man/udevadm.xml

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   6   SPDX-License-Identifier: LGPL-2.1+
   7
   8   This file is part of systemd.
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  10   Copyright 2010-2013 Kay Sievers
  11 -->
  12
  13 <refentry id="udevadm"
  14           xmlns:xi="http://www.w3.org/2001/XInclude">
  15
  16   <refentryinfo>
  17     <title>udevadm</title>
  18     <productname>systemd</productname>
  19     <authorgroup>
  20       <author>
  21         <contrib>Developer</contrib>
  22         <firstname>Kay</firstname>
  23         <surname>Sievers</surname>
  24         <email>kay@vrfy.org</email>
  25       </author>
  26     </authorgroup>
  27   </refentryinfo>
  28
  29   <refmeta>
  30     <refentrytitle>udevadm</refentrytitle>
  31     <manvolnum>8</manvolnum>
  32   </refmeta>
  33
  34   <refnamediv>
  35     <refname>udevadm</refname><refpurpose>udev management tool</refpurpose>
  36   </refnamediv>
  37
  38   <refsynopsisdiv>
  39     <cmdsynopsis>
  40       <command>udevadm</command>
  41         <arg><option>--debug</option></arg>
  42         <arg><option>--version</option></arg>
  43         <arg><option>--help</option></arg>
  44     </cmdsynopsis>
  45     <cmdsynopsis>
  46       <command>udevadm info <optional>options</optional> <optional>devpath</optional></command>
  47     </cmdsynopsis>
  48     <cmdsynopsis>
  49       <command>udevadm trigger <optional>options</optional> <optional>devpath</optional></command>
  50     </cmdsynopsis>
  51     <cmdsynopsis>
  52       <command>udevadm settle <optional>options</optional></command>
  53     </cmdsynopsis>
  54     <cmdsynopsis>
  55       <command>udevadm control <replaceable>option</replaceable></command>
  56     </cmdsynopsis>
  57     <cmdsynopsis>
  58       <command>udevadm monitor <optional>options</optional></command>
  59     </cmdsynopsis>
  60     <cmdsynopsis>
  61       <command>udevadm test <optional>options</optional> <replaceable>devpath</replaceable></command>
  62     </cmdsynopsis>
  63     <cmdsynopsis>
  64       <command>udevadm test-builtin <optional>options</optional> <replaceable>command</replaceable> <replaceable>devpath</replaceable></command>
  65     </cmdsynopsis>
  66   </refsynopsisdiv>
  67
  68   <refsect1><title>Description</title>
  69     <para><command>udevadm</command> expects a command and command
  70     specific options.  It controls the runtime behavior of
  71     <command>systemd-udevd</command>, requests kernel events, manages
  72     the event queue, and provides simple debugging mechanisms.</para>
  73   </refsect1>
  74
  75   <refsect1><title>Options</title>
  76     <variablelist>
  77       <varlistentry>
  78         <term><option>-d</option></term>
  79         <term><option>--debug</option></term>
  80         <listitem>
  81           <para>Print debug messages to standard error. This option is implied in <command>udevadm test</command> and
  82           <command>udevadm test-builtin</command> commands.</para>
  83         </listitem>
  84       </varlistentry>
  85
  86       <xi:include href="standard-options.xml" xpointer="help" />
  87     </variablelist>
  88
  89     <refsect2><title>udevadm info
  90       <arg choice="opt"><replaceable>options</replaceable></arg>
  91       <arg choice="opt"><replaceable>devpath</replaceable>|<replaceable>file</replaceable></arg>
  92     </title>
  93
  94       <para>Queries the udev database for device information
  95       stored in the udev database. It can also query the properties
  96       of a device from its sysfs representation to help creating udev
  97       rules that match this device.</para>
  98       <variablelist>
  99         <varlistentry>
 100           <term><option>-q</option></term>
 101           <term><option>--query=<replaceable>TYPE</replaceable></option></term>
 102           <listitem>
 103             <para>Query the database for the specified type of device
 104             data. It needs the <option>--path</option> or
 105             <option>--name</option> to identify the specified device.
 106             Valid <replaceable>TYPE</replaceable>s are:
 107             <constant>name</constant>, <constant>symlink</constant>,
 108             <constant>path</constant>, <constant>property</constant>,
 109             <constant>all</constant>.</para>
 110           </listitem>
 111         </varlistentry>
 112         <varlistentry>
 113           <term><option>-p</option></term>
 114           <term><option>--path=<replaceable>DEVPATH</replaceable></option></term>
 115           <listitem>
 116             <para>The <filename>/sys</filename> path of the device to
 117             query, e.g.
