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, 125 insertions, 0 deletions

diff --git a/man/libudev.xml b/man/libudev.xml
new file mode 100644
index 000000000..5660b9d99
--- /dev/null
+++ b/man/libudev.xml
@@ -0,0 +1,125 @@
+<?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="libudev"
+  xmlns:xi="http://www.w3.org/2001/XInclude">
+
+  <refentryinfo>
+    <title>libudev</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>libudev</refentrytitle>
+    <manvolnum>3</manvolnum>
+  </refmeta>
+
+  <refnamediv>
+    <refname>libudev</refname>
+    <refpurpose>API for enumerating and introspecting local devices</refpurpose>
+  </refnamediv>
+
+  <refsynopsisdiv>
+    <funcsynopsis>
+      <funcsynopsisinfo>#include &lt;libudev.h&gt;</funcsynopsisinfo>
+    </funcsynopsis>
+
+    <cmdsynopsis>
+      <command>pkg-config --cflags --libs libudev</command>
+    </cmdsynopsis>
+  </refsynopsisdiv>
+
+  <refsect1>
+    <title>Description</title>
+
+    <para><filename>libudev.h</filename> provides APIs to introspect
+    and enumerate devices on the local system.</para>
+
+    <para>All functions require a libudev context to operate. This
+    context can be create via
+    <citerefentry><refentrytitle>udev_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
+    It is used to track library state and link objects together. No
+    global state is used by libudev, everything is always linked to
+    a udev context. Furthermore, multiple different udev contexts can
+    be used in parallel by multiple threads. However, a single context
+    must not be accessed by multiple threads in parallel. The caller
+    is responsible of providing suitable locking if they intend to use
+    it from multiple threads.</para>
+
+    <para>To introspect a local device on a system, a udev device
+    object can be created via
+    <citerefentry><refentrytitle>udev_device_new_from_syspath</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+    and friends. The device object allows to query current state,
+    read and write attributes and lookup properties of the device in
+    question.</para>
+
+    <para>To enumerate local devices on the system, an enumeration
+    object can be created via
+    <citerefentry><refentrytitle>udev_enumerate_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
+
+    <para>To monitor the local system for hotplugged or unplugged
+    devices, a monitor can be created via
+    <citerefentry><refentrytitle>udev_monitor_new_from_netlink</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
+
+    <para>Whenever libudev returns a list of objects, the
+    <citerefentry><refentrytitle>udev_list_entry</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+    API should be used to iterate, access and modify those lists.</para>
+
+    <para>Furthermore, libudev also exports legacy APIs that should
+    not be used by new software (and as such are not documented as
+    part of this manual). This includes the hardware-database known
+    as <constant>udev_hwdb</constant> (please use the new
+    <citerefentry><refentrytitle>sd-hwdb</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+    API instead) and the <constant>udev_queue</constant> object to
+    query the udev-daemon (which should not be used by new software
+    at all).</para>
+  </refsect1>
+
+  <refsect1>
+    <title>See Also</title>
+    <para>
+      <citerefentry><refentrytitle>udev_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>udev_device_new_from_syspath</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>udev_enumerate_new</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>udev_monitor_new_from_netlink</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>udev_list_entry</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>sd-device</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry><refentrytitle>sd-hwdb</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+      <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+    </para>
+  </refsect1>
+
+</refentry>