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diff --git a/man/sd_bus_send.xml b/man/sd_bus_send.xml new file mode 100644 index 0000000..315ad07 --- /dev/null +++ b/man/sd_bus_send.xml @@ -0,0 +1,168 @@ +<?xml version='1.0'?> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> +<!-- SPDX-License-Identifier: LGPL-2.1-or-later --> + +<refentry id="sd_bus_send" + xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd_bus_send</title> + <productname>systemd</productname> + </refentryinfo> + + <refmeta> + <refentrytitle>sd_bus_send</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_bus_send</refname> + <refname>sd_bus_send_to</refname> + <refname>sd_bus_message_send</refname> + + <refpurpose>Queue a D-Bus message for transfer</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>int <function>sd_bus_send</function></funcdef> + <paramdef>sd_bus *<parameter>bus</parameter></paramdef> + <paramdef>sd_bus_message *<parameter>m</parameter></paramdef> + <paramdef>uint64_t *<parameter>cookie</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_bus_send_to</function></funcdef> + <paramdef>sd_bus *<parameter>bus</parameter></paramdef> + <paramdef>sd_bus_message *<parameter>m</parameter></paramdef> + <paramdef>const char *<parameter>destination</parameter></paramdef> + <paramdef>uint64_t *<parameter>cookie</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int sd_bus_message_send</funcdef> + <paramdef>sd_bus_message *<parameter>m</parameter></paramdef> + </funcprototype> + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_bus_send()</function> queues the bus message object <parameter>m</parameter> for + transfer. If <parameter>bus</parameter> is <constant>NULL</constant>, the bus that + <parameter>m</parameter> is attached to is used. <parameter>bus</parameter> only needs to be set when the + message is sent to a different bus than the one it's attached to, for example when forwarding messages. + If the output parameter <parameter>cookie</parameter> is not <constant>NULL</constant>, it is set to the + message identifier. This value can later be used to match incoming replies to their corresponding + messages. If <parameter>cookie</parameter> is set to <constant>NULL</constant> and the message is not + sealed, <function>sd_bus_send()</function> assumes the message <parameter>m</parameter> doesn't expect a + reply and adds the necessary headers to indicate this.</para> + + <para>Note that in most scenarios, <function>sd_bus_send()</function> should not be called + directly. Instead, use higher level functions such as + <citerefentry><refentrytitle>sd_bus_call_method</refentrytitle><manvolnum>3</manvolnum></citerefentry> and + <citerefentry><refentrytitle>sd_bus_reply_method_return</refentrytitle><manvolnum>3</manvolnum></citerefentry> + which call <function>sd_bus_send()</function> internally.</para> + + <para><function>sd_bus_send_to()</function> is a shorthand for sending a message to a specific + destination. It's main use case is to simplify sending unicast signal messages (signals that only have a + single receiver). It's behavior is similar to calling + <citerefentry><refentrytitle>sd_bus_message_set_destination</refentrytitle><manvolnum>3</manvolnum></citerefentry> + followed by calling <function>sd_bus_send()</function>.</para> + + <para><function>sd_bus_send()</function>/<function>sd_bus_send_to()</function> will write the message + directly to the underlying transport (e.g. kernel socket buffer) if possible. If the connection is not + set up fully yet the message is queued locally. If the transport buffers are congested any unwritten + message data is queued locally, too. If the connection has been closed or is currently being closed the + call fails. + <citerefentry><refentrytitle>sd_bus_process</refentrytitle><manvolnum>3</manvolnum></citerefentry> should + be invoked to write out any queued message data to the transport.</para> + + <para><function>sd_bus_message_send()</function> is the same as <function>sd_bus_send()</function> but + without the first and last argument. <function>sd_bus_message_send(m)</function> is equivalent to + <function>sd_bus_send(sd_bus_message_get_bus(m), m, NULL)</function>.</para> + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para>On success, these functions return a non-negative integer. On failure, they return a negative + errno-style error code.</para> + + <refsect2 id='errors'> + <title>Errors</title> + + <para>Returned errors may indicate the following problems:</para> + + <variablelist> + <varlistentry> + <term><constant>-EINVAL</constant></term> + + <listitem><para>The input parameter <parameter>m</parameter> is <constant>NULL</constant>. + </para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-EOPNOTSUPP</constant></term> + + <listitem><para>The bus connection does not support sending file descriptors. + </para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ECHILD</constant></term> + + <listitem><para>The bus connection was allocated in a parent process and is being reused in a child + process after <function>fork()</function>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ENOBUFS</constant></term> + + <listitem><para>The bus connection's write queue is full.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ENOTCONN</constant></term> + + <listitem><para>The input parameter <parameter>bus</parameter> is + <constant>NULL</constant> or the bus is not connected.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ECONNRESET</constant></term> + + <listitem><para>The bus connection was closed while waiting for the response. + </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>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_call_method</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_bus_message_set_destination</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_bus_reply_method_return</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_bus_process</refentrytitle><manvolnum>3</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |