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2521N/A

2521N/A<refentry id="sd_bus_message_append_string_memfd"

2521N/A xmlns:xi="http://www.w3.org/2001/XInclude">

3998N/A

2521N/A <refentryinfo>

3998N/A <title>sd_bus_message_append_string_memfd</title>

2521N/A <productname>systemd</productname>

4194N/A

3817N/A <authorgroup>

2521N/A <author>

2521N/A <contrib>A monkey with a typewriter</contrib>

2521N/A <firstname>Zbigniew</firstname>

2521N/A <surname>Jędrzejewski-Szmek</surname>

2521N/A <email>zbyszek@in.waw.pl</email>

2521N/A </author>

2521N/A </authorgroup>

2521N/A </refentryinfo>

2521N/A

2521N/A <refmeta>

2521N/A <refentrytitle>sd_bus_message_append_string_memfd</refentrytitle>

2521N/A <manvolnum>3</manvolnum>

2521N/A </refmeta>

2521N/A

2521N/A <refnamediv>

2521N/A <refname>sd_bus_message_append_string_memfd</refname>

2521N/A <refname>sd_bus_message_append_string_iovec</refname>

2521N/A <refname>sd_bus_message_append_string_space</refname>

2521N/A

2521N/A <refpurpose>Attach a string to a message</refpurpose>

2521N/A </refnamediv>

<refsynopsisdiv>

<funcsynopsis>

<funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>

<funcprototype>

<funcdef>int sd_bus_message_append_string_memfd</funcdef>

<paramdef>sd_bus_message *<parameter>m</parameter></paramdef>

<paramdef>int <parameter>memfd</parameter></paramdef>

</funcprototype>

<funcprototype>

<funcdef>int sd_bus_message_append_string_iovec</funcdef>

<paramdef>sd_bus_message *<parameter>m</parameter></paramdef>

<paramdef>const struct iovec *<parameter>iov</parameter></paramdef>

<paramdef>unsigned <parameter>n</parameter></paramdef>

</funcprototype>

<funcprototype>

<funcdef>int sd_bus_message_append_string_space</funcdef>

<paramdef>sd_bus_message *<parameter>m</parameter></paramdef>

<paramdef>size_t <parameter>size</parameter></paramdef>

<paramdef>char **<parameter>s</parameter></paramdef>

</funcprototype>

</funcsynopsis>

</refsynopsisdiv>

<refsect1>

<title>Description</title>

<para>The functions

<function>sd_bus_message_append_string_memfd</function> and

<function>sd_bus_message_append_string_iovec</function> can be

used to append a single string (item of type <literal>s</literal>)

to message <parameter>m</parameter>.</para>

<para>In case of

<function>sd_bus_message_append_string_memfd</function>, the

contents of <parameter>memfd</parameter> are the string. They must

satisfy the same constraints as described for the

<literal>s</literal> type in

<citerefentry><refentrytitle>sd_bus_message_append_basic</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>

<para>In case of

<function>sd_bus_message_append_string_iovec</function>, the

payload of <parameter>iov</parameter> is the string. It must

satisfy the same constraints as described for the

<literal>s</literal> type in

<citerefentry><refentrytitle>sd_bus_message_append_basic</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>

<para>The <parameter>iov</parameter> argument must point to

<parameter>n</parameter> <structname>struct iovec</structname>

structures. Each structure may have the

<structname>iov_base</structname> field set, in which case the

memory pointed to will be copied into the message, or unset, in

which case a block of spaces (ASCII 32) of length

<structname>iov_len</structname> will be inserted. The

memory pointed at by <parameter>iov</parameter> may be changed

after this call.</para>

<para>The

<function>sd_bus_message_append_string_space</function> function appends

space for a string to message <parameter>m</parameter>. It behaves

similar to <function>sd_bus_message_append_basic</function> with

type <literal>s</literal>, but instead of copying a string into

the message, it returns a pointer to the destination area to

the caller in pointer <parameter>p</parameter>. Space for the string

of length <parameter>size</parameter> plus the terminating

<constant>NUL</constant> is allocated.</para>

</refsect1>

<refsect1>

<title>Return Value</title>

<para>On success, those calls return 0 or a positive integer. On

failure, they returns a negative errno-style error code.</para>

</refsect1>

<xi:include href="sd_bus_message_append_basic.xml" xpointer="errors" />

<refsect1>

<title>Notes</title>

<para>The functions described here are available as a shared library,

which can be compiled and linked to with the

<constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>

file.</para>

</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_append_basic</refentrytitle><manvolnum>3</manvolnum></citerefentry>,

<ulink url="http://dbus.freedesktop.org/doc/dbus-specification.html">The D-Bus specification</ulink>

</para>

</refsect1>

</refentry>