1 <?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
6 SPDX-License-Identifier: LGPL-2.1+
9 <refentry id="sd_bus_message_append_string_memfd"
10 xmlns:xi="http://www.w3.org/2001/XInclude">
13 <title>sd_bus_message_append_string_memfd</title>
14 <productname>elogind</productname>
18 <refentrytitle>sd_bus_message_append_string_memfd</refentrytitle>
19 <manvolnum>3</manvolnum>
23 <refname>sd_bus_message_append_string_memfd</refname>
24 <refname>sd_bus_message_append_string_iovec</refname>
25 <refname>sd_bus_message_append_string_space</refname>
27 <refpurpose>Attach a string to a message</refpurpose>
32 <funcsynopsisinfo>#include <elogind/sd-bus.h></funcsynopsisinfo>
35 <funcdef>int sd_bus_message_append_string_memfd</funcdef>
36 <paramdef>sd_bus_message *<parameter>m</parameter></paramdef>
37 <paramdef>int <parameter>memfd</parameter></paramdef>
41 <funcdef>int sd_bus_message_append_string_iovec</funcdef>
42 <paramdef>sd_bus_message *<parameter>m</parameter></paramdef>
43 <paramdef>const struct iovec *<parameter>iov</parameter></paramdef>
44 <paramdef>unsigned <parameter>n</parameter></paramdef>
48 <funcdef>int sd_bus_message_append_string_space</funcdef>
49 <paramdef>sd_bus_message *<parameter>m</parameter></paramdef>
50 <paramdef>size_t <parameter>size</parameter></paramdef>
51 <paramdef>char **<parameter>s</parameter></paramdef>
57 <title>Description</title>
60 <function>sd_bus_message_append_string_memfd</function> and
61 <function>sd_bus_message_append_string_iovec</function> can be
62 used to append a single string (item of type <literal>s</literal>)
63 to message <parameter>m</parameter>.</para>
66 <function>sd_bus_message_append_string_memfd</function>, the
67 contents of <parameter>memfd</parameter> are the string. They must
68 satisfy the same constraints as described for the
69 <literal>s</literal> type in
70 <citerefentry><refentrytitle>sd_bus_message_append_basic</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
73 <function>sd_bus_message_append_string_iovec</function>, the
74 payload of <parameter>iov</parameter> is the string. It must
75 satisfy the same constraints as described for the
76 <literal>s</literal> type in
77 <citerefentry><refentrytitle>sd_bus_message_append_basic</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
79 <para>The <parameter>iov</parameter> argument must point to
80 <parameter>n</parameter> <structname>struct iovec</structname>
81 structures. Each structure may have the
82 <structname>iov_base</structname> field set, in which case the
83 memory pointed to will be copied into the message, or unset, in
84 which case a block of spaces (ASCII 32) of length
85 <structname>iov_len</structname> will be inserted. The
86 memory pointed at by <parameter>iov</parameter> may be changed
87 after this call.</para>
90 <function>sd_bus_message_append_string_space</function> function appends
91 space for a string to message <parameter>m</parameter>. It behaves
92 similar to <function>sd_bus_message_append_basic</function> with
93 type <literal>s</literal>, but instead of copying a string into
94 the message, it returns a pointer to the destination area to
95 the caller in pointer <parameter>p</parameter>. Space for the string
96 of length <parameter>size</parameter> plus the terminating
97 <constant>NUL</constant> is allocated.</para>
101 <title>Return Value</title>
103 <para>On success, those calls return 0 or a positive integer. On
104 failure, they returns a negative errno-style error code.</para>
107 <xi:include href="sd_bus_message_append_basic.xml" xpointer="errors" />
109 <xi:include href="libelogind-pkgconfig.xml" />
112 <title>See Also</title>
115 <!-- 0 /// elogind is in section 8
116 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
118 <citerefentry><refentrytitle>elogind</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
120 <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
121 <citerefentry><refentrytitle>sd_bus_message_append_basic</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
122 <ulink url="http://dbus.freedesktop.org/doc/dbus-specification.html">The D-Bus specification</ulink>