<?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">

<refentry id="sd_bus_message_append_array" conditional="ENABLE_KDBUS"

xmlns:xi="http://www.w3.org/2001/XInclude">

<refentryinfo>

<title>sd_bus_message_append_array</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_message_append_array</refentrytitle>

<manvolnum>3</manvolnum>

</refmeta>

<refnamediv>

<refname>sd_bus_message_append_array</refname>

<refname>sd_bus_message_append_array_memfd</refname>

<refname>sd_bus_message_append_array_iovec</refname>

<refname>sd_bus_message_append_array_space</refname>

<refpurpose>Attach an array of items to a message</refpurpose>

</refnamediv>

<refsynopsisdiv>

<funcsynopsis>

<funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>

<funcprototype>

<funcdef>int sd_bus_message_append_array</funcdef>

<paramdef>sd_bus_message *<parameter>m</parameter></paramdef>

<paramdef>char <parameter>type</parameter></paramdef>

<paramdef>char void *<parameter>ptr</parameter></paramdef>

<paramdef>size_t <parameter>size</parameter></paramdef>

</funcprototype>

<funcprototype>

<funcdef>int sd_bus_message_append_array_memfd</funcdef>

<paramdef>sd_bus_message *<parameter>m</parameter></paramdef>

<paramdef>char <parameter>type</parameter></paramdef>

<paramdef>sd_memfd *<parameter>memfd</parameter></paramdef>

</funcprototype>

<funcprototype>

<funcdef>int sd_bus_message_append_array_iovec</funcdef>

<paramdef>sd_bus_message *<parameter>m</parameter></paramdef>

<paramdef>char <parameter>type</parameter></paramdef>

<paramdef>const struct iovec *<parameter>iov</parameter></paramdef>

<paramdef>unsigned <parameter>n</parameter></paramdef>

</funcprototype>

<funcprototype>

<funcdef>int sd_bus_message_append_array_space</funcdef>

<paramdef>char <parameter>type</parameter></paramdef>

<paramdef>size_t <parameter>size</parameter></paramdef>

<paramdef>char void **<parameter>ptr</parameter></paramdef>

</funcprototype>

</funcsynopsis>

</refsynopsisdiv>

<refsect1>

<title>Description</title>

<para>The <function>sd_bus_message_append_array</function> functionc

appends items to message <parameter>m</parameter> as the single

array. A container will be opened, items appended, and the

container closed. Parameter <parameter>type</parameter> determines

how pointer <parameter>p</parameter> is interpreted.

<parameter>type</parameter> must be one of the "trivial" types

<literal>y</literal>, <literal>n</literal>, <literal>q</literal>,

<literal>i</literal>, <literal>u</literal>, <literal>x</literal>,

<literal>t</literal>, <literal>d</literal> (but not

<literal>b</literal>), as defined by the

<ulink url="http://dbus.freedesktop.org/doc/dbus-specification.html#basic-types">Basic Types</ulink>

section of the D-Bus specification, and listed in

<citerefentry><refentrytitle>sd_bus_message_append_basic</refentrytitle><manvolnum>3</manvolnum></citerefentry>.

Pointer <parameter>p</parameter> must point to an array of of size

<parameter>size</parameter> bytes containing items of the

respective type. Size <parameter>size</parameter> must be a

multiple of the size of the type <parameter>type</parameter>. As a

special case, <parameter>p</parameter> may be

<constant>NULL</constant>, if <parameter>size</parameter> is 0.

</para>

<para>The memory pointed at by <parameter>p</parameter> is copied

into the memory area containing the message and may be changed

after this call.</para>

<para>The

<function>sd_bus_message_append_array_memfd</function> function appends

items to message <parameter>m</parameter>, similarly to

<function>sd_bus_message_append_array</function>. Contents of the

memory file descriptor <parameter>memfd</parameter> are used as

the contents of the array. Their size must be a multiple of the

size of the type <parameter>type</parameter>.</para>

<para>The descriptor specified with <parameter>memfd</parameter>

will be sealed and cannot be modified after this call.</para>

<para>The

<function>sd_bus_message_append_array_iovec</function> function appends

items to message <parameter>m</parameter>, similarly to

<function>sd_bus_message_append_array</function>. Contents of the

iovec <parameter>iov</parameter> are used as the contents of the

array. The total size of <parameter>iov</parameter> payload (the

sum of <structfield>iov_len</structfield> fields) must be a multiple

of the size of the type <parameter>type</parameter>.</para>

<para>The <parameter>iov</parameter> argument must point to

<parameter>n</parameter> <structname>struct iovec</structname>

structures. Each structure may have the

<structname>iov_base</structname> field set, in which case the

memory pointed to will be copied into the message, or unset, in

which case a block of zeros of length

<structname>iov_len</structname> bytes will be inserted. The

memory pointed at by <parameter>iov</parameter> may be changed

after this call.</para>

<para>The

<function>sd_bus_message_append_array_space</function> function appends

space for an array of items to message <parameter>m</parameter>.

It behaves the same as

<function>sd_bus_message_append_array</function>, but instead

of copying items to the message, it returns a pointer to the

destination area to the caller in pointer <parameter>p</parameter>.

</para>

</refsect1>

<refsect1>

<title>Return Value</title>

<para>On success, these calls return 0 or a positive integer. On

failure, they returns a negative errno-style error code.</para>

</refsect1>

<xi:include href="sd_bus_message_append_basic.xml" xpointer="errors" />

<refsect1>

<title>Notes</title>

<para><function>sd_bus_append_array()</function> and other

functions described here are available as a shared library, which

can be compiled and linked to with the

<constant>libsystemd</constant> <citerefentry project='die-net'><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_message_append</refentrytitle><manvolnum>3</manvolnum></citerefentry>,

<citerefentry><refentrytitle>sd_bus_message_append_basic</refentrytitle><manvolnum>3</manvolnum></citerefentry>,

<ulink url="http://dbus.freedesktop.org/doc/dbus-specification.html">The D-Bus specification</ulink>

</para>

</refsect1>

</refentry>