man/udevadm.xml

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   5 <!--
   6   SPDX-License-Identifier: LGPL-2.1+
   7
   8   Copyright © 2010-2013 Kay Sievers
   9 -->
  10
  11 <refentry id="udevadm"
  12           xmlns:xi="http://www.w3.org/2001/XInclude">
  13
  14   <refentryinfo>
  15     <title>udevadm</title>
  16     <productname>systemd</productname>
  17     <authorgroup>
  18       <author>
  19         <contrib>Developer</contrib>
  20         <firstname>Kay</firstname>
  21         <surname>Sievers</surname>
  22         <email>kay@vrfy.org</email>
  23       </author>
  24     </authorgroup>
  25   </refentryinfo>
  26
  27   <refmeta>
  28     <refentrytitle>udevadm</refentrytitle>
  29     <manvolnum>8</manvolnum>
  30   </refmeta>
  31
  32   <refnamediv>
  33     <refname>udevadm</refname><refpurpose>udev management tool</refpurpose>
  34   </refnamediv>
  35
  36   <refsynopsisdiv>
  37     <cmdsynopsis>
  38       <command>udevadm</command>
  39         <arg><option>--debug</option></arg>
  40         <arg><option>--version</option></arg>
  41         <arg><option>--help</option></arg>
  42     </cmdsynopsis>
  43     <cmdsynopsis>
  44       <command>udevadm info <optional>options</optional> <optional>devpath</optional></command>
  45     </cmdsynopsis>
  46     <cmdsynopsis>
  47       <command>udevadm trigger <optional>options</optional> <optional>devpath</optional></command>
  48     </cmdsynopsis>
  49     <cmdsynopsis>
  50       <command>udevadm settle <optional>options</optional></command>
  51     </cmdsynopsis>
  52     <cmdsynopsis>
  53       <command>udevadm control <replaceable>option</replaceable></command>
  54     </cmdsynopsis>
  55     <cmdsynopsis>
  56       <command>udevadm monitor <optional>options</optional></command>
  57     </cmdsynopsis>
  58     <cmdsynopsis>
  59       <command>udevadm test <optional>options</optional> <replaceable>devpath</replaceable></command>
  60     </cmdsynopsis>
  61     <cmdsynopsis>
  62       <command>udevadm test-builtin <optional>options</optional> <replaceable>command</replaceable> <replaceable>devpath</replaceable></command>
  63     </cmdsynopsis>
  64   </refsynopsisdiv>
  65
  66   <refsect1><title>Description</title>
  67     <para><command>udevadm</command> expects a command and command
  68     specific options.  It controls the runtime behavior of
  69     <command>systemd-udevd</command>, requests kernel events, manages
  70     the event queue, and provides simple debugging mechanisms.</para>
  71   </refsect1>
  72
  73   <refsect1><title>Options</title>
  74     <variablelist>
  75       <varlistentry>
  76         <term><option>-d</option></term>
  77         <term><option>--debug</option></term>
  78         <listitem>
  79           <para>Print debug messages to standard error. This option is implied in <command>udevadm test</command> and
  80           <command>udevadm test-builtin</command> commands.</para>
  81         </listitem>
  82       </varlistentry>
  83
  84       <xi:include href="standard-options.xml" xpointer="help" />
  85     </variablelist>
  86
  87     <refsect2><title>udevadm info
  88       <arg choice="opt"><replaceable>options</replaceable></arg>
  89       <arg choice="opt"><replaceable>devpath</replaceable>|<replaceable>file</replaceable></arg>
  90     </title>
  91
  92       <para>Queries the udev database for device information
  93       stored in the udev database. It can also query the properties
  94       of a device from its sysfs representation to help creating udev
  95       rules that match this device.</para>
  96       <variablelist>
  97         <varlistentry>
  98           <term><option>-q</option></term>
  99           <term><option>--query=<replaceable>TYPE</replaceable></option></term>
 100           <listitem>
 101             <para>Query the database for the specified type of device
 102             data. It needs the <option>--path</option> or
 103             <option>--name</option> to identify the specified device.
 104             Valid <replaceable>TYPE</replaceable>s are:
 105             <constant>name</constant>, <constant>symlink</constant>,
 106             <constant>path</constant>, <constant>property</constant>,
 107             <constant>all</constant>.</para>
 108           </listitem>
 109         </varlistentry>
 110         <varlistentry>
 111           <term><option>-p</option></term>
 112           <term><option>--path=<replaceable>DEVPATH</replaceable></option></term>
 113           <listitem>
 114             <para>The <filename>/sys</filename> path of the device to
 115             query, e.g.
