man/udevadm.xml

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  25
  26 <refentry id="udevadm">
  27   <refentryinfo>
  28     <title>udevadm</title>
  29     <productname>systemd</productname>
  30     <authorgroup>
  31       <author>
  32         <contrib>Developer</contrib>
  33         <firstname>Kay</firstname>
  34         <surname>Sievers</surname>
  35         <email>kay@vrfy.org</email>
  36       </author>
  37     </authorgroup>
  38   </refentryinfo>
  39
  40   <refmeta>
  41     <refentrytitle>udevadm</refentrytitle>
  42     <manvolnum>8</manvolnum>
  43   </refmeta>
  44
  45   <refnamediv>
  46     <refname>udevadm</refname><refpurpose>udev management tool</refpurpose>
  47   </refnamediv>
  48
  49   <refsynopsisdiv>
  50     <cmdsynopsis>
  51       <command>udevadm</command>
  52         <arg><option>--debug</option></arg>
  53         <arg><option>--version</option></arg>
  54         <arg><option>--help</option></arg>
  55     </cmdsynopsis>
  56     <cmdsynopsis>
  57       <command>udevadm info <replaceable>options</replaceable></command>
  58     </cmdsynopsis>
  59     <cmdsynopsis>
  60       <command>udevadm trigger <optional>options</optional></command>
  61     </cmdsynopsis>
  62     <cmdsynopsis>
  63       <command>udevadm settle <optional>options</optional></command>
  64     </cmdsynopsis>
  65     <cmdsynopsis>
  66       <command>udevadm control <replaceable>command</replaceable></command>
  67     </cmdsynopsis>
  68     <cmdsynopsis>
  69       <command>udevadm monitor <optional>options</optional></command>
  70     </cmdsynopsis>
  71     <cmdsynopsis>
  72       <command>udevadm test <optional>options</optional> <replaceable>devpath</replaceable></command>
  73     </cmdsynopsis>
  74     <cmdsynopsis>
  75       <command>udevadm test-builtin <optional>options</optional> <replaceable>command</replaceable> <replaceable>devpath</replaceable></command>
  76     </cmdsynopsis>
  77   </refsynopsisdiv>
  78
  79   <refsect1><title>Description</title>
  80     <para><command>udevadm</command> expects a command and command
  81     specific options.  It controls the runtime behavior of
  82     <command>systemd-udevd</command>, requests kernel events, manages
  83     the event queue, and provides simple debugging mechanisms.</para>
  84   </refsect1>
  85
  86   <refsect1><title>Options</title>
  87     <variablelist>
  88       <varlistentry>
  89         <term><option>--debug</option></term>
  90         <listitem>
  91           <para>Print debug messages to standard error.</para>
  92         </listitem>
  93       </varlistentry>
  94       <varlistentry>
  95         <term><option>--version</option></term>
  96         <listitem>
  97           <para>Print version number.</para>
  98         </listitem>
  99       </varlistentry>
 100       <varlistentry>
 101         <term><option>-h</option></term>
 102         <term><option>--help</option></term>
 103         <listitem>
 104           <para>Print help text.</para>
 105         </listitem>
 106       </varlistentry>
 107     </variablelist>
 108
 109     <refsect2><title>udevadm info
 110       <arg choice="opt"><replaceable>options</replaceable></arg>
 111       <arg choice="opt"><replaceable>devpath</replaceable>|<replaceable>file</replaceable></arg>
 112     </title>
 113
 114       <para>Queries the udev database for device information
 115       stored in the udev database. It can also query the properties
 116       of a device from its sysfs representation to help creating udev
 117       rules that match this device.</para>
 118       <variablelist>
 119         <varlistentry>
 120           <term><option>-q</option></term>
 121           <term><option>--query=<replaceable>TYPE</replaceable></option></term>
 122           <listitem>
 123             <para>Query the database for the specified type of device
 124             data. It needs the <option>--path</option> or
 125             <option>--name</option> to identify the specified device.
 126             Valid <replaceable>TYPE</replaceable>s are:
 127             <constant>name</constant>, <constant>symlink</constant>,
 128             <constant>path</constant>, <constant>property</constant>,
 129             <constant>all</constant>.</para>
 130           </listitem>
 131         </varlistentry>
 132         <varlistentry>
 133           <term><option>-p</option></term>
 134           <term><option>--path=<replaceable>DEVPATH</replaceable></option></term>
 135           <listitem>
 136             <para>The <filename>/sys</filename> path of the device to
 137             query, e.g.
 138             <filename><optional>/sys</optional>/class/block/sda</filename>.
