man/udevadm.xml

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   6 <refentry id="udevadm">
   7   <refentryinfo>
   8     <title>udevadm</title>
   9     <productname>systemd</productname>
  10     <authorgroup>
  11       <author>
  12         <contrib>Developer</contrib>
  13         <firstname>Kay</firstname>
  14         <surname>Sievers</surname>
  15         <email>kay@vrfy.org</email>
  16       </author>
  17     </authorgroup>
  18   </refentryinfo>
  19
  20   <refmeta>
  21     <refentrytitle>udevadm</refentrytitle>
  22     <manvolnum>8</manvolnum>
  23   </refmeta>
  24
  25   <refnamediv>
  26     <refname>udevadm</refname><refpurpose>udev management tool</refpurpose>
  27   </refnamediv>
  28
  29   <refsynopsisdiv>
  30     <cmdsynopsis>
  31       <command>udevadm</command>
  32         <arg><option>--debug</option></arg>
  33         <arg><option>--version</option></arg>
  34         <arg><option>--help</option></arg>
  35     </cmdsynopsis>
  36     <cmdsynopsis>
  37       <command>udevadm info <replaceable>options</replaceable></command>
  38     </cmdsynopsis>
  39     <cmdsynopsis>
  40       <command>udevadm trigger <optional>options</optional></command>
  41     </cmdsynopsis>
  42     <cmdsynopsis>
  43       <command>udevadm settle <optional>options</optional></command>
  44     </cmdsynopsis>
  45     <cmdsynopsis>
  46       <command>udevadm control <replaceable>command</replaceable></command>
  47     </cmdsynopsis>
  48     <cmdsynopsis>
  49       <command>udevadm monitor <optional>options</optional></command>
  50     </cmdsynopsis>
  51     <cmdsynopsis>
  52       <command>udevadm hwdb <optional>options</optional></command>
  53     </cmdsynopsis>
  54     <cmdsynopsis>
  55       <command>udevadm test <optional>options</optional> <replaceable>devpath</replaceable></command>
  56     </cmdsynopsis>
  57     <cmdsynopsis>
  58       <command>udevadm test-builtin <optional>options</optional> <replaceable>command</replaceable> <replaceable>devpath</replaceable></command>
  59     </cmdsynopsis>
  60   </refsynopsisdiv>
  61
  62   <refsect1><title>Description</title>
  63     <para><command>udevadm</command> expects a command and command
  64     specific options.  It controls the runtime behavior of
  65     <command>systemd-udevd</command>, requests kernel events, manages
  66     the event queue, and provides simple debugging mechanisms.</para>
  67   </refsect1>
  68
  69   <refsect1><title>OPTIONS</title>
  70     <variablelist>
  71       <varlistentry>
  72         <term><option>--debug</option></term>
  73         <listitem>
  74           <para>Print debug messages to standard error.</para>
  75         </listitem>
  76       </varlistentry>
  77       <varlistentry>
  78         <term><option>--version</option></term>
  79         <listitem>
  80           <para>Print version number.</para>
  81         </listitem>
  82       </varlistentry>
  83       <varlistentry>
  84         <term><option>-h</option></term>
  85         <term><option>--help</option></term>
  86         <listitem>
  87           <para>Print help text.</para>
  88         </listitem>
  89       </varlistentry>
  90     </variablelist>
  91
  92     <refsect2><title>udevadm info <optional><replaceable>OPTIONS</replaceable></optional> <optional><replaceable>DEVPATH</replaceable>|<replaceable>FILE</replaceable></optional></title>
  93       <para>Queries the udev database for device information
  94       stored in the udev database. It can also query the properties
  95       of a device from its sysfs representation to help creating udev
  96       rules that match this device.</para>
  97       <variablelist>
  98         <varlistentry>
  99           <term><option>-q</option></term>
 100           <term><option>--query=<replaceable>TYPE</replaceable></option></term>
 101           <listitem>
 102             <para>Query the database for the specified type of device
 103             data. It needs the <option>--path</option> or
 104             <option>--name</option> to identify the specified device.
 105             Valid <replaceable>TYPE</replaceable>s are:
 106             <constant>name</constant>, <constant>symlink</constant>,
 107             <constant>path</constant>, <constant>property</constant>,
 108             <constant>all</constant>.</para>
 109           </listitem>
 110         </varlistentry>
 111         <varlistentry>
 112           <term><option>-p</option></term>
 113           <term><option>--path=<replaceable>DEVPATH</replaceable></option></term>
 114           <listitem>
 115             <para>The <filename>/sys</filename> path of the device to
 116             query, e.g.
