+++ /dev/null
-<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
-<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
-"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
-
-<!--
- This file is part of systemd.
-
- Copyright 2014 Zbigniew Jędrzejewski-Szmek
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
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- Lesser General Public License for more details.
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- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
--->
-
-<refentry id="sd_bus_message_append" conditional="ENABLE_KDBUS"
- xmlns:xi="http://www.w3.org/2001/XInclude">
-
- <refentryinfo>
- <title>sd_bus_message_append</title>
- <productname>systemd</productname>
-
- <authorgroup>
- <author>
- <contrib>A monkey with a typewriter</contrib>
- <firstname>Zbigniew</firstname>
- <surname>Jędrzejewski-Szmek</surname>
- <email>zbyszek@in.waw.pl</email>
- </author>
- </authorgroup>
- </refentryinfo>
-
- <refmeta>
- <refentrytitle>sd_bus_message_append</refentrytitle>
- <manvolnum>3</manvolnum>
- </refmeta>
-
- <refnamediv>
- <refname>sd_bus_message_append</refname>
-
- <refpurpose>Attach parts of message based on a format string</refpurpose>
- </refnamediv>
-
- <refsynopsisdiv>
- <funcsynopsis>
- <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo>
-
- <funcprototype>
- <funcdef>int sd_bus_message_append</funcdef>
- <paramdef>sd_bus_message *<parameter>m</parameter></paramdef>
- <paramdef>const char *<parameter>types</parameter></paramdef>
- <paramdef>...</paramdef>
- </funcprototype>
- </funcsynopsis>
- </refsynopsisdiv>
-
- <refsect1>
- <title>Description</title>
-
- <para>The <function>sd_bus_message_append</function> function appends
- a sequence of items to message <parameter>m</parameter>. The
- format string <parameter>types</parameter> describes the types of
- arguments that follow.</para>
-
- <para>The format string is composed of the elements shown in the
- table below. It contains zero or more single "complete types".
- Each complete type may be one of the basic types or a fully
- described container type. A container type may be a structure, a
- variant type code, an array with its element type, or a dictionary
- with its entry type. The format string is
- <constant>NUL</constant>-terminated.</para>
-
- <para>In case of a basic type, one argument of the corresponding
- type is expected.</para>
-
- <para>A structure is denoted by a sequence of complete types
- between <literal>(</literal> and <literal>)</literal>. This
- sequence cannot be empty — it must contain at least one type.
- Arguments corresponding to this nested sequence follow the same
- rules as if they were not nested.</para>
-
- <para>A variant is denoted by <literal>v</literal>. Correspoding
- arguments must include a format string denoting a complete type,
- and following that, arguments corresponding to the specified type.
- </para>
-
- <para>An array is denoted by <literal>a</literal> followed by a
- complete type. Corresponding arguments must include the size of
- the array, and then repeated this number of times, arguments
- corresponding to the nested type.</para>
-
- <para>A dictionary is an array of dictionary entries, denoted by
- <literal>a</literal> followed by a pair of complete types between
- <literal>{</literal> and <literal>}</literal>. The first of those
- types must be a basic type. Corresponding arguments must include
- the size of the dictionary, and then repeated this number of
- times, arguments corresponding to each of the two nested
- types.</para>
-
- <table>
- <title>Item format specifiers</title>
-
- <tgroup cols='4'>
- <xi:include href="sd_bus_message_append_basic.xml" xpointer="xpointer(//table[@id='format-specifiers'])//colspec" />
- <xi:include href="sd_bus_message_append_basic.xml" xpointer="xpointer(//table[@id='format-specifiers']//thead)" />
-
- <tbody>