 116             <filename><optional>/sys</optional>/class/block/sda</filename>.
 117             Note that this option usually is not very useful, since
 118             <command>udev</command> can guess the type of the
 119             argument, so <command>udevadm info
 120             --path=/class/block/sda</command> is equivalent to
 121             <command>udevadm info /sys/class/block/sda</command>.</para>
 122           </listitem>
 123         </varlistentry>
 124         <varlistentry>
 125           <term><option>-n</option></term>
 126           <term><option>--name=<replaceable>FILE</replaceable></option></term>
 127           <listitem>
 128             <para>The name of the device node or a symlink to query,
 129             e.g. <filename><optional>/dev</optional>/sda</filename>.
 130             Note that this option usually is not very useful, since
 131             <command>udev</command> can guess the type of the
 132             argument, so <command>udevadm info --name=sda</command> is
 133             equivalent to <command>udevadm info /dev/sda</command>.</para>
 134           </listitem>
 135         </varlistentry>
 136         <varlistentry>
 137           <term><option>-r</option></term>
 138           <term><option>--root</option></term>
 139           <listitem>
 140             <para>Print absolute paths in <command>name</command> or <command>symlink</command>
 141             query.</para>
 142           </listitem>
 143         </varlistentry>
 144         <varlistentry>
 145           <term><option>-a</option></term>
 146           <term><option>--attribute-walk</option></term>
 147           <listitem>
 148             <para>Print all sysfs properties of the specified device that can be used
 149             in udev rules to match the specified device. It prints all devices
 150             along the chain, up to the root of sysfs that can be used in udev rules.</para>
 151           </listitem>
 152         </varlistentry>
 153         <varlistentry>
 154           <term><option>-x</option></term>
 155           <term><option>--export</option></term>
 156           <listitem>
 157             <para>Print output as key/value pairs. Values are enclosed in single quotes.</para>
 158           </listitem>
 159         </varlistentry>
 160         <varlistentry>
 161           <term><option>-P</option></term>
 162           <term><option>--export-prefix=<replaceable>NAME</replaceable></option></term>
 163           <listitem>
 164             <para>Add a prefix to the key name of exported values.</para>
 165           </listitem>
 166         </varlistentry>
 167         <varlistentry>
 168           <term><option>-d</option></term>
 169           <term><option>--device-id-of-file=<replaceable>FILE</replaceable></option></term>
 170           <listitem>
 171             <para>Print major/minor numbers of the underlying device, where the file
 172             lives on.</para>
 173           </listitem>
 174         </varlistentry>
 175         <varlistentry>
 176           <term><option>-e</option></term>
 177           <term><option>--export-db</option></term>
 178           <listitem>
 179             <para>Export the content of the udev database.</para>
 180           </listitem>
 181         </varlistentry>
 182         <varlistentry>
 183           <term><option>-c</option></term>
 184           <term><option>--cleanup-db</option></term>
 185           <listitem>
 186             <para>Cleanup the udev database.</para>
 187           </listitem>
 188         </varlistentry>
 189
 190         <xi:include href="standard-options.xml" xpointer="help" />
 191       </variablelist>
 192
 193       <para>In addition, an optional positional argument can be used
 194       to specify a device name or a sys path. It must start with
 195       <filename>/dev</filename> or <filename>/sys</filename>
 196       respectively.</para>
 197     </refsect2>
 198
 199     <refsect2><title>udevadm trigger
 200       <arg choice="opt"><replaceable>options</replaceable></arg>
 201       <arg choice="opt" rep="repeat"><replaceable>devpath</replaceable>|<replaceable>file</replaceable></arg></title>
 202       <para>Request device events from the kernel. Primarily used to replay events at system coldplug time.</para>
 203       <variablelist>
 204         <varlistentry>
 205           <term><option>-v</option></term>
 206           <term><option>--verbose</option></term>
 207           <listitem>
 208             <para>Print the list of devices which will be triggered.</para>
 209           </listitem>
 210         </varlistentry>
 211         <varlistentry>
 212           <term><option>-n</option></term>
 213           <term><option>--dry-run</option></term>
 214           <listitem>
 215             <para>Do not actually trigger the event.</para>
 216           </listitem>
 217         </varlistentry>
 218         <varlistentry>
 219           <term><option>-t</option></term>
 220           <term><option>--type=<replaceable>TYPE</replaceable></option></term>
 221           <listitem>
 222             <para>Trigger a specific type of devices. Valid types are:
 223             <command>devices</command>, <command>subsystems</command>.
