Adding upstream version 252.22.upstream/252.22upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 237 insertions, 0 deletions

diff --git a/man/sd_bus_message_read_basic.xml b/man/sd_bus_message_read_basic.xml
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+<?xml version='1.0'?>
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
+  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+
+<!--
+  SPDX-License-Identifier: LGPL-2.1-or-later
+
+  Copyright © 2016 Julian Orth
+-->
+
+<refentry id="sd_bus_message_read_basic">
+
+  <refentryinfo>
+    <title>sd_bus_message_read_basic</title>
+    <productname>systemd</productname>
+  </refentryinfo>
+
+  <refmeta>
+    <refentrytitle>sd_bus_message_read_basic</refentrytitle>
+    <manvolnum>3</manvolnum>
+  </refmeta>
+
+  <refnamediv>
+    <refname>sd_bus_message_read_basic</refname>
+
+    <refpurpose>Read a basic type from a message</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <funcsynopsis>
+      <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
+
+      <funcprototype>
+        <funcdef>int <function>sd_bus_message_read_basic</function></funcdef>
+        <paramdef>sd_bus_message *<parameter>m</parameter></paramdef>
+        <paramdef>char <parameter>type</parameter></paramdef>
+        <paramdef>void *<parameter>p</parameter></paramdef>
+      </funcprototype>
+    </funcsynopsis>
+  </refsynopsisdiv>
+
+  <refsect1>
+    <title>Description</title>
+
+    <para>
+      <function>sd_bus_message_read_basic()</function> reads a basic type from a
+      message and advances the read position in the message. The set of basic
+      types and their ascii codes passed in <parameter>type</parameter> are
+      described in the <ulink
+        url="https://dbus.freedesktop.org/doc/dbus-specification.html">D-Bus
+        Specification</ulink>.
+    </para>
+
+    <para>
+      If <parameter>p</parameter> is not <constant>NULL</constant>, it should contain a pointer to an
+      appropriate object. For example, if <parameter>type</parameter> is <constant>'y'</constant>, the object
+      passed in <parameter>p</parameter> should have type <type>uint8_t *</type>. If
+      <parameter>type</parameter> is <constant>'s'</constant>, the object passed in <parameter>p</parameter>
+      should have type <type>const char **</type>. Note that, if the basic type is a pointer (e.g.,
+      <type>const char *</type> in the case of a string), the pointer is only borrowed and the contents must
+      be copied if they are to be used after the end of the message's lifetime. Similarly, during the
+      lifetime of such a pointer, the message must not be modified. If <parameter>type</parameter> is
+      <constant>'h'</constant> (UNIX file descriptor), the descriptor is not duplicated by this call and the
+      returned descriptor remains in possession of the message object, and needs to be duplicated by the
+      caller in order to keep an open reference to it after the message object is freed (for example by
+      calling <literal>fcntl(fd, FD_DUPFD_CLOEXEC, 3)</literal>). See the table below for a complete list of
+      allowed types.
+    </para>
+
+    <table id='format-specifiers'>
+      <title>Item type specifiers</title>
+
+      <tgroup cols='4'>
+        <colspec colname='specifier' />
+        <colspec colname='constant' />
+        <colspec colname='description' />
+        <colspec colname='ctype' />
+        <thead>
+          <row>
+            <entry>Specifier</entry>
+            <entry>Constant</entry>
+            <entry>Description</entry>
+            <entry>Expected C Type</entry>
+          </row>
+        </thead>
+        <tbody>
+          <row>
+            <entry><literal>y</literal></entry>
+            <entry><constant>SD_BUS_TYPE_BYTE</constant></entry>
+            <entry>8bit unsigned integer</entry>
+            <entry><type>uint8_t *</type></entry>
+          </row>
+
+          <row>
+            <entry><literal>b</literal></entry>
+            <entry><constant>SD_BUS_TYPE_BOOLEAN</constant></entry>
+            <entry>boolean</entry>
+            <entry><type>int *</type> (NB: not <type>bool *</type>)</entry>
+          </row>
+
+          <row>
+            <entry><literal>n</literal></entry>
+            <entry><constant>SD_BUS_TYPE_INT16</constant></entry>
+            <entry>16bit signed integer</entry>
