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" rep="repeat"><replaceable>devpath</replaceable>|<replaceable>file</replaceable>|<replaceable>unit</replaceable></arg>
  80     </title>
  81
  82       <para>Query the udev database for device information.</para>
  83
  84       <para>Positional arguments should be used to specify one or more devices. Each one may be a device name
  85       (in which case it must start with <filename>/dev/</filename>), a sys path (in which case it must start
  86       with <filename>/sys/</filename>), or a systemd device unit name (in which case it must end with
  87       <literal>.device</literal>, see
  88       <citerefentry><refentrytitle>systemd.device</refentrytitle><manvolnum>5</manvolnum></citerefentry>).
  89       </para>
  90
  91       <variablelist>
  92         <varlistentry>
  93           <term><option>-q</option></term>
  94           <term><option>--query=<replaceable>TYPE</replaceable></option></term>
  95           <listitem>
  96             <para>Query the database for the specified type of device data.
  97             Valid <replaceable>TYPE</replaceable>s are:
  98             <constant>name</constant>, <constant>symlink</constant>,
  99             <constant>path</constant>, <constant>property</constant>,
 100             <constant>all</constant>.</para>
 101           </listitem>
 102         </varlistentry>
 103
 104         <varlistentry>
 105           <term><option>-p</option></term>
 106           <term><option>--path=<replaceable>DEVPATH</replaceable></option></term>
 107           <listitem>
 108             <para>The <filename>/sys</filename> path of the device to query, e.g.
 109             <filename><optional>/sys</optional>/class/block/sda</filename>. This option is an alternative to
 110             the positional argument with a <filename>/sys/</filename> prefix. <command>udevadm info
 111             --path=/class/block/sda</command> is equivalent to <command>udevadm info
 112             /sys/class/block/sda</command>.</para>
 113           </listitem>
 114         </varlistentry>
 115         <varlistentry>
 116           <term><option>-n</option></term>
 117           <term><option>--name=<replaceable>FILE</replaceable></option></term>
 118           <listitem>
 119             <para>The name of the device node or a symlink to query,
 120             e.g. <filename><optional>/dev</optional>/sda</filename>. This option is an alternative to the
 121             positional argument with a <filename>/dev/</filename> prefix. <command>udevadm info
 122             --name=sda</command> is equivalent to <command>udevadm info /dev/sda</command>.</para>
 123           </listitem>
 124         </varlistentry>
 125         <varlistentry>
 126           <term><option>-r</option></term>
 127           <term><option>--root</option></term>
 128           <listitem>
 129             <para>Print absolute paths in <command>name</command> or <command>symlink</command>
 130             query.</para>
 131           </listitem>
 132         </varlistentry>
 133         <varlistentry>
 134           <term><option>-a</option></term>
 135           <term><option>--attribute-walk</option></term>
 136           <listitem>
 137             <para>Print all sysfs properties of the specified device that can be used
 138             in udev rules to match the specified device. It prints all devices
 139             along the chain, up to the root of sysfs that can be used in udev rules.</para>
 140           </listitem>
 141         </varlistentry>
 142         <varlistentry>
 143           <term><option>-x</option></term>
 144           <term><option>--export</option></term>
 145           <listitem>
 146             <para>Print output as key/value pairs. Values are enclosed in single quotes.
 147             This takes effects only when <option>--query=property</option> or
 148             <option>--device-id-of-file=<replaceable>FILE</replaceable></option> is specified.</para>
 149           </listitem>
 150         </varlistentry>
 151         <varlistentry>
 152           <term><option>-P</option></term>
 153           <term><option>--export-prefix=<replaceable>NAME</replaceable></option></term>
 154           <listitem>
 155             <para>Add a prefix to the key name of exported values.
 156             This implies <option>--export</option>.</para>
 157           </listitem>
 158         </varlistentry>
 159         <varlistentry>
 160           <term><option>-d</option></term>
 161           <term><option>--device-id-of-file=<replaceable>FILE</replaceable></option></term>
 162           <listitem>
 163             <para>Print major/minor numbers of the underlying device, where the file lives on.