 224             The default value is <command>devices</command>.</para>
 225           </listitem>
 226         </varlistentry>
 227         <varlistentry>
 228           <term><option>-c</option></term>
 229           <term><option>--action=<replaceable>ACTION</replaceable></option></term>
 230           <listitem>
 231             <para>Type of event to be triggered. The default value is
 232             <command>change</command>.</para>
 233           </listitem>
 234         </varlistentry>
 235         <varlistentry>
 236           <term><option>-s</option></term>
 237           <term><option>--subsystem-match=<replaceable>SUBSYSTEM</replaceable></option></term>
 238           <listitem>
 239             <para>Trigger events for devices which belong to a
 240             matching subsystem. This option can be specified multiple
 241             times and supports shell style pattern matching.</para>
 242           </listitem>
 243         </varlistentry>
 244         <varlistentry>
 245           <term><option>-S</option></term>
 246           <term><option>--subsystem-nomatch=<replaceable>SUBSYSTEM</replaceable></option></term>
 247           <listitem>
 248             <para>Do not trigger events for devices which belong to a matching subsystem. This option
 249             can be specified multiple times and supports shell style pattern matching.</para>
 250           </listitem>
 251         </varlistentry>
 252         <varlistentry>
 253           <term><option>-a</option></term>
 254           <term><option>--attr-match=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
 255           <listitem>
 256             <para>Trigger events for devices with a matching sysfs
 257             attribute. If a value is specified along with the
 258             attribute name, the content of the attribute is matched
 259             against the given value using shell style pattern
 260             matching. If no value is specified, the existence of the
 261             sysfs attribute is checked. This option can be specified
 262             multiple times.</para>
 263           </listitem>
 264         </varlistentry>
 265         <varlistentry>
 266           <term><option>-A</option></term>
 267           <term><option>--attr-nomatch=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
 268           <listitem>
 269             <para>Do not trigger events for devices with a matching
 270             sysfs attribute. If a value is specified along with the
 271             attribute name, the content of the attribute is matched
 272             against the given value using shell style pattern
 273             matching. If no value is specified, the existence of the
 274             sysfs attribute is checked. This option can be specified
 275             multiple times.</para>
 276           </listitem>
 277         </varlistentry>
 278         <varlistentry>
 279           <term><option>-p</option></term>
 280           <term><option>--property-match=<replaceable>PROPERTY</replaceable>=<replaceable>VALUE</replaceable></option></term>
 281           <listitem>
 282             <para>Trigger events for devices with a matching property
 283             value. This option can be specified multiple times and
 284             supports shell style pattern matching.</para>
 285           </listitem>
 286         </varlistentry>
 287         <varlistentry>
 288           <term><option>-g</option></term>
 289           <term><option>--tag-match=<replaceable>PROPERTY</replaceable></option></term>
 290           <listitem>
 291             <para>Trigger events for devices with a matching tag. This
 292             option can be specified multiple times.</para>
 293           </listitem>
 294         </varlistentry>
 295         <varlistentry>
 296           <term><option>-y</option></term>
 297           <term><option>--sysname-match=<replaceable>PATH</replaceable></option></term>
 298           <listitem>
 299             <para>Trigger events for devices for which the last component
 300             (i.e. the filename) of the <filename>/sys</filename> path matches
 301             the specified <replaceable>PATH</replaceable>. This option can be
 302             specified multiple times and also supports shell style pattern
 303             matching.</para>
 304           </listitem>
 305         </varlistentry>
 306         <varlistentry>
 307           <term><option>--name-match=<replaceable>NAME</replaceable></option></term>
 308           <listitem>
 309             <para>Trigger events for devices with a matching
 310             device path. This option can be specified multiple
 311             times.</para>
 312           </listitem>
 313         </varlistentry>
 314         <varlistentry>
 315           <term><option>-b</option></term>
 316           <term><option>--parent-match=<replaceable>SYSPATH</replaceable></option></term>
 317           <listitem>
 318             <para>Trigger events for all children of a given
 319             device.</para>
 320           </listitem>
 321         </varlistentry>
 322         <varlistentry>
 323           <term><option>-w</option></term>
 324           <term><option>--settle</option></term>
 325           <listitem>
 326             <para>Apart from triggering events, also waits for those events to
 327             finish. Note that this is different from calling <command>udevadm
 328             settle</command>. <command>udevadm settle</command> waits for all
 329             events to finish. This option only waits for events triggered by
 330             the same command to finish.</para>
