man/udevadm.xml

   1 <?xml version='1.0'?>
   2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
   3   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
   4 <!-- SPDX-License-Identifier: LGPL-2.1+ -->
   5
   6 <refentry id="udevadm"
   7           xmlns:xi="http://www.w3.org/2001/XInclude">
   8
   9   <refentryinfo>
  10     <title>udevadm</title>
  11     <productname>systemd</productname>
  12   </refentryinfo>
  13
  14   <refmeta>
  15     <refentrytitle>udevadm</refentrytitle>
  16     <manvolnum>8</manvolnum>
  17   </refmeta>
  18
  19   <refnamediv>
  20     <refname>udevadm</refname><refpurpose>udev management tool</refpurpose>
  21   </refnamediv>
  22
  23   <refsynopsisdiv>
  24     <cmdsynopsis>
  25       <command>udevadm</command>
  26         <arg><option>--debug</option></arg>
  27         <arg><option>--version</option></arg>
  28         <arg><option>--help</option></arg>
  29     </cmdsynopsis>
  30     <cmdsynopsis>
  31       <command>udevadm info <optional>options</optional> <optional>devpath</optional></command>
  32     </cmdsynopsis>
  33     <cmdsynopsis>
  34       <command>udevadm trigger <optional>options</optional> <optional>devpath</optional></command>
  35     </cmdsynopsis>
  36     <cmdsynopsis>
  37       <command>udevadm settle <optional>options</optional></command>
  38     </cmdsynopsis>
  39     <cmdsynopsis>
  40       <command>udevadm control <replaceable>option</replaceable></command>
  41     </cmdsynopsis>
  42     <cmdsynopsis>
  43       <command>udevadm monitor <optional>options</optional></command>
  44     </cmdsynopsis>
  45     <cmdsynopsis>
  46       <command>udevadm test <optional>options</optional> <replaceable>devpath</replaceable></command>
  47     </cmdsynopsis>
  48     <cmdsynopsis>
  49       <command>udevadm test-builtin <optional>options</optional> <replaceable>command</replaceable> <replaceable>devpath</replaceable></command>
  50     </cmdsynopsis>
  51   </refsynopsisdiv>
  52
  53   <refsect1><title>Description</title>
  54     <para><command>udevadm</command> expects a command and command
  55     specific options.  It controls the runtime behavior of
  56     <command>systemd-udevd</command>, requests kernel events, manages
  57     the event queue, and provides simple debugging mechanisms.</para>
  58   </refsect1>
  59
  60   <refsect1><title>Options</title>
  61     <variablelist>
  62       <varlistentry>
  63         <term><option>-d</option></term>
  64         <term><option>--debug</option></term>
  65         <listitem>
  66           <para>Print debug messages to standard error. This option is implied in <command>udevadm test</command> and
  67           <command>udevadm test-builtin</command> commands.</para>
  68         </listitem>
  69       </varlistentry>
  70
  71       <xi:include href="standard-options.xml" xpointer="help" />
  72     </variablelist>
  73
  74     <refsect2><title>udevadm info
  75       <arg choice="opt"><replaceable>options</replaceable></arg>
  76       <arg choice="opt" rep="repeat"><replaceable>devpath</replaceable>|<replaceable>file</replaceable>|<replaceable>unit</replaceable></arg>
  77     </title>
  78
  79       <para>Query the udev database for device information.</para>
  80
  81       <para>Positional arguments should be used to specify one or more devices. Each one may be a device name
  82       (in which case it must start with <filename>/dev/</filename>), a sys path (in which case it must start
  83       with <filename>/sys/</filename>), or a systemd device unit name (in which case it must end with
  84       <literal>.device</literal>, see
  85       <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
  86       </para>
  87
  88       <variablelist>
  89         <varlistentry>
  90           <term><option>-q</option></term>
  91           <term><option>--query=<replaceable>TYPE</replaceable></option></term>
  92           <listitem>
  93             <para>Query the database for the specified type of device data.
  94             Valid <replaceable>TYPE</replaceable>s are:
  95             <constant>name</constant>, <constant>symlink</constant>,
  96             <constant>path</constant>, <constant>property</constant>,
  97             <constant>all</constant>.</para>
  98           </listitem>
  99         </varlistentry>
 100
 101         <varlistentry>
 102           <term><option>-p</option></term>
 103           <term><option>--path=<replaceable>DEVPATH</replaceable></option></term>
 104           <listitem>
 105             <para>The <filename>/sys</filename> path of the device to query, e.g.
