man/udevadm.xml

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  25
  26 <refentry id="udevadm"
  27           xmlns:xi="http://www.w3.org/2001/XInclude">
  28
  29   <refentryinfo>
  30     <title>udevadm</title>
  31     <productname>systemd</productname>
  32     <authorgroup>
  33       <author>
  34         <contrib>Developer</contrib>
  35         <firstname>Kay</firstname>
  36         <surname>Sievers</surname>
  37         <email>kay@vrfy.org</email>
  38       </author>
  39     </authorgroup>
  40   </refentryinfo>
  41
  42   <refmeta>
  43     <refentrytitle>udevadm</refentrytitle>
  44     <manvolnum>8</manvolnum>
  45   </refmeta>
  46
  47   <refnamediv>
  48     <refname>udevadm</refname><refpurpose>udev management tool</refpurpose>
  49   </refnamediv>
  50
  51   <refsynopsisdiv>
  52     <cmdsynopsis>
  53       <command>udevadm</command>
  54         <arg><option>--debug</option></arg>
  55         <arg><option>--version</option></arg>
  56         <arg><option>--help</option></arg>
  57     </cmdsynopsis>
  58     <cmdsynopsis>
  59       <command>udevadm info <optional>options</optional> <optional>devpath</optional></command>
  60     </cmdsynopsis>
  61     <cmdsynopsis>
  62       <command>udevadm trigger <optional>options</optional> <optional>devpath</optional></command>
  63     </cmdsynopsis>
  64     <cmdsynopsis>
  65       <command>udevadm settle <optional>options</optional></command>
  66     </cmdsynopsis>
  67     <cmdsynopsis>
  68       <command>udevadm control <replaceable>option</replaceable></command>
  69     </cmdsynopsis>
  70     <cmdsynopsis>
  71       <command>udevadm monitor <optional>options</optional></command>
  72     </cmdsynopsis>
  73     <cmdsynopsis>
  74       <command>udevadm test <optional>options</optional> <replaceable>devpath</replaceable></command>
  75     </cmdsynopsis>
  76     <cmdsynopsis>
  77       <command>udevadm test-builtin <optional>options</optional> <replaceable>command</replaceable> <replaceable>devpath</replaceable></command>
  78     </cmdsynopsis>
  79   </refsynopsisdiv>
  80
  81   <refsect1><title>Description</title>
  82     <para><command>udevadm</command> expects a command and command
  83     specific options.  It controls the runtime behavior of
  84     <command>systemd-udevd</command>, requests kernel events, manages
  85     the event queue, and provides simple debugging mechanisms.</para>
  86   </refsect1>
  87
  88   <refsect1><title>Options</title>
  89     <variablelist>
  90       <varlistentry>
  91         <term><option>-d</option></term>
  92         <term><option>--debug</option></term>
  93         <listitem>
  94           <para>Print debug messages to standard error.</para>
  95         </listitem>
  96       </varlistentry>
  97
  98       <xi:include href="standard-options.xml" xpointer="help" />
  99     </variablelist>
 100
 101     <refsect2><title>udevadm info
 102       <arg choice="opt"><replaceable>options</replaceable></arg>
 103       <arg choice="opt"><replaceable>devpath</replaceable>|<replaceable>file</replaceable></arg>
 104     </title>
 105
 106       <para>Queries the udev database for device information
 107       stored in the udev database. It can also query the properties
 108       of a device from its sysfs representation to help creating udev
 109       rules that match this device.</para>
 110       <variablelist>
 111         <varlistentry>
 112           <term><option>-q</option></term>
 113           <term><option>--query=<replaceable>TYPE</replaceable></option></term>
 114           <listitem>
 115             <para>Query the database for the specified type of device
 116             data. It needs the <option>--path</option> or
 117             <option>--name</option> to identify the specified device.
 118             Valid <replaceable>TYPE</replaceable>s are:
 119             <constant>name</constant>, <constant>symlink</constant>,
 120             <constant>path</constant>, <constant>property</constant>,
 121             <constant>all</constant>.</para>
 122           </listitem>
 123         </varlistentry>
 124         <varlistentry>
 125           <term><option>-p</option></term>
 126           <term><option>--path=<replaceable>DEVPATH</replaceable></option></term>
 127           <listitem>
 128             <para>The <filename>/sys</filename> path of the device to
 129             query, e.g.
