man/udevadm.xml

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