man/udevadm.xml

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   8
   9 <refentry id="udevadm"
  10           xmlns:xi="http://www.w3.org/2001/XInclude">
  11
  12   <refentryinfo>
  13     <title>udevadm</title>
  14     <productname>systemd</productname>
  15   </refentryinfo>
  16
  17   <refmeta>
  18     <refentrytitle>udevadm</refentrytitle>
  19     <manvolnum>8</manvolnum>
  20   </refmeta>
  21
  22   <refnamediv>
  23     <refname>udevadm</refname><refpurpose>udev management tool</refpurpose>
  24   </refnamediv>
  25
  26   <refsynopsisdiv>
  27     <cmdsynopsis>
  28       <command>udevadm</command>
  29         <arg><option>--debug</option></arg>
  30         <arg><option>--version</option></arg>
  31         <arg><option>--help</option></arg>
  32     </cmdsynopsis>
  33     <cmdsynopsis>
  34       <command>udevadm info <optional>options</optional> <optional>devpath</optional></command>
  35     </cmdsynopsis>
  36     <cmdsynopsis>
  37       <command>udevadm trigger <optional>options</optional> <optional>devpath</optional></command>
  38     </cmdsynopsis>
  39     <cmdsynopsis>
  40       <command>udevadm settle <optional>options</optional></command>
  41     </cmdsynopsis>
  42     <cmdsynopsis>
  43       <command>udevadm control <replaceable>option</replaceable></command>
  44     </cmdsynopsis>
  45     <cmdsynopsis>
  46       <command>udevadm monitor <optional>options</optional></command>
  47     </cmdsynopsis>
  48     <cmdsynopsis>
  49       <command>udevadm test <optional>options</optional> <replaceable>devpath</replaceable></command>
  50     </cmdsynopsis>
  51     <cmdsynopsis>
  52       <command>udevadm test-builtin <optional>options</optional> <replaceable>command</replaceable> <replaceable>devpath</replaceable></command>
  53     </cmdsynopsis>
  54   </refsynopsisdiv>
  55
  56   <refsect1><title>Description</title>
  57     <para><command>udevadm</command> expects a command and command
  58     specific options.  It controls the runtime behavior of
  59     <command>systemd-udevd</command>, requests kernel events, manages
  60     the event queue, and provides simple debugging mechanisms.</para>
  61   </refsect1>
  62
  63   <refsect1><title>Options</title>
  64     <variablelist>
  65       <varlistentry>
  66         <term><option>-d</option></term>
  67         <term><option>--debug</option></term>
  68         <listitem>
  69           <para>Print debug messages to standard error. This option is implied in <command>udevadm test</command> and
  70           <command>udevadm test-builtin</command> commands.</para>
  71         </listitem>
  72       </varlistentry>
  73
  74       <xi:include href="standard-options.xml" xpointer="help" />
  75     </variablelist>
  76
  77     <refsect2><title>udevadm info
  78       <arg choice="opt"><replaceable>options</replaceable></arg>
  79       <arg choice="opt"><replaceable>devpath</replaceable>|<replaceable>file</replaceable></arg>
  80     </title>
  81
  82       <para>Queries the udev database for device information
  83       stored in the udev database. It can also query the properties
  84       of a device from its sysfs representation to help creating udev
  85       rules that match this device.</para>
  86       <variablelist>
  87         <varlistentry>
  88           <term><option>-q</option></term>
  89           <term><option>--query=<replaceable>TYPE</replaceable></option></term>
  90           <listitem>
  91             <para>Query the database for the specified type of device
  92             data. It needs the <option>--path</option> or
  93             <option>--name</option> to identify the specified device.
  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         <varlistentry>
 101           <term><option>-p</option></term>
 102           <term><option>--path=<replaceable>DEVPATH</replaceable></option></term>
 103           <listitem>
 104             <para>The <filename>/sys</filename> path of the device to
 105             query, e.g.
 106             <filename><optional>/sys</optional>/class/block/sda</filename>.
