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1<?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
2<?xml-stylesheet type="text/xsl" href="http://docbook.sourceforge.net/release/xsl/current/xhtml/docbook.xsl"?>
3<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
4  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
5
6<refentry id="udevadm">
7  <refentryinfo>
8    <title>udevadm</title>
9    <productname>eudev</productname>
10    <authorgroup>
11      <author>
12        <contrib>Developer</contrib>
13        <firstname>Kay</firstname>
14        <surname>Sievers</surname>
15        <email>kay@vrfy.org</email>
16      </author>
17    </authorgroup>
18  </refentryinfo>
19
20  <refmeta>
21    <refentrytitle>udevadm</refentrytitle>
22    <manvolnum>8</manvolnum>
23  </refmeta>
24
25  <refnamediv>
26    <refname>udevadm</refname><refpurpose>udev management tool</refpurpose>
27  </refnamediv>
28
29  <refsynopsisdiv>
30    <cmdsynopsis>
31      <command>udevadm</command>
32        <arg><option>--debug</option></arg>
33        <arg><option>--version</option></arg>
34        <arg><option>--help</option></arg>
35    </cmdsynopsis>
36    <cmdsynopsis>
37      <command>udevadm info <replaceable>options</replaceable></command>
38    </cmdsynopsis>
39    <cmdsynopsis>
40      <command>udevadm trigger <optional>options</optional></command>
41    </cmdsynopsis>
42    <cmdsynopsis>
43      <command>udevadm settle <optional>options</optional></command>
44    </cmdsynopsis>
45    <cmdsynopsis>
46      <command>udevadm control <replaceable>command</replaceable></command>
47    </cmdsynopsis>
48    <cmdsynopsis>
49      <command>udevadm monitor <optional>options</optional></command>
50    </cmdsynopsis>
51    <cmdsynopsis>
52      <command>udevadm hwdb <optional>options</optional></command>
53    </cmdsynopsis>
54    <cmdsynopsis>
55      <command>udevadm test <optional>options</optional> <replaceable>devpath</replaceable></command>
56    </cmdsynopsis>
57    <cmdsynopsis>
58      <command>udevadm test-builtin <optional>options</optional> <replaceable>command</replaceable> <replaceable>devpath</replaceable></command>
59    </cmdsynopsis>
60  </refsynopsisdiv>
61
62  <refsect1><title>Description</title>
63    <para><command>udevadm</command> expects a command and command
64    specific options.  It controls the runtime behavior of
65    <command>udev</command>, requests kernel events, manages
66    the event queue, and provides simple debugging mechanisms.</para>
67  </refsect1>
68
69  <refsect1><title>Options</title>
70    <variablelist>
71      <varlistentry>
72        <term><option>--debug</option></term>
73        <listitem>
74          <para>Print debug messages to standard error.</para>
75        </listitem>
76      </varlistentry>
77      <varlistentry>
78        <term><option>--version</option></term>
79        <listitem>
80          <para>Print version number.</para>
81        </listitem>
82      </varlistentry>
83      <varlistentry>
84        <term><option>-h</option></term>
85        <term><option>--help</option></term>
86        <listitem>
87          <para>Print help text.</para>
88        </listitem>
89      </varlistentry>
90    </variablelist>
91
92    <refsect2><title>udevadm info
93      <arg choice="opt"><replaceable>options</replaceable></arg>
94      <arg choice="opt"><replaceable>devpath</replaceable>|<replaceable>file</replaceable></arg>
95    </title>
96
97      <para>Queries the udev database for device information
98      stored in the udev database. It can also query the properties
99      of a device from its sysfs representation to help creating udev
100      rules that match this device.</para>
101      <variablelist>
102        <varlistentry>
103          <term><option>-q</option></term>
104          <term><option>--query=<replaceable>TYPE</replaceable></option></term>
105          <listitem>
106            <para>Query the database for the specified type of device
107            data. It needs the <option>--path</option> or
108            <option>--name</option> to identify the specified device.
109            Valid <replaceable>TYPE</replaceable>s are:
110            <constant>name</constant>, <constant>symlink</constant>,
111            <constant>path</constant>, <constant>property</constant>,
112            <constant>all</constant>.</para>
113          </listitem>
114        </varlistentry>
115        <varlistentry>
116          <term><option>-p</option></term>
117          <term><option>--path=<replaceable>DEVPATH</replaceable></option></term>
118          <listitem>
119            <para>The <filename>/sys</filename> path of the device to
120            query, e.g.