 130             <filename><optional>/sys</optional>/class/block/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
 134             --devpath=/class/block/sda</command> is equivalent to
 135             <command>udevadm /sys/class/block/sda</command>.</para>
 136           </listitem>
 137         </varlistentry>
 138         <varlistentry>
 139           <term><option>-n</option></term>
 140           <term><option>--name=<replaceable>FILE</replaceable></option></term>
 141           <listitem>
 142             <para>The name of the device node or a symlink to query,
 143             e.g. <filename><optional>/dev</optional>/sda</filename>.
 144             Note that this option usually is not very useful, since
 145             <command>udev</command> can guess the type of the
 146             argument, so <command>udevadm --name=sda</command> is
 147             equivalent to <command>udevadm /dev/sda</command>.</para>
 148           </listitem>
 149         </varlistentry>
 150         <varlistentry>
 151           <term><option>-r</option></term>
 152           <term><option>--root</option></term>
 153           <listitem>
 154             <para>Print absolute paths in <command>name</command> or <command>symlink</command>
 155             query.</para>
 156           </listitem>
 157         </varlistentry>
 158         <varlistentry>
 159           <term><option>-a</option></term>
 160           <term><option>--attribute-walk</option></term>
 161           <listitem>
 162             <para>Print all sysfs properties of the specified device that can be used
 163             in udev rules to match the specified device. It prints all devices
 164             along the chain, up to the root of sysfs that can be used in udev rules.</para>
 165           </listitem>
 166         </varlistentry>
 167         <varlistentry>
 168           <term><option>-x</option></term>
 169           <term><option>--export</option></term>
 170           <listitem>
 171             <para>Print output as key/value pairs. Values are enclosed in single quotes.</para>
 172           </listitem>
 173         </varlistentry>
 174         <varlistentry>
 175           <term><option>-P</option></term>
 176           <term><option>--export-prefix=<replaceable>NAME</replaceable></option></term>
 177           <listitem>
 178             <para>Add a prefix to the key name of exported values.</para>
 179           </listitem>
 180         </varlistentry>
 181         <varlistentry>
 182           <term><option>-d</option></term>
 183           <term><option>--device-id-of-file=<replaceable>FILE</replaceable></option></term>
 184           <listitem>
 185             <para>Print major/minor numbers of the underlying device, where the file
 186             lives on.</para>
 187           </listitem>
 188         </varlistentry>
 189         <varlistentry>
 190           <term><option>-e</option></term>
 191           <term><option>--export-db</option></term>
 192           <listitem>
 193             <para>Export the content of the udev database.</para>
 194           </listitem>
 195         </varlistentry>
 196         <varlistentry>
 197           <term><option>-c</option></term>
 198           <term><option>--cleanup-db</option></term>
 199           <listitem>
 200             <para>Cleanup the udev database.</para>
 201           </listitem>
 202         </varlistentry>
 203
 204         <xi:include href="standard-options.xml" xpointer="help" />
 205       </variablelist>
 206
 207       <para>In addition, an optional positional argument can be used
 208       to specify a device name or a sys path. It must start with
 209       <filename>/dev</filename> or <filename>/sys</filename>
 210       respectively.</para>
 211     </refsect2>
 212
 213     <refsect2><title>udevadm trigger
 214       <arg choice="opt"><replaceable>options</replaceable></arg>
 215       <arg choice="opt" rep="repeat"><replaceable>devpath</replaceable>|<replaceable>file</replaceable></arg></title>
 216       <para>Request device events from the kernel. Primarily used to replay events at system coldplug time.</para>
 217       <variablelist>
 218         <varlistentry>
 219           <term><option>-v</option></term>
 220           <term><option>--verbose</option></term>
 221           <listitem>
 222             <para>Print the list of devices which will be triggered.</para>
 223           </listitem>
 224         </varlistentry>
 225         <varlistentry>
 226           <term><option>-n</option></term>
 227           <term><option>--dry-run</option></term>
 228           <listitem>
 229             <para>Do not actually trigger the event.</para>
 230           </listitem>
 231         </varlistentry>
 232         <varlistentry>
 233           <term><option>-t</option></term>
 234           <term><option>--type=<replaceable>TYPE</replaceable></option></term>
 235           <listitem>
 236             <para>Trigger a specific type of devices. Valid types are:
 237             <command>devices</command>, <command>subsystems</command>.