 107             Note that this option usually is not very useful, since
 108             <command>udev</command> can guess the type of the
 109             argument, so <command>udevadm info
 110             --path=/class/block/sda</command> is equivalent to
 111             <command>udevadm info /sys/class/block/sda</command>.</para>
 112           </listitem>
 113         </varlistentry>
 114         <varlistentry>
 115           <term><option>-n</option></term>
 116           <term><option>--name=<replaceable>FILE</replaceable></option></term>
 117           <listitem>
 118             <para>The name of the device node or a symlink to query,
 119             e.g. <filename><optional>/dev</optional>/sda</filename>.
 120             Note that this option usually is not very useful, since
 121             <command>udev</command> can guess the type of the
 122             argument, so <command>udevadm info --name=sda</command> is
 123             equivalent to <command>udevadm info /dev/sda</command>.</para>
 124           </listitem>
 125         </varlistentry>
 126         <varlistentry>
 127           <term><option>-r</option></term>
 128           <term><option>--root</option></term>
 129           <listitem>
 130             <para>Print absolute paths in <command>name</command> or <command>symlink</command>
 131             query.</para>
 132           </listitem>
 133         </varlistentry>
 134         <varlistentry>
 135           <term><option>-a</option></term>
 136           <term><option>--attribute-walk</option></term>
 137           <listitem>
 138             <para>Print all sysfs properties of the specified device that can be used
 139             in udev rules to match the specified device. It prints all devices
 140             along the chain, up to the root of sysfs that can be used in udev rules.</para>
 141           </listitem>
 142         </varlistentry>
 143         <varlistentry>
 144           <term><option>-x</option></term>
 145           <term><option>--export</option></term>
 146           <listitem>
 147             <para>Print output as key/value pairs. Values are enclosed in single quotes.</para>
 148           </listitem>
 149         </varlistentry>
 150         <varlistentry>
 151           <term><option>-P</option></term>
 152           <term><option>--export-prefix=<replaceable>NAME</replaceable></option></term>
 153           <listitem>
 154             <para>Add a prefix to the key name of exported values.</para>
 155           </listitem>
 156         </varlistentry>
 157         <varlistentry>
 158           <term><option>-d</option></term>
 159           <term><option>--device-id-of-file=<replaceable>FILE</replaceable></option></term>
 160           <listitem>
 161             <para>Print major/minor numbers of the underlying device, where the file
 162             lives on.</para>
 163           </listitem>
 164         </varlistentry>
 165         <varlistentry>
 166           <term><option>-e</option></term>
 167           <term><option>--export-db</option></term>
 168           <listitem>
 169             <para>Export the content of the udev database.</para>
 170           </listitem>
 171         </varlistentry>
 172         <varlistentry>
 173           <term><option>-c</option></term>
 174           <term><option>--cleanup-db</option></term>
 175           <listitem>
 176             <para>Cleanup the udev database.</para>
 177           </listitem>
 178         </varlistentry>
 179
 180         <xi:include href="standard-options.xml" xpointer="help" />
 181       </variablelist>
 182
 183       <para>In addition, an optional positional argument can be used
 184       to specify a device name or a sys path. It must start with
 185       <filename>/dev</filename> or <filename>/sys</filename>
 186       respectively.</para>
 187     </refsect2>
 188
 189     <refsect2><title>udevadm trigger
 190       <arg choice="opt"><replaceable>options</replaceable></arg>
 191       <arg choice="opt" rep="repeat"><replaceable>devpath</replaceable>|<replaceable>file</replaceable></arg></title>
 192       <para>Request device events from the kernel. Primarily used to replay events at system coldplug time.</para>
 193       <variablelist>
 194         <varlistentry>
 195           <term><option>-v</option></term>
 196           <term><option>--verbose</option></term>
 197           <listitem>
 198             <para>Print the list of devices which will be triggered.</para>
 199           </listitem>
 200         </varlistentry>
 201         <varlistentry>
 202           <term><option>-n</option></term>
 203           <term><option>--dry-run</option></term>
 204           <listitem>
 205             <para>Do not actually trigger the event.</para>
 206           </listitem>
 207         </varlistentry>
 208         <varlistentry>
 209           <term><option>-t</option></term>
 210           <term><option>--type=<replaceable>TYPE</replaceable></option></term>
 211           <listitem>
 212             <para>Trigger a specific type of devices. Valid types are:
 213             <command>devices</command>, <command>subsystems</command>.
