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diff --git a/man/sd_bus_message_read_array.xml b/man/sd_bus_message_read_array.xml new file mode 100644 index 0000000..daff909 --- /dev/null +++ b/man/sd_bus_message_read_array.xml @@ -0,0 +1,116 @@ +<?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_message_read_array"> + + <refentryinfo> + <title>sd_bus_message_read_array</title> + <productname>systemd</productname> + </refentryinfo> + + <refmeta> + <refentrytitle>sd_bus_message_read_array</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_bus_message_read_array</refname> + + <refpurpose>Access an array of elements in a message</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>int <function>sd_bus_message_read_array</function></funcdef> + <paramdef>sd_bus_message *<parameter>m</parameter></paramdef> + <paramdef>char <parameter>type</parameter></paramdef> + <paramdef>const void **<parameter>ptr</parameter></paramdef> + <paramdef>size_t *<parameter>size</parameter></paramdef> + </funcprototype> + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_bus_message_read_array()</function> provides access to an array elements in the + bus message <parameter>m</parameter>. The "read pointer" in the message must be right before an array of type + <parameter>type</parameter>. As a special case, <parameter>type</parameter> may be + <constant>NUL</constant>, in which case any trivial type is acceptable. A pointer to the array data is returned + in the parameter <parameter>ptr</parameter> and the size of array data (in bytes) is returned in the + parameter <parameter>size</parameter>. If the returned <parameter>size</parameter> parameter is 0, a + valid non-null pointer will be returned as <parameter>ptr</parameter>, but it may not be + dereferenced. The data is aligned as appropriate for the data type. The data is part of the message — it + may not be modified and is valid only as long as the message is referenced. After this function returns, + the "read pointer" points at the next element after the array.</para> + + <para>Note that this function only supports arrays of trivial types, i.e. arrays of booleans, the various + integer types, as well as floating point numbers. In particular it may not be used for arrays of strings, + structures or similar.</para> + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para> + On success and when an array was read, <function>sd_bus_message_read_array()</function> returns an + integer greater than zero. If invoked while inside a container element (such as an array, e.g. when + operating on an array of arrays) and the final element of the outer container has been read already and + the read pointer is thus behind the last element of the outer container this call returns 0 (and the + returned pointer will be <constant>NULL</constant> and the size will be 0). 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>Specified type is invalid or not a trivial type (see above), or the message + parameter or one of the output parameters are <constant>NULL</constant>.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-EOPNOTSUPP</constant></term> + + <listitem><para>The byte order in the message is different than native byte + order.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-EPERM</constant></term> + + <listitem><para>The message is not sealed.</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-EBADMSG</constant></term> + + <listitem><para>The message cannot be parsed.</para></listitem> + </varlistentry> + + </variablelist> + </refsect2> + </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_read</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_bus_message_read_strv</refentrytitle><manvolnum>3</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |