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>systemd
</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
<systemd/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=
"libsystemd-pkgconfig.xml" />
112 <title>See Also
</title>
115 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
116 <citerefentry><refentrytitle>sd-bus
</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
117 <citerefentry><refentrytitle>sd_bus_message_append_basic
</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
118 <ulink url=
"http://dbus.freedesktop.org/doc/dbus-specification.html">The D-Bus specification
</ulink>