 214             The default value is <command>devices</command>.</para>
 215           </listitem>
 216         </varlistentry>
 217         <varlistentry>
 218           <term><option>-c</option></term>
 219           <term><option>--action=<replaceable>ACTION</replaceable></option></term>
 220           <listitem>
 221             <para>Type of event to be triggered. The default value is
 222             <command>change</command>.</para>
 223           </listitem>
 224         </varlistentry>
 225         <varlistentry>
 226           <term><option>-s</option></term>
 227           <term><option>--subsystem-match=<replaceable>SUBSYSTEM</replaceable></option></term>
 228           <listitem>
 229             <para>Trigger events for devices which belong to a
 230             matching subsystem. This option can be specified multiple
 231             times and supports shell style pattern matching.</para>
 232           </listitem>
 233         </varlistentry>
 234         <varlistentry>
 235           <term><option>-S</option></term>
 236           <term><option>--subsystem-nomatch=<replaceable>SUBSYSTEM</replaceable></option></term>
 237           <listitem>
 238             <para>Do not trigger events for devices which belong to a matching subsystem. This option
 239             can be specified multiple times and supports shell style pattern matching.</para>
 240           </listitem>
 241         </varlistentry>
 242         <varlistentry>
 243           <term><option>-a</option></term>
 244           <term><option>--attr-match=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
 245           <listitem>
 246             <para>Trigger events for devices with a matching sysfs
 247             attribute. If a value is specified along with the
 248             attribute name, the content of the attribute is matched
 249             against the given value using shell style pattern
 250             matching. If no value is specified, the existence of the
 251             sysfs attribute is checked. This option can be specified
 252             multiple times.</para>
 253           </listitem>
 254         </varlistentry>
 255         <varlistentry>
 256           <term><option>-A</option></term>
 257           <term><option>--attr-nomatch=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
 258           <listitem>
 259             <para>Do not trigger events for devices with a matching
 260             sysfs attribute. If a value is specified along with the
 261             attribute name, the content of the attribute is matched
 262             against the given value using shell style pattern
 263             matching. If no value is specified, the existence of the
 264             sysfs attribute is checked. This option can be specified
 265             multiple times.</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
 273             value. This option can be specified multiple times and
 274             supports shell style pattern matching.</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. This
 282             option can be specified multiple times.</para>
 283           </listitem>
 284         </varlistentry>
 285         <varlistentry>
 286           <term><option>-y</option></term>
 287           <term><option>--sysname-match=<replaceable>PATH</replaceable></option></term>
 288           <listitem>
 289             <para>Trigger events for devices for which the last component
 290             (i.e. the filename) of the <filename>/sys</filename> path matches
 291             the specified <replaceable>PATH</replaceable>. This option can be
 292             specified multiple times and also supports shell style pattern
 293             matching.</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
 300             device path. This option can be specified multiple
 301             times.</para>
 302           </listitem>
 303         </varlistentry>
 304         <varlistentry>
 305           <term><option>-b</option></term>
 306           <term><option>--parent-match=<replaceable>SYSPATH</replaceable></option></term>
 307           <listitem>
 308             <para>Trigger events for all children of a given
 309             device.</para>
 310           </listitem>
 311         </varlistentry>
 312         <varlistentry>
 313           <term><option>-w</option></term>
 314           <term><option>--settle</option></term>
 315           <listitem>
 316             <para>Apart from triggering events, also waits for those events to
 317             finish. Note that this is different from calling <command>udevadm
 318             settle</command>. <command>udevadm settle</command> waits for all
 319             events to finish. This option only waits for events triggered by
 320             the same command to finish.</para>
 321           </listitem>
 322         </varlistentry>
 323
 324         <xi:include href="standard-options.xml" xpointer="help" />
 325       </variablelist>
 326
 327       <para>In addition, optional positional arguments can be used
 328       to specify device names or sys paths. They must start with
 329       <filename>/dev</filename> or <filename>/sys</filename>
 330       respectively.</para>