 117             <filename><optional>/sys</optional>/class/block/sda</filename>.
 118             Note that this option usually is not very useful, since
 119             <command>udev</command> can guess the type of the
 120             argument, so <command>udevadm
 121             --devpath=/class/block/sda</command> is equivalent to
 122             <command>udevadm /sys/class/block/sda</command>.</para>
 123           </listitem>
 124         </varlistentry>
 125         <varlistentry>
 126           <term><option>-n</option></term>
 127           <term><option>--name=<replaceable>FILE</replaceable></option></term>
 128           <listitem>
 129             <para>The name of the device node or a symlink to query,
 130             e.g. <filename><optional>/dev</optional>/sda</filename>.
 131             Note that this option usually is not very useful, since
 132             <command>udev</command> can guess the type of the
 133             argument, so <command>udevadm --name=sda</command> is
 134             equivalent to <command>udevadm /dev/sda</command>.</para>
 135           </listitem>
 136         </varlistentry>
 137         <varlistentry>
 138           <term><option>-r</option></term>
 139           <term><option>--root</option></term>
 140           <listitem>
 141             <para>Print absolute paths in <command>name</command> or <command>symlink</command>
 142             query.</para>
 143           </listitem>
 144         </varlistentry>
 145         <varlistentry>
 146           <term><option>-a</option></term>
 147           <term><option>--attribute-walk</option></term>
 148           <listitem>
 149             <para>Print all sysfs properties of the specified device that can be used
 150             in udev rules to match the specified device. It prints all devices
 151             along the chain, up to the root of sysfs that can be used in udev rules.</para>
 152           </listitem>
 153         </varlistentry>
 154         <varlistentry>
 155           <term><option>-x</option></term>
 156           <term><option>--export</option></term>
 157           <listitem>
 158             <para>Print output as key/value pairs. Values are enclosed in single quotes.</para>
 159           </listitem>
 160         </varlistentry>
 161         <varlistentry>
 162           <term><option>-P</option></term>
 163           <term><option>--export-prefix=<replaceable>NAME</replaceable></option></term>
 164           <listitem>
 165             <para>Add a prefix to the key name of exported values.</para>
 166           </listitem>
 167         </varlistentry>
 168         <varlistentry>
 169           <term><option>-d</option></term>
 170           <term><option>--device-id-of-file=<replaceable>FILE</replaceable></option></term>
 171           <listitem>
 172             <para>Print major/minor numbers of the underlying device, where the file
 173             lives on.</para>
 174           </listitem>
 175         </varlistentry>
 176         <varlistentry>
 177           <term><option>-e</option></term>
 178           <term><option>--export-db</option></term>
 179           <listitem>
 180             <para>Export the content of the udev database.</para>
 181           </listitem>
 182         </varlistentry>
 183         <varlistentry>
 184           <term><option>-c</option></term>
 185           <term><option>--cleanup-db</option></term>
 186           <listitem>
 187             <para>Cleanup the udev database.</para>
 188           </listitem>
 189         </varlistentry>
 190         <varlistentry>
 191           <term><option>--version</option></term>
 192           <listitem>
 193             <para>Print version.</para>
 194           </listitem>
 195         </varlistentry>
 196         <varlistentry>
 197           <term><option>-h</option></term>
 198           <term><option>--help</option></term>
 199           <listitem>
 200             <para>Print help text.</para>
 201           </listitem>
 202         </varlistentry>
 203       </variablelist>
 204     </refsect2>
 205
 206     <refsect2><title>udevadm trigger <optional>options</optional></title>
 207       <para>Request device events from the kernel. Primarily used to replay events at system coldplug time.</para>
 208       <variablelist>
 209         <varlistentry>
 210           <term><option>-v</option></term>
 211           <term><option>--verbose</option></term>
 212           <listitem>
 213             <para>Print the list of devices which will be triggered.</para>
 214           </listitem>
 215         </varlistentry>
 216         <varlistentry>
 217           <term><option>-n</option></term>
 218           <term><option>--dry-run</option></term>
 219           <listitem>
 220             <para>Do not actually trigger the event.</para>
 221           </listitem>
 222         </varlistentry>
 223         <varlistentry>
 224           <term><option>-t</option></term>
 225           <term><option>--type=<replaceable>TYPE</replaceable></option></term>
 226           <listitem>
 227             <para>Trigger a specific type of devices. Valid types are:
 228             <command>devices</command>, <command>subsystems</command>.