 118             <filename><optional>/sys</optional>/class/block/sda</filename>.
 119             Note that this option usually is not very useful, since
 120             <command>udev</command> can guess the type of the
 121             argument, so <command>udevadm info
 122             --path=/class/block/sda</command> is equivalent to
 123             <command>udevadm info /sys/class/block/sda</command>.</para>
 124           </listitem>
 125         </varlistentry>
 126         <varlistentry>
 127           <term><option>-n</option></term>
 128           <term><option>--name=<replaceable>FILE</replaceable></option></term>
 129           <listitem>
 130             <para>The name of the device node or a symlink to query,
 131             e.g. <filename><optional>/dev</optional>/sda</filename>.
 132             Note that this option usually is not very useful, since
 133             <command>udev</command> can guess the type of the
 134             argument, so <command>udevadm info --name=sda</command> is
 135             equivalent to <command>udevadm info /dev/sda</command>.</para>
 136           </listitem>
 137         </varlistentry>
 138         <varlistentry>
 139           <term><option>-r</option></term>
 140           <term><option>--root</option></term>
 141           <listitem>
 142             <para>Print absolute paths in <command>name</command> or <command>symlink</command>
 143             query.</para>
 144           </listitem>
 145         </varlistentry>
 146         <varlistentry>
 147           <term><option>-a</option></term>
 148           <term><option>--attribute-walk</option></term>
 149           <listitem>
 150             <para>Print all sysfs properties of the specified device that can be used
 151             in udev rules to match the specified device. It prints all devices
 152             along the chain, up to the root of sysfs that can be used in udev rules.</para>
 153           </listitem>
 154         </varlistentry>
 155         <varlistentry>
 156           <term><option>-x</option></term>
 157           <term><option>--export</option></term>
 158           <listitem>
 159             <para>Print output as key/value pairs. Values are enclosed in single quotes.</para>
 160           </listitem>
 161         </varlistentry>
 162         <varlistentry>
 163           <term><option>-P</option></term>
 164           <term><option>--export-prefix=<replaceable>NAME</replaceable></option></term>
 165           <listitem>
 166             <para>Add a prefix to the key name of exported values.</para>
 167           </listitem>
 168         </varlistentry>
 169         <varlistentry>
 170           <term><option>-d</option></term>
 171           <term><option>--device-id-of-file=<replaceable>FILE</replaceable></option></term>
 172           <listitem>
 173             <para>Print major/minor numbers of the underlying device, where the file
 174             lives on.</para>
 175           </listitem>
 176         </varlistentry>
 177         <varlistentry>
 178           <term><option>-e</option></term>
 179           <term><option>--export-db</option></term>
 180           <listitem>
 181             <para>Export the content of the udev database.</para>
 182           </listitem>
 183         </varlistentry>
 184         <varlistentry>
 185           <term><option>-c</option></term>
 186           <term><option>--cleanup-db</option></term>
 187           <listitem>
 188             <para>Cleanup the udev database.</para>
 189           </listitem>
 190         </varlistentry>
 191
 192         <xi:include href="standard-options.xml" xpointer="help" />
 193       </variablelist>
 194
 195       <para>In addition, an optional positional argument can be used
 196       to specify a device name or a sys path. It must start with
 197       <filename>/dev</filename> or <filename>/sys</filename>
 198       respectively.</para>
 199     </refsect2>
 200
 201     <refsect2><title>udevadm trigger
 202       <arg choice="opt"><replaceable>options</replaceable></arg>
 203       <arg choice="opt" rep="repeat"><replaceable>devpath</replaceable>|<replaceable>file</replaceable></arg></title>
 204       <para>Request device events from the kernel. Primarily used to replay events at system coldplug time.</para>
 205       <variablelist>
 206         <varlistentry>
 207           <term><option>-v</option></term>
 208           <term><option>--verbose</option></term>
 209           <listitem>
 210             <para>Print the list of devices which will be triggered.</para>
 211           </listitem>
 212         </varlistentry>
 213         <varlistentry>
 214           <term><option>-n</option></term>
 215           <term><option>--dry-run</option></term>
 216           <listitem>
 217             <para>Do not actually trigger the event.</para>
 218           </listitem>
 219         </varlistentry>
 220         <varlistentry>
 221           <term><option>-t</option></term>
 222           <term><option>--type=<replaceable>TYPE</replaceable></option></term>
 223           <listitem>
 224             <para>Trigger a specific type of devices. Valid types are:
 225             <command>devices</command>, <command>subsystems</command>.