121            <filename><optional>/sys</optional>/class/block/sda</filename>.
122            Note that this option usually is not very useful, since
123            <command>udev</command> can guess the type of the
124            argument, so <command>udevadm
125            --devpath=/class/block/sda</command> is equivalent to
126            <command>udevadm /sys/class/block/sda</command>.</para>
127          </listitem>
128        </varlistentry>
129        <varlistentry>
130          <term><option>-n</option></term>
131          <term><option>--name=<replaceable>FILE</replaceable></option></term>
132          <listitem>
133            <para>The name of the device node or a symlink to query,
134            e.g. <filename><optional>/dev</optional>/sda</filename>.
135            Note that this option usually is not very useful, since
136            <command>udev</command> can guess the type of the
137            argument, so <command>udevadm --name=sda</command> is
138            equivalent to <command>udevadm /dev/sda</command>.</para>
139          </listitem>
140        </varlistentry>
141        <varlistentry>
142          <term><option>-r</option></term>
143          <term><option>--root</option></term>
144          <listitem>
145            <para>Print absolute paths in <command>name</command> or <command>symlink</command>
146            query.</para>
147          </listitem>
148        </varlistentry>
149        <varlistentry>
150          <term><option>-a</option></term>
151          <term><option>--attribute-walk</option></term>
152          <listitem>
153            <para>Print all sysfs properties of the specified device that can be used
154            in udev rules to match the specified device. It prints all devices
155            along the chain, up to the root of sysfs that can be used in udev rules.</para>
156          </listitem>
157        </varlistentry>
158        <varlistentry>
159          <term><option>-x</option></term>
160          <term><option>--export</option></term>
161          <listitem>
162            <para>Print output as key/value pairs. Values are enclosed in single quotes.</para>
163          </listitem>
164        </varlistentry>
165        <varlistentry>
166          <term><option>-P</option></term>
167          <term><option>--export-prefix=<replaceable>NAME</replaceable></option></term>
168          <listitem>
169            <para>Add a prefix to the key name of exported values.</para>
170          </listitem>
171        </varlistentry>
172        <varlistentry>
173          <term><option>-d</option></term>
174          <term><option>--device-id-of-file=<replaceable>FILE</replaceable></option></term>
175          <listitem>
176            <para>Print major/minor numbers of the underlying device, where the file
177            lives on.</para>
178          </listitem>
179        </varlistentry>
180        <varlistentry>
181          <term><option>-e</option></term>
182          <term><option>--export-db</option></term>
183          <listitem>
184            <para>Export the content of the udev database.</para>
185          </listitem>
186        </varlistentry>
187        <varlistentry>
188          <term><option>-c</option></term>
189          <term><option>--cleanup-db</option></term>
190          <listitem>
191            <para>Cleanup the udev database.</para>
192          </listitem>
193        </varlistentry>
194        <varlistentry>
195          <term><option>--version</option></term>
196          <listitem>
197            <para>Print version.</para>
198          </listitem>
199        </varlistentry>
200        <varlistentry>
201          <term><option>-h</option></term>
202          <term><option>--help</option></term>
203          <listitem>
204            <para>Print help text.</para>
205          </listitem>
206        </varlistentry>
207      </variablelist>
208
209      <para>In addition an optional positional argument can be used
210      to specify a device name or a sys path. It must start with
211      <filename>/dev</filename> or <filename>/sys</filename>
212      respectively.</para>
213    </refsect2>
214
215    <refsect2><title>udevadm trigger
216      <arg choice="opt"><replaceable>options</replaceable></arg>
217      <arg choice="opt" rep="repeat"><replaceable>devpath</replaceable>|<replaceable>file</replaceable></arg></title>
218      <para>Request device events from the kernel. Primarily used to replay events at system coldplug time.</para>
219      <variablelist>
220        <varlistentry>
221          <term><option>-v</option></term>
222          <term><option>--verbose</option></term>
223          <listitem>
224            <para>Print the list of devices which will be triggered.</para>
225          </listitem>
226        </varlistentry>
227        <varlistentry>
228          <term><option>-n</option></term>
229          <term><option>--dry-run</option></term>
230          <listitem>
231            <para>Do not actually trigger the event.</para>
232          </listitem>
233        </varlistentry>
234        <varlistentry>
235          <term><option>-t</option></term>
236          <term><option>--type=<replaceable>TYPE</replaceable></option></term>
237          <listitem>
238            <para>Trigger a specific type of devices. Valid types are:
239            <command>devices</command>, <command>subsystems</command>.
240            The default value is <command>devices</command>.</para>
241          </listitem>
242        </varlistentry>
243        <varlistentry>
244          <term><option>-c</option></term>
245          <term><option>--action=<replaceable>ACTION</replaceable></option></term>
246          <listitem>
247            <para>Type of event to be triggered. The default value is
248            <command>change</command>.</para>
249          </listitem>
250        </varlistentry>
251        <varlistentry>
252          <term><option>-s</option></term>
253          <term><option>--subsystem-match=<replaceable>SUBSYSTEM</replaceable></option></term>
254          <listitem>
255            <para>Trigger events for devices which belong to a
256            matching subsystem. This option can be specified multiple
257            times and supports shell style pattern matching.</para>
258          </listitem>
259        </varlistentry>
260        <varlistentry>
261          <term><option>-S</option></term>
262          <term><option>--subsystem-nomatch=<replaceable>SUBSYSTEM</replaceable></option></term>
263          <listitem>
264            <para>Do not trigger events for devices which belong to a matching subsystem. This option
265            can be specified multiple times and supports shell style pattern matching.</para>
266          </listitem>
267        </varlistentry>
268        <varlistentry>
269          <term><option>-a</option></term>
270          <term><option>--attr-match=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
271          <listitem>
272            <para>Trigger events for devices with a matching sysfs
273            attribute. If a value is specified along with the
274            attribute name, the content of the attribute is matched
275            against the given value using shell style pattern
276            matching. If no value is specified, the existence of the
277            sysfs attribute is checked. This option can be specified
278            multiple times.</para>
279          </listitem>
280        </varlistentry>
281        <varlistentry>
282          <term><option>-A</option></term>
283          <term><option>--attr-nomatch=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
284          <listitem>
285            <para>Do not trigger events for devices with a matching
286            sysfs attribute. If a value is specified along with the
287            attribute name, the content of the attribute is matched
288            against the given value using shell style pattern
289            matching. If no value is specified, the existence of the
290            sysfs attribute is checked. This option can be specified
291            multiple times.</para>
292          </listitem>
293        </varlistentry>
294        <varlistentry>
295          <term><option>-p</option></term>
296          <term><option>--property-match=<replaceable>PROPERTY</replaceable>=<replaceable>VALUE</replaceable></option></term>
297          <listitem>
298            <para>Trigger events for devices with a matching property
299            value. This option can be specified multiple times and
300            supports shell style pattern matching.</para>
301          </listitem>
302        </varlistentry>
303        <varlistentry>
304          <term><option>-g</option></term>
305          <term><option>--tag-match=<replaceable>PROPERTY</replaceable></option></term>
306          <listitem>
307            <para>Trigger events for devices with a matching tag. This
308            option can be specified multiple times.</para>
309          </listitem>
310        </varlistentry>
311        <varlistentry>
312          <term><option>-y</option></term>
313          <term><option>--sysname-match=<replaceable>PATH</replaceable></option></term>
314          <listitem>
315            <para>Trigger events for devices with a matching sys
316            device path. This option can be specified multiple times
317            and supports shell style pattern 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 options 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>-h</option></term>
338          <term><option>--help</option></term>
339          <listitem>
340            <para>Print help text.</para>
341          </listitem>
342        </varlistentry>
343      </variablelist>
344
345      <para>In addition optional positional arguments can be used
346      to specify device names or sys paths. They must start with
347      <filename>/dev</filename> or <filename>/sys</filename>
348      respectively.</para>
349    </refsect2>
350
351    <refsect2><title>udevadm settle
352      <arg choice="opt"><replaceable>options</replaceable></arg>
353    </title>
354      <para>Watches the udev event queue, and exits if all current events are handled.</para>
355      <variablelist>
356        <varlistentry>
357          <term><option>-t</option></term>