 164             If this is specified, all positional arguments are ignored.</para>
 165           </listitem>
 166         </varlistentry>
 167         <varlistentry>
 168           <term><option>-e</option></term>
 169           <term><option>--export-db</option></term>
 170           <listitem>
 171             <para>Export the content of the udev database.</para>
 172           </listitem>
 173         </varlistentry>
 174         <varlistentry>
 175           <term><option>-c</option></term>
 176           <term><option>--cleanup-db</option></term>
 177           <listitem>
 178             <para>Cleanup the udev database.</para>
 179           </listitem>
 180         </varlistentry>
 181
 182         <xi:include href="standard-options.xml" xpointer="help" />
 183       </variablelist>
 184     </refsect2>
 185
 186     <refsect2><title>udevadm trigger
 187       <arg choice="opt"><replaceable>options</replaceable></arg>
 188       <arg choice="opt"><replaceable>devpath</replaceable>|<replaceable>file</replaceable>|<replaceable>unit</replaceable></arg>
 189       </title>
 190       <para>Request device events from the kernel. Primarily used to replay events at system coldplug time.</para>
 191
 192       <para>Takes device specifications as positional arguments. See the description of <command>info</command>
 193       above.</para>
 194
 195       <variablelist>
 196         <varlistentry>
 197           <term><option>-v</option></term>
 198           <term><option>--verbose</option></term>
 199           <listitem>
 200             <para>Print the list of devices which will be triggered.</para>
 201           </listitem>
 202         </varlistentry>
 203         <varlistentry>
 204           <term><option>-n</option></term>
 205           <term><option>--dry-run</option></term>
 206           <listitem>
 207             <para>Do not actually trigger the event.</para>
 208           </listitem>
 209         </varlistentry>
 210         <varlistentry>
 211           <term><option>-t</option></term>
 212           <term><option>--type=<replaceable>TYPE</replaceable></option></term>
 213           <listitem>
 214             <para>Trigger a specific type of devices. Valid types are:
 215             <command>devices</command>, <command>subsystems</command>.
 216             The default value is <command>devices</command>.</para>
 217           </listitem>
 218         </varlistentry>
 219         <varlistentry>
 220           <term><option>-c</option></term>
 221           <term><option>--action=<replaceable>ACTION</replaceable></option></term>
 222           <listitem>
 223             <para>Type of event to be triggered. The default value is
 224             <command>change</command>.</para>
 225           </listitem>
 226         </varlistentry>
 227         <varlistentry>
 228           <term><option>-s</option></term>
 229           <term><option>--subsystem-match=<replaceable>SUBSYSTEM</replaceable></option></term>
 230           <listitem>
 231             <para>Trigger events for devices which belong to a
 232             matching subsystem. This option supports shell style pattern matching.
 233             When this option is specified more than once, then each matching result is ORed, that is,
 234             all the devices in each subsystem are triggered.</para>
 235           </listitem>
 236         </varlistentry>
 237         <varlistentry>
 238           <term><option>-S</option></term>
 239           <term><option>--subsystem-nomatch=<replaceable>SUBSYSTEM</replaceable></option></term>
 240           <listitem>
 241             <para>Do not trigger events for devices which belong to a matching subsystem. This option
 242             supports shell style pattern matching. When this option is specified more than once,
 243             then each matching result is ANDed, that is, devices which do not match all specified
 244             subsystems are triggered.</para>
 245           </listitem>
 246         </varlistentry>
 247         <varlistentry>
 248           <term><option>-a</option></term>
 249           <term><option>--attr-match=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
 250           <listitem>
 251             <para>Trigger events for devices with a matching sysfs attribute. If a value is specified along
 252             with the attribute name, the content of the attribute is matched against the given value using
 253             shell style pattern matching. If no value is specified, the existence of the sysfs attribute is
 254             checked. When this option is specified multiple times, then each matching result is ANDed,
 255             that is, only devices which have all specified attributes are triggered.</para>
 256           </listitem>
 257         </varlistentry>
 258         <varlistentry>
 259           <term><option>-A</option></term>
 260           <term><option>--attr-nomatch=<replaceable>ATTRIBUTE</replaceable>=<replaceable>VALUE</replaceable></option></term>
 261           <listitem>
 262             <para>Do not trigger events for devices with a matching sysfs attribute. If a value is specified
 263             along with the attribute name, the content of the attribute is matched against the given value
 264             using shell style pattern matching. If no value is specified, the existence of the sysfs attribute