 106             <filename><optional>/sys</optional>/class/block/sda</filename>. This option is an alternative to
 107             the positional argument with a <filename>/sys/</filename> prefix. <command>udevadm info
 108             --path=/class/block/sda</command> is equivalent to <command>udevadm info
 109             /sys/class/block/sda</command>.</para>
 110           </listitem>
 111         </varlistentry>
 112         <varlistentry>
 113           <term><option>-n</option></term>
 114           <term><option>--name=<replaceable>FILE</replaceable></option></term>
 115           <listitem>
 116             <para>The name of the device node or a symlink to query,
 117             e.g. <filename><optional>/dev</optional>/sda</filename>. This option is an alternative to the
 118             positional argument with a <filename>/dev/</filename> prefix. <command>udevadm info
 119             --name=sda</command> is equivalent to <command>udevadm info /dev/sda</command>.</para>
 120           </listitem>
 121         </varlistentry>
 122         <varlistentry>
 123           <term><option>-r</option></term>
 124           <term><option>--root</option></term>
 125           <listitem>
 126             <para>Print absolute paths in <command>name</command> or <command>symlink</command>
 127             query.</para>
 128           </listitem>
 129         </varlistentry>
 130         <varlistentry>
 131           <term><option>-a</option></term>
 132           <term><option>--attribute-walk</option></term>
 133           <listitem>
 134             <para>Print all sysfs properties of the specified device that can be used
 135             in udev rules to match the specified device. It prints all devices
 136             along the chain, up to the root of sysfs that can be used in udev rules.</para>
 137           </listitem>
 138         </varlistentry>
 139         <varlistentry>
 140           <term><option>-x</option></term>
 141           <term><option>--export</option></term>
 142           <listitem>
 143             <para>Print output as key/value pairs. Values are enclosed in single quotes.
 144             This takes effects only when <option>--query=property</option> or
 145             <option>--device-id-of-file=<replaceable>FILE</replaceable></option> is specified.</para>
 146           </listitem>
 147         </varlistentry>
 148         <varlistentry>
 149           <term><option>-P</option></term>
 150           <term><option>--export-prefix=<replaceable>NAME</replaceable></option></term>
 151           <listitem>
 152             <para>Add a prefix to the key name of exported values.
 153             This implies <option>--export</option>.</para>
 154           </listitem>
 155         </varlistentry>
 156         <varlistentry>
 157           <term><option>-d</option></term>
 158           <term><option>--device-id-of-file=<replaceable>FILE</replaceable></option></term>
 159           <listitem>
 160             <para>Print major/minor numbers of the underlying device, where the file lives on.
 161             If this is specified, all positional arguments are ignored.</para>
 162           </listitem>
 163         </varlistentry>
 164         <varlistentry>
 165           <term><option>-e</option></term>
 166           <term><option>--export-db</option></term>
 167           <listitem>
 168             <para>Export the content of the udev database.</para>
 169           </listitem>
 170         </varlistentry>
 171         <varlistentry>
 172           <term><option>-c</option></term>
 173           <term><option>--cleanup-db</option></term>
 174           <listitem>
 175             <para>Cleanup the udev database.</para>
 176           </listitem>
 177         </varlistentry>
 178
 179         <xi:include href="standard-options.xml" xpointer="help" />
 180       </variablelist>
 181     </refsect2>
 182
 183     <refsect2><title>udevadm trigger
 184       <arg choice="opt"><replaceable>options</replaceable></arg>
 185       <arg choice="opt"><replaceable>devpath</replaceable>|<replaceable>file</replaceable>|<replaceable>unit</replaceable></arg>
 186       </title>
 187       <para>Request device events from the kernel. Primarily used to replay events at system coldplug time.</para>
 188
 189       <para>Takes device specifications as positional arguments. See the description of <command>info</command>
 190       above.</para>
 191
 192       <variablelist>
 193         <varlistentry>
 194           <term><option>-v</option></term>
 195           <term><option>--verbose</option></term>
 196           <listitem>
 197             <para>Print the list of devices which will be triggered.</para>
 198           </listitem>
 199         </varlistentry>
 200         <varlistentry>
 201           <term><option>-n</option></term>
 202           <term><option>--dry-run</option></term>
 203           <listitem>
 204             <para>Do not actually trigger the event.</para>
 205           </listitem>
 206         </varlistentry>
 207         <varlistentry>
 208           <term><option>-t</option></term>
 209           <term><option>--type=<replaceable>TYPE</replaceable></option></term>
 210           <listitem>
 211             <para>Trigger a specific type of devices. Valid types are:
 212             <command>devices</command>, <command>subsystems</command>.
