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979 lines
46 KiB
XML
979 lines
46 KiB
XML
<?xml version='1.0'?>
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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
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"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
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<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
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<refentry id="udevadm"
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xmlns:xi="http://www.w3.org/2001/XInclude">
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<refentryinfo>
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<title>udevadm</title>
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<productname>systemd</productname>
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</refentryinfo>
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<refmeta>
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<refentrytitle>udevadm</refentrytitle>
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<manvolnum>8</manvolnum>
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</refmeta>
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<refnamediv>
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<refname>udevadm</refname><refpurpose>udev management tool</refpurpose>
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</refnamediv>
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<refsynopsisdiv>
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<cmdsynopsis>
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<command>udevadm</command>
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<arg><option>--debug</option></arg>
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<arg><option>--version</option></arg>
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<arg><option>--help</option></arg>
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</cmdsynopsis>
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<cmdsynopsis>
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<command>udevadm info <optional>options</optional> <optional>devpath</optional></command>
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</cmdsynopsis>
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<cmdsynopsis>
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<command>udevadm trigger <optional>options</optional> <optional>devpath</optional></command>
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</cmdsynopsis>
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<cmdsynopsis>
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<command>udevadm settle <optional>options</optional></command>
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</cmdsynopsis>
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||
<cmdsynopsis>
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<command>udevadm control <replaceable>option</replaceable></command>
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</cmdsynopsis>
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||
<cmdsynopsis>
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<command>udevadm monitor <optional>options</optional></command>
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</cmdsynopsis>
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<cmdsynopsis>
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<command>udevadm test <optional>options</optional> <replaceable>devpath</replaceable></command>
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</cmdsynopsis>
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<cmdsynopsis>
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<command>udevadm test-builtin <optional>options</optional> <replaceable>command</replaceable> <replaceable>devpath</replaceable></command>
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</cmdsynopsis>
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<cmdsynopsis>
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<command>udevadm verify</command>
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<arg choice="opt" rep="repeat">options</arg>
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<arg choice="opt" rep="repeat"><replaceable>file</replaceable></arg>
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</cmdsynopsis>
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<cmdsynopsis>
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<command>udevadm wait <optional>options</optional> <replaceable>device|syspath</replaceable></command>
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</cmdsynopsis>
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<cmdsynopsis>
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<command>udevadm lock <optional>options</optional> <replaceable>command</replaceable></command>
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</cmdsynopsis>
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</refsynopsisdiv>
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<refsect1><title>Description</title>
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<para><command>udevadm</command> expects a command and command
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specific options. It controls the runtime behavior of
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<command>systemd-udevd</command>, requests kernel events, manages
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the event queue, and provides simple debugging mechanisms.</para>
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</refsect1>
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<refsect1><title>Options</title>
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<variablelist>
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<varlistentry>
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<term><option>-d</option></term>
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<term><option>--debug</option></term>
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<listitem>
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<para>Print debug messages to standard error. This option is implied in <command>udevadm test</command> and
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<command>udevadm test-builtin</command> commands.</para>
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</listitem>
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</varlistentry>
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<xi:include href="standard-options.xml" xpointer="help" />
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</variablelist>
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<refsect2><title>udevadm info
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<arg choice="opt"><replaceable>options</replaceable></arg>
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<arg choice="opt" rep="repeat"><replaceable>devpath</replaceable>|<replaceable>file</replaceable>|<replaceable>unit</replaceable></arg>
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</title>
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<para>Query the udev database for device information.</para>
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<para>Positional arguments should be used to specify one or more devices. Each one may be a device name
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(in which case it must start with <filename>/dev/</filename>), a sys path (in which case it must start
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with <filename>/sys/</filename>), or a systemd device unit name (in which case it must end with
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<literal>.device</literal>, see
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<citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
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</para>
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<variablelist>
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<varlistentry>
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<term><option>-q</option></term>
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<term><option>--query=<replaceable>TYPE</replaceable></option></term>
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<listitem>
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<para>Query the database for the specified type of device data.
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Valid <replaceable>TYPE</replaceable>s are:
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<constant>name</constant>, <constant>symlink</constant>,
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<constant>path</constant>, <constant>property</constant>,
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<constant>all</constant>.</para>
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</listitem>
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||
</varlistentry>
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<varlistentry>
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<term><option>--property=<replaceable>NAME</replaceable></option></term>
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<listitem>
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<para>When showing device properties using the <option>--query=property</option>
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option, limit display to properties specified in the argument. The argument should
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be a comma-separated list of property names. If not specified, all known properties
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are shown.</para>
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</listitem>
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||
</varlistentry>
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||
<varlistentry>
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<term><option>--value</option></term>
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||
<listitem>
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<para>When showing device properties using the <option>--query=property</option>
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option, print only their values, and skip the property name and <literal>=</literal>.</para>
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||
<para>Cannot be used together with <option>-x/--export</option> or
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<option>-P/--export-prefix</option>.</para>
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||
</listitem>
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||
</varlistentry>
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||
<varlistentry>
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<term><option>-p</option></term>
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<term><option>--path=<replaceable>DEVPATH</replaceable></option></term>
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<listitem>
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<para>The <filename>/sys/</filename> path of the device to query, e.g.
