Yu Watanabe
37db22d38b
Then, added explanations for the missing arguments. Also mentioned that the memfd is sealed by the function. (cherry picked from commit 20604d980057da1a606339fb7a660242e8d2db02)
128 lines
5.8 KiB
XML
128 lines
5.8 KiB
XML
<?xml version='1.0'?>
|
|
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
|
|
"http://www.oasis-open.org/docbook/xml/4.5/docbookx.dtd">
|
|
<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
|
|
|
|
<refentry id="sd_bus_message_append_string_memfd"
|
|
xmlns:xi="http://www.w3.org/2001/XInclude">
|
|
|
|
<refentryinfo>
|
|
<title>sd_bus_message_append_string_memfd</title>
|
|
<productname>systemd</productname>
|
|
</refentryinfo>
|
|
|
|
<refmeta>
|
|
<refentrytitle>sd_bus_message_append_string_memfd</refentrytitle>
|
|
<manvolnum>3</manvolnum>
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>sd_bus_message_append_string_memfd</refname>
|
|
<refname>sd_bus_message_append_string_iovec</refname>
|
|
<refname>sd_bus_message_append_string_space</refname>
|
|
|
|
<refpurpose>Attach a string to a message</refpurpose>
|
|
</refnamediv>
|
|
|
|
<refsynopsisdiv>
|
|
<funcsynopsis>
|
|
<funcsynopsisinfo>#include <systemd/sd-bus.h></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>
|
|
<paramdef>uint64_t <parameter>offset</parameter></paramdef>
|
|
<paramdef>uint64_t <parameter>size</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>ret</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> starting at the specified <parameter>offset</parameter> and of the specified
|
|
<parameter>size</parameter> are used as the string. <parameter>size</parameter> must include the
|
|
terminating <constant>NUL</constant> byte, i.e. the resulting string has length
|
|
<parameter>size</parameter> - 1. If <parameter>offset</parameter> is zero and <parameter>size</parameter>
|
|
is <constant>UINT64_MAX</constant>, the full contents of the memory file descriptor are used, and hence
|
|
must themselves end in a <constant>NUL</constant> byte. If <parameter>offset</parameter> plus
|
|
<parameter>size</parameter> exceeds the actual size of the memory file descriptor, this call fails with
|
|
<constant>-EMSGSIZE</constant>. The memory file descriptor is sealed by this call if it has not been
|
|
sealed yet, and cannot be modified after this call. The appended contents 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>ret</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 return a negative
|
|
errno-style error code.</para>
|
|
|
|
<xi:include href="sd_bus_message_append_basic.xml" xpointer="errors" />
|
|
</refsect1>
|
|
|
|
<xi:include href="libsystemd-notes.xml"/>
|
|
|
|
<refsect1>
|
|
<title>See Also</title>
|
|
|
|
<para><simplelist type="inline">
|
|
<member><citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry></member>
|
|
<member><citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
|
|
<member><citerefentry><refentrytitle>sd_bus_message_append_basic</refentrytitle><manvolnum>3</manvolnum></citerefentry></member>
|
|
<member><ulink url="https://dbus.freedesktop.org/doc/dbus-specification.html">The D-Bus specification</ulink></member>
|
|
</simplelist></para>
|
|
</refsect1>
|
|
|
|
</refentry>
|