 265             is checked. When this option is specified multiple times, then each matching result is ANDed,
 266             that is, only devices which have none of the specified attributes are triggered.</para>
 267           </listitem>
 268         </varlistentry>
 269         <varlistentry>
 270           <term><option>-p</option></term>
 271           <term><option>--property-match=<replaceable>PROPERTY</replaceable>=<replaceable>VALUE</replaceable></option></term>
 272           <listitem>
 273             <para>Trigger events for devices with a matching property value. This option supports shell style
 274             pattern matching. When this option is specified more than once, then each matching result is ORed,
 275             that is, devices which have one of the specified properties are triggered.</para>
 276           </listitem>
 277         </varlistentry>
 278         <varlistentry>
 279           <term><option>-g</option></term>
 280           <term><option>--tag-match=<replaceable>PROPERTY</replaceable></option></term>
 281           <listitem>
 282             <para>Trigger events for devices with a matching tag. When this option is specified multiple times,
 283             then each matching result is ANDed, that is, devices which have all specified tags are triggered.</para>
 284           </listitem>
 285         </varlistentry>
 286         <varlistentry>
 287           <term><option>-y</option></term>
 288           <term><option>--sysname-match=<replaceable>NAME</replaceable></option></term>
 289           <listitem>
 290             <para>Trigger events for devices for which the last component (i.e. the filename) of the
 291             <filename>/sys</filename> path matches the specified <replaceable>PATH</replaceable>. This option
 292             supports shell style pattern matching. When this option is specified more than once, then each
 293             matching result is ORed, that is, all devices which have any of the specified
 294             <replaceable>NAME</replaceable> are triggered.</para>
 295           </listitem>
 296         </varlistentry>
 297         <varlistentry>
 298           <term><option>--name-match=<replaceable>NAME</replaceable></option></term>
 299           <listitem>
 300             <para>Trigger events for devices with a matching device path. When this option is specified more than once,
 301             then each matching result is ORed, that is, all specified devices are triggered.</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 device. When this option is specified more than once,
 309             then each matching result is ORed, that is, all children of each specified device are triggered.</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         <varlistentry>
 324           <term><option>--wait-daemon[=<replaceable>SECONDS</replaceable>]</option></term>
 325           <listitem>
 326             <para>Before triggering uevents, wait for systemd-udevd daemon to be initialized.
 327             Optionally takes timeout value. Default timeout is 5 seconds. This is equivalent to invoke
 328             invoking <command>udevadm control --ping</command> before <command>udevadm trigger</command>.</para>
 329           </listitem>
 330         </varlistentry>
 331
 332         <xi:include href="standard-options.xml" xpointer="help" />
 333       </variablelist>
 334
 335       <para>In addition, optional positional arguments can be used
 336       to specify device names or sys paths. They must start with
 337       <filename>/dev</filename> or <filename>/sys</filename>
 338       respectively.</para>
 339     </refsect2>
 340
 341     <refsect2><title>udevadm settle
 342       <arg choice="opt"><replaceable>options</replaceable></arg>
 343     </title>
 344       <para>Watches the udev event queue, and exits if all current events are handled.</para>
 345       <variablelist>
 346         <varlistentry>
 347           <term><option>-t</option></term>
 348           <term><option>--timeout=<replaceable>SECONDS</replaceable></option></term>
 349           <listitem>
 350             <para>Maximum number of seconds to wait for the event
 351             queue to become empty. The default value is 120 seconds. A
 352             value of 0 will check if the queue is empty and always
 353             return immediately.</para>
 354           </listitem>
 355         </varlistentry>
 356         <varlistentry>
 357           <term><option>-E</option></term>
 358           <term><option>--exit-if-exists=<replaceable>FILE</replaceable></option></term>
 359           <listitem>
 360             <para>Stop waiting if file exists.</para>
 361           </listitem>
 362         </varlistentry>
 363
 364         <xi:include href="standard-options.xml" xpointer="help" />
 365       </variablelist>
 366     </refsect2>
 367
 368     <refsect2><title>udevadm control <replaceable>option</replaceable></title>
 369       <para>Modify the internal state of the running udev daemon.</para>
 370       <variablelist>
 371         <varlistentry>
 372           <term><option>-e</option></term>
 373           <term><option>--exit</option></term>
 374           <listitem>
 375             <para>Signal and wait for systemd-udevd to exit. No option except for
 376             <option>--timeout</option> can be specified after this option.