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<filename><optional>/sys/</optional>/class/block/sda</filename>. This option is an alternative to
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the positional argument with a <filename>/sys/</filename> prefix. <command>udevadm info
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--path=/class/block/sda</command> is equivalent to <command>udevadm info
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/sys/class/block/sda</command>.</para>
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</listitem>
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||
</varlistentry>
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<varlistentry>
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<term><option>-n</option></term>
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<term><option>--name=<replaceable>FILE</replaceable></option></term>
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<listitem>
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<para>The name of the device node or a symlink to query,
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e.g. <filename><optional>/dev/</optional>/sda</filename>. This option is an alternative to the
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positional argument with a <filename>/dev/</filename> prefix. <command>udevadm info
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--name=sda</command> is equivalent to <command>udevadm info /dev/sda</command>.</para>
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||
</listitem>
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||
</varlistentry>
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<varlistentry>
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<term><option>-r</option></term>
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<term><option>--root</option></term>
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<listitem>
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<para>Print absolute paths in <command>name</command> or <command>symlink</command>
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query.</para>
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</listitem>
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||
</varlistentry>
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||
<varlistentry>
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<term><option>-a</option></term>
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<term><option>--attribute-walk</option></term>
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<listitem>
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<para>Print all sysfs properties of the specified device that can be used
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in udev rules to match the specified device. It prints all devices
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along the chain, up to the root of sysfs that can be used in udev rules.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><option>-t</option></term>
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<term><option>--tree</option></term>
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<listitem>
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<para>Display a sysfs tree. This recursively iterates through the sysfs hierarchy and displays it
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in a tree structure. If a path is specified only the subtree below and its parent directories are
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shown. This will show both device and subsystem items.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><option>-x</option></term>
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<term><option>--export</option></term>
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<listitem>
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<para>Print output as key/value pairs. Values are enclosed in single quotes.
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This takes effects only when <option>--query=property</option> or
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<option>--device-id-of-file=<replaceable>FILE</replaceable></option> is specified.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><option>-P</option></term>
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<term><option>--export-prefix=<replaceable>NAME</replaceable></option></term>
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<listitem>
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||
<para>Add a prefix to the key name of exported values.
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This implies <option>--export</option>.</para>
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||
</listitem>
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||
</varlistentry>
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<varlistentry>
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<term><option>-d</option></term>
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<term><option>--device-id-of-file=<replaceable>FILE</replaceable></option></term>
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<listitem>
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<para>Print major/minor numbers of the underlying device, where the file lives on.
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If this is specified, all positional arguments are ignored.</para>
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</listitem>
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||
</varlistentry>
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<varlistentry>
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||
<term><option>-e</option></term>
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||
<term><option>--export-db</option></term>
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||
<listitem>
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<para>Export the content of the udev database.</para>
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||
</listitem>
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</varlistentry>
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<varlistentry>
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<term><option>-c</option></term>
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<term><option>--cleanup-db</option></term>
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<listitem>
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<para>Cleanup the udev database.</para>
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||
</listitem>
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</varlistentry>
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||
<varlistentry>
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||
<term><option>-w<optional>SECONDS</optional></option></term>
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||
<term><option>--wait-for-initialization<optional>=SECONDS</optional></option></term>
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||
<listitem>
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||
<para>Wait for device to be initialized. If argument <replaceable>SECONDS</replaceable>
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||
is not specified, the default is to wait forever.</para>
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||
</listitem>
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||
</varlistentry>
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||
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||
<xi:include href="standard-options.xml" xpointer="help" />
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||
<xi:include href="standard-options.xml" xpointer="no-pager" />
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||
</variablelist>
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||
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||
<para>The generated output shows the current device database entry in a terse format. Each line shown
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is prefixed with one of the following characters:</para>
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||
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||
<table>
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||
<title><command>udevadm info</command> output prefixes</title>
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<tgroup cols='2' align='left' colsep='1' rowsep='1'>
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<colspec colname="prefix" />
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||
<colspec colname="meaning" />
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||
<thead>
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||
<row>
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<entry>Prefix</entry>
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||
<entry>Meaning</entry>
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||
</row>
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||
</thead>
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||
<tbody>
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||
<row>
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||
<entry><literal>P:</literal></entry>
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<entry>Device path in <filename>/sys/</filename></entry>
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||
</row>
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||
<row>
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||
<entry><literal>M:</literal></entry>
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||
<entry>Device name in <filename>/sys/</filename> (i.e. the last component of <literal>P:</literal>)</entry>
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||
</row>
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||
<row>
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||
<entry><literal>R:</literal></entry>
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<entry>Device number in <filename>/sys/</filename> (i.e. the numeric suffix of the last component of <literal>P:</literal>)</entry>
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||
</row>
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||
<row>
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||
<entry><literal>U:</literal></entry>
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||
<entry>Kernel subsystem</entry>
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||
</row>
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||
<row>
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||
<entry><literal>T:</literal></entry>
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||
<entry>Kernel device type within subsystem</entry>
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||
</row>
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||
<row>
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||
<entry><literal>D:</literal></entry>
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||
<entry>Kernel device node major/minor</entry>
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||
</row>
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||
<row>
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||
<entry><literal>I:</literal></entry>
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<entry>Network interface index</entry>
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</row>
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||
<row>
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||
<entry><literal>N:</literal></entry>
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<entry>Kernel device node name</entry>
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||
</row>
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||
<row>
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||
<entry><literal>L:</literal></entry>
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||
<entry>Device node symlink priority</entry>
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||
</row>
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||
<row>
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||
<entry><literal>S:</literal></entry>
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||
<entry>Device node symlink</entry>
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||
</row>
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||
<row>
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||
<entry><literal>Q:</literal></entry>
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||
<entry>Block device sequence number (DISKSEQ)</entry>
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||
</row>
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||
<row>
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||
<entry><literal>V:</literal></entry>
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||
<entry>Attached driver</entry>
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||
</row>
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||
<row>
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||
<entry><literal>E:</literal></entry>
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||
<entry>Device property</entry>
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||
</row>
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||
</tbody>
|
||
</tgroup>
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||
</table>
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||
</refsect2>
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||
|
||
<refsect2><title>udevadm trigger
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||
<arg choice="opt"><replaceable>options</replaceable></arg>
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||
<arg choice="opt"><replaceable>devpath</replaceable>|<replaceable>file</replaceable>|<replaceable>unit</replaceable></arg>
|
||
</title>
|
||
<para>Request device events from the kernel. Primarily used to replay events at system coldplug time.</para>
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||
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||
<para>Takes device specifications as positional arguments. See the description of <command>info</command>
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above.</para>
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||
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||
<variablelist>
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||
<varlistentry>
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||
<term><option>-v</option></term>
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||
<term><option>--verbose</option></term>
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||
<listitem>
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||
<para>Print the list of devices which will be triggered.</para>
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||
</listitem>
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||
</varlistentry>
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||
<varlistentry>
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||
<term><option>-n</option></term>
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||
<term><option>--dry-run</option></term>
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||
<listitem>
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||
<para>Do not actually trigger the event.</para>
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||
</listitem>
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||
</varlistentry>
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||
<varlistentry>
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||
<term><option>-q</option></term>
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||
<term><option>--quiet</option></term>
|
||
<listitem>
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||
<para>Suppress error logging in triggering events.</para>
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||
</listitem>
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||
</varlistentry>
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||
<varlistentry>
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||
<term><option>-t</option></term>
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||
<term><option>--type=<replaceable>TYPE</replaceable></option></term>
|
||
<listitem>
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||
<para>Trigger a specific type of devices. Valid types are <literal>all</literal>,
|
||
<literal>devices</literal>, and <literal>subsystems</literal>. The default value is
|
||
<literal>devices</literal>.</para>
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||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
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||
<term><option>-c</option></term>
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||
<term><option>--action=<replaceable>ACTION</replaceable></option></term>
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||
<listitem>
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||
<para>Type of event to be triggered. Possible actions are <literal>add</literal>,
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||
<literal>remove</literal>, <literal>change</literal>, <literal>move</literal>,
|
||
<literal>online</literal>, <literal>offline</literal>, <literal>bind</literal>,
|
||
and <literal>unbind</literal>. Also, the special value <literal>help</literal> can be used
|
||
to list the possible actions. The default value is <literal>change</literal>.
|
||
</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>--prioritized-subsystem=<replaceable>SUBSYSTEM<optional>,<replaceable>SUBSYSTEM</replaceable>…</optional></replaceable></option></term>
|
||
<listitem>
|
||
<para>Takes a comma separated list of subsystems. When triggering events for devices, the
|
||
devices from the specified subsystems and their parents are triggered first. For example,
|
||
if <option>--prioritized-subsystem=block,net</option>, then firstly all block devices and
|
||
their parents are triggered, in the next all network devices and their parents are
|
||
triggered, and lastly the other devices are triggered. This option can be specified
|
||
multiple times, and in that case the lists of the subsystems will be merged. That is,
|
||
<option>--prioritized-subsystem=block --prioritized-subsystem=net</option> is equivalent to
|
||
<option>--prioritized-subsystem=block,net</option>.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-s</option></term>
|
||
<term><option>--subsystem-match=<replaceable>SUBSYSTEM</replaceable></option></term>
|
||
<listitem>
|
||
<para>Trigger events for devices which belong to a
|
||
matching subsystem. This option supports shell style pattern matching.
|
||
When this option is specified more than once, then each matching result is ORed, that is,
|
||
all the devices in each subsystem are triggered.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-S</option></term>
|
||
<term><option>--subsystem-nomatch=<replaceable>SUBSYSTEM</replaceable></option></term>
|
||
<listitem>
|
||
<para>Do not trigger events for devices which belong to a matching subsystem. This option
|
||
supports shell style pattern matching. When this option is specified more than once,
|
||
then each matching result is ANDed, that is, devices which do not match all specified
|
||
subsystems are triggered.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-a</option></term>
|
||
<term><option>--attr-match=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
|
||
<listitem>
|
||
<para>Trigger events for devices with a matching sysfs attribute. If a value is specified along
|
||
with the attribute name, the content of the attribute is matched against the given value using
|
||
shell style pattern matching. If no value is specified, the existence of the sysfs attribute is
|
||
checked. When this option is specified multiple times, then each matching result is ANDed,
|
||
that is, only devices which have all specified attributes are triggered.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-A</option></term>
|
||
<term><option>--attr-nomatch=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
|
||
<listitem>
|
||
<para>Do not trigger events for devices with a matching sysfs attribute. If a value is specified
|
||
along with the attribute name, the content of the attribute is matched against the given value
|
||
using shell style pattern matching. If no value is specified, the existence of the sysfs attribute
|
||
is checked. When this option is specified multiple times, then each matching result is ANDed,
|
||
that is, only devices which have none of the specified attributes are triggered.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-p</option></term>
|
||
<term><option>--property-match=<replaceable>PROPERTY</replaceable>=<replaceable>VALUE</replaceable></option></term>
|
||
<listitem>
|
||
<para>Trigger events for devices with a matching property value. This option supports shell style
|
||
pattern matching. When this option is specified more than once, then each matching result is ORed,
|
||
that is, devices which have one of the specified properties are triggered.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-g</option></term>
|
||
<term><option>--tag-match=<replaceable>TAG</replaceable></option></term>
|
||
<listitem>
|
||
<para>Trigger events for devices with a matching tag. When this option is specified multiple times,
|
||
then each matching result is ANDed, that is, devices which have all specified tags are triggered.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-y</option></term>
|
||
<term><option>--sysname-match=<replaceable>NAME</replaceable></option></term>
|
||
<listitem>
|
||
<para>Trigger events for devices for which the last component (i.e. the filename) of the
|
||
<filename>/sys/</filename> path matches the specified <replaceable>PATH</replaceable>. This option
|
||
supports shell style pattern matching. When this option is specified more than once, then each
|
||
matching result is ORed, that is, all devices which have any of the specified
|
||
<replaceable>NAME</replaceable> are triggered.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>--name-match=<replaceable>NAME</replaceable></option></term>
|
||
<listitem>
|
||
<para>Trigger events for devices with a matching device path. When this option is specified more than once,
|
||
then each matching result is ORed, that is, all specified devices are triggered.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-b</option></term>
|
||
<term><option>--parent-match=<replaceable>SYSPATH</replaceable></option></term>
|
||
<listitem>
|
||
<para>Trigger events for all children of a given device. When this option is specified more than once,
|
||
then each matching result is ORed, that is, all children of each specified device are triggered.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>--initialized-match</option></term>
|
||
<term><option>--initialized-nomatch</option></term>
|
||
<listitem>
|
||
<para>When <option>--initialized-match</option> is specified, trigger events for devices
|
||
that are already initialized by <command>systemd-udevd</command>, and skip devices that
|
||
are not initialized yet.</para>
|
||
<para>When <option>--initialized-nomatch</option> is specified, trigger events for devices
|
||
that are not initialized by <command>systemd-udevd</command> yet, and skip devices that
|
||
are already initialized.</para>
|
||
<para>Typically, it is essential that applications which intend to use such a match, make
|
||
sure a suitable udev rule is installed that sets at least one property on devices that
|
||
shall be matched. See also Initialized Devices section below for more details.</para>
|
||
<para>WARNING: <option>--initialized-nomatch</option> can potentially save a significant
|
||
amount of time compared to re-triggering all devices in the system and e.g. can be used to
|
||
optimize boot time. However, this is not safe to be used in a boot sequence in general.
|
||
Especially, when udev rules for a device depend on its parent devices (e.g.
|
||
<literal>ATTRS</literal> or <literal>IMPORT{parent}</literal> keys, see
|
||
<citerefentry><refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum></citerefentry>
|
||
for more details), the final state of the device becomes easily unstable with this option.
|
||
</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-w</option></term>
|
||
<term><option>--settle</option></term>
|
||
<listitem>
|
||
<para>Apart from triggering events, also waits for those events to
|
||
finish. Note that this is different from calling <command>udevadm
|
||
settle</command>. <command>udevadm settle</command> waits for all
|
||
events to finish. This option only waits for events triggered by
|
||
the same command to finish.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>--uuid</option></term>
|
||
<listitem>
|
||
<para>Trigger the synthetic device events, and associate a randomized UUID with each. These UUIDs
|
||
are printed to standard output, one line for each event. These UUIDs are included in the uevent
|
||
environment block (in the <literal>SYNTH_UUID=</literal> property) and may be used to track
|
||
delivery of the generated events.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>--wait-daemon[=<replaceable>SECONDS</replaceable>]</option></term>
|
||
<listitem>
|
||
<para>Before triggering uevents, wait for systemd-udevd daemon to be initialized.