 229             The default value is <command>devices</command>.</para>
 230           </listitem>
 231         </varlistentry>
 232         <varlistentry>
 233           <term><option>-c</option></term>
 234           <term><option>--action=<replaceable>ACTION</replaceable></option></term>
 235           <listitem>
 236             <para>Type of event to be triggered. The default value is
 237             <command>change</command>.</para>
 238           </listitem>
 239         </varlistentry>
 240         <varlistentry>
 241           <term><option>-s</option></term>
 242           <term><option>--subsystem-match=<replaceable>SUBSYSTEM</replaceable></option></term>
 243           <listitem>
 244             <para>Trigger events for devices which belong to a
 245             matching subsystem. This option can be specified multiple
 246             times and supports shell style pattern matching.</para>
 247           </listitem>
 248         </varlistentry>
 249         <varlistentry>
 250           <term><option>-S</option></term>
 251           <term><option>--subsystem-nomatch=<replaceable>SUBSYSTEM</replaceable></option></term>
 252           <listitem>
 253             <para>Do not trigger events for devices which belong to a matching subsystem. This option
 254             can be specified multiple times and supports shell style pattern matching.</para>
 255           </listitem>
 256         </varlistentry>
 257         <varlistentry>
 258           <term><option>-a</option></term>
 259           <term><option>--attr-match=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
 260           <listitem>
 261             <para>Trigger events for devices with a matching sysfs
 262             attribute. If a value is specified along with the
 263             attribute name, the content of the attribute is matched
 264             against the given value using shell style pattern
 265             matching. If no value is specified, the existence of the
 266             sysfs attribute is checked. This option can be specified
 267             multiple times.</para>
 268           </listitem>
 269         </varlistentry>
 270         <varlistentry>
 271           <term><option>-A</option></term>
 272           <term><option>--attr-nomatch=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
 273           <listitem>
 274             <para>Do not trigger events for devices with a matching
 275             sysfs attribute. If a value is specified along with the
 276             attribute name, the content of the attribute is matched
 277             against the given value using shell style pattern
 278             matching. If no value is specified, the existence of the
 279             sysfs attribute is checked. This option can be specified
 280             multiple times.</para>
 281           </listitem>
 282         </varlistentry>
 283         <varlistentry>
 284           <term><option>-p</option></term>
 285           <term><option>--property-match=<replaceable>PROPERTY</replaceable>=<replaceable>VALUE</replaceable></option></term>
 286           <listitem>
 287             <para>Trigger events for devices with a matching property
 288             value. This option can be specified multiple times and
 289             supports shell style pattern matching.</para>
 290           </listitem>
 291         </varlistentry>
 292         <varlistentry>
 293           <term><option>-g</option></term>
 294           <term><option>--tag-match=<replaceable>PROPERTY</replaceable></option></term>
 295           <listitem>
 296             <para>Trigger events for devices with a matching tag. This
 297             option can be specified multiple times.</para>
 298           </listitem>
 299         </varlistentry>
 300         <varlistentry>
 301           <term><option>-y</option></term>
 302           <term><option>--sysname-match=<replaceable>NAME</replaceable></option></term>
 303           <listitem>
 304             <para>Trigger events for devices with a matching sys
 305             device name. This option can be specified multiple times
 306             and supports shell style pattern matching.</para>
 307           </listitem>
 308         </varlistentry>
 309         <varlistentry>
 310           <term><option>-b</option></term>
 311           <term><option>--parent-match=<replaceable>SYSPATH</replaceable></option></term>
 312           <listitem>
 313             <para>Trigger events for all children of a given
 314             device.</para>
 315           </listitem>
 316         </varlistentry>
 317         <varlistentry>
 318           <term><option>-h</option></term>
 319           <term><option>--help</option></term>
 320           <listitem>
 321             <para>Print help text.</para>
 322           </listitem>
 323         </varlistentry>
 324       </variablelist>
 325     </refsect2>
 326
 327     <refsect2><title>udevadm settle <optional>options</optional></title>
 328       <para>Watches the udev event queue, and exits if all current events are handled.</para>