 139             Note that this option usually is not very useful, since
 140             <command>udev</command> can guess the type of the
 141             argument, so <command>udevadm
 142             --devpath=/class/block/sda</command> is equivalent to
 143             <command>udevadm /sys/class/block/sda</command>.</para>
 144           </listitem>
 145         </varlistentry>
 146         <varlistentry>
 147           <term><option>-n</option></term>
 148           <term><option>--name=<replaceable>FILE</replaceable></option></term>
 149           <listitem>
 150             <para>The name of the device node or a symlink to query,
 151             e.g. <filename><optional>/dev</optional>/sda</filename>.
 152             Note that this option usually is not very useful, since
 153             <command>udev</command> can guess the type of the
 154             argument, so <command>udevadm --name=sda</command> is
 155             equivalent to <command>udevadm /dev/sda</command>.</para>
 156           </listitem>
 157         </varlistentry>
 158         <varlistentry>
 159           <term><option>-r</option></term>
 160           <term><option>--root</option></term>
 161           <listitem>
 162             <para>Print absolute paths in <command>name</command> or <command>symlink</command>
 163             query.</para>
 164           </listitem>
 165         </varlistentry>
 166         <varlistentry>
 167           <term><option>-a</option></term>
 168           <term><option>--attribute-walk</option></term>
 169           <listitem>
 170             <para>Print all sysfs properties of the specified device that can be used
 171             in udev rules to match the specified device. It prints all devices
 172             along the chain, up to the root of sysfs that can be used in udev rules.</para>
 173           </listitem>
 174         </varlistentry>
 175         <varlistentry>
 176           <term><option>-x</option></term>
 177           <term><option>--export</option></term>
 178           <listitem>
 179             <para>Print output as key/value pairs. Values are enclosed in single quotes.</para>
 180           </listitem>
 181         </varlistentry>
 182         <varlistentry>
 183           <term><option>-P</option></term>
 184           <term><option>--export-prefix=<replaceable>NAME</replaceable></option></term>
 185           <listitem>
 186             <para>Add a prefix to the key name of exported values.</para>
 187           </listitem>
 188         </varlistentry>
 189         <varlistentry>
 190           <term><option>-d</option></term>
 191           <term><option>--device-id-of-file=<replaceable>FILE</replaceable></option></term>
 192           <listitem>
 193             <para>Print major/minor numbers of the underlying device, where the file
 194             lives on.</para>
 195           </listitem>
 196         </varlistentry>
 197         <varlistentry>
 198           <term><option>-e</option></term>
 199           <term><option>--export-db</option></term>
 200           <listitem>
 201             <para>Export the content of the udev database.</para>
 202           </listitem>
 203         </varlistentry>
 204         <varlistentry>
 205           <term><option>-c</option></term>
 206           <term><option>--cleanup-db</option></term>
 207           <listitem>
 208             <para>Cleanup the udev database.</para>
 209           </listitem>
 210         </varlistentry>
 211         <varlistentry>
 212           <term><option>--version</option></term>
 213           <listitem>
 214             <para>Print version.</para>
 215           </listitem>
 216         </varlistentry>
 217         <varlistentry>
 218           <term><option>-h</option></term>
 219           <term><option>--help</option></term>
 220           <listitem>
 221             <para>Print help text.</para>
 222           </listitem>
 223         </varlistentry>
 224       </variablelist>
 225
 226       <para>In addition, an optional positional argument can be used
 227       to specify a device name or a sys path. It must start with
 228       <filename>/dev</filename> or <filename>/sys</filename>
 229       respectively.</para>
 230     </refsect2>
 231
 232     <refsect2><title>udevadm trigger
 233       <arg choice="opt"><replaceable>options</replaceable></arg>
 234       <arg choice="opt" rep="repeat"><replaceable>devpath</replaceable>|<replaceable>file</replaceable></arg></title>
 235       <para>Request device events from the kernel. Primarily used to replay events at system coldplug time.</para>
 236       <variablelist>
 237         <varlistentry>
 238           <term><option>-v</option></term>
 239           <term><option>--verbose</option></term>
 240           <listitem>
 241             <para>Print the list of devices which will be triggered.</para>
 242           </listitem>
 243         </varlistentry>
 244         <varlistentry>
 245           <term><option>-n</option></term>
 246           <term><option>--dry-run</option></term>
 247           <listitem>
 248             <para>Do not actually trigger the event.</para>
 249           </listitem>
 250         </varlistentry>
 251         <varlistentry>
 252           <term><option>-t</option></term>
 253           <term><option>--type=<replaceable>TYPE</replaceable></option></term>
 254           <listitem>
 255             <para>Trigger a specific type of devices. Valid types are:
 256             <command>devices</command>, <command>subsystems</command>.
