man/udev_new.xml

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  11   Copyright 2015 David Herrmann <dh.herrmann@gmail.com>
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  26
  27 <refentry id="udev_new"
  28   xmlns:xi="http://www.w3.org/2001/XInclude">
  29
  30   <refentryinfo>
  31     <title>udev_new</title>
  32     <productname>systemd</productname>
  33
  34     <authorgroup>
  35       <author>
  36         <contrib>Developer</contrib>
  37         <firstname>David</firstname>
  38         <surname>Herrmann</surname>
  39         <email>dh.herrmann@gmail.com</email>
  40       </author>
  41     </authorgroup>
  42   </refentryinfo>
  43
  44   <refmeta>
  45     <refentrytitle>udev_new</refentrytitle>
  46     <manvolnum>3</manvolnum>
  47   </refmeta>
  48
  49   <refnamediv>
  50     <refname>udev_new</refname>
  51     <refname>udev_ref</refname>
  52     <refname>udev_unref</refname>
  53
  54     <refpurpose>Create, acquire and release a udev context object</refpurpose>
  55   </refnamediv>
  56
  57   <refsynopsisdiv>
  58     <funcsynopsis>
  59       <funcsynopsisinfo>#include &lt;libudev.h&gt;</funcsynopsisinfo>
  60
  61       <funcprototype>
  62         <funcdef>struct udev *<function>udev_new</function></funcdef>
  63         <paramdef><parameter>void</parameter></paramdef>
  64       </funcprototype>
  65
  66       <funcprototype>
  67         <funcdef>struct udev *<function>udev_ref</function></funcdef>
  68         <paramdef>struct udev *<parameter>udev</parameter></paramdef>
  69       </funcprototype>
  70
  71       <funcprototype>
  72         <funcdef>struct udev *<function>udev_unref</function></funcdef>
  73         <paramdef>struct udev *<parameter>udev</parameter></paramdef>
  74       </funcprototype>
  75
  76     </funcsynopsis>
  77   </refsynopsisdiv>
  78
  79   <refsect1>
  80     <title>Description</title>
  81
  82     <para><function>udev_new()</function> allocates a new udev context
  83     object and returns a pointer to it. This object is opaque and must
  84     not be accessed by the caller via different means than functions
  85     provided by libudev. Initially, the reference count of the context
  86     is 1. You can acquire further references, and drop gained references
  87     via <function>udev_ref()</function> and
  88     <function>udev_unref()</function>. Once the reference count hits 0,
  89     the context object is destroyed and freed.</para>
  90   </refsect1>
  91
  92   <refsect1>
  93     <title>Return Value</title>
  94
  95     <para>On success, <function>udev_new()</function> returns a pointer
  96     to the allocated udev context. On failure, <constant>NULL</constant>
  97     is returned. <function>udev_ref()</function> returns the argument
  98     that it was passed, unmodified. <function>udev_unref()</function>
  99     always returns <constant>NULL</constant>.</para>
 100   </refsect1>
 101
 102   <refsect1>
 103     <title>See Also</title>
 104
 105     <para>
 106       <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 107     </para>
 108   </refsect1>
 109
 110 </refentry>