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systemd-stable/man/sd_bus_message_read_strv.xml
Zbigniew Jędrzejewski-Szmek 63ab06c4d2 sd-bus: extend sd_bus_message_read_strv() to paths and signatures
It's rather convenient to be able to read all three types with this function.
Strictly speaking this change is not fully compatible, in case someone was
relying on sd_bus_message_read_strv() returning an error for anything except
"as", but I hope nobody was doing that.
2021-02-12 11:36:24 +01:00

100 lines
3.3 KiB
XML

<?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_strv">
<refentryinfo>
<title>sd_bus_message_read_strv</title>
<productname>systemd</productname>
</refentryinfo>
<refmeta>
<refentrytitle>sd_bus_message_read_strv</refentrytitle>
<manvolnum>3</manvolnum>
</refmeta>
<refnamediv>
<refname>sd_bus_message_read_strv</refname>
<refpurpose>Access an array of strings in a message</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
<funcprototype>
<funcdef>int <function>sd_bus_message_read_strv</function></funcdef>
<paramdef>sd_bus_message *<parameter>m</parameter></paramdef>
<paramdef>char ***<parameter>l</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><function>sd_bus_message_read_strv()</function> gives access to an array of string-like items in
message <parameter>m</parameter>. The "read pointer" in the message must be right before an array of
strings (D-Bus type <literal>as</literal>), object paths (D-Bus type <literal>ao</literal>), or
signatures (D-Bus type <literal>ag</literal>). On success, a pointer to a
<constant>NULL</constant>-terminated array of strings is returned in the output parameter
<parameter>l</parameter>. Note that ownership of this array is transferred to the caller. Hence, the
caller is responsible for freeing this array and its contents.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
<para>On success, <function>sd_bus_message_read_strv()</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><parameter>m</parameter> or <parameter>l</parameter> are <constant>NULL</constant>.
</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>
<varlistentry>
<term><constant>-ENXIO</constant></term>
<listitem><para>The message "read pointer" is not right before an array of the appropriate type.
</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>
</para>
</refsect1>
</refentry>