 331     </refsect2>
 332
 333     <refsect2><title>udevadm settle
 334       <arg choice="opt"><replaceable>options</replaceable></arg>
 335     </title>
 336       <para>Watches the udev event queue, and exits if all current events are handled.</para>
 337       <variablelist>
 338         <varlistentry>
 339           <term><option>-t</option></term>
 340           <term><option>--timeout=<replaceable>SECONDS</replaceable></option></term>
 341           <listitem>
 342             <para>Maximum number of seconds to wait for the event
 343             queue to become empty. The default value is 120 seconds. A
 344             value of 0 will check if the queue is empty and always
 345             return immediately.</para>
 346           </listitem>
 347         </varlistentry>
 348         <varlistentry>
 349           <term><option>-E</option></term>
 350           <term><option>--exit-if-exists=<replaceable>FILE</replaceable></option></term>
 351           <listitem>
 352             <para>Stop waiting if file exists.</para>
 353           </listitem>
 354         </varlistentry>
 355
 356         <xi:include href="standard-options.xml" xpointer="help" />
 357       </variablelist>
 358     </refsect2>
 359
 360     <refsect2><title>udevadm control <replaceable>option</replaceable></title>
 361       <para>Modify the internal state of the running udev daemon.</para>
 362       <variablelist>
 363         <varlistentry>
 364           <term><option>-e</option></term>
 365           <term><option>--exit</option></term>
 366           <listitem>
 367             <para>Signal and wait for systemd-udevd to exit.</para>
 368           </listitem>
 369         </varlistentry>
 370         <varlistentry>
 371           <term><option>-l</option></term>
 372           <term><option>--log-priority=<replaceable>value</replaceable></option></term>
 373           <listitem>
 374             <para>Set the internal log level of
 375             <filename>systemd-udevd</filename>. Valid values are the
 376             numerical syslog priorities or their textual
 377             representations: <option>emerg</option>,
 378             <option>alert</option>, <option>crit</option>,
 379             <option>err</option>, <option>warning</option>,
 380             <option>notice</option>, <option>info</option>, and
 381             <option>debug</option>.</para>
 382           </listitem>
 383         </varlistentry>
 384         <varlistentry>
 385           <term><option>-s</option></term>
 386           <term><option>--stop-exec-queue</option></term>
 387           <listitem>
 388             <para>Signal systemd-udevd to stop executing new events. Incoming events
 389             will be queued.</para>
 390           </listitem>
 391         </varlistentry>
 392         <varlistentry>
 393           <term><option>-S</option></term>
 394           <term><option>--start-exec-queue</option></term>
 395           <listitem>
 396             <para>Signal systemd-udevd to enable the execution of events.</para>
 397           </listitem>
 398         </varlistentry>
 399         <varlistentry>
 400           <term><option>-R</option></term>
 401           <term><option>--reload</option></term>
 402           <listitem>
 403             <para>Signal systemd-udevd to reload the rules files and other databases like the kernel
 404             module index. Reloading rules and databases does not apply any changes to already
 405             existing devices; the new configuration will only be applied to new events.</para>
 406           </listitem>
 407         </varlistentry>
 408         <varlistentry>
 409           <term><option>-p</option></term>
 410           <term><option>--property=<replaceable>KEY</replaceable>=<replaceable>value</replaceable></option></term>
 411           <listitem>
 412             <para>Set a global property for all events.</para>
 413           </listitem>
 414         </varlistentry>
 415         <varlistentry>
 416           <term><option>-m</option></term>
 417           <term><option>--children-max=</option><replaceable>value</replaceable></term>
 418           <listitem>
 419             <para>Set the maximum number of events, systemd-udevd will handle at the
 420             same time.</para>
 421           </listitem>
 422         </varlistentry>
 423         <varlistentry>
 424           <term><option>-t</option></term>
 425           <term><option>--timeout=</option><replaceable>seconds</replaceable></term>
 426           <listitem>
 427             <para>The maximum number of seconds to wait for a reply from systemd-udevd.</para>
 428           </listitem>
 429         </varlistentry>
 430
 431         <xi:include href="standard-options.xml" xpointer="help" />
 432       </variablelist>
 433     </refsect2>
 434
 435     <refsect2><title>udevadm monitor
 436       <arg choice="opt"><replaceable>options</replaceable></arg>
 437     </title>
 438       <para>Listens to the kernel uevents and events sent out by a udev rule
 439       and prints the devpath of the event to the console. It can be used to analyze the
 440       event timing, by comparing the timestamps of the kernel uevent and the udev event.
