]>
Commit | Line | Data |
---|---|---|
7f9f55e1 | 1 | <?xml version='1.0'?> |
3a54a157 | 2 | <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" |
7f9f55e1 ZJS |
3 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> |
4 | <!-- SPDX-License-Identifier: LGPL-2.1+ --> | |
5 | ||
6 | <refentry id="sd_bus_message_read_array"> | |
7 | ||
8 | <refentryinfo> | |
9 | <title>sd_bus_message_read_array</title> | |
10 | <productname>systemd</productname> | |
11 | </refentryinfo> | |
12 | ||
13 | <refmeta> | |
14 | <refentrytitle>sd_bus_message_read_array</refentrytitle> | |
15 | <manvolnum>3</manvolnum> | |
16 | </refmeta> | |
17 | ||
18 | <refnamediv> | |
19 | <refname>sd_bus_message_read_array</refname> | |
20 | ||
21 | <refpurpose>Access an array of elements in a message</refpurpose> | |
22 | </refnamediv> | |
23 | ||
24 | <refsynopsisdiv> | |
25 | <funcsynopsis> | |
26 | <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> | |
27 | ||
28 | <funcprototype> | |
29 | <funcdef>int <function>sd_bus_message_read_array</function></funcdef> | |
30 | <paramdef>sd_bus_message *<parameter>m</parameter></paramdef> | |
31 | <paramdef>char <parameter>type</parameter></paramdef> | |
32 | <paramdef>const void **<parameter>ptr</parameter></paramdef> | |
33 | <paramdef>size_t *<parameter>size</parameter></paramdef> | |
34 | </funcprototype> | |
35 | </funcsynopsis> | |
36 | </refsynopsisdiv> | |
37 | ||
38 | <refsect1> | |
39 | <title>Description</title> | |
40 | ||
41 | <para><function>sd_bus_message_read_array()</function> gives access to an element array in | |
42 | message <parameter>m</parameter>. The "read pointer" in the message must be right before an | |
43 | array of type <parameter>type</parameter>. As a special case, <parameter>type</parameter> may be | |
44 | <constant>NUL</constant>, in which case any type is acceptable. A pointer to the array data is | |
45 | returned in the parameter <parameter>ptr</parameter> and the size of array data (in bytes) is | |
46 | returned in the parameter <parameter>size</parameter>. If <parameter>size</parameter> is 0, a | |
47 | valid non-null pointer will be returned, but it may not be dereferenced. The data is aligned as | |
48 | appropriate for the data type. The data is part of the message — it may not be modified and is | |
49 | valid only as long as the message is referenced. After this function returns, the "read pointer" | |
50 | points at the next element after the array.</para> | |
51 | </refsect1> | |
52 | ||
53 | <refsect1> | |
54 | <title>Return Value</title> | |
55 | ||
56 | <para> | |
57 | On success, <function>sd_bus_message_read_array()</function> returns 0 or | |
58 | a positive integer. On failure, it returns a negative errno-style error | |
59 | code. | |
60 | </para> | |
61 | </refsect1> | |
62 | ||
63 | <refsect1 id='errors'> | |
64 | <title>Errors</title> | |
65 | ||
66 | <para>Returned errors may indicate the following problems:</para> | |
67 | ||
68 | <variablelist> | |
69 | <varlistentry> | |
70 | <term><constant>-EINVAL</constant></term> | |
71 | ||
72 | <listitem><para>Specified type is invalid or the message parameter or one of the output | |
73 | parameters are <constant>NULL</constant>.</para></listitem> | |
74 | </varlistentry> | |
75 | ||
76 | <varlistentry> | |
77 | <term><constant>-EOPNOTSUPP</constant></term> | |
78 | ||
79 | <listitem><para>The byte order in the message is different than native byte | |
80 | order.</para></listitem> | |
81 | </varlistentry> | |
82 | ||
83 | <varlistentry> | |
84 | <term><constant>-EPERM</constant></term> | |
85 | ||
86 | <listitem><para>The message is not sealed.</para></listitem> | |
87 | </varlistentry> | |
88 | ||
89 | <varlistentry> | |
90 | <term><constant>-EBADMSG</constant></term> | |
91 | ||
92 | <listitem><para>The message cannot be parsed.</para></listitem> | |
93 | </varlistentry> | |
94 | ||
95 | </variablelist> | |
96 | </refsect1> | |
97 | ||
98 | <refsect1> | |
99 | <title>See Also</title> | |
100 | ||
101 | <para> | |
102 | <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
103 | <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>, | |
104 | <citerefentry><refentrytitle>sd_bus_message_read</refentrytitle><manvolnum>3</manvolnum></citerefentry> | |
105 | </para> | |
106 | </refsect1> | |
107 | ||
108 | </refentry> |