<para>Usually udev runs as <citerefentry><refentrytitle>udevd</refentrytitle>
<manvolnum>8</manvolnum></citerefentry> and receives uevents directly from the
- kernel if a device is added or removed form the system.</para>
+ kernel if a device is added or removed from the system.</para>
<para>If udev receives a device event, it matches its configured rules
against the available device attributes provided in sysfs to identify the device.
- Rules that match, may provide additional device information or specify a device
+ Rules that match may provide additional device information or specify a device
node name and multiple symlink names and instruct udev to run additional programs
as part of the device event handling.</para>
</refsect1>
<refsect1><title>CONFIGURATION</title>
- <para>All udev configuration files are placed in <filename>/etc/udev/*</filename>.
- Every file consists of a set of lines of text. All empty lines or lines beginning
- with '#' will be ignored.</para>
+ <para>udev configuration files are placed in <filename>/etc/udev/</filename>
+ and <filename>/lib/udev/</filename>. All empty lines, or lines beginning with
+ '#' will be ignored.</para>
<refsect2><title>Configuration file</title>
<para>udev expects its main configuration file at <filename>/etc/udev/udev.conf</filename>.
</listitem>
</varlistentry>
- <varlistentry>
- <term><option>udev_rules</option></term>
- <listitem>
- <para>The name of the udev rules file or directory to look for files
- with the suffix <filename>.rules</filename>. Multiple rule files are
- read in lexical order. The default value is
- <filename>/etc/udev/rules.d</filename>.</para>
- </listitem>
- </varlistentry>
-
<varlistentry>
<term><option>udev_log</option></term>
<listitem>
<refsect2><title>Rules files</title>
<para>The udev rules are read from the files located in the
- <filename>/etc/udev/rules.d</filename> directory or at the location specified
- value in the configuration file. Every line in the rules file contains at least
+ default rules directory <filename>/lib/udev/rules.d/</filename>,
+ the custom rules directory <filename>/etc/udev/rules.d/</filename>
+ and the temporary rules directory <filename>/dev/.udev/rules.d/</filename>.
+ All rule files are sorted and processed in lexical order, regardless
+ in which of these directories they live. Every line in the rules file contains at least
one key value pair. There are two kind of keys, match and assignment keys.
If all match keys are matching against its value, the rule gets applied and the
assign keys get the specified value assigned.</para>
pointing to the node, or run a specified program as part of the event handling.
If no matching rule is found, the default device node name is used.</para>
- <para>A rule may consists of a list of one or more key value pairs separated by
+ <para>A rule may consist of a list of one or more key value pairs separated by
a comma. Each key has a distinct operation, depending on the used operator. Valid
operators are:</para>
<variablelist>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>NAME</option></term>
+ <listitem>
+ <para>Match the name of the node or network interface. It can
+ be used once the NAME key has been set in one of the preceding
+ rules.</para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>SUBSYSTEM</option></term>
<listitem>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>TEST{<replaceable>octal mode mask</replaceable>}</option></term>
+ <listitem>
+ <para>Test the existence of a file. An octal mode mask can be specified
+ if needed.</para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>PROGRAM</option></term>
<listitem>
event process for a long period of time may block all further events for
this or a dependent device. Long running tasks need to be immediately
detached from the event process itself.</para>
+ <para>If the specifiefd string starts with
+ <option>socket:<replaceable>path</replaceable></option>, all current event
+ values will be passed to the specified socket, as a message in the same
+ format the kernel sends an uevent. If the first character of the specified path
+ is an @ character, an abstract namespace socket is used, instead of an existing
+ socket file.</para>
</listitem>
</varlistentry>
</varlistentry>
</variablelist>
<para>If no option is given, udev will choose between <option>program</option>
- and <option>file</option> based on the executable bit of of the file
+ and <option>file</option> based on the executable bit of the file
permissions.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><option>WAIT_FOR_SYSFS</option></term>
+ <term><option>WAIT_FOR</option></term>
<listitem>
- <para>Wait for the specified sysfs file of the device to be created. Can be used
- to fight against kernel sysfs timing issues.</para>
+ <para>Wait for a file to become available.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>OPTIONS</option></term>
<listitem>
- <para><option>last_rule</option> stops further rules application. No later rules
- will have any effect.
- <option>ignore_device</option> will ignore this event completely.
- <option>ignore_remove</option> will ignore any later remove event for this
- device. This may be useful as a workaround for broken device drivers.