 213             The default value is <command>devices</command>.</para>
 214           </listitem>
 215         </varlistentry>
 216         <varlistentry>
 217           <term><option>-c</option></term>
 218           <term><option>--action=<replaceable>ACTION</replaceable></option></term>
 219           <listitem>
 220             <para>Type of event to be triggered. Possible actions are <literal>add</literal>,
 221             <literal>remove</literal>, <literal>change</literal>, <literal>move</literal>,
 222             <literal>online</literal>, <literal>offline</literal>, <literal>bind</literal>,
 223             and <literal>unbind</literal>. The default value is <literal>change</literal>.</para>
 224           </listitem>
 225         </varlistentry>
 226         <varlistentry>
 227           <term><option>-s</option></term>
 228           <term><option>--subsystem-match=<replaceable>SUBSYSTEM</replaceable></option></term>
 229           <listitem>
 230             <para>Trigger events for devices which belong to a
 231             matching subsystem. This option supports shell style pattern matching.
 232             When this option is specified more than once, then each matching result is ORed, that is,
 233             all the devices in each subsystem are triggered.</para>
 234           </listitem>
 235         </varlistentry>
 236         <varlistentry>
 237           <term><option>-S</option></term>
 238           <term><option>--subsystem-nomatch=<replaceable>SUBSYSTEM</replaceable></option></term>
 239           <listitem>
 240             <para>Do not trigger events for devices which belong to a matching subsystem. This option
 241             supports shell style pattern matching. When this option is specified more than once,
 242             then each matching result is ANDed, that is, devices which do not match all specified
 243             subsystems are triggered.</para>
 244           </listitem>
 245         </varlistentry>
 246         <varlistentry>
 247           <term><option>-a</option></term>
 248           <term><option>--attr-match=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
 249           <listitem>
 250             <para>Trigger events for devices with a matching sysfs attribute. If a value is specified along
 251             with the attribute name, the content of the attribute is matched against the given value using
 252             shell style pattern matching. If no value is specified, the existence of the sysfs attribute is
 253             checked. When this option is specified multiple times, then each matching result is ANDed,
 254             that is, only devices which have all specified attributes are triggered.</para>
 255           </listitem>
 256         </varlistentry>
 257         <varlistentry>
 258           <term><option>-A</option></term>
 259           <term><option>--attr-nomatch=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
 260           <listitem>
 261             <para>Do not trigger events for devices with a matching sysfs attribute. If a value is specified
 262             along with the attribute name, the content of the attribute is matched against the given value
 263             using shell style pattern matching. If no value is specified, the existence of the sysfs attribute
 264             is checked. When this option is specified multiple times, then each matching result is ANDed,
 265             that is, only devices which have none of the specified attributes are triggered.</para>
 266           </listitem>
 267         </varlistentry>
 268         <varlistentry>
 269           <term><option>-p</option></term>
 270           <term><option>--property-match=<replaceable>PROPERTY</replaceable>=<replaceable>VALUE</replaceable></option></term>
 271           <listitem>
 272             <para>Trigger events for devices with a matching property value. This option supports shell style
 273             pattern matching. When this option is specified more than once, then each matching result is ORed,
 274             that is, devices which have one of the specified properties are triggered.</para>
 275           </listitem>
 276         </varlistentry>
 277         <varlistentry>
 278           <term><option>-g</option></term>
 279           <term><option>--tag-match=<replaceable>PROPERTY</replaceable></option></term>
 280           <listitem>
 281             <para>Trigger events for devices with a matching tag. When this option is specified multiple times,
 282             then each matching result is ANDed, that is, devices which have all specified tags are triggered.</para>
 283           </listitem>
 284         </varlistentry>
 285         <varlistentry>
 286           <term><option>-y</option></term>
 287           <term><option>--sysname-match=<replaceable>NAME</replaceable></option></term>
 288           <listitem>