358          <term><option>--timeout=<replaceable>SECONDS</replaceable></option></term>
359          <listitem>
360            <para>Maximum number of seconds to wait for the event
361            queue to become empty. The default value is 120 seconds. A
362            value of 0 will check if the queue is empty and always
363            return immediately.</para>
364          </listitem>
365        </varlistentry>
366        <varlistentry>
367          <term><option>-E</option></term>
368          <term><option>--exit-if-exists=<replaceable>FILE</replaceable></option></term>
369          <listitem>
370            <para>Stop waiting if file exists.</para>
371          </listitem>
372        </varlistentry>
373        <varlistentry>
374          <term><option>-h</option></term>
375          <term><option>--help</option></term>
376          <listitem>
377            <para>Print help text.</para>
378          </listitem>
379        </varlistentry>
380      </variablelist>
381    </refsect2>
382
383    <refsect2><title>udevadm control <replaceable>command</replaceable></title>
384      <para>Modify the internal state of the running udev daemon.</para>
385      <variablelist>
386        <varlistentry>
387          <term><option>-x</option></term>
388          <term><option>--exit</option></term>
389          <listitem>
390            <para>Signal and wait for udevd to exit.</para>
391          </listitem>
392        </varlistentry>
393        <varlistentry>
394          <term><option>-l</option></term>
395          <term><option>--log-priority=<replaceable>value</replaceable></option></term>
396          <listitem>
397            <para>Set the internal log level of
398            <filename>udevd</filename>. Valid values are the
399            numerical syslog priorities or their textual
400            representations: <option>emerg</option>,
401            <option>alert</option>, <option>crit</option>,
402            <option>err</option>, <option>warning</option>,
403            <option>notice</option>, <option>info</option>, and
404            <option>debug</option>.</para>
405          </listitem>
406        </varlistentry>
407        <varlistentry>
408          <term><option>-s</option></term>
409          <term><option>--stop-exec-queue</option></term>
410          <listitem>
411            <para>Signal udevd to stop executing new events. Incoming events
412            will be queued.</para>
413          </listitem>
414        </varlistentry>
415        <varlistentry>
416          <term><option>-S</option></term>
417          <term><option>--start-exec-queue</option></term>
418          <listitem>
419            <para>Signal udevd to enable the execution of events.</para>
420          </listitem>
421        </varlistentry>
422        <varlistentry>
423          <term><option>-R</option></term>
424          <term><option>--reload</option></term>
425          <listitem>
426            <para>Signal udevd to reload the rules files and other databases like the kernel
427            module index. Reloading rules and databases does not apply any changes to already
428            existing devices; the new configuration will only be applied to new events.</para>
429          </listitem>
430        </varlistentry>
431        <varlistentry>
432          <term><option>-p</option></term>
433          <term><option>--property=<replaceable>KEY</replaceable>=<replaceable>value</replaceable></option></term>
434          <listitem>
435            <para>Set a global property for all events.</para>
436          </listitem>
437        </varlistentry>
438        <varlistentry>
439          <term><option>-m</option></term>
440          <term><option>--children-max=</option><replaceable>value</replaceable></term>
441          <listitem>
442            <para>Set the maximum number of events, udevd will handle at the
443            same time.</para>
444          </listitem>
445        </varlistentry>
446        <varlistentry>
447          <term><option>--timeout=</option><replaceable>seconds</replaceable></term>
448          <listitem>
449            <para>The maximum number of seconds to wait for a reply from udevd.</para>
450          </listitem>
451        </varlistentry>
452        <varlistentry>
453          <term><option>-h</option></term>
454          <term><option>--help</option></term>
455          <listitem>
456            <para>Print help text.</para>
457          </listitem>
458        </varlistentry>
459      </variablelist>
460    </refsect2>
461
462    <refsect2><title>udevadm monitor
463      <arg choice="opt"><replaceable>options</replaceable></arg>
464    </title>
465      <para>Listens to the kernel uevents and events sent out by a udev rule
466      and prints the devpath of the event to the console. It can be used to analyze the
467      event timing, by comparing the timestamps of the kernel uevent and the udev event.