 331           </listitem>
 332         </varlistentry>
 333
 334         <xi:include href="standard-options.xml" xpointer="help" />
 335       </variablelist>
 336
 337       <para>In addition, optional positional arguments can be used
 338       to specify device names or sys paths. They must start with
 339       <filename>/dev</filename> or <filename>/sys</filename>
 340       respectively.</para>
 341     </refsect2>
 342
 343     <refsect2><title>udevadm settle
 344       <arg choice="opt"><replaceable>options</replaceable></arg>
 345     </title>
 346       <para>Watches the udev event queue, and exits if all current events are handled.</para>
 347       <variablelist>
 348         <varlistentry>
 349           <term><option>-t</option></term>
 350           <term><option>--timeout=<replaceable>SECONDS</replaceable></option></term>
 351           <listitem>
 352             <para>Maximum number of seconds to wait for the event
 353             queue to become empty. The default value is 120 seconds. A
 354             value of 0 will check if the queue is empty and always
 355             return immediately.</para>
 356           </listitem>
 357         </varlistentry>
 358         <varlistentry>
 359           <term><option>-E</option></term>
 360           <term><option>--exit-if-exists=<replaceable>FILE</replaceable></option></term>
 361           <listitem>
 362             <para>Stop waiting if file exists.</para>
 363           </listitem>
 364         </varlistentry>
 365
 366         <xi:include href="standard-options.xml" xpointer="help" />
 367       </variablelist>
 368     </refsect2>
 369
 370     <refsect2><title>udevadm control <replaceable>option</replaceable></title>
 371       <para>Modify the internal state of the running udev daemon.</para>
 372       <variablelist>
 373         <varlistentry>
 374           <term><option>-e</option></term>
 375           <term><option>--exit</option></term>
 376           <listitem>
 377             <para>Signal and wait for systemd-udevd to exit.</para>
 378           </listitem>
 379         </varlistentry>
 380         <varlistentry>
 381           <term><option>-l</option></term>
 382           <term><option>--log-priority=<replaceable>value</replaceable></option></term>
 383           <listitem>
 384             <para>Set the internal log level of
 385             <filename>systemd-udevd</filename>. Valid values are the
 386             numerical syslog priorities or their textual
 387             representations: <option>emerg</option>,
 388             <option>alert</option>, <option>crit</option>,
 389             <option>err</option>, <option>warning</option>,
 390             <option>notice</option>, <option>info</option>, and
 391             <option>debug</option>.</para>
 392           </listitem>
 393         </varlistentry>
 394         <varlistentry>
 395           <term><option>-s</option></term>
 396           <term><option>--stop-exec-queue</option></term>
 397           <listitem>
 398             <para>Signal systemd-udevd to stop executing new events. Incoming events
 399             will be queued.</para>
 400           </listitem>
 401         </varlistentry>
 402         <varlistentry>
 403           <term><option>-S</option></term>
 404           <term><option>--start-exec-queue</option></term>
 405           <listitem>
 406             <para>Signal systemd-udevd to enable the execution of events.</para>
 407           </listitem>
 408         </varlistentry>
 409         <varlistentry>
 410           <term><option>-R</option></term>
 411           <term><option>--reload</option></term>
 412           <listitem>
 413             <para>Signal systemd-udevd to reload the rules files and other databases like the kernel
 414             module index. Reloading rules and databases does not apply any changes to already
 415             existing devices; the new configuration will only be applied to new events.</para>
 416           </listitem>
 417         </varlistentry>
 418         <varlistentry>
 419           <term><option>-p</option></term>
 420           <term><option>--property=<replaceable>KEY</replaceable>=<replaceable>value</replaceable></option></term>
 421           <listitem>
 422             <para>Set a global property for all events.</para>
 423           </listitem>
 424         </varlistentry>
 425         <varlistentry>
 426           <term><option>-m</option></term>
 427           <term><option>--children-max=</option><replaceable>value</replaceable></term>
 428           <listitem>
 429             <para>Set the maximum number of events, systemd-udevd will handle at the
 430             same time.</para>
 431           </listitem>
 432         </varlistentry>
 433         <varlistentry>
 434           <term><option>-t</option></term>
 435           <term><option>--timeout=</option><replaceable>seconds</replaceable></term>
 436           <listitem>
 437             <para>The maximum number of seconds to wait for a reply from systemd-udevd.</para>
 438           </listitem>
 439         </varlistentry>
 440
 441         <xi:include href="standard-options.xml" xpointer="help" />
 442       </variablelist>
 443     </refsect2>
 444
 445     <refsect2><title>udevadm monitor
 446       <arg choice="opt"><replaceable>options</replaceable></arg>
 447     </title>
 448       <para>Listens to the kernel uevents and events sent out by a udev rule
 449       and prints the devpath of the event to the console. It can be used to analyze the
 450       event timing, by comparing the timestamps of the kernel uevent and the udev event.
