man: add libudev man-pages (skeletons)

This adds man-pages for most of the libudev symbols we export. Similar
symbols are grouped together in a single man-page, with respective links
added. All man-pages contain the full skeleton including NAME, SYNOPSIS,
RETURN VALUE and SEE ALSO. However, most of them still lack the
DESCRIPTION part. This should be copied from the gtkdoc descriptions in
src/libudev/libudev*.[ch]. Any help is welcome! (the whole skeleton is
already done, so it's really just about the prose-part of the man-pages to
be written).

Missing from the man-pages are the following parts:
  - udev_set_log_fn()
  - udev_[gs]et_log_priority()
  - udev_[gs]et_userdata()
  - udev_list_entry_foreach()
  - udev_device_get_seqnum()
  - udev_device_get_usec_since_initialized()
  - udev_util_encode_string()
These are considered legacy, afaik. If not, please feel free to add them
now!

Furthermore, udev-hwdb and udev-queue are not documented at all (for the
same reasons).

1 files changed, 110 insertions, 0 deletions

diff --git a/man/udev_new.xml b/man/udev_new.xml
new file mode 100644
index 0000000000..587835a3ca
--- /dev/null
+++ b/man/udev_new.xml
@@ -0,0 +1,110 @@
+<?xml version='1.0'?> <!--*-nxml-*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd" [
+<!ENTITY % entities SYSTEM "custom-entities.ent" >
+%entities;
+]>
+
+<!--
+  This file is part of systemd.
+
+  Copyright 2015 David Herrmann <dh.herrmann@gmail.com>
+
+  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
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  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="udev_new"
+  xmlns:xi="http://www.w3.org/2001/XInclude">
+
+  <refentryinfo>
+    <title>udev_new</title>
+    <productname>systemd</productname>
+
+    <authorgroup>
+      <author>
+        <contrib>Developer</contrib>
+        <firstname>David</firstname>
+        <surname>Herrmann</surname>
+        <email>dh.herrmann@gmail.com</email>
+      </author>
+    </authorgroup>
+  </refentryinfo>
+
+  <refmeta>
+    <refentrytitle>udev_new</refentrytitle>
+    <manvolnum>3</manvolnum>
+  </refmeta>
+
+  <refnamediv>
+    <refname>udev_new</refname>
+    <refname>udev_ref</refname>
+    <refname>udev_unref</refname>
+
+    <refpurpose>Create, acquire and release a udev context object</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <funcsynopsis>
+      <funcsynopsisinfo>#include &lt;libudev.h&gt;</funcsynopsisinfo>
+
+      <funcprototype>
+        <funcdef>struct udev *<function>udev_new</function></funcdef>
+        <paramdef><parameter>void</parameter></paramdef>
+      </funcprototype>
+
+      <funcprototype>
+        <funcdef>struct udev *<function>udev_ref</function></funcdef>
+        <paramdef>struct udev *<parameter>udev</parameter></paramdef>
+      </funcprototype>
+
+      <funcprototype>
+        <funcdef>struct udev *<function>udev_unref</function></funcdef>
+        <paramdef>struct udev *<parameter>udev</parameter></paramdef>
+      </funcprototype>
+
+    </funcsynopsis>
+  </refsynopsisdiv>
+
+  <refsect1>
+    <title>Description</title>
+
+    <para><function>udev_new()</function> allocates a new udev context
+    object and returns a pointer to it. This object is opaque and must
+    not be accessed by the caller via different means than functions
+    provided by libudev. Initially, the reference count of the context
+    is 1. You can acquire further references, and drop gained references
+    via <function>udev_ref()</function> and
+    <function>udev_unref()</function>. Once the reference count hits 0,
+    the context object is destroyed and freed.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>Return Value</title>
+
+    <para>On success, <function>udev_new()</function> returns a pointer
+    to the allocated udev context. On failure, <constant>NULL</constant>
+    is returned. <function>udev_ref()</function> returns the argument
+    that it was passed, unmodified. <function>udev_unref()</function>
+    always returns <constant>NULL</constant>.</para>
+  </refsect1>
+
+  <refsect1>
+    <title>See Also</title>
+
+    <para>
+      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+    </para>
+  </refsect1>
+
+</refentry>