|
||
Optionally takes timeout value. Default timeout is 5 seconds. This is equivalent to invoking
|
||
<command>udevadm control --ping</command> before <command>udevadm trigger</command>.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<xi:include href="standard-options.xml" xpointer="help" />
|
||
</variablelist>
|
||
|
||
<para>In addition, optional positional arguments can be used
|
||
to specify device names or sys paths. They must start with
|
||
<filename>/dev/</filename> or <filename>/sys/</filename>
|
||
respectively.</para>
|
||
</refsect2>
|
||
|
||
<refsect2><title>udevadm settle
|
||
<arg choice="opt"><replaceable>options</replaceable></arg>
|
||
</title>
|
||
<para>Watches the udev event queue, and exits if all current events are handled.</para>
|
||
<variablelist>
|
||
<varlistentry>
|
||
<term><option>-t</option></term>
|
||
<term><option>--timeout=<replaceable>SECONDS</replaceable></option></term>
|
||
<listitem>
|
||
<para>Maximum number of seconds to wait for the event
|
||
queue to become empty. The default value is 120 seconds. A
|
||
value of 0 will check if the queue is empty and always
|
||
return immediately. A non-zero value will return an exit
|
||
code of 0 if queue became empty before timeout was reached,
|
||
non-zero otherwise.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-E</option></term>
|
||
<term><option>--exit-if-exists=<replaceable>FILE</replaceable></option></term>
|
||
<listitem>
|
||
<para>Stop waiting if file exists.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<xi:include href="standard-options.xml" xpointer="help" />
|
||
</variablelist>
|
||
|
||
<para>See
|
||
<citerefentry><refentrytitle>systemd-udev-settle.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
|
||
for more information.</para>
|
||
</refsect2>
|
||
|
||
<refsect2><title>udevadm control <replaceable>option</replaceable></title>
|
||
<para>Modify the internal state of the running udev daemon.</para>
|
||
<variablelist>
|
||
<varlistentry>
|
||
<term><option>-e</option></term>
|
||
<term><option>--exit</option></term>
|
||
<listitem>
|
||
<para>Signal and wait for systemd-udevd to exit. No option except for
|
||
<option>--timeout</option> can be specified after this option.
|
||
Note that <filename>systemd-udevd.service</filename> contains
|
||
<option>Restart=always</option> and so as a result, this option restarts systemd-udevd.
|
||
If you want to stop <filename>systemd-udevd.service</filename>, please use the following:
|
||
<programlisting>systemctl stop systemd-udevd-control.socket systemd-udevd-kernel.socket systemd-udevd.service</programlisting>
|
||
</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-l</option></term>
|
||
<term><option>--log-level=<replaceable>value</replaceable></option></term>
|
||
<listitem>
|
||
<para>Set the internal log level of
|
||
<filename>systemd-udevd</filename>. Valid values are the
|
||
numerical syslog priorities or their textual
|
||
representations: <option>emerg</option>,
|
||
<option>alert</option>, <option>crit</option>,
|
||
<option>err</option>, <option>warning</option>,
|
||
<option>notice</option>, <option>info</option>, and
|
||
<option>debug</option>.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-s</option></term>
|
||
<term><option>--stop-exec-queue</option></term>
|
||
<listitem>
|
||
<para>Signal systemd-udevd to stop executing new events. Incoming events
|
||
will be queued.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-S</option></term>
|
||
<term><option>--start-exec-queue</option></term>
|
||
<listitem>
|
||
<para>Signal systemd-udevd to enable the execution of events.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-R</option></term>
|
||
<term><option>--reload</option></term>
|
||
<listitem>
|
||
<para>Signal systemd-udevd to reload the rules files and other databases like the kernel
|
||
module index. Reloading rules and databases does not apply any changes to already
|
||
existing devices; the new configuration will only be applied to new events.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-p</option></term>
|
||
<term><option>--property=<replaceable>KEY</replaceable>=<replaceable>value</replaceable></option></term>
|
||
<listitem>
|
||
<para>Set a global property for all events.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-m</option></term>
|
||
<term><option>--children-max=</option><replaceable>value</replaceable></term>
|
||
<listitem>
|
||
<para>Set the maximum number of events, systemd-udevd will handle at the
|
||
same time.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>--ping</option></term>
|
||
<listitem>
|
||
<para>Send a ping message to systemd-udevd and wait for the reply. This may be useful to check that
|
||
systemd-udevd daemon is running.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-t</option></term>
|
||
<term><option>--timeout=</option><replaceable>seconds</replaceable></term>
|
||
<listitem>
|
||
<para>The maximum number of seconds to wait for a reply from systemd-udevd.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<xi:include href="standard-options.xml" xpointer="help" />
|
||
</variablelist>
|
||
</refsect2>
|
||
|
||
<refsect2><title>udevadm monitor
|
||
<arg choice="opt"><replaceable>options</replaceable></arg>
|
||
</title>
|
||
<para>Listens to the kernel uevents and events sent out by a udev rule
|
||
and prints the devpath of the event to the console. It can be used to analyze the
|
||
event timing, by comparing the timestamps of the kernel uevent and the udev event.
