man: add sd_bus_message_new_signal(3)

diff --git a/man/rules/meson.build b/man/rules/meson.build
index 305876f72b810eb3a8362642e9d1d936c041adb8..df7ea47470a1f21a3b1824ef35659666321f1b63 100644 (file)
--- a/man/rules/meson.build
+++ b/man/rules/meson.build
@@ -216,6 +216,7 @@ manpages = [
    'sd_bus_message_new_method_errnof',
    'sd_bus_message_new_method_errorf'],
   ''],
+ ['sd_bus_message_new_signal', '3', [], ''],
  ['sd_bus_message_read', '3', ['sd_bus_message_readv'], ''],
  ['sd_bus_message_read_basic', '3', [], ''],
  ['sd_bus_message_set_destination', '3', ['sd_bus_message_set_sender'], ''],

diff --git a/man/sd-bus.xml b/man/sd-bus.xml
index 8c7b60743c92f8691d97f9811cf6ae79ed994e5e..6210f40dc244493e91da7e09b2b815ef1321c973 100644 (file)
--- a/man/sd-bus.xml
+++ b/man/sd-bus.xml
@@ -61,6 +61,7 @@
 <citerefentry><refentrytitle>sd_bus_message_get_cookie</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 <citerefentry><refentrytitle>sd_bus_message_get_monotonic_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 <citerefentry><refentrytitle>sd_bus_message_new_method_error</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+<citerefentry><refentrytitle>sd_bus_message_new_signal</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 <citerefentry><refentrytitle>sd_bus_message_read_basic</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 <citerefentry><refentrytitle>sd_bus_message_read</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 <citerefentry><refentrytitle>sd_bus_message_set_destination</refentrytitle><manvolnum>3</manvolnum></citerefentry>,

diff --git a/man/sd_bus_message_new_signal.xml b/man/sd_bus_message_new_signal.xml
new file mode 100644 (file)
index 0000000..1c7629c
--- /dev/null
+++ b/man/sd_bus_message_new_signal.xml
@@ -0,0 +1,116 @@
+<?xml version='1.0'?>
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+<!-- SPDX-License-Identifier: LGPL-2.1+ -->
+
+<refentry id="sd_bus_message_new_signal"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
+
+  <refentryinfo>
+    <title>sd_bus_message_new_signal</title>
+    <productname>systemd</productname>
+  </refentryinfo>
+
+  <refmeta>
+    <refentrytitle>sd_bus_message_new_signal</refentrytitle>
+    <manvolnum>3</manvolnum>
+  </refmeta>
+
+  <refnamediv>
+    <refname>sd_bus_message_new_signal</refname>
+
+    <refpurpose>Create a signal message</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <funcsynopsis>
+      <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
+
+      <funcprototype>
+        <funcdef>int sd_bus_message_new_signal</funcdef>
+        <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
+        <paramdef>sd_bus_message **<parameter>m</parameter></paramdef>
+        <paramdef>const char *<parameter>path</parameter></paramdef>
+        <paramdef>const char *<parameter>interface</parameter></paramdef>
+        <paramdef>const char *<parameter>member</parameter></paramdef>
+      </funcprototype>
+    </funcsynopsis>
+  </refsynopsisdiv>
+
+  <refsect1>
+    <title>Description</title>
+
+    <para>The <function>sd_bus_message_new_signal()</function> function creates a new bus message
+    object that encapsulates a D-Bus signal, and returns it in the <parameter>m</parameter> output
+    parameter. The signal will be sent to path <parameter>path</parameter>, on the interface
+    <parameter>interface</parameter>, member <parameter>member</parameter>. When this message is
+    sent, no reply is expected.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>Return Value</title>
+
+    <para>This function returns 0 if the message object was successfully created, and a negative
+    errno-style error code otherwise.</para>
+  </refsect1>
+
+  <refsect1 id='errors'>
+    <title>Errors</title>
+
+    <para>Returned errors may indicate the following problems:</para>
+
+    <variablelist>
+      <varlistentry>
+        <term><constant>-EINVAL</constant></term>
+
+        <listitem><para>The output parameter <parameter>m</parameter> is
+        <constant>NULL</constant>.</para>
+
+        <para>The <parameter>path</parameter> parameter is not a valid D-Bus path
+        (<literal>/an/object/path</literal>), the <parameter>interface</parameter> parameter is not
+        a valid D-Bus interface name (<literal>an.interface.name</literal>), or the
+        <parameter>member</parameter> parameter is not a valid D-Bus member
+        (<literal>Name</literal>).</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><constant>-ENOTCONN</constant></term>
+
+        <listitem><para>The bus parameter <parameter>bus</parameter> is <constant>NULL</constant> or
+        the bus is not connected.</para></listitem>
+      </varlistentry>
+
+      <varlistentry>
+        <term><constant>-ENOMEM</constant></term>
+
+        <listitem><para>Memory allocation failed.</para></listitem>
+      </varlistentry>
+    </variablelist>
+  </refsect1>
+
+  <xi:include href="libsystemd-pkgconfig.xml" />
+
+  <refsect1>
+    <title>Examples</title>
+
+    <example>
+      <title>Send a simple signal</title>
+
+      <programlisting><xi:include href="send-unit-files-changed.c" parse="text" /></programlisting>
+
+      <para>This function in systemd sources is used to emit the
+      <literal>UnitFilesChanged</literal> signal when the unit files have been changed.
+      </para>
+    </example>
+  </refsect1>
+
+  <refsect1>
+    <title>See Also</title>
+
+    <para>
+      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+    </para>
+  </refsect1>
+
+</refentry>

diff --git a/man/send-unit-files-changed.c b/man/send-unit-files-changed.c
new file mode 100644 (file)
index 0000000..aecfbcb
--- /dev/null
+++ b/man/send-unit-files-changed.c
@@ -0,0 +1,16 @@
+#include <systemd/sd-bus.h>
+#define _cleanup_(f) __attribute__((cleanup(f)))
+
+int send_unit_files_changed(sd_bus *bus) {
+  _cleanup_(sd_bus_message_unrefp) sd_bus_message *message = NULL;
+  int r;
+
+  r = sd_bus_message_new_signal(bus, &message,
+                                "/org/freedesktop/systemd1",
+                                "org.freedesktop.systemd1.Manager",
+                                "UnitFilesChanged");
+  if (r < 0)
+    return r;
+
+  return sd_bus_send(bus, message, NULL);
+}