- <xi:include href="sd_bus_message_append_basic.xml" xpointer="xpointer(//table[@id='format-specifiers']//tbody/*)" />
-
- <row>
- <entry><literal>a</literal></entry>
- <entry><constant>SD_BUS_TYPE_ARRAY</constant></entry>
- <entry>array</entry>
- <entry>determined by array type and size</entry>
- </row>
-
- <row>
- <entry><literal>v</literal></entry>
- <entry><constant>SD_BUS_TYPE_VARIANT</constant></entry>
- <entry>variant</entry>
- <entry>determined by the type argument</entry>
- </row>
-
- <row>
- <entry><literal>(</literal></entry>
- <entry><constant>SD_BUS_TYPE_STRUCT_BEGIN</constant></entry>
- <entry>array start</entry>
- <entry morerows="1">determined by the nested types</entry>
- </row>
- <row>
- <entry><literal>)</literal></entry>
- <entry><constant>SD_BUS_TYPE_STRUCT_END</constant></entry>
- <entry>array end</entry>
- </row>
-
- <row>
- <entry><literal>{</literal></entry>
- <entry><constant>SD_BUS_TYPE_DICT_ENTRY_BEGIN</constant></entry>
- <entry>dictionary entry start</entry>
- <entry morerows="1">determined by the nested types</entry>
- </row>
- <row>
- <entry><literal>}</literal></entry>
- <entry><constant>SD_BUS_TYPE_DICT_ENTRY_END</constant></entry>
- <entry>dictionary entry end</entry>
- </row>
- </tbody>
- </tgroup>
- </table>
- </refsect1>
-
- <refsect1>
- <title>Types string grammar</title>
-
- <programlisting>types ::= complete_type*
-complete_type ::= basic_type | variant | structure | array | dictionary
-basic_type ::= "y" | "n" | "q" | "u" | "i" | "x" | "t" | "d" |
- "b" | "h" |
- "s" | "o" | "g"
-variant ::= "v"
-structure ::= "(" complete_type+ ")"
-array ::= "a" complete_type
-dictionary ::= "a" "{" basic_type complete_type "}"
-</programlisting>
- </refsect1>
-
- <refsect1>
- <title>Examples</title>
-
- <para>Append a single basic type (the string <literal>a string</literal>):
- </para>
-
- <programlisting>sd_bus_message *m;
-...
-sd_bus_message_append(m, "s", "a string");</programlisting>
-
- <para>Append all types of integers:</para>
-
- <programlisting>uint8_t y = 1;
-int16_t n = 2;
-uint16_t q = 3;
-int32_t i = 4;
-uint32_t u = 5;
-int32_t x = 6;
-uint32_t t = 7;
-double d = 8.0;
-sd_bus_message_append(m, "ynqiuxtd", y, n, q, i, u, x, t, d);</programlisting>
-
- <para>Append a structure composed of string and a D-Bus path:</para>
-
- <programlisting>sd_bus_message_append(m, "(so)", "a string", "/a/path");
-</programlisting>
-
- <para>Append an array of UNIX file descriptors:</para>
-
- <programlisting>sd_bus_message_append(m, "ah", 3, STDIN_FILENO, STDOUT_FILENO, STDERR_FILENO);
-</programlisting>
-
- <para>Append a variant, with the real type "g" (signature),
- and value "sdbusisgood":</para>
-
- <programlisting>sd_bus_message_append(m, "v", "g", "sdbusisgood");</programlisting>
-
- <para>Append a dictionary containing the mapping {1=>"a", 2=>"b", 3=>""}:
- </para>
-
- <programlisting>sd_bus_message_append(m, "a{is}", 3, 1, "a", 2, "b", 3, NULL);
- </programlisting>
- </refsect1>
-
- <refsect1>
- <title>Return Value</title>
-
- <para>On success, this call returns 0 or a positive
- integer. On failure, this call 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><function>sd_bus_open_user()</function> and other functions
- described here are available as a shared library, which can be
- compiled and linked to with the
- <constant>libsystemd-bus</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_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>sd_bus_ref</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>sd_bus_unref</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
- <citerefentry project='die-net'><refentrytitle>ssh</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>systemd-machined.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>machinectl</refentrytitle><manvolnum>1</manvolnum></citerefentry>
- </para>
- </refsect1>
-
-</refentry>
~ianmdlvl / elogind.git / blobdiff