 226             The default value is <command>devices</command>.</para>
 227           </listitem>
 228         </varlistentry>
 229         <varlistentry>
 230           <term><option>-c</option></term>
 231           <term><option>--action=<replaceable>ACTION</replaceable></option></term>
 232           <listitem>
 233             <para>Type of event to be triggered. The default value is
 234             <command>change</command>.</para>
 235           </listitem>
 236         </varlistentry>
 237         <varlistentry>
 238           <term><option>-s</option></term>
 239           <term><option>--subsystem-match=<replaceable>SUBSYSTEM</replaceable></option></term>
 240           <listitem>
 241             <para>Trigger events for devices which belong to a
 242             matching subsystem. This option can be specified multiple
 243             times and supports shell style pattern matching.</para>
 244           </listitem>
 245         </varlistentry>
 246         <varlistentry>
 247           <term><option>-S</option></term>
 248           <term><option>--subsystem-nomatch=<replaceable>SUBSYSTEM</replaceable></option></term>
 249           <listitem>
 250             <para>Do not trigger events for devices which belong to a matching subsystem. This option
 251             can be specified multiple times and supports shell style pattern matching.</para>
 252           </listitem>
 253         </varlistentry>
 254         <varlistentry>
 255           <term><option>-a</option></term>
 256           <term><option>--attr-match=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
 257           <listitem>
 258             <para>Trigger events for devices with a matching sysfs
 259             attribute. If a value is specified along with the
 260             attribute name, the content of the attribute is matched
 261             against the given value using shell style pattern
 262             matching. If no value is specified, the existence of the
 263             sysfs attribute is checked. This option can be specified
 264             multiple times.</para>
 265           </listitem>
 266         </varlistentry>
 267         <varlistentry>
 268           <term><option>-A</option></term>
 269           <term><option>--attr-nomatch=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
 270           <listitem>
 271             <para>Do not trigger events for devices with a matching
 272             sysfs attribute. If a value is specified along with the
 273             attribute name, the content of the attribute is matched
 274             against the given value using shell style pattern
 275             matching. If no value is specified, the existence of the
 276             sysfs attribute is checked. This option can be specified
 277             multiple times.</para>
 278           </listitem>
 279         </varlistentry>
 280         <varlistentry>
 281           <term><option>-p</option></term>
 282           <term><option>--property-match=<replaceable>PROPERTY</replaceable>=<replaceable>VALUE</replaceable></option></term>
 283           <listitem>
 284             <para>Trigger events for devices with a matching property
 285             value. This option can be specified multiple times and
 286             supports shell style pattern matching.</para>
 287           </listitem>
 288         </varlistentry>
 289         <varlistentry>
 290           <term><option>-g</option></term>
 291           <term><option>--tag-match=<replaceable>PROPERTY</replaceable></option></term>
 292           <listitem>
 293             <para>Trigger events for devices with a matching tag. This
 294             option can be specified multiple times.</para>
 295           </listitem>
 296         </varlistentry>
 297         <varlistentry>
 298           <term><option>-y</option></term>
 299           <term><option>--sysname-match=<replaceable>PATH</replaceable></option></term>
 300           <listitem>
 301             <para>Trigger events for devices for which the last component
 302             (i.e. the filename) of the <filename>/sys</filename> path matches
 303             the specified <replaceable>PATH</replaceable>. This option can be
 304             specified multiple times and also supports shell style pattern
 305             matching.</para>
 306           </listitem>
 307         </varlistentry>
 308         <varlistentry>
 309           <term><option>--name-match=<replaceable>NAME</replaceable></option></term>
 310           <listitem>
 311             <para>Trigger events for devices with a matching
 312             device path. This option can be specified multiple
 313             times.</para>
 314           </listitem>
 315         </varlistentry>
 316         <varlistentry>
 317           <term><option>-b</option></term>
 318           <term><option>--parent-match=<replaceable>SYSPATH</replaceable></option></term>
 319           <listitem>
 320             <para>Trigger events for all children of a given
 321             device.</para>
 322           </listitem>
 323         </varlistentry>
 324         <varlistentry>
 325           <term><option>-w</option></term>
 326           <term><option>--settle</option></term>
 327           <listitem>
 328             <para>Apart from triggering events, also waits for those events to
 329             finish. Note that this is different from calling <command>udevadm
 330             settle</command>. <command>udevadm settle</command> waits for all
 331             events to finish. This option only waits for events triggered by
 332             the same command to finish.</para>