 377             Note that <filename>systemd-udevd.service</filename> contains
 378             <option>Restart=always</option> and so as a result, this option restarts systemd-udevd.
 379             If you want to stop <filename>systemd-udevd.service</filename>, please use the following:
 380             <programlisting>systemctl stop systemd-udevd-control.socket systemd-udevd-kernel.socket systemd-udevd.service</programlisting>
 381             </para>
 382           </listitem>
 383         </varlistentry>
 384         <varlistentry>
 385           <term><option>-l</option></term>
 386           <term><option>--log-priority=<replaceable>value</replaceable></option></term>
 387           <listitem>
 388             <para>Set the internal log level of
 389             <filename>systemd-udevd</filename>. Valid values are the
 390             numerical syslog priorities or their textual
 391             representations: <option>emerg</option>,
 392             <option>alert</option>, <option>crit</option>,
 393             <option>err</option>, <option>warning</option>,
 394             <option>notice</option>, <option>info</option>, and
 395             <option>debug</option>.</para>
 396           </listitem>
 397         </varlistentry>
 398         <varlistentry>
 399           <term><option>-s</option></term>
 400           <term><option>--stop-exec-queue</option></term>
 401           <listitem>
 402             <para>Signal systemd-udevd to stop executing new events. Incoming events
 403             will be queued.</para>
 404           </listitem>
 405         </varlistentry>
 406         <varlistentry>
 407           <term><option>-S</option></term>
 408           <term><option>--start-exec-queue</option></term>
 409           <listitem>
 410             <para>Signal systemd-udevd to enable the execution of events.</para>
 411           </listitem>
 412         </varlistentry>
 413         <varlistentry>
 414           <term><option>-R</option></term>
 415           <term><option>--reload</option></term>
 416           <listitem>
 417             <para>Signal systemd-udevd to reload the rules files and other databases like the kernel
 418             module index. Reloading rules and databases does not apply any changes to already
 419             existing devices; the new configuration will only be applied to new events.</para>
 420           </listitem>
 421         </varlistentry>
 422         <varlistentry>
 423           <term><option>-p</option></term>
 424           <term><option>--property=<replaceable>KEY</replaceable>=<replaceable>value</replaceable></option></term>
 425           <listitem>
 426             <para>Set a global property for all events.</para>
 427           </listitem>
 428         </varlistentry>
 429         <varlistentry>
 430           <term><option>-m</option></term>
 431           <term><option>--children-max=</option><replaceable>value</replaceable></term>
 432           <listitem>
 433             <para>Set the maximum number of events, systemd-udevd will handle at the
 434             same time.</para>
 435           </listitem>
 436         </varlistentry>
 437         <varlistentry>
 438           <term><option>--ping</option></term>
 439           <listitem>
 440             <para>Send a ping message to systemd-udevd and wait for the reply. This may be useful to check that
 441             systemd-udevd daemon is running.</para>
 442           </listitem>
 443         </varlistentry>
 444         <varlistentry>
 445           <term><option>-t</option></term>
 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
 452         <xi:include href="standard-options.xml" xpointer="help" />
 453       </variablelist>
 454     </refsect2>
 455
 456     <refsect2><title>udevadm monitor
 457       <arg choice="opt"><replaceable>options</replaceable></arg>
 458     </title>
 459       <para>Listens to the kernel uevents and events sent out by a udev rule
 460       and prints the devpath of the event to the console. It can be used to analyze the
 461       event timing, by comparing the timestamps of the kernel uevent and the udev event.