 257             The default value is <command>devices</command>.</para>
 258           </listitem>
 259         </varlistentry>
 260         <varlistentry>
 261           <term><option>-c</option></term>
 262           <term><option>--action=<replaceable>ACTION</replaceable></option></term>
 263           <listitem>
 264             <para>Type of event to be triggered. The default value is
 265             <command>change</command>.</para>
 266           </listitem>
 267         </varlistentry>
 268         <varlistentry>
 269           <term><option>-s</option></term>
 270           <term><option>--subsystem-match=<replaceable>SUBSYSTEM</replaceable></option></term>
 271           <listitem>
 272             <para>Trigger events for devices which belong to a
 273             matching subsystem. This option can be specified multiple
 274             times and supports shell style pattern matching.</para>
 275           </listitem>
 276         </varlistentry>
 277         <varlistentry>
 278           <term><option>-S</option></term>
 279           <term><option>--subsystem-nomatch=<replaceable>SUBSYSTEM</replaceable></option></term>
 280           <listitem>
 281             <para>Do not trigger events for devices which belong to a matching subsystem. This option
 282             can be specified multiple times and supports shell style pattern matching.</para>
 283           </listitem>
 284         </varlistentry>
 285         <varlistentry>
 286           <term><option>-a</option></term>
 287           <term><option>--attr-match=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
 288           <listitem>
 289             <para>Trigger events for devices with a matching sysfs
 290             attribute. If a value is specified along with the
 291             attribute name, the content of the attribute is matched
 292             against the given value using shell style pattern
 293             matching. If no value is specified, the existence of the
 294             sysfs attribute is checked. This option can be specified
 295             multiple times.</para>
 296           </listitem>
 297         </varlistentry>
 298         <varlistentry>
 299           <term><option>-A</option></term>
 300           <term><option>--attr-nomatch=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
 301           <listitem>
 302             <para>Do not trigger events for devices with a matching
 303             sysfs attribute. If a value is specified along with the
 304             attribute name, the content of the attribute is matched
 305             against the given value using shell style pattern
 306             matching. If no value is specified, the existence of the
 307             sysfs attribute is checked. This option can be specified
 308             multiple times.</para>
 309           </listitem>
 310         </varlistentry>
 311         <varlistentry>
 312           <term><option>-p</option></term>
 313           <term><option>--property-match=<replaceable>PROPERTY</replaceable>=<replaceable>VALUE</replaceable></option></term>
 314           <listitem>
 315             <para>Trigger events for devices with a matching property
 316             value. This option can be specified multiple times and
 317             supports shell style pattern matching.</para>
 318           </listitem>
 319         </varlistentry>
 320         <varlistentry>
 321           <term><option>-g</option></term>
 322           <term><option>--tag-match=<replaceable>PROPERTY</replaceable></option></term>
 323           <listitem>
 324             <para>Trigger events for devices with a matching tag. This
 325             option can be specified multiple times.</para>
 326           </listitem>
 327         </varlistentry>
 328         <varlistentry>
 329           <term><option>-y</option></term>
 330           <term><option>--sysname-match=<replaceable>PATH</replaceable></option></term>
 331           <listitem>
 332             <para>Trigger events for devices for which the last component
 333             (i.e. the filename) of the <filename>/sys</filename> path matches
 334             the specified <replaceable>PATH</replaceable>. This option can be
 335             specified multiple times and also supports shell style pattern
 336             matching.</para>
 337           </listitem>
 338         </varlistentry>
 339         <varlistentry>
 340           <term><option>--name-match=<replaceable>NAME</replaceable></option></term>
 341           <listitem>
 342             <para>Trigger events for devices with a matching
 343             device path. This option can be specified multiple
 344             times.</para>
 345           </listitem>
 346         </varlistentry>
 347         <varlistentry>
 348           <term><option>-b</option></term>
 349           <term><option>--parent-match=<replaceable>SYSPATH</replaceable></option></term>
 350           <listitem>
 351             <para>Trigger events for all children of a given
 352             device.</para>
 353           </listitem>
 354         </varlistentry>
 355         <varlistentry>
 356           <term><option>-h</option></term>
 357           <term><option>--help</option></term>
 358           <listitem>
 359             <para>Print help text.</para>
 360           </listitem>
 361         </varlistentry>
 362       </variablelist>
 363
 364       <para>In addition, optional positional arguments can be used
 365       to specify device names or sys paths. They must start with
 366       <filename>/dev</filename> or <filename>/sys</filename>