 333           </listitem>
 334         </varlistentry>
 335
 336         <xi:include href="standard-options.xml" xpointer="help" />
 337       </variablelist>
 338
 339       <para>In addition, optional positional arguments can be used
 340       to specify device names or sys paths. They must start with
 341       <filename>/dev</filename> or <filename>/sys</filename>
 342       respectively.</para>
 343     </refsect2>
 344
 345     <refsect2><title>udevadm settle
 346       <arg choice="opt"><replaceable>options</replaceable></arg>
 347     </title>
 348       <para>Watches the udev event queue, and exits if all current events are handled.</para>
 349       <variablelist>
 350         <varlistentry>
 351           <term><option>-t</option></term>
 352           <term><option>--timeout=<replaceable>SECONDS</replaceable></option></term>
 353           <listitem>
 354             <para>Maximum number of seconds to wait for the event
 355             queue to become empty. The default value is 120 seconds. A
 356             value of 0 will check if the queue is empty and always
 357             return immediately.</para>
 358           </listitem>
 359         </varlistentry>
 360         <varlistentry>
 361           <term><option>-E</option></term>
 362           <term><option>--exit-if-exists=<replaceable>FILE</replaceable></option></term>
 363           <listitem>
 364             <para>Stop waiting if file exists.</para>
 365           </listitem>
 366         </varlistentry>
 367
 368         <xi:include href="standard-options.xml" xpointer="help" />
 369       </variablelist>
 370     </refsect2>
 371
 372     <refsect2><title>udevadm control <replaceable>option</replaceable></title>
 373       <para>Modify the internal state of the running udev daemon.</para>
 374       <variablelist>
 375         <varlistentry>
 376           <term><option>-e</option></term>
 377           <term><option>--exit</option></term>
 378           <listitem>
 379             <para>Signal and wait for systemd-udevd to exit.</para>
 380           </listitem>
 381         </varlistentry>
 382         <varlistentry>
 383           <term><option>-l</option></term>
 384           <term><option>--log-priority=<replaceable>value</replaceable></option></term>
 385           <listitem>
 386             <para>Set the internal log level of
 387             <filename>systemd-udevd</filename>. Valid values are the
 388             numerical syslog priorities or their textual
 389             representations: <option>emerg</option>,
 390             <option>alert</option>, <option>crit</option>,
 391             <option>err</option>, <option>warning</option>,
 392             <option>notice</option>, <option>info</option>, and
 393             <option>debug</option>.</para>
 394           </listitem>
 395         </varlistentry>
 396         <varlistentry>
 397           <term><option>-s</option></term>
 398           <term><option>--stop-exec-queue</option></term>
 399           <listitem>
 400             <para>Signal systemd-udevd to stop executing new events. Incoming events
 401             will be queued.</para>
 402           </listitem>
 403         </varlistentry>
 404         <varlistentry>
 405           <term><option>-S</option></term>
 406           <term><option>--start-exec-queue</option></term>
 407           <listitem>
 408             <para>Signal systemd-udevd to enable the execution of events.</para>
 409           </listitem>
 410         </varlistentry>
 411         <varlistentry>
 412           <term><option>-R</option></term>
 413           <term><option>--reload</option></term>
 414           <listitem>
 415             <para>Signal systemd-udevd to reload the rules files and other databases like the kernel
 416             module index. Reloading rules and databases does not apply any changes to already
 417             existing devices; the new configuration will only be applied to new events.</para>
 418           </listitem>
 419         </varlistentry>
 420         <varlistentry>
 421           <term><option>-p</option></term>
 422           <term><option>--property=<replaceable>KEY</replaceable>=<replaceable>value</replaceable></option></term>
 423           <listitem>
 424             <para>Set a global property for all events.</para>
 425           </listitem>
 426         </varlistentry>
 427         <varlistentry>
 428           <term><option>-m</option></term>
 429           <term><option>--children-max=</option><replaceable>value</replaceable></term>
 430           <listitem>
 431             <para>Set the maximum number of events, systemd-udevd will handle at the
 432             same time.</para>
 433           </listitem>
 434         </varlistentry>
 435         <varlistentry>
 436           <term><option>-t</option></term>
 437           <term><option>--timeout=</option><replaceable>seconds</replaceable></term>
 438           <listitem>
 439             <para>The maximum number of seconds to wait for a reply from systemd-udevd.</para>
 440           </listitem>
 441         </varlistentry>
 442
 443         <xi:include href="standard-options.xml" xpointer="help" />
 444       </variablelist>
 445     </refsect2>
 446
 447     <refsect2><title>udevadm monitor
 448       <arg choice="opt"><replaceable>options</replaceable></arg>
 449     </title>
 450       <para>Listens to the kernel uevents and events sent out by a udev rule
 451       and prints the devpath of the event to the console. It can be used to analyze the
 452       event timing, by comparing the timestamps of the kernel uevent and the udev event.
