2 <!DOCTYPE refentry PUBLIC
"-//OASIS//DTD DocBook XML V4.5//EN"
3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
4 <!-- SPDX-License-Identifier: LGPL-2.1+ -->
6 <refentry id=
"sd_bus_message_append_string_memfd"
7 xmlns:
xi=
"http://www.w3.org/2001/XInclude">
10 <title>sd_bus_message_append_string_memfd
</title>
11 <productname>systemd
</productname>
15 <refentrytitle>sd_bus_message_append_string_memfd
</refentrytitle>
16 <manvolnum>3</manvolnum>
20 <refname>sd_bus_message_append_string_memfd
</refname>
21 <refname>sd_bus_message_append_string_iovec
</refname>
22 <refname>sd_bus_message_append_string_space
</refname>
24 <refpurpose>Attach a string to a message
</refpurpose>
29 <funcsynopsisinfo>#include
<systemd/sd-bus.h
></funcsynopsisinfo>
32 <funcdef>int sd_bus_message_append_string_memfd
</funcdef>
33 <paramdef>sd_bus_message *
<parameter>m
</parameter></paramdef>
34 <paramdef>int
<parameter>memfd
</parameter></paramdef>
38 <funcdef>int sd_bus_message_append_string_iovec
</funcdef>
39 <paramdef>sd_bus_message *
<parameter>m
</parameter></paramdef>
40 <paramdef>const struct iovec *
<parameter>iov
</parameter></paramdef>
41 <paramdef>unsigned
<parameter>n
</parameter></paramdef>
45 <funcdef>int sd_bus_message_append_string_space
</funcdef>
46 <paramdef>sd_bus_message *
<parameter>m
</parameter></paramdef>
47 <paramdef>size_t
<parameter>size
</parameter></paramdef>
48 <paramdef>char **
<parameter>s
</parameter></paramdef>
54 <title>Description
</title>
57 <function>sd_bus_message_append_string_memfd
</function> and
58 <function>sd_bus_message_append_string_iovec
</function> can be
59 used to append a single string (item of type
<literal>s
</literal>)
60 to message
<parameter>m
</parameter>.
</para>
63 <function>sd_bus_message_append_string_memfd
</function>, the
64 contents of
<parameter>memfd
</parameter> are the string. They must
65 satisfy the same constraints as described for the
66 <literal>s
</literal> type in
67 <citerefentry><refentrytitle>sd_bus_message_append_basic
</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
</para>
70 <function>sd_bus_message_append_string_iovec
</function>, the
71 payload of
<parameter>iov
</parameter> is the string. It must
72 satisfy the same constraints as described for the
73 <literal>s
</literal> type in
74 <citerefentry><refentrytitle>sd_bus_message_append_basic
</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
</para>
76 <para>The
<parameter>iov
</parameter> argument must point to
77 <parameter>n
</parameter> <structname>struct iovec
</structname>
78 structures. Each structure may have the
79 <structname>iov_base
</structname> field set, in which case the
80 memory pointed to will be copied into the message, or unset, in
81 which case a block of spaces (ASCII
32) of length
82 <structname>iov_len
</structname> will be inserted. The
83 memory pointed at by
<parameter>iov
</parameter> may be changed
84 after this call.
</para>
87 <function>sd_bus_message_append_string_space
</function> function appends
88 space for a string to message
<parameter>m
</parameter>. It behaves
89 similar to
<function>sd_bus_message_append_basic
</function> with
90 type
<literal>s
</literal>, but instead of copying a string into
91 the message, it returns a pointer to the destination area to
92 the caller in pointer
<parameter>p
</parameter>. Space for the string
93 of length
<parameter>size
</parameter> plus the terminating
94 <constant>NUL
</constant> is allocated.
</para>
98 <title>Return Value
</title>
100 <para>On success, those calls return
0 or a positive integer. On failure, they return a negative
101 errno-style error code.
</para>
103 <xi:include href=
"sd_bus_message_append_basic.xml" xpointer=
"errors" />
106 <xi:include href=
"libsystemd-pkgconfig.xml" />
109 <title>See Also
</title>
112 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
113 <citerefentry><refentrytitle>sd-bus
</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
114 <citerefentry><refentrytitle>sd_bus_message_append_basic
</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
115 <ulink url=
"http://dbus.freedesktop.org/doc/dbus-specification.html">The D-Bus specification
</ulink>