 289             <para>Trigger events for devices for which the last component (i.e. the filename) of the
 290             <filename>/sys</filename> path matches the specified <replaceable>PATH</replaceable>. This option
 291             supports shell style pattern matching. When this option is specified more than once, then each
 292             matching result is ORed, that is, all devices which have any of the specified
 293             <replaceable>NAME</replaceable> are triggered.</para>
 294           </listitem>
 295         </varlistentry>
 296         <varlistentry>
 297           <term><option>--name-match=<replaceable>NAME</replaceable></option></term>
 298           <listitem>
 299             <para>Trigger events for devices with a matching device path. When this option is specified more than once,
 300             then each matching result is ORed, that is, all specified devices are triggered.</para>
 301           </listitem>
 302         </varlistentry>
 303         <varlistentry>
 304           <term><option>-b</option></term>
 305           <term><option>--parent-match=<replaceable>SYSPATH</replaceable></option></term>
 306           <listitem>
 307             <para>Trigger events for all children of a given device. When this option is specified more than once,
 308             then each matching result is ORed, that is, all children of each specified device are triggered.</para>
 309           </listitem>
 310         </varlistentry>
 311         <varlistentry>
 312           <term><option>-w</option></term>
 313           <term><option>--settle</option></term>
 314           <listitem>
 315             <para>Apart from triggering events, also waits for those events to
 316             finish. Note that this is different from calling <command>udevadm
 317             settle</command>. <command>udevadm settle</command> waits for all
 318             events to finish. This option only waits for events triggered by
 319             the same command to finish.</para>
 320           </listitem>
 321         </varlistentry>
 322         <varlistentry>
 323           <term><option>--wait-daemon[=<replaceable>SECONDS</replaceable>]</option></term>
 324           <listitem>
 325             <para>Before triggering uevents, wait for systemd-udevd daemon to be initialized.
 326             Optionally takes timeout value. Default timeout is 5 seconds. This is equivalent to invoke
 327             invoking <command>udevadm control --ping</command> before <command>udevadm trigger</command>.</para>
 328           </listitem>
 329         </varlistentry>
 330
 331         <xi:include href="standard-options.xml" xpointer="help" />
 332       </variablelist>
 333
 334       <para>In addition, optional positional arguments can be used
 335       to specify device names or sys paths. They must start with
 336       <filename>/dev</filename> or <filename>/sys</filename>
 337       respectively.</para>
 338     </refsect2>
 339
 340     <refsect2><title>udevadm settle
 341       <arg choice="opt"><replaceable>options</replaceable></arg>
 342     </title>
 343       <para>Watches the udev event queue, and exits if all current events are handled.</para>
 344       <variablelist>
 345         <varlistentry>
 346           <term><option>-t</option></term>
 347           <term><option>--timeout=<replaceable>SECONDS</replaceable></option></term>
 348           <listitem>
 349             <para>Maximum number of seconds to wait for the event
 350             queue to become empty. The default value is 120 seconds. A
 351             value of 0 will check if the queue is empty and always
 352             return immediately.</para>
 353           </listitem>
 354         </varlistentry>
 355         <varlistentry>
 356           <term><option>-E</option></term>
 357           <term><option>--exit-if-exists=<replaceable>FILE</replaceable></option></term>
 358           <listitem>
 359             <para>Stop waiting if file exists.</para>
 360           </listitem>
 361         </varlistentry>
 362
 363         <xi:include href="standard-options.xml" xpointer="help" />
 364       </variablelist>
 365     </refsect2>
 366
 367     <refsect2><title>udevadm control <replaceable>option</replaceable></title>
 368       <para>Modify the internal state of the running udev daemon.</para>
 369       <variablelist>
 370         <varlistentry>
 371           <term><option>-e</option></term>
 372           <term><option>--exit</option></term>
 373           <listitem>
 374             <para>Signal and wait for systemd-udevd to exit. No option except for
 375             <option>--timeout</option> can be specified after this option.
 376             Note that <filename>systemd-udevd.service</filename> contains
 377             <option>Restart=always</option> and so as a result, this option restarts systemd-udevd.