- <option>all_partitions</option> will create the device nodes for all available
- partitions of a block device. This may be useful for removable media devices where
- media changes are not detected.</para>
+ <para>Rule and device options:</para>
+ <variablelist>
+ <varlistentry>
+ <term><option>last_rule</option></term>
+ <listitem>
+ <para>Stops further rules application. No later rules will have
+ any effect.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><option>ignore_device</option></term>
+ <listitem>
+ <para>Ignore this event completely.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><option>ignore_remove</option></term>
+ <listitem>
+ <para>Do not remove the device node when the device goes away. This may be
+ useful as a workaround for broken device drivers.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><option>link_priority=<replaceable>value</replaceable></option></term>
+ <listitem>
+ <para>Specify the priority of the created symlinks. Devices with higher
+ priorities overwrite existing symlinks of other devices. The default is 0.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><option>all_partitions</option></term>
+ <listitem>
+ <para>Create the device nodes for all available partitions of a block device.
+ This may be useful for removable media devices where media changes are not
+ detected.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><option>event_timeout=</option></term>
+ <listitem>
+ <para>Number of seconds an event will wait for operations to finish, before it
+ will terminate itself.</para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <term><option>string_escape=<replaceable>none|replace</replaceable></option></term>
+ <listitem>
+ <para>Usually control and other possibly unsafe characters are replaced
+ in strings used for device naming. The mode of replacement can be specified
+ with this option.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
</listitem>
</varlistentry>
</variablelist>
<para>The <option>NAME</option>, <option>SYMLINK</option>, <option>PROGRAM</option>,
- <option>OWNER</option>, <option>GROUP</option> and <option>RUN</option>
+ <option>OWNER</option>, <option>GROUP</option>, <option>MODE</option> and <option>RUN</option>
fields support simple printf-like string substitutions. The <option>RUN</option>
format chars gets applied after all rules have been processed, right before the program
is executed. It allows the use of the complete environment set by earlier matching
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>$driver</option></term>
+ <listitem>
+ <para>The driver name of the device matched while searching the devpath upwards for
+ <option>SUBSYSTEMS</option>, <option>KERNELS</option>, <option>DRIVERS</option> and <option>ATTRS</option>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>$attr{<replaceable>file</replaceable>}</option>, <option>%s{<replaceable>file</replaceable>}</option></term>
<listitem>
<para>The value of a sysfs attribute found at the device, where
all keys of the rule have matched. If the matching device does not have
- such an attribute, all devices along the chain of parents are searched
- for a matching attribute.
+ such an attribute, follow the chain of parent devices and use the value
+ of the first attribute that matches.
If the attribute is a symlink, the last element of the symlink target is
returned as the value.</para>
</listitem>
</varlistentry>
<varlistentry>
- <term><option>$minor</option> <option>%m</option></term>
+ <term><option>$minor</option>, <option>%m</option></term>
<listitem>
<para>The kernel minor number for the device.</para>
</listitem>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>$name</option></term>
+ <listitem>
+ <para>The current name of the device node. If not changed by a rule, it is the
+ name of the kernel device.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>$links</option></term>
+ <listitem>
+ <para>The current list of symlinks, separated by a space character. The value is
+ only set if an earlier rule assigned a value, or during a remove events.</para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>$root</option>, <option>%r</option></term>
<listitem>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>$sys</option>, <option>%S</option></term>
+ <listitem>
+ <para>The sysfs mount point.</para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>$tempnode</option>, <option>%N</option></term>
<listitem>
<refsect1><title>AUTHOR</title>
<para>Written by Greg Kroah-Hartman <email>greg@kroah.com</email> and
Kay Sievers <email>kay.sievers@vrfy.org</email>. With much help from
- Dan Stekloff <email>dsteklof@us.ibm.com</email> and many others.</para>
+ Dan Stekloff and many others.</para>
</refsect1>
<refsect1>
<refentrytitle>udevd</refentrytitle><manvolnum>8</manvolnum>
</citerefentry>,
<citerefentry>
- <refentrytitle>udevinfo</refentrytitle><manvolnum>8</manvolnum>
- </citerefentry>,
- <citerefentry>
- <refentrytitle>udevmonitor</refentrytitle><manvolnum>8</manvolnum>
+ <refentrytitle>udevadm</refentrytitle><manvolnum>8</manvolnum>
</citerefentry></para>
</refsect1>
</refentry>
~ianmdlvl / elogind.git / blobdiff