 329       <variablelist>
 330         <varlistentry>
 331           <term><option>-t</option></term>
 332           <term><option>--timeout=<replaceable>SECONDS</replaceable></option></term>
 333           <listitem>
 334             <para>Maximum number of seconds to wait for the event
 335             queue to become empty. The default value is 120 seconds. A
 336             value of 0 will check if the queue is empty and always
 337             return immediately.</para>
 338           </listitem>
 339         </varlistentry>
 340         <varlistentry>
 341           <term><option>-E</option></term>
 342           <term><option>--exit-if-exists=<replaceable>FILE</replaceable></option></term>
 343           <listitem>
 344             <para>Stop waiting if file exists.</para>
 345           </listitem>
 346         </varlistentry>
 347         <varlistentry>
 348           <term><option>-h</option></term>
 349           <term><option>--help</option></term>
 350           <listitem>
 351             <para>Print help text.</para>
 352           </listitem>
 353         </varlistentry>
 354       </variablelist>
 355     </refsect2>
 356
 357     <refsect2><title>udevadm control <replaceable>command</replaceable></title>
 358       <para>Modify the internal state of the running udev daemon.</para>
 359       <variablelist>
 360         <varlistentry>
 361           <term><option>-x</option></term>
 362           <term><option>--exit</option></term>
 363           <listitem>
 364             <para>Signal and wait for systemd-udevd to exit.</para>
 365           </listitem>
 366         </varlistentry>
 367         <varlistentry>
 368           <term><option>-l</option></term>
 369           <term><option>--log-priority=<replaceable>value</replaceable></option></term>
 370           <listitem>
 371             <para>Set the internal log level of systemd-udevd. Valid values are the numerical
 372             syslog priorities or their textual representations: <option>err</option>,
 373             <option>info</option> and <option>debug</option>.</para>
 374           </listitem>
 375         </varlistentry>
 376         <varlistentry>
 377           <term><option>-s</option></term>
 378           <term><option>--stop-exec-queue</option></term>
 379           <listitem>
 380             <para>Signal systemd-udevd to stop executing new events. Incoming events
 381             will be queued.</para>
 382           </listitem>
 383         </varlistentry>
 384         <varlistentry>
 385           <term><option>-S</option></term>
 386           <term><option>--start-exec-queue</option></term>
 387           <listitem>
 388             <para>Signal systemd-udevd to enable the execution of events.</para>
 389           </listitem>
 390         </varlistentry>
 391         <varlistentry>
 392           <term><option>-R</option></term>
 393           <term><option>--reload</option></term>
 394           <listitem>
 395             <para>Signal systemd-udevd to reload the rules files and other databases like the kernel
 396             module index. Reloading rules and databases does not apply any changes to already
 397             existing devices; the new configuration will only be applied to new events.</para>
 398           </listitem>
 399         </varlistentry>
 400         <varlistentry>
 401           <term><option>-p</option></term>
 402           <term><option>--property=<replaceable>KEY</replaceable>=<replaceable>value</replaceable></option></term>
 403           <listitem>
 404             <para>Set a global property for all events.</para>
 405           </listitem>
 406         </varlistentry>
 407         <varlistentry>
 408           <term><option>-m</option></term>
 409           <term><option>--children-max=</option><replaceable>value</replaceable></term>
 410           <listitem>
 411             <para>Set the maximum number of events, systemd-udevd will handle at the
 412             same time.</para>
 413           </listitem>
 414         </varlistentry>
 415         <varlistentry>
 416           <term><option>--timeout=</option><replaceable>seconds</replaceable></term>
 417           <listitem>
 418             <para>The maximum number of seconds to wait for a reply from systemd-udevd.</para>
 419           </listitem>
 420         </varlistentry>
 421         <varlistentry>
 422           <term><option>-h</option></term>
 423           <term><option>--help</option></term>
 424           <listitem>
 425             <para>Print help text.</para>
 426           </listitem>
 427         </varlistentry>
 428       </variablelist>
 429     </refsect2>
 430
 431     <refsect2><title>udevadm monitor <optional>options</optional></title>
 432       <para>Listens to the kernel uevents and events sent out by a udev rule
 433       and prints the devpath of the event to the console. It can be used to analyze the
 434       event timing, by comparing the timestamps of the kernel uevent and the udev event.
