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