+            <entry><type>int16_t *</type></entry>
+          </row>
+
+          <row>
+            <entry><literal>q</literal></entry>
+            <entry><constant>SD_BUS_TYPE_UINT16</constant></entry>
+            <entry>16bit unsigned integer</entry>
+            <entry><type>uint16_t *</type></entry>
+          </row>
+
+          <row>
+            <entry><literal>i</literal></entry>
+            <entry><constant>SD_BUS_TYPE_INT32</constant></entry>
+            <entry>32bit signed integer</entry>
+            <entry><type>int32_t *</type></entry>
+          </row>
+
+          <row>
+            <entry><literal>u</literal></entry>
+            <entry><constant>SD_BUS_TYPE_UINT32</constant></entry>
+            <entry>32bit unsigned integer</entry>
+            <entry><type>uint32_t *</type></entry>
+          </row>
+
+          <row>
+            <entry><literal>x</literal></entry>
+            <entry><constant>SD_BUS_TYPE_INT64</constant></entry>
+            <entry>64bit signed integer</entry>
+            <entry><type>int64_t *</type></entry>
+          </row>
+
+          <row>
+            <entry><literal>t</literal></entry>
+            <entry><constant>SD_BUS_TYPE_UINT64</constant></entry>
+            <entry>64bit unsigned integer</entry>
+            <entry><type>uint64_t *</type></entry>
+          </row>
+
+          <row>
+            <entry><literal>d</literal></entry>
+            <entry><constant>SD_BUS_TYPE_DOUBLE</constant></entry>
+            <entry>IEEE 754 double precision floating-point</entry>
+            <entry><type>double *</type></entry>
+          </row>
+
+          <row>
+            <entry><literal>s</literal></entry>
+            <entry><constant>SD_BUS_TYPE_STRING</constant></entry>
+            <entry>UTF-8 string</entry>
+            <entry><type>const char **</type></entry>
+          </row>
+
+          <row>
+            <entry><literal>o</literal></entry>
+            <entry><constant>SD_BUS_TYPE_OBJECT_PATH</constant></entry>
+            <entry>D-Bus object path string</entry>
+            <entry><type>const char **</type></entry>
+          </row>
+
+          <row>
+            <entry><literal>g</literal></entry>
+            <entry><constant>SD_BUS_TYPE_SIGNATURE</constant></entry>
+            <entry>D-Bus signature string</entry>
+            <entry><type>const char **</type></entry>
+          </row>
+
+          <row>
+            <entry><literal>h</literal></entry>
+            <entry><constant>SD_BUS_TYPE_UNIX_FD</constant></entry>
+            <entry>UNIX file descriptor</entry>
+            <entry><type>int *</type></entry>
+          </row>
+       </tbody>
+      </tgroup>
+    </table>
+
+    <para>
+      If there is no object of the specified type at the current position in the
+      message, an error is returned.
+    </para>
+  </refsect1>
+
+  <refsect1>
+    <title>Return Value</title>
+
+    <para>
+      On success, <function>sd_bus_message_read_basic()</function> returns a positive integer.
+      If the end of the currently opened array has been reached, it returns 0.
+      On failure, it returns a negative errno-style error code.
+    </para>
+
+    <refsect2 id='errors'>
+      <title>Errors</title>
+
+      <para>Returned errors may indicate the following problems:</para>
+
+      <variablelist>
+        <varlistentry id="errors-einval">
+          <term><constant>-EINVAL</constant></term>
+
+          <listitem><para>Specified type string is invalid or the message parameter is
+          <constant>NULL</constant>.</para></listitem>
+        </varlistentry>
+
+        <varlistentry id="errors-enxio">
+          <term><constant>-ENXIO</constant></term>
+
+          <listitem><para>The message does not contain the specified type at current position.
+          </para></listitem>
+        </varlistentry>
+
+        <varlistentry id="errors-ebadmsg">
+          <term><constant>-EBADMSG</constant></term>
+
+          <listitem><para>The message cannot be parsed.</para></listitem>
+        </varlistentry>
+      </variablelist>
+    </refsect2>
+  </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>,
+      <citerefentry><refentrytitle>sd_bus_message_skip</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>sd_bus_message_read</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+    </para>
+  </refsect1>
+
+</refentry>