 367       respectively.</para>
 368     </refsect2>
 369
 370     <refsect2><title>udevadm settle
 371       <arg choice="opt"><replaceable>options</replaceable></arg>
 372     </title>
 373       <para>Watches the udev event queue, and exits if all current events are handled.</para>
 374       <variablelist>
 375         <varlistentry>
 376           <term><option>-t</option></term>
 377           <term><option>--timeout=<replaceable>SECONDS</replaceable></option></term>
 378           <listitem>
 379             <para>Maximum number of seconds to wait for the event
 380             queue to become empty. The default value is 120 seconds. A
 381             value of 0 will check if the queue is empty and always
 382             return immediately.</para>
 383           </listitem>
 384         </varlistentry>
 385         <varlistentry>
 386           <term><option>-E</option></term>
 387           <term><option>--exit-if-exists=<replaceable>FILE</replaceable></option></term>
 388           <listitem>
 389             <para>Stop waiting if file exists.</para>
 390           </listitem>
 391         </varlistentry>
 392         <varlistentry>
 393           <term><option>-h</option></term>
 394           <term><option>--help</option></term>
 395           <listitem>
 396             <para>Print help text.</para>
 397           </listitem>
 398         </varlistentry>
 399       </variablelist>
 400     </refsect2>
 401
 402     <refsect2><title>udevadm control <replaceable>command</replaceable></title>
 403       <para>Modify the internal state of the running udev daemon.</para>
 404       <variablelist>
 405         <varlistentry>
 406           <term><option>-e</option></term>
 407           <term><option>--exit</option></term>
 408           <listitem>
 409             <para>Signal and wait for systemd-udevd to exit.</para>
 410           </listitem>
 411         </varlistentry>
 412         <varlistentry>
 413           <term><option>-l</option></term>
 414           <term><option>--log-priority=<replaceable>value</replaceable></option></term>
 415           <listitem>
 416             <para>Set the internal log level of
 417             <filename>systemd-udevd</filename>. Valid values are the
 418             numerical syslog priorities or their textual
 419             representations: <option>emerg</option>,
 420             <option>alert</option>, <option>crit</option>,
 421             <option>err</option>, <option>warning</option>,
 422             <option>notice</option>, <option>info</option>, and
 423             <option>debug</option>.</para>
 424           </listitem>
 425         </varlistentry>
 426         <varlistentry>
 427           <term><option>-s</option></term>
 428           <term><option>--stop-exec-queue</option></term>
 429           <listitem>
 430             <para>Signal systemd-udevd to stop executing new events. Incoming events
 431             will be queued.</para>
 432           </listitem>
 433         </varlistentry>
 434         <varlistentry>
 435           <term><option>-S</option></term>
 436           <term><option>--start-exec-queue</option></term>
 437           <listitem>
 438             <para>Signal systemd-udevd to enable the execution of events.</para>
 439           </listitem>
 440         </varlistentry>
 441         <varlistentry>
 442           <term><option>-R</option></term>
 443           <term><option>--reload</option></term>
 444           <listitem>
 445             <para>Signal systemd-udevd to reload the rules files and other databases like the kernel
 446             module index. Reloading rules and databases does not apply any changes to already
 447             existing devices; the new configuration will only be applied to new events.</para>
 448           </listitem>
 449         </varlistentry>
 450         <varlistentry>
 451           <term><option>-p</option></term>
 452           <term><option>--property=<replaceable>KEY</replaceable>=<replaceable>value</replaceable></option></term>
 453           <listitem>
 454             <para>Set a global property for all events.</para>
 455           </listitem>
 456         </varlistentry>
 457         <varlistentry>
 458           <term><option>-m</option></term>
 459           <term><option>--children-max=</option><replaceable>value</replaceable></term>
 460           <listitem>
 461             <para>Set the maximum number of events, systemd-udevd will handle at the
 462             same time.</para>
 463           </listitem>
 464         </varlistentry>
 465         <varlistentry>
 466           <term><option>--timeout=</option><replaceable>seconds</replaceable></term>
 467           <listitem>
 468             <para>The maximum number of seconds to wait for a reply from systemd-udevd.</para>
 469           </listitem>
 470         </varlistentry>
 471         <varlistentry>
 472           <term><option>-h</option></term>
 473           <term><option>--help</option></term>
 474           <listitem>
 475             <para>Print help text.</para>
 476           </listitem>
 477         </varlistentry>
 478       </variablelist>
 479     </refsect2>
 480
 481     <refsect2><title>udevadm monitor
 482       <arg choice="opt"><replaceable>options</replaceable></arg>
 483     </title>
 484       <para>Listens to the kernel uevents and events sent out by a udev rule
 485       and prints the devpath of the event to the console. It can be used to analyze the
 486       event timing, by comparing the timestamps of the kernel uevent and the udev event.