 238             The default value is <command>devices</command>.</para>
 239           </listitem>
 240         </varlistentry>
 241         <varlistentry>
 242           <term><option>-c</option></term>
 243           <term><option>--action=<replaceable>ACTION</replaceable></option></term>
 244           <listitem>
 245             <para>Type of event to be triggered. The default value is
 246             <command>change</command>.</para>
 247           </listitem>
 248         </varlistentry>
 249         <varlistentry>
 250           <term><option>-s</option></term>
 251           <term><option>--subsystem-match=<replaceable>SUBSYSTEM</replaceable></option></term>
 252           <listitem>
 253             <para>Trigger events for devices which belong to a
 254             matching subsystem. This option can be specified multiple
 255             times and supports shell style pattern matching.</para>
 256           </listitem>
 257         </varlistentry>
 258         <varlistentry>
 259           <term><option>-S</option></term>
 260           <term><option>--subsystem-nomatch=<replaceable>SUBSYSTEM</replaceable></option></term>
 261           <listitem>
 262             <para>Do not trigger events for devices which belong to a matching subsystem. This option
 263             can be specified multiple times and supports shell style pattern matching.</para>
 264           </listitem>
 265         </varlistentry>
 266         <varlistentry>
 267           <term><option>-a</option></term>
 268           <term><option>--attr-match=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
 269           <listitem>
 270             <para>Trigger events for devices with a matching sysfs
 271             attribute. If a value is specified along with the
 272             attribute name, the content of the attribute is matched
 273             against the given value using shell style pattern
 274             matching. If no value is specified, the existence of the
 275             sysfs attribute is checked. This option can be specified
 276             multiple times.</para>
 277           </listitem>
 278         </varlistentry>
 279         <varlistentry>
 280           <term><option>-A</option></term>
 281           <term><option>--attr-nomatch=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
 282           <listitem>
 283             <para>Do not trigger events for devices with a matching
 284             sysfs attribute. If a value is specified along with the
 285             attribute name, the content of the attribute is matched
 286             against the given value using shell style pattern
 287             matching. If no value is specified, the existence of the
 288             sysfs attribute is checked. This option can be specified
 289             multiple times.</para>
 290           </listitem>
 291         </varlistentry>
 292         <varlistentry>
 293           <term><option>-p</option></term>
 294           <term><option>--property-match=<replaceable>PROPERTY</replaceable>=<replaceable>VALUE</replaceable></option></term>
 295           <listitem>
 296             <para>Trigger events for devices with a matching property
 297             value. This option can be specified multiple times and
 298             supports shell style pattern matching.</para>
 299           </listitem>
 300         </varlistentry>
 301         <varlistentry>
 302           <term><option>-g</option></term>
 303           <term><option>--tag-match=<replaceable>PROPERTY</replaceable></option></term>
 304           <listitem>
 305             <para>Trigger events for devices with a matching tag. This
 306             option can be specified multiple times.</para>
 307           </listitem>
 308         </varlistentry>
 309         <varlistentry>
 310           <term><option>-y</option></term>
 311           <term><option>--sysname-match=<replaceable>PATH</replaceable></option></term>
 312           <listitem>
 313             <para>Trigger events for devices for which the last component
 314             (i.e. the filename) of the <filename>/sys</filename> path matches
 315             the specified <replaceable>PATH</replaceable>. This option can be
 316             specified multiple times and also supports shell style pattern
 317             matching.</para>
 318           </listitem>
 319         </varlistentry>
 320         <varlistentry>
 321           <term><option>--name-match=<replaceable>NAME</replaceable></option></term>
 322           <listitem>
 323             <para>Trigger events for devices with a matching
 324             device path. This option can be specified multiple
 325             times.</para>
 326           </listitem>
 327         </varlistentry>
 328         <varlistentry>
 329           <term><option>-b</option></term>
 330           <term><option>--parent-match=<replaceable>SYSPATH</replaceable></option></term>
 331           <listitem>
 332             <para>Trigger events for all children of a given
 333             device.</para>
 334           </listitem>
 335         </varlistentry>
 336         <varlistentry>
 337           <term><option>-w</option></term>
 338           <term><option>--settle</option></term>
 339           <listitem>
 340             <para>Apart from triggering events, also waits for those events to
 341             finish. Note that this is different from calling <command>udevadm
 342             settle</command>. <command>udevadm settle</command> waits for all
 343             events to finish. This option only waits for events triggered by
 344             the same command to finish.</para>