468      </para>
469      <variablelist>
470        <varlistentry>
471          <term><option>-k</option></term>
472          <term><option>--kernel</option></term>
473          <listitem>
474            <para>Print the kernel uevents.</para>
475          </listitem>
476        </varlistentry>
477        <varlistentry>
478          <term><option>-u</option></term>
479          <term><option>--udev</option></term>
480          <listitem>
481            <para>Print the udev event after the rule processing.</para>
482          </listitem>
483        </varlistentry>
484        <varlistentry>
485          <term><option>-p</option></term>
486          <term><option>--property</option></term>
487          <listitem>
488            <para>Also print the properties of the event.</para>
489          </listitem>
490        </varlistentry>
491        <varlistentry>
492          <term><option>-s</option></term>
493          <term><option>--subsystem-match=<replaceable>string[/string]</replaceable></option></term>
494          <listitem>
495            <para>Filter events by subsystem[/devtype]. Only udev events with a matching subsystem value will pass.</para>
496          </listitem>
497        </varlistentry>
498        <varlistentry>
499          <term><option>-t</option></term>
500          <term><option>--tag-match=<replaceable>string</replaceable></option></term>
501          <listitem>
502            <para>Filter events by property. Only udev events with a given tag attached will pass.</para>
503          </listitem>
504        </varlistentry>
505        <varlistentry>
506          <term><option>-h</option></term>
507          <term><option>--help</option></term>
508          <listitem>
509            <para>Print help text.</para>
510          </listitem>
511        </varlistentry>
512      </variablelist>
513    </refsect2>
514
515    <refsect2><title>udevadm hwdb
516      <arg choice="opt"><replaceable>options</replaceable></arg>
517    </title>
518      <para>Maintain the hardware database index in <filename>/etc/udev/hwdb.bin</filename>.</para>
519      <variablelist>
520        <varlistentry>
521          <term><option>-u</option></term>
522          <term><option>--update</option></term>
523          <listitem>
524            <para>Compile the hardware database information located in /usr/lib/udev/hwdb.d/,
525            /etc/udev/hwdb.d/ and store it in <filename>/etc/udev/hwdb.bin</filename>. This should be done after
526            any update to the source files; it will not be called automatically. The running
527            udev daemon will detect a new database on its own and does not need to be
528            notified about it.</para>
529          </listitem>
530        </varlistentry>
531        <varlistentry>
532          <term><option>-t</option></term>
533          <term><option>--test=<replaceable>string</replaceable></option></term>
534          <listitem>
535            <para>Query the database with a modalias string, and print the
536            retrieved properties.</para>
537          </listitem>
538        </varlistentry>
539        <varlistentry>
540          <term><option>-r</option></term>
541          <term><option>--root=<replaceable>string</replaceable></option></term>
542          <listitem>
543            <para>Alternative root path in the file system for reading and writing files.</para>
544          </listitem>
545        </varlistentry>
546        <varlistentry>
547          <term><option>-h</option></term>
548          <term><option>--help</option></term>
549          <listitem>
550            <para>Print help text.</para>
551          </listitem>
552        </varlistentry>
553      </variablelist>
554    </refsect2>
555
556    <refsect2><title>udevadm test
557      <arg choice="opt"><replaceable>options</replaceable></arg>
558      <arg><replaceable>devpath</replaceable></arg>
559    </title>
560      <para>Simulate a udev event run for the given device, and print debug output.</para>
561      <variablelist>
562        <varlistentry>
563          <term><option>-a</option></term>
564          <term><option>--action=<replaceable>string</replaceable></option></term>
565          <listitem>
566            <para>The action string.</para>
567          </listitem>
568        </varlistentry>
569        <varlistentry>
570          <term><option>-N</option></term>
571          <term><option>--resolve-names=<constant>early</constant>|<constant>late</constant>|<constant>never</constant></option></term>
572          <listitem>
573            <para>Specify when udevadm should resolve names of users
574            and groups.  When set to <constant>early</constant> (the
575            default), names will be resolved when the rules are
576            parsed. When set to <constant>late</constant>, names will
577            be resolved for every event. When set to
578            <constant>never</constant>, names will never be resolved
579            and all devices will be owned by root.</para>
580          </listitem>
581        </varlistentry>
582        <varlistentry>
583          <term><option>-h</option></term>
584          <term><option>--help</option></term>
585          <listitem>
586            <para>Print help text.</para>
587          </listitem>
588        </varlistentry>
589      </variablelist>
590    </refsect2>
591
592    <refsect2><title>udevadm test-builtin
593      <arg choice="opt"><replaceable>options</replaceable></arg>
594      <arg><replaceable>command</replaceable></arg>
595      <arg><replaceable>devpath</replaceable></arg>
596    </title>
597      <para>Run a built-in command <replaceable>COMMAND</replaceable>
598      for device <replaceable>DEVPATH</replaceable>, and print debug
599      output.</para>
600      <variablelist>
601        <varlistentry>
602          <term><option>-h</option></term>
603          <term><option>--help</option></term>
604          <listitem>
605            <para>Print help text.</para>
606          </listitem>
607        </varlistentry>
608      </variablelist>
609    </refsect2>
610  </refsect1>
611
612  <refsect1>
613    <title>See Also</title>
614    <para><citerefentry>
615        <refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum>
616    </citerefentry>,
617    <citerefentry>
618        <refentrytitle>udevd.service</refentrytitle><manvolnum>8</manvolnum>
619    </citerefentry></para>
620  </refsect1>
621</refentry>
622