 487       </para>
 488       <variablelist>
 489         <varlistentry>
 490           <term><option>-k</option></term>
 491           <term><option>--kernel</option></term>
 492           <listitem>
 493             <para>Print the kernel uevents.</para>
 494           </listitem>
 495         </varlistentry>
 496         <varlistentry>
 497           <term><option>-u</option></term>
 498           <term><option>--udev</option></term>
 499           <listitem>
 500             <para>Print the udev event after the rule processing.</para>
 501           </listitem>
 502         </varlistentry>
 503         <varlistentry>
 504           <term><option>-p</option></term>
 505           <term><option>--property</option></term>
 506           <listitem>
 507             <para>Also print the properties of the event.</para>
 508           </listitem>
 509         </varlistentry>
 510         <varlistentry>
 511           <term><option>-s</option></term>
 512           <term><option>--subsystem-match=<replaceable>string[/string]</replaceable></option></term>
 513           <listitem>
 514             <para>Filter kernel uevents and udev events by subsystem[/devtype]. Only events with a matching subsystem value will pass.</para>
 515           </listitem>
 516         </varlistentry>
 517         <varlistentry>
 518           <term><option>-t</option></term>
 519           <term><option>--tag-match=<replaceable>string</replaceable></option></term>
 520           <listitem>
 521             <para>Filter udev events by tag. Only udev events with a given tag attached will pass.</para>
 522           </listitem>
 523         </varlistentry>
 524         <varlistentry>
 525           <term><option>-h</option></term>
 526           <term><option>--help</option></term>
 527           <listitem>
 528             <para>Print help text.</para>
 529           </listitem>
 530         </varlistentry>
 531       </variablelist>
 532     </refsect2>
 533
 534     <refsect2><title>udevadm test
 535       <arg choice="opt"><replaceable>options</replaceable></arg>
 536       <arg><replaceable>devpath</replaceable></arg>
 537     </title>
 538       <para>Simulate a udev event run for the given device, and print debug output.</para>
 539       <variablelist>
 540         <varlistentry>
 541           <term><option>-a</option></term>
 542           <term><option>--action=<replaceable>string</replaceable></option></term>
 543           <listitem>
 544             <para>The action string.</para>
 545           </listitem>
 546         </varlistentry>
 547         <varlistentry>
 548           <term><option>-N</option></term>
 549           <term><option>--resolve-names=<constant>early</constant>|<constant>late</constant>|<constant>never</constant></option></term>
 550           <listitem>
 551             <para>Specify when udevadm should resolve names of users
 552             and groups.  When set to <constant>early</constant> (the
 553             default), names will be resolved when the rules are
 554             parsed. When set to <constant>late</constant>, names will
 555             be resolved for every event. When set to
 556             <constant>never</constant>, names will never be resolved
 557             and all devices will be owned by root.</para>
 558           </listitem>
 559         </varlistentry>
 560         <varlistentry>
 561           <term><option>-h</option></term>
 562           <term><option>--help</option></term>
 563           <listitem>
 564             <para>Print help text.</para>
 565           </listitem>
 566         </varlistentry>
 567       </variablelist>
 568     </refsect2>
 569
 570     <refsect2><title>udevadm test-builtin
 571       <arg choice="opt"><replaceable>options</replaceable></arg>
 572       <arg><replaceable>command</replaceable></arg>
 573       <arg><replaceable>devpath</replaceable></arg>
 574     </title>
 575       <para>Run a built-in command <replaceable>COMMAND</replaceable>
 576       for device <replaceable>DEVPATH</replaceable>, and print debug
 577       output.</para>
 578       <variablelist>
 579         <varlistentry>
 580           <term><option>-h</option></term>
 581           <term><option>--help</option></term>
 582           <listitem>
 583             <para>Print help text.</para>
 584           </listitem>
 585         </varlistentry>
 586       </variablelist>
 587     </refsect2>
 588   </refsect1>
 589
 590   <refsect1>
 591     <title>See Also</title>
 592     <para><citerefentry>
 593         <refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum>
 594     </citerefentry>,
 595     <citerefentry>
 596         <refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum>
 597     </citerefentry></para>
 598   </refsect1>
 599 </refentry>