 453       </para>
 454       <variablelist>
 455         <varlistentry>
 456           <term><option>-k</option></term>
 457           <term><option>--kernel</option></term>
 458           <listitem>
 459             <para>Print the kernel uevents.</para>
 460           </listitem>
 461         </varlistentry>
 462         <varlistentry>
 463           <term><option>-u</option></term>
 464           <term><option>--udev</option></term>
 465           <listitem>
 466             <para>Print the udev event after the rule processing.</para>
 467           </listitem>
 468         </varlistentry>
 469         <varlistentry>
 470           <term><option>-p</option></term>
 471           <term><option>--property</option></term>
 472           <listitem>
 473             <para>Also print the properties of the event.</para>
 474           </listitem>
 475         </varlistentry>
 476         <varlistentry>
 477           <term><option>-s</option></term>
 478           <term><option>--subsystem-match=<replaceable>string[/string]</replaceable></option></term>
 479           <listitem>
 480             <para>Filter kernel uevents and udev events by subsystem[/devtype]. Only events with a matching subsystem value will pass.</para>
 481           </listitem>
 482         </varlistentry>
 483         <varlistentry>
 484           <term><option>-t</option></term>
 485           <term><option>--tag-match=<replaceable>string</replaceable></option></term>
 486           <listitem>
 487             <para>Filter udev events by tag. Only udev events with a given tag attached will pass.</para>
 488           </listitem>
 489         </varlistentry>
 490
 491         <xi:include href="standard-options.xml" xpointer="help" />
 492       </variablelist>
 493     </refsect2>
 494
 495     <refsect2><title>udevadm test
 496       <arg choice="opt"><replaceable>options</replaceable></arg>
 497       <arg><replaceable>devpath</replaceable></arg>
 498     </title>
 499       <para>Simulate a udev event run for the given device, and print debug output.</para>
 500       <variablelist>
 501         <varlistentry>
 502           <term><option>-a</option></term>
 503           <term><option>--action=<replaceable>string</replaceable></option></term>
 504           <listitem>
 505             <para>The action string.</para>
 506           </listitem>
 507         </varlistentry>
 508         <varlistentry>
 509           <term><option>-N</option></term>
 510           <term><option>--resolve-names=<constant>early</constant>|<constant>late</constant>|<constant>never</constant></option></term>
 511           <listitem>
 512             <para>Specify when udevadm should resolve names of users
 513             and groups.  When set to <constant>early</constant> (the
 514             default), names will be resolved when the rules are
 515             parsed. When set to <constant>late</constant>, names will
 516             be resolved for every event. When set to
 517             <constant>never</constant>, names will never be resolved
 518             and all devices will be owned by root.</para>
 519           </listitem>
 520         </varlistentry>
 521
 522         <xi:include href="standard-options.xml" xpointer="help" />
 523       </variablelist>
 524     </refsect2>
 525
 526     <refsect2><title>udevadm test-builtin
 527       <arg choice="opt"><replaceable>options</replaceable></arg>
 528       <arg><replaceable>command</replaceable></arg>
 529       <arg><replaceable>devpath</replaceable></arg>
 530     </title>
 531       <para>Run a built-in command <replaceable>COMMAND</replaceable>
 532       for device <replaceable>DEVPATH</replaceable>, and print debug
 533       output.</para>
 534       <variablelist>
 535         <xi:include href="standard-options.xml" xpointer="help" />
 536       </variablelist>
 537     </refsect2>
 538   </refsect1>
 539
 540   <refsect1>
 541     <title>See Also</title>
 542     <para><citerefentry>
 543         <refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum>
 544     </citerefentry>,
 545     <citerefentry>
 546         <refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum>
 547     </citerefentry></para>
 548   </refsect1>
 549 </refentry>