 345           </listitem>
 346         </varlistentry>
 347
 348         <xi:include href="standard-options.xml" xpointer="help" />
 349       </variablelist>
 350
 351       <para>In addition, optional positional arguments can be used
 352       to specify device names or sys paths. They must start with
 353       <filename>/dev</filename> or <filename>/sys</filename>
 354       respectively.</para>
 355     </refsect2>
 356
 357     <refsect2><title>udevadm settle
 358       <arg choice="opt"><replaceable>options</replaceable></arg>
 359     </title>
 360       <para>Watches the udev event queue, and exits if all current events are handled.</para>
 361       <variablelist>
 362         <varlistentry>
 363           <term><option>-t</option></term>
 364           <term><option>--timeout=<replaceable>SECONDS</replaceable></option></term>
 365           <listitem>
 366             <para>Maximum number of seconds to wait for the event
 367             queue to become empty. The default value is 120 seconds. A
 368             value of 0 will check if the queue is empty and always
 369             return immediately.</para>
 370           </listitem>
 371         </varlistentry>
 372         <varlistentry>
 373           <term><option>-E</option></term>
 374           <term><option>--exit-if-exists=<replaceable>FILE</replaceable></option></term>
 375           <listitem>
 376             <para>Stop waiting if file exists.</para>
 377           </listitem>
 378         </varlistentry>
 379
 380         <xi:include href="standard-options.xml" xpointer="help" />
 381       </variablelist>
 382     </refsect2>
 383
 384     <refsect2><title>udevadm control <replaceable>option</replaceable></title>
 385       <para>Modify the internal state of the running udev daemon.</para>
 386       <variablelist>
 387         <varlistentry>
 388           <term><option>-e</option></term>
 389           <term><option>--exit</option></term>
 390           <listitem>
 391             <para>Signal and wait for systemd-udevd to exit.</para>
 392           </listitem>
 393         </varlistentry>
 394         <varlistentry>
 395           <term><option>-l</option></term>
 396           <term><option>--log-priority=<replaceable>value</replaceable></option></term>
 397           <listitem>
 398             <para>Set the internal log level of
 399             <filename>systemd-udevd</filename>. Valid values are the
 400             numerical syslog priorities or their textual
 401             representations: <option>emerg</option>,
 402             <option>alert</option>, <option>crit</option>,
 403             <option>err</option>, <option>warning</option>,
 404             <option>notice</option>, <option>info</option>, and
 405             <option>debug</option>.</para>
 406           </listitem>
 407         </varlistentry>
 408         <varlistentry>
 409           <term><option>-s</option></term>
 410           <term><option>--stop-exec-queue</option></term>
 411           <listitem>
 412             <para>Signal systemd-udevd to stop executing new events. Incoming events
 413             will be queued.</para>
 414           </listitem>
 415         </varlistentry>
 416         <varlistentry>
 417           <term><option>-S</option></term>
 418           <term><option>--start-exec-queue</option></term>
 419           <listitem>
 420             <para>Signal systemd-udevd to enable the execution of events.</para>
 421           </listitem>
 422         </varlistentry>
 423         <varlistentry>
 424           <term><option>-R</option></term>
 425           <term><option>--reload</option></term>
 426           <listitem>
 427             <para>Signal systemd-udevd to reload the rules files and other databases like the kernel
 428             module index. Reloading rules and databases does not apply any changes to already
 429             existing devices; the new configuration will only be applied to new events.</para>
 430           </listitem>
 431         </varlistentry>
 432         <varlistentry>
 433           <term><option>-p</option></term>
 434           <term><option>--property=<replaceable>KEY</replaceable>=<replaceable>value</replaceable></option></term>
 435           <listitem>
 436             <para>Set a global property for all events.</para>
 437           </listitem>
 438         </varlistentry>
 439         <varlistentry>
 440           <term><option>-m</option></term>
 441           <term><option>--children-max=</option><replaceable>value</replaceable></term>
 442           <listitem>
 443             <para>Set the maximum number of events, systemd-udevd will handle at the
 444             same time.</para>
 445           </listitem>
 446         </varlistentry>
 447         <varlistentry>
 448           <term><option>-t</option></term>
 449           <term><option>--timeout=</option><replaceable>seconds</replaceable></term>
 450           <listitem>
 451             <para>The maximum number of seconds to wait for a reply from systemd-udevd.</para>
 452           </listitem>
 453         </varlistentry>
 454
 455         <xi:include href="standard-options.xml" xpointer="help" />
 456       </variablelist>
 457     </refsect2>
 458
 459     <refsect2><title>udevadm monitor
 460       <arg choice="opt"><replaceable>options</replaceable></arg>
 461     </title>
 462       <para>Listens to the kernel uevents and events sent out by a udev rule
 463       and prints the devpath of the event to the console. It can be used to analyze the
 464       event timing, by comparing the timestamps of the kernel uevent and the udev event.
