handler for a set of dynamic child objects, use
|
|
<citerefentry><refentrytitle>sd_bus_add_fallback_vtable</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
|
|
</para>
|
|
|
|
<para>When <function>sd_bus_add_node_enumerator()</function> succeeds, a slot is created
|
|
internally. If the output parameter <replaceable>slot</replaceable> is <constant>NULL</constant>,
|
|
a "floating" slot object is created, see
|
|
<citerefentry><refentrytitle>sd_bus_slot_set_floating</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
|
|
Otherwise, a pointer to the slot object is returned. In that case, the reference to the slot
|
|
object should be dropped when the node enumerator is not needed anymore, see
|
|
<citerefentry><refentrytitle>sd_bus_slot_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
|
|
</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Return Value</title>
|
|
|
|
<para>On success, <function>sd_bus_add_node_enumerator()</function> returns a non-negative
|
|
integer. On failure, it returns a negative errno-style error code.</para>
|
|
|
|
<refsect2>
|
|
<title>Errors</title>
|
|
|
|
<para>Returned errors may indicate the following problems:</para>
|
|
|
|
<variablelist>
|
|
<varlistentry>
|
|
<term><constant>-EINVAL</constant></term>
|
|
|
|
<listitem><para>One of the required parameters is <constant>NULL</constant> or
|
|
<parameter>path</parameter> is not a valid object path.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><constant>-ENOPKG</constant></term>
|
|
|
|
<listitem><para>The bus cannot be resolved.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><constant>-ECHILD</constant></term>
|
|
|
|
<listitem><para>The bus was created in a different process, library or module instance.</para></listitem>
|
|
</varlistentry>
|
|
|
|
<varlistentry>
|
|
<term><constant>-ENOMEM</constant></term>
|
|
|
|
<listitem><para>Memory allocation failed.</para></listitem>
|
|
</varlistentry>
|
|
</variablelist>
|
|
</refsect2>
|
|
</refsect1>
|
|
|
|
<xi:include href="libsystemd-pkgconfig.xml" />
|
|
|
|
<refsect1>
|
|
<title>History</title>
|
|
<para><function>sd_bus_node_enumerator_t()</function> and
|
|
<function>sd_bus_add_node_enumerator()</function> were added in version 221.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>See Also</title>
|
|
|
|
<para><simplelist type="inline">
|
|
<member><citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
|
|
<member><citerefentry><refentrytitle>busctl</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
|
|
<member><citerefentry><refentrytitle>sd_bus_add_fallback_vtable</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
|
|
<member><citerefentry><refentrytitle>sd_bus_slot_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
|
|
</simplelist></para>
|
|
</refsect1>
|
|
</refentry>
|