 441       </para>
 442       <variablelist>
 443         <varlistentry>
 444           <term><option>-k</option></term>
 445           <term><option>--kernel</option></term>
 446           <listitem>
 447             <para>Print the kernel uevents.</para>
 448           </listitem>
 449         </varlistentry>
 450         <varlistentry>
 451           <term><option>-u</option></term>
 452           <term><option>--udev</option></term>
 453           <listitem>
 454             <para>Print the udev event after the rule processing.</para>
 455           </listitem>
 456         </varlistentry>
 457         <varlistentry>
 458           <term><option>-p</option></term>
 459           <term><option>--property</option></term>
 460           <listitem>
 461             <para>Also print the properties of the event.</para>
 462           </listitem>
 463         </varlistentry>
 464         <varlistentry>
 465           <term><option>-s</option></term>
 466           <term><option>--subsystem-match=<replaceable>string[/string]</replaceable></option></term>
 467           <listitem>
 468             <para>Filter kernel uevents and udev events by subsystem[/devtype]. Only events with a matching subsystem value will pass.</para>
 469           </listitem>
 470         </varlistentry>
 471         <varlistentry>
 472           <term><option>-t</option></term>
 473           <term><option>--tag-match=<replaceable>string</replaceable></option></term>
 474           <listitem>
 475             <para>Filter udev events by tag. Only udev events with a given tag attached will pass.</para>
 476           </listitem>
 477         </varlistentry>
 478
 479         <xi:include href="standard-options.xml" xpointer="help" />
 480       </variablelist>
 481     </refsect2>
 482
 483     <refsect2><title>udevadm test
 484       <arg choice="opt"><replaceable>options</replaceable></arg>
 485       <arg><replaceable>devpath</replaceable></arg>
 486     </title>
 487       <para>Simulate a udev event run for the given device, and print debug output.</para>
 488       <variablelist>
 489         <varlistentry>
 490           <term><option>-a</option></term>
 491           <term><option>--action=<replaceable>string</replaceable></option></term>
 492           <listitem>
 493             <para>The action string.</para>
 494           </listitem>
 495         </varlistentry>
 496         <varlistentry>
 497           <term><option>-N</option></term>
 498           <term><option>--resolve-names=<constant>early</constant>|<constant>late</constant>|<constant>never</constant></option></term>
 499           <listitem>
 500             <para>Specify when udevadm should resolve names of users
 501             and groups.  When set to <constant>early</constant> (the
 502             default), names will be resolved when the rules are
 503             parsed. When set to <constant>late</constant>, names will
 504             be resolved for every event. When set to
 505             <constant>never</constant>, names will never be resolved
 506             and all devices will be owned by root.</para>
 507           </listitem>
 508         </varlistentry>
 509
 510         <xi:include href="standard-options.xml" xpointer="help" />
 511       </variablelist>
 512     </refsect2>
 513
 514     <refsect2><title>udevadm test-builtin
 515       <arg choice="opt"><replaceable>options</replaceable></arg>
 516       <arg><replaceable>command</replaceable></arg>
 517       <arg><replaceable>devpath</replaceable></arg>
 518     </title>
 519       <para>Run a built-in command <replaceable>COMMAND</replaceable>
 520       for device <replaceable>DEVPATH</replaceable>, and print debug
 521       output.</para>
 522       <variablelist>
 523         <xi:include href="standard-options.xml" xpointer="help" />
 524       </variablelist>
 525     </refsect2>
 526   </refsect1>
 527
 528   <refsect1>
 529     <title>See Also</title>
 530     <para><citerefentry>
 531         <refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum>
 532     </citerefentry>,
 533     <citerefentry>
 534         <refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum>
 535     </citerefentry></para>
 536   </refsect1>
 537 </refentry>