|
||
</para>
|
||
<variablelist>
|
||
<varlistentry>
|
||
<term><option>-k</option></term>
|
||
<term><option>--kernel</option></term>
|
||
<listitem>
|
||
<para>Print the kernel uevents.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-u</option></term>
|
||
<term><option>--udev</option></term>
|
||
<listitem>
|
||
<para>Print the udev event after the rule processing.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-p</option></term>
|
||
<term><option>--property</option></term>
|
||
<listitem>
|
||
<para>Also print the properties of the event.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-s</option></term>
|
||
<term><option>--subsystem-match=<replaceable>string[/string]</replaceable></option></term>
|
||
<listitem>
|
||
<para>Filter kernel uevents and udev events by subsystem[/devtype]. Only events with a matching subsystem value will pass.
|
||
When this option is specified more than once, then each matching result is ORed, that is, all devices in the specified
|
||
subsystems are monitored.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-t</option></term>
|
||
<term><option>--tag-match=<replaceable>string</replaceable></option></term>
|
||
<listitem>
|
||
<para>Filter udev events by tag. Only udev events with a given tag attached will pass.
|
||
When this option is specified more than once, then each matching result is ORed, that is, devices which have one of the
|
||
specified tags are monitored.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<xi:include href="standard-options.xml" xpointer="help" />
|
||
</variablelist>
|
||
</refsect2>
|
||
|
||
<refsect2><title>udevadm test
|
||
<arg choice="opt"><replaceable>options</replaceable></arg>
|
||
<arg choice="opt"><replaceable>devpath</replaceable>|<replaceable>file</replaceable>|<replaceable>unit</replaceable></arg>
|
||
</title>
|
||
<para>Simulate a udev event run for the given device, and print debug output.</para>
|
||
<variablelist>
|
||
<varlistentry>
|
||
<term><option>-a</option></term>
|
||
<term><option>--action=<replaceable>ACTION</replaceable></option></term>
|
||
<listitem>
|
||
<para>Type of event to be simulated. Possible actions are <literal>add</literal>,
|
||
<literal>remove</literal>, <literal>change</literal>, <literal>move</literal>,
|
||
<literal>online</literal>, <literal>offline</literal>, <literal>bind</literal>,
|
||
and <literal>unbind</literal>. Also, the special value <literal>help</literal> can be used
|
||
to list the possible actions. The default value is <literal>add</literal>.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
<varlistentry>
|
||
<term><option>-N</option></term>
|
||
<term><option>--resolve-names=<constant>early</constant>|<constant>late</constant>|<constant>never</constant></option></term>
|
||
<listitem>
|
||
<para>Specify when udevadm should resolve names of users
|
||
and groups. When set to <constant>early</constant> (the
|
||
default), names will be resolved when the rules are
|
||
parsed. When set to <constant>late</constant>, names will
|
||
be resolved for every event. When set to
|
||
<constant>never</constant>, names will never be resolved
|
||
and all devices will be owned by root.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<xi:include href="standard-options.xml" xpointer="help" />
|
||
</variablelist>
|
||
</refsect2>
|
||
|
||
<refsect2><title>udevadm test-builtin
|
||
<arg choice="opt"><replaceable>options</replaceable></arg>
|
||
<arg><replaceable>command</replaceable></arg>
|
||
<arg choice="opt"><replaceable>devpath</replaceable>|<replaceable>file</replaceable>|<replaceable>unit</replaceable></arg>
|
||
</title>
|
||
<para>Run a built-in command <replaceable>COMMAND</replaceable>
|
||
for device <replaceable>DEVPATH</replaceable>, and print debug
|
||
output.</para>
|
||
<variablelist>
|
||
<varlistentry>
|
||
<term><option>-a</option></term>
|
||
<term><option>--action=<replaceable>ACTION</replaceable></option></term>
|
||
<listitem>
|
||
<para>Type of event to be simulated. Possible actions are <literal>add</literal>,
|
||
<literal>remove</literal>, <literal>change</literal>, <literal>move</literal>,
|
||
<literal>online</literal>, <literal>offline</literal>, <literal>bind</literal>,
|
||
and <literal>unbind</literal>. Also, the special value <literal>help</literal> can be used
|
||
to list the possible actions. The default value is <literal>add</literal>.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<xi:include href="standard-options.xml" xpointer="help" />
|
||
<xi:include href="standard-options.xml" xpointer="version" />
|
||
</variablelist>
|
||
</refsect2>
|
||
|
||
<refsect2>
|
||
<title>udevadm verify
|
||
<arg choice="opt"><replaceable>options</replaceable></arg>
|
||
<arg choice="opt" rep="repeat"><replaceable>file</replaceable></arg>
|
||
…
|
||
</title>
|
||
|
||
<para>Verify syntactic and semantic correctness of udev rules files.</para>
|
||
|
||
<para>Positional arguments could be used to specify one or more files to check.