 435       </para>
 436       <variablelist>
 437         <varlistentry>
 438           <term><option>-k</option></term>
 439           <term><option>--kernel</option></term>
 440           <listitem>
 441             <para>Print the kernel uevents.</para>
 442           </listitem>
 443         </varlistentry>
 444         <varlistentry>
 445           <term><option>-u</option></term>
 446           <term><option>--udev</option></term>
 447           <listitem>
 448             <para>Print the udev event after the rule processing.</para>
 449           </listitem>
 450         </varlistentry>
 451         <varlistentry>
 452           <term><option>-p</option></term>
 453           <term><option>--property</option></term>
 454           <listitem>
 455             <para>Also print the properties of the event.</para>
 456           </listitem>
 457         </varlistentry>
 458         <varlistentry>
 459           <term><option>-s</option></term>
 460           <term><option>--subsystem-match=<replaceable>string[/string]</replaceable></option></term>
 461           <listitem>
 462             <para>Filter events by subsystem[/devtype]. Only udev events with a matching subsystem value will pass.</para>
 463           </listitem>
 464         </varlistentry>
 465         <varlistentry>
 466           <term><option>-t</option></term>
 467           <term><option>--tag-match=<replaceable>string</replaceable></option></term>
 468           <listitem>
 469             <para>Filter events by property. Only udev events with a given tag attached will pass.</para>
 470           </listitem>
 471         </varlistentry>
 472         <varlistentry>
 473           <term><option>-h</option></term>
 474           <term><option>--help</option></term>
 475           <listitem>
 476             <para>Print help text.</para>
 477           </listitem>
 478         </varlistentry>
 479       </variablelist>
 480     </refsect2>
 481
 482     <refsect2><title>udevadm hwdb <optional>options</optional></title>
 483       <para>Maintain the hardware database index in <filename>/etc/udev/hwdb.bin</filename>.</para>
 484       <variablelist>
 485         <varlistentry>
 486           <term><option>-u</option></term>
 487           <term><option>--update</option></term>
 488           <listitem>
 489             <para>Compile the hardware database information located in /usr/lib/udev/hwdb.d/,
 490             /etc/udev/hwdb.d/ and store it in <filename>/etc/udev/hwdb.bin</filename>. This should be done after
 491             any update to the source files; it will not be called automatically. The running
 492             udev daemon will detect a new database on its own and does not need to be
 493             notified about it.</para>
 494           </listitem>
 495         </varlistentry>
 496         <varlistentry>
 497           <term><option>-t</option></term>
 498           <term><option>--test=<replaceable>string</replaceable></option></term>
 499           <listitem>
 500             <para>Query the database with a modalias string, and print the
 501             retrieved properties.</para>
 502           </listitem>
 503         </varlistentry>
 504         <varlistentry>
 505           <term><option>-r</option></term>
 506           <term><option>--root=<replaceable>string</replaceable></option></term>
 507           <listitem>
 508             <para>Alternative root path in the file system for reading and writing files.</para>
 509           </listitem>
 510         </varlistentry>
 511         <varlistentry>
 512           <term><option>-h</option></term>
 513           <term><option>--help</option></term>
 514           <listitem>
 515             <para>Print help text.</para>
 516           </listitem>
 517         </varlistentry>
 518       </variablelist>
 519     </refsect2>
 520
 521     <refsect2><title>udevadm test <optional>options</optional> <replaceable>devpath</replaceable></title>
 522       <para>Simulate a udev event run for the given device, and print debug output.</para>
 523       <variablelist>
 524         <varlistentry>
 525           <term><option>-a</option></term>
 526           <term><option>--action=<replaceable>string</replaceable></option></term>
 527           <listitem>
 528             <para>The action string.</para>
 529           </listitem>
 530         </varlistentry>
 531         <varlistentry>
 532           <term><option>-N</option></term>
 533           <term><option>--resolve-names=<constant>early</constant>|<constant>late</constant>|<constant>never</constant></option></term>
 534           <listitem>
 535             <para>Specify when udevadm should resolve names of users
 536             and groups.  When set to <constant>early</constant> (the
 537             default), names will be resolved when the rules are
 538             parsed. When set to <constant>late</constant>, names will
 539             be resolved for every event. When set to
 540             <constant>never</constant>, names will never be resolved
 541             and all devices will be owned by root.</para>
 542           </listitem>
 543         </varlistentry>
 544         <varlistentry>
 545           <term><option>-h</option></term>
 546           <term><option>--help</option></term>
 547           <listitem>
 548             <para>Print help text.</para>
 549           </listitem>
 550         </varlistentry>
 551       </variablelist>
 552     </refsect2>
 553
 554     <refsect2><title>udevadm test-builtin <optional>options</optional> <replaceable>COMMAND</replaceable> <replaceable>DEVPATH</replaceable></title>
 555       <para>Run a built-in command <replaceable>COMMAND</replaceable>
 556       for device <replaceable>DEVPATH</replaceable>, and print debug
 557       output.</para>
 558       <variablelist>
 559         <varlistentry>
 560           <term><option>-h</option></term>
 561           <term><option>--help</option></term>
 562           <listitem>
 563             <para>Print help text.</para>
 564           </listitem>
 565         </varlistentry>
 566       </variablelist>
 567     </refsect2>
 568   </refsect1>
 569
 570   <refsect1>
 571     <title>See Also</title>
 572     <para><citerefentry>
 573         <refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum>
 574     </citerefentry>,
 575     <citerefentry>
 576         <refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum>
 577     </citerefentry></para>
 578   </refsect1>
 579 </refentry>