src/udevd.xml

   1 <?xml version='1.0'?>
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   3 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
   4   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   5
   6 <refentry id="udevd">
   7   <refentryinfo>
   8     <title>udevd</title>
   9     <productname>udev</productname>
  10   </refentryinfo>
  11
  12   <refmeta>
  13     <refentrytitle>udevd</refentrytitle>
  14     <manvolnum>8</manvolnum>
  15     <refmiscinfo class="version"></refmiscinfo>
  16   </refmeta>
  17
  18   <refnamediv>
  19     <refname>udevd</refname><refpurpose>event managing daemon</refpurpose>
  20   </refnamediv>
  21
  22   <refsynopsisdiv>
  23     <cmdsynopsis>
  24       <command>udevd</command>
  25       <arg><option>--daemon</option></arg>
  26       <arg><option>--debug</option></arg>
  27       <arg><option>--children-max=</option></arg>
  28       <arg><option>--exec-delay=</option></arg>
  29       <arg><option>--resolve-names=early|late|never</option></arg>
  30       <arg><option>--version</option></arg>
  31       <arg><option>--help</option></arg>
  32     </cmdsynopsis>
  33   </refsynopsisdiv>
  34
  35   <refsect1><title>Description</title>
  36     <para>udevd listens to kernel uevents. For every event, udevd executes matching
  37     instructions specified in udev rules. See <citerefentry>
  38         <refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum>
  39       </citerefentry>.</para>
  40     <para>On startup the content of the directory <filename>/usr/lib/udev/devices</filename>
  41     is copied to <filename>/dev</filename>. If kernel modules specify static device
  42     nodes, these nodes are created even without a corresponding kernel device, to
  43     allow on-demand loading of kernel modules. Matching permissions specified in udev
  44     rules are applied to these static device nodes.</para>
  45     <para>The behavior of the running daemon can be changed with
  46     <command>udevadm control</command>.</para>
  47   </refsect1>
  48
  49   <refsect1><title>Options</title>
  50     <variablelist>
  51       <varlistentry>
  52         <term><option>--daemon</option></term>
  53         <listitem>
  54           <para>Detach and run in the background.</para>
  55         </listitem>
  56       </varlistentry>
  57       <varlistentry>
  58         <term><option>--debug</option></term>
  59         <listitem>
  60           <para>Print debug messages to stderr.</para>
  61         </listitem>
  62       </varlistentry>
  63       <varlistentry>
  64         <term><option>--children-max=</option></term>
  65         <listitem>
  66           <para>Limit the number of parallel executed events.</para>
  67         </listitem>
  68       </varlistentry>
  69       <varlistentry>
  70         <term><option>--exec-delay=</option></term>
  71         <listitem>
  72           <para>Number of seconds to delay the execution of RUN instructions.
  73           This might be useful when debugging system crashes during coldplug
  74           cause by loading non-working kernel modules.</para>
  75         </listitem>
  76       </varlistentry>
  77       <varlistentry>
  78         <term><option>--resolve-names=</option></term>
  79         <listitem>
  80           <para>Specify when udevd should resolve names of users and groups.
  81           When set to <option>early</option> (the default) names will be
  82           resolved when the rules are parsed.  When set to
  83           <option>late</option> names will be resolved for every event.
  84           When set to <option>never</option> names will never be resolved
  85           and all devices will be owned by root.</para>
  86         </listitem>
  87       </varlistentry>
  88       <varlistentry>
  89         <term><option>--version</option></term>
  90         <listitem>
  91           <para>Print version number.</para>
  92         </listitem>
  93       </varlistentry>
  94       <varlistentry>
  95         <term><option>--help</option></term>
  96         <listitem>
  97           <para>Print help text.</para>
  98         </listitem>
  99       </varlistentry>
 100     </variablelist>
 101   </refsect1>
 102
 103   <refsect1><title>Environment</title>
 104     <variablelist>
 105       <varlistentry>
 106         <term><varname>UDEV_LOG=</varname></term>
 107         <listitem>
 108           <para>Set the logging priority.</para>
 109         </listitem>
 110       </varlistentry>
 111     </variablelist>
 112  </refsect1>
 113
 114   <refsect1><title>Kernel command line</title>
 115     <variablelist>
 116       <varlistentry>
 117         <term><varname>udev.log-priority=</varname></term>
 118         <listitem>
 119           <para>Set the logging priority.</para>
 120         </listitem>
 121       </varlistentry>
 122       <varlistentry>
 123         <term><varname>udev.children-max=</varname></term>
 124         <listitem>
 125           <para>Limit the number of parallel executed events.</para>
 126         </listitem>
 127       </varlistentry>
 128       <varlistentry>
 129         <term><varname>udev.exec-delay=</varname></term>
 130         <listitem>
 131           <para>Number of seconds to delay the execution of RUN instructions.
 132           This might be useful when debugging system crashes during coldplug
 133           cause by loading non-working kernel modules.</para>
 134         </listitem>
 135       </varlistentry>
 136     </variablelist>
 137  </refsect1>
 138
 139   <refsect1><title>Author</title>
 140     <para>Written by Kay Sievers <email>kay.sievers@vrfy.org</email>.</para>
 141   </refsect1>
 142
 143   <refsect1>
 144     <title>See Also</title>
 145     <para><citerefentry>
 146         <refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum>
 147       </citerefentry>, <citerefentry>
 148         <refentrytitle>udevadm</refentrytitle><manvolnum>8</manvolnum>
 149     </citerefentry></para>
 150   </refsect1>
 151 </refentry>