|
||
If no files are specified, the udev rules are read from the files located in
|
||
the same udev/rules.d directories that are processed by the udev daemon.</para>
|
||
|
||
<para>The exit status is <constant>0</constant> if all specified udev rules files
|
||
are syntactically and semantically correct, and a non-zero error code otherwise.</para>
|
||
|
||
<variablelist>
|
||
<varlistentry>
|
||
<term><option>-N</option></term>
|
||
<term><option>--resolve-names=<constant>early</constant>|<constant>never</constant></option></term>
|
||
<listitem>
|
||
<para>Specify when udevadm should resolve names of users
|
||
and groups. When set to <constant>early</constant> (the
|
||
default), names will be resolved when the rules are
|
||
parsed. When set to <constant>never</constant>, names will
|
||
never be resolved.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><option>--root=<replaceable>PATH</replaceable></option></term>
|
||
<listitem>
|
||
<para>When looking for udev rules files located in udev/rules.d directories,
|
||
operate on files underneath the specified root path <replaceable>PATH</replaceable>.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<xi:include href="standard-options.xml" xpointer="help" />
|
||
</variablelist>
|
||
</refsect2>
|
||
|
||
<refsect2>
|
||
<title>udevadm wait
|
||
<arg choice="opt"><replaceable>options</replaceable></arg>
|
||
<arg choice="opt"><replaceable>device|syspath</replaceable></arg>
|
||
…
|
||
</title>
|
||
|
||
<para>Wait for devices or device symlinks being created and initialized by
|
||
<command>systemd-udevd</command>. Each device path must start with
|
||
<literal>/dev/</literal> or <literal>/sys/</literal>, e.g. <literal>/dev/sda</literal>,
|
||
<literal>/dev/disk/by-path/pci-0000:3c:00.0-nvme-1-part1</literal>,
|
||
<literal>/sys/devices/pci0000:00/0000:00:1f.6/net/eth0</literal>, or
|
||
<literal>/sys/class/net/eth0</literal>. This can take multiple devices. This may be useful for
|
||
waiting for devices being processed by <command>systemd-udevd</command> after e.g. partitioning
|
||
or formatting the devices.</para>
|
||
|
||
<variablelist>
|
||
<varlistentry>
|
||
<term><option>-t</option></term>
|
||
<term><option>--timeout=<replaceable>SECONDS</replaceable></option></term>
|
||
<listitem>
|
||
<para>Maximum number of seconds to wait for the specified devices or device symlinks being
|
||
created, initialized, or removed. The default value is <literal>infinity</literal>.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><option>--initialized=<replaceable>BOOL</replaceable></option></term>
|
||
<listitem>
|
||
<para>Check if <command>systemd-udevd</command> initialized devices. Defaults to true. When
|
||
false, the command only checks if the specified devices exist. Set false to this setting if
|
||
there is no udev rules for the specified devices, as the devices will never be considered
|
||
as initialized in that case. See Initialized Devices section below for more details.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><option>--removed</option></term>
|
||
<listitem>
|
||
<para>When specified, the command wait for devices being removed instead of created or
|
||
initialized. If this is specified, <option>--initialized=</option> will be ignored.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><option>--settle</option></term>
|
||
<listitem>
|
||
<para>When specified, also watches the udev event queue, and wait for all queued events
|
||
being processed by <command>systemd-udevd</command>.</para>
|
||
</listitem>
|
||
</varlistentry>
|
||
|
||
<xi:include href="standard-options.xml" xpointer="help" />
|
||
</variablelist>
|
||
</refsect2>
|
||
|
||
<refsect2>
|
||
<title>udevadm lock
|
||
<arg choice="opt"><replaceable>options</replaceable></arg>
|
||
<arg choice="opt"><replaceable>command</replaceable></arg>
|
||
…
|
||
</title>
|
||
|
||
<para><command>udevadm lock</command> takes an (advisory) exclusive lock on a block device (or all
|
||
specified devices), as per <ulink url="https://systemd.io/BLOCK_DEVICE_LOCKING">Locking Block Device
|
||
Access</ulink> and invokes a program with the locks taken. When the invoked program exits the locks
|
||
are automatically released and its return value is propagated as exit code of <command>udevadm
|
||
lock</command>.</para>
|
||
|
||
<para>This tool is in particular useful to ensure that
|
||
<citerefentry><refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>
|
||
does not probe a block device while changes are made to it, for example partitions created or file
|
||
systems formatted. Note that many tools that interface with block devices natively support taking
|
||
relevant locks, see for example
|
||
<citerefentry project='man-pages'><refentrytitle>sfdisk</refentrytitle><manvolnum>8</manvolnum></citerefentry>'s
|
||
<option>--lock</option> switch.</para>
|
||
|
||
<para>The command expects at least one block device specified via <option>--device=</option> or
|
||
<option>--backing=</option>, and a command line to execute as arguments.</para>
|
||
|
||
<variablelist>
|
||
<varlistentry>
|
||
<term><option>--device=<replaceable>DEVICE</replaceable></option></term>
|
||
<term><option>-d <replaceable>DEVICE</replaceable></option></term>