 462       </para>
 463       <variablelist>
 464         <varlistentry>
 465           <term><option>-k</option></term>
 466           <term><option>--kernel</option></term>
 467           <listitem>
 468             <para>Print the kernel uevents.</para>
 469           </listitem>
 470         </varlistentry>
 471         <varlistentry>
 472           <term><option>-u</option></term>
 473           <term><option>--udev</option></term>
 474           <listitem>
 475             <para>Print the udev event after the rule processing.</para>
 476           </listitem>
 477         </varlistentry>
 478         <varlistentry>
 479           <term><option>-p</option></term>
 480           <term><option>--property</option></term>
 481           <listitem>
 482             <para>Also print the properties of the event.</para>
 483           </listitem>
 484         </varlistentry>
 485         <varlistentry>
 486           <term><option>-s</option></term>
 487           <term><option>--subsystem-match=<replaceable>string[/string]</replaceable></option></term>
 488           <listitem>
 489             <para>Filter kernel uevents and udev events by subsystem[/devtype]. Only events with a matching subsystem value will pass.
 490             When this option is specified more than once, then each matching result is ORed, that is, all devices in the specified
 491             subsystems are monitored.</para>
 492           </listitem>
 493         </varlistentry>
 494         <varlistentry>
 495           <term><option>-t</option></term>
 496           <term><option>--tag-match=<replaceable>string</replaceable></option></term>
 497           <listitem>
 498             <para>Filter udev events by tag. Only udev events with a given tag attached will pass.
 499             When this option is specified more than once, then each matching result is ORed, that is, devices which have one of the
 500             specified tags are monitored.</para>
 501           </listitem>
 502         </varlistentry>
 503
 504         <xi:include href="standard-options.xml" xpointer="help" />
 505       </variablelist>
 506     </refsect2>
 507
 508     <refsect2><title>udevadm test
 509       <arg choice="opt"><replaceable>options</replaceable></arg>
 510       <arg><replaceable>devpath</replaceable></arg>
 511     </title>
 512       <para>Simulate a udev event run for the given device, and print debug output.</para>
 513       <variablelist>
 514         <varlistentry>
 515           <term><option>-a</option></term>
 516           <term><option>--action=<replaceable>string</replaceable></option></term>
 517           <listitem>
 518             <para>The action string.</para>
 519           </listitem>
 520         </varlistentry>
 521         <varlistentry>
 522           <term><option>-N</option></term>
 523           <term><option>--resolve-names=<constant>early</constant>|<constant>late</constant>|<constant>never</constant></option></term>
 524           <listitem>
 525             <para>Specify when udevadm should resolve names of users
 526             and groups.  When set to <constant>early</constant> (the
 527             default), names will be resolved when the rules are
 528             parsed. When set to <constant>late</constant>, names will
 529             be resolved for every event. When set to
 530             <constant>never</constant>, names will never be resolved
 531             and all devices will be owned by root.</para>
 532           </listitem>
 533         </varlistentry>
 534
 535         <xi:include href="standard-options.xml" xpointer="help" />
 536       </variablelist>
 537     </refsect2>
 538
 539     <refsect2><title>udevadm test-builtin
 540       <arg choice="opt"><replaceable>options</replaceable></arg>
 541       <arg><replaceable>command</replaceable></arg>
 542       <arg><replaceable>devpath</replaceable></arg>
 543     </title>
 544       <para>Run a built-in command <replaceable>COMMAND</replaceable>
 545       for device <replaceable>DEVPATH</replaceable>, and print debug
 546       output.</para>
 547       <variablelist>
 548         <xi:include href="standard-options.xml" xpointer="help" />
 549       </variablelist>
 550     </refsect2>
 551   </refsect1>
 552
 553   <refsect1>
 554     <title>See Also</title>
 555     <para><citerefentry>
 556         <refentrytitle>udev</refentrytitle><manvolnum>7</manvolnum>
 557     </citerefentry>,
 558     <citerefentry>
 559         <refentrytitle>systemd-udevd.service</refentrytitle><manvolnum>8</manvolnum>
 560     </citerefentry></para>
 561   </refsect1>
 562 </refentry>