 378             If you want to stop <filename>systemd-udevd.service</filename>, please use the following:
 379             <programlisting>systemctl stop systemd-udevd-control.socket systemd-udevd-kernel.socket systemd-udevd.service</programlisting>
 380             </para>
 381           </listitem>
 382         </varlistentry>
 383         <varlistentry>
 384           <term><option>-l</option></term>
 385           <term><option>--log-priority=<replaceable>value</replaceable></option></term>
 386           <listitem>
 387             <para>Set the internal log level of
 388             <filename>systemd-udevd</filename>. Valid values are the
 389             numerical syslog priorities or their textual
 390             representations: <option>emerg</option>,
 391             <option>alert</option>, <option>crit</option>,
 392             <option>err</option>, <option>warning</option>,
 393             <option>notice</option>, <option>info</option>, and
 394             <option>debug</option>.</para>
 395           </listitem>
 396         </varlistentry>
 397         <varlistentry>
 398           <term><option>-s</option></term>
 399           <term><option>--stop-exec-queue</option></term>
 400           <listitem>
 401             <para>Signal systemd-udevd to stop executing new events. Incoming events
 402             will be queued.</para>
 403           </listitem>
 404         </varlistentry>
 405         <varlistentry>
 406           <term><option>-S</option></term>
 407           <term><option>--start-exec-queue</option></term>
 408           <listitem>
 409             <para>Signal systemd-udevd to enable the execution of events.</para>
 410           </listitem>
 411         </varlistentry>
 412         <varlistentry>
 413           <term><option>-R</option></term>
 414           <term><option>--reload</option></term>
 415           <listitem>
 416             <para>Signal systemd-udevd to reload the rules files and other databases like the kernel
 417             module index. Reloading rules and databases does not apply any changes to already
 418             existing devices; the new configuration will only be applied to new events.</para>
 419           </listitem>
 420         </varlistentry>
 421         <varlistentry>
 422           <term><option>-p</option></term>
 423           <term><option>--property=<replaceable>KEY</replaceable>=<replaceable>value</replaceable></option></term>
 424           <listitem>
 425             <para>Set a global property for all events.</para>
 426           </listitem>
 427         </varlistentry>
 428         <varlistentry>
 429           <term><option>-m</option></term>
 430           <term><option>--children-max=</option><replaceable>value</replaceable></term>
 431           <listitem>
 432             <para>Set the maximum number of events, systemd-udevd will handle at the
 433             same time.</para>
 434           </listitem>
 435         </varlistentry>
 436         <varlistentry>
 437           <term><option>--ping</option></term>
 438           <listitem>
 439             <para>Send a ping message to systemd-udevd and wait for the reply. This may be useful to check that
 440             systemd-udevd daemon is running.</para>
 441           </listitem>
 442         </varlistentry>
 443         <varlistentry>
 444           <term><option>-t</option></term>
 445           <term><option>--timeout=</option><replaceable>seconds</replaceable></term>
 446           <listitem>
 447             <para>The maximum number of seconds to wait for a reply from systemd-udevd.</para>
 448           </listitem>
 449         </varlistentry>
 450
 451         <xi:include href="standard-options.xml" xpointer="help" />
 452       </variablelist>
 453     </refsect2>
 454
 455     <refsect2><title>udevadm monitor
 456       <arg choice="opt"><replaceable>options</replaceable></arg>
 457     </title>
 458       <para>Listens to the kernel uevents and events sent out by a udev rule
 459       and prints the devpath of the event to the console. It can be used to analyze the
 460       event timing, by comparing the timestamps of the kernel uevent and the udev event.
 461       </para>
 462       <variablelist>
 463         <varlistentry>
 464           <term><option>-k</option></term>
 465           <term><option>--kernel</option></term>
 466           <listitem>
 467             <para>Print the kernel uevents.</para>
 468           </listitem>
 469         </varlistentry>
 470         <varlistentry>
 471           <term><option>-u</option></term>
 472           <term><option>--udev</option></term>
 473           <listitem>
 474             <para>Print the udev event after the rule processing.</para>
 475           </listitem>
 476         </varlistentry>
 477         <varlistentry>
 478           <term><option>-p</option></term>
 479           <term><option>--property</option></term>
 480           <listitem>
 481             <para>Also print the properties of the event.</para>
 482           </listitem>
 483         </varlistentry>
 484         <varlistentry>
 485           <term><option>-s</option></term>
 486           <term><option>--subsystem-match=<replaceable>string[/string]</replaceable></option></term>
 487           <listitem>
 488             <para>Filter kernel uevents and udev events by subsystem[/devtype]. Only events with a matching subsystem value will pass.
 489             When this option is specified more than once, then each matching result is ORed, that is, all devices in the specified
 490             subsystems are monitored.</para>
 491           </listitem>
 492         </varlistentry>
 493         <varlistentry>
 494           <term><option>-t</option></term>
 495           <term><option>--tag-match=<replaceable>string</replaceable></option></term>
 496           <listitem>
 497             <para>Filter udev events by tag. Only udev events with a given tag attached will pass.
 498             When this option is specified more than once, then each matching result is ORed, that is, devices which have one of the
 499             specified tags are monitored.</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>