|
||
|
||
<listitem><para>Takes a path to a device node of the device to lock. This switch may be used
|
||
multiple times (and in combination with <option>--backing=</option>) in order to lock multiple
|
||
devices. If a partition block device node is specified the containing "whole" block device is
|
||
automatically determined and used for the lock, as per the specification. If multiple devices are
|
||
specified, they are deduplicated, sorted by the major/minor of their device nodes and then locked
|
||
in order.</para>
|
||
|
||
<para>This switch must be used at least once, to specify at least one device to
|
||
lock. (Alternatively, use <option>--backing=</option>, see below.)</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><option>--backing=<replaceable>PATH</replaceable></option></term>
|
||
<term><option>-b <replaceable>PATH</replaceable></option></term>
|
||
|
||
<listitem><para>If a path to a device node is specified, identical to
|
||
<option>--device=</option>. However, this switch alternatively accepts a path to a regular file or
|
||
directory, in which case the block device of the file system the file/directory resides on is
|
||
automatically determined and used as if it was specified with
|
||
<option>--device=</option>.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><option>--timeout=<replaceable>SECS</replaceable></option></term>
|
||
<term><option>-t <replaceable>SECS</replaceable></option></term>
|
||
|
||
<listitem><para>Specifies how long to wait at most until all locks can be taken. Takes a value in
|
||
seconds, or in the usual supported time units, see
|
||
<citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>. If
|
||
specified as zero the lock is attempted and if not successful the invocation will immediately
|
||
fail. If passed as <literal>infinity</literal> (the default) the invocation will wait indefinitely
|
||
until the lock can be acquired. If the lock cannot be taken in the specified time the specified
|
||
command will not be executed and the invocation will fail.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<varlistentry>
|
||
<term><option>--print</option></term>
|
||
<term><option>-p</option></term>
|
||
|
||
<listitem><para>Instead of locking the specified devices and executing a command, just print the
|
||
device paths that would be locked, and execute no command. This command is useful to determine
|
||
the "whole" block device in case a partition block device is specified. The devices will be sorted
|
||
by their device node major number as primary ordering key and the minor number as secondary
|
||
ordering key (i.e. they are shown in the order they'd be locked). Note that the number of lines
|
||
printed here can be less than the number of <option>--device=</option> and
|
||
<option>--backing=</option> switches specified in case these resolve to the same "whole"
|
||
devices.</para></listitem>
|
||
</varlistentry>
|
||
|
||
<xi:include href="standard-options.xml" xpointer="help" />
|
||
</variablelist>
|
||
</refsect2>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>Initialized Devices</title>
|
||
|
||
<para>Initialized devices are those for which at least one udev rule already completed execution
|
||
– for any action but <literal>remove</literal> — that set a property or other device setting (and
|
||
thus has an entry in the udev device database). Devices are no longer considered initialized if a
|
||
<literal>remove</literal> action is seen for them (which removes their entry in the udev device
|
||
database). Note that devices that have no udev rules are never considered initialized, but might
|
||
still be announced via the sd-device API (or similar).</para>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>Example</title>
|
||
|
||
<example>
|
||
<title>Format a File System</title>
|
||
|
||
<para>Take a lock on the backing block device while creating a file system, to ensure that
|
||
<command>systemd-udevd</command> doesn't probe or announce the new superblock before it is
|
||
comprehensively written:</para>
|
||
|
||
<programlisting># udevadm lock --device=/dev/sda1 mkfs.ext4 /dev/sda1</programlisting>
|
||
</example>
|
||
|
||
<example>
|
||
<title>Format a RAID File System</title>
|
||
|
||
<para>Similar, but take locks on multiple devices at once:</para>
|
||
|
||
<programlisting># udevadm lock --device=/dev/sda1 --device=/dev/sdb1 mkfs.btrfs /dev/sda1 /dev/sdb1</programlisting>
|
||
</example>
|
||
|
||
<example>
|
||
<title>Copy in a File System</title>
|
||
|
||
<para>Take a lock on the backing block device while copying in a prepared file system image, to ensure
|
||
that <command>systemd-udevd</command> doesn't probe or announce the new superblock before it is fully
|
||
written:</para>
|
||
|
||
<programlisting># udevadm lock -d /dev/sda1 dd if=fs.raw of=/dev/sda1</programlisting>
|
||
</example>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>See Also</title>
|
||
<para><citerefentry>
|
||
<refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum>
|
||
</citerefentry>,
|
||
<citerefentry>
|
||
<refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum>
|
||
</citerefentry></para>
|
||
</refsect1>
|
||
</refentry>
|