 465       </para>
 466       <variablelist>
 467         <varlistentry>
 468           <term><option>-k</option></term>
 469           <term><option>--kernel</option></term>
 470           <listitem>
 471             <para>Print the kernel uevents.</para>
 472           </listitem>
 473         </varlistentry>
 474         <varlistentry>
 475           <term><option>-u</option></term>
 476           <term><option>--udev</option></term>
 477           <listitem>
 478             <para>Print the udev event after the rule processing.</para>
 479           </listitem>
 480         </varlistentry>
 481         <varlistentry>
 482           <term><option>-p</option></term>
 483           <term><option>--property</option></term>
 484           <listitem>
 485             <para>Also print the properties of the event.</para>
 486           </listitem>
 487         </varlistentry>
 488         <varlistentry>
 489           <term><option>-s</option></term>
 490           <term><option>--subsystem-match=<replaceable>string[/string]</replaceable></option></term>
 491           <listitem>
 492             <para>Filter kernel uevents and udev events by subsystem[/devtype]. Only events with a matching subsystem value will pass.</para>
 493           </listitem>
 494         </varlistentry>
 495         <varlistentry>
 496           <term><option>-t</option></term>
 497           <term><option>--tag-match=<replaceable>string</replaceable></option></term>
 498           <listitem>
 499             <para>Filter udev events by tag. Only udev events with a given tag attached will pass.</para>
 500           </listitem>
 501         </varlistentry>
 502
 503         <xi:include href="standard-options.xml" xpointer="help" />
 504       </variablelist>
 505     </refsect2>
 506
 507     <refsect2><title>udevadm test
 508       <arg choice="opt"><replaceable>options</replaceable></arg>
 509       <arg><replaceable>devpath</replaceable></arg>
 510     </title>
 511       <para>Simulate a udev event run for the given device, and print debug output.</para>
 512       <variablelist>
 513         <varlistentry>
 514           <term><option>-a</option></term>
 515           <term><option>--action=<replaceable>string</replaceable></option></term>
 516           <listitem>
 517             <para>The action string.</para>
 518           </listitem>
 519         </varlistentry>
 520         <varlistentry>
 521           <term><option>-N</option></term>
 522           <term><option>--resolve-names=<constant>early</constant>|<constant>late</constant>|<constant>never</constant></option></term>
 523           <listitem>
 524             <para>Specify when udevadm should resolve names of users
 525             and groups.  When set to <constant>early</constant> (the
 526             default), names will be resolved when the rules are
 527             parsed. When set to <constant>late</constant>, names will
 528             be resolved for every event. When set to
 529             <constant>never</constant>, names will never be resolved
 530             and all devices will be owned by root.</para>
 531           </listitem>
 532         </varlistentry>
 533
 534         <xi:include href="standard-options.xml" xpointer="help" />
 535       </variablelist>
 536     </refsect2>
 537
 538     <refsect2><title>udevadm test-builtin
 539       <arg choice="opt"><replaceable>options</replaceable></arg>
 540       <arg><replaceable>command</replaceable></arg>
 541       <arg><replaceable>devpath</replaceable></arg>
 542     </title>
 543       <para>Run a built-in command <replaceable>COMMAND</replaceable>
 544       for device <replaceable>DEVPATH</replaceable>, and print debug
 545       output.</para>
 546       <variablelist>
 547         <xi:include href="standard-options.xml" xpointer="help" />
 548       </variablelist>
 549     </refsect2>
 550   </refsect1>
 551
 552   <refsect1>
 553     <title>See Also</title>
 554     <para><citerefentry>
 555         <refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum>
 556     </citerefentry>,
 557     <citerefentry>
 558         <refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum>
 559     </citerefentry></para>
 560   </refsect1>
 561 </refentry>