 451       </para>
 452       <variablelist>
 453         <varlistentry>
 454           <term><option>-k</option></term>
 455           <term><option>--kernel</option></term>
 456           <listitem>
 457             <para>Print the kernel uevents.</para>
 458           </listitem>
 459         </varlistentry>
 460         <varlistentry>
 461           <term><option>-u</option></term>
 462           <term><option>--udev</option></term>
 463           <listitem>
 464             <para>Print the udev event after the rule processing.</para>
 465           </listitem>
 466         </varlistentry>
 467         <varlistentry>
 468           <term><option>-p</option></term>
 469           <term><option>--property</option></term>
 470           <listitem>
 471             <para>Also print the properties of the event.</para>
 472           </listitem>
 473         </varlistentry>
 474         <varlistentry>
 475           <term><option>-s</option></term>
 476           <term><option>--subsystem-match=<replaceable>string[/string]</replaceable></option></term>
 477           <listitem>
 478             <para>Filter kernel uevents and udev events by subsystem[/devtype]. Only events with a matching subsystem value will pass.</para>
 479           </listitem>
 480         </varlistentry>
 481         <varlistentry>
 482           <term><option>-t</option></term>
 483           <term><option>--tag-match=<replaceable>string</replaceable></option></term>
 484           <listitem>
 485             <para>Filter udev events by tag. Only udev events with a given tag attached will pass.</para>
 486           </listitem>
 487         </varlistentry>
 488
 489         <xi:include href="standard-options.xml" xpointer="help" />
 490       </variablelist>
 491     </refsect2>
 492
 493     <refsect2><title>udevadm test
 494       <arg choice="opt"><replaceable>options</replaceable></arg>
 495       <arg><replaceable>devpath</replaceable></arg>
 496     </title>
 497       <para>Simulate a udev event run for the given device, and print debug output.</para>
 498       <variablelist>
 499         <varlistentry>
 500           <term><option>-a</option></term>
 501           <term><option>--action=<replaceable>string</replaceable></option></term>
 502           <listitem>
 503             <para>The action string.</para>
 504           </listitem>
 505         </varlistentry>
 506         <varlistentry>
 507           <term><option>-N</option></term>
 508           <term><option>--resolve-names=<constant>early</constant>|<constant>late</constant>|<constant>never</constant></option></term>
 509           <listitem>
 510             <para>Specify when udevadm should resolve names of users
 511             and groups.  When set to <constant>early</constant> (the
 512             default), names will be resolved when the rules are
 513             parsed. When set to <constant>late</constant>, names will
 514             be resolved for every event. When set to
 515             <constant>never</constant>, names will never be resolved
 516             and all devices will be owned by root.</para>
 517           </listitem>
 518         </varlistentry>
 519
 520         <xi:include href="standard-options.xml" xpointer="help" />
 521       </variablelist>
 522     </refsect2>
 523
 524     <refsect2><title>udevadm test-builtin
 525       <arg choice="opt"><replaceable>options</replaceable></arg>
 526       <arg><replaceable>command</replaceable></arg>
 527       <arg><replaceable>devpath</replaceable></arg>
 528     </title>
 529       <para>Run a built-in command <replaceable>COMMAND</replaceable>
 530       for device <replaceable>DEVPATH</replaceable>, and print debug
 531       output.</para>
 532       <variablelist>
 533         <xi:include href="standard-options.xml" xpointer="help" />
 534       </variablelist>
 535     </refsect2>
 536   </refsect1>
 537
 538   <refsect1>
 539     <title>See Also</title>
 540     <para><citerefentry>
 541         <refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum>
 542     </citerefentry>,
 543     <citerefentry>
 544         <refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum>
 545     </citerefentry></para>
 546   </refsect1>
 547 </refentry>