<refentry>
<refentryinfo>
<title>udev</title>
- <date>August 2005</date>
<productname>udev</productname>
</refentryinfo>
<refmeta>
<refentrytitle>udev</refentrytitle>
<manvolnum>7</manvolnum>
- <refmiscinfo class="version"></refmiscinfo>
</refmeta>
<refnamediv>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>SYMLINK</option></term>
+ <listitem>
+ <para>Match the name of a symlink targeting the node. It can
+ be used once a SYMLINK key has been set in one of the preceding
+ rules. There may be multiple symlinks; only one needs to match.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>SUBSYSTEM</option></term>
<listitem>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>TAG</option></term>
+ <listitem>
+ <para>Match against a device tag.</para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><option>TEST{<replaceable>octal mode mask</replaceable>}</option></term>
<listitem>
<varlistentry>
<term><option>NAME</option></term>
<listitem>
- <para>The name of the node to be created, or the name the network interface
- should be renamed to.</para>
+ <para>The name, a network interface should be renamed to, or the name
+ a device node should be named. Usually the kernel provides the defined
+ node name, or even creates and removes the node before udev receives
+ any event. Changing the node name from the kernel's default may result
+ in unexpected behavior and is not supported. Udev is only expected to
+ handle device node permissions and to create additional symlinks, which
+ do not conflict with the kernel device node names.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>SYMLINK</option></term>
<listitem>
- <para>The name of a symlink targeting the node. Every matching rule can add
- this value to the list of symlinks to be created along with the device node.
+ <para>The name of a symlink targeting the node. Every matching rule will add
+ this value to the list of symlinks to be created along with the device node.
Multiple symlinks may be specified by separating the names by the space
- character.</para>
+ character. In case multiple devices claim the same name, the link will
+ always point to the device with the highest link_priority. If the current device
+ goes away, the links will be re-evaluated and the device with the next highest
+ link_priority will own the link. If no link_priority is specified, the order
+ of the devices, and which of them will own the link, is undefined. Claiming
+ the same name for a node and links may result in unexpected behavior and is
+ not supported.
+ </para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>ENV{<replaceable>key</replaceable>}</option></term>
<listitem>
- <para>Set a device property value.</para>
+ <para>Set a device property value. Property names with a leading '.'
+ are not stored in the database or exported to external tool or events.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>TAG</option></term>
+ <listitem>
+ <para>Attach a tag to a device. This is used to filter events for users
+ of libudev's monitor functionality, or to enumerate a group of tagged
+ devices. The implementation can only work efficiently if only a few
+ tags are attached to a device. It is only meant to be used in
+ contexts with specific device filter requirements, and not as a
+ general-purpose flag. Excessive use might result in inefficient event
+ handling.</para>
</listitem>
</varlistentry>
device. This can only be used for very short running tasks. Running an
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>
+ detached from the event process itself. If the option
+ <option>RUN{<replaceable>fail_event_on_error</replaceable>}</option> is
+ specified, and the executed program returns non-zero, the event will be
+ marked as failed for a possible later handling.</para>
+ <para>If no path is given, the program must be in
+ <filename>/lib/udev</filename>, otherwise the full path must be
+ specified.</para>
<para>If the specified 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>
+ <para>Program name and arguments are separated with spaces. To
+ include spaces in an argument, use single quotes. Please note
+ that this does not run through a shell.</para>
</listitem>
</varlistentry>
<term><option>program</option></term>
<listitem>
<para>Execute an external program specified as the assigned value and
- import its output, which must be in environment key format.</para>
+ import its output, which must be in environment key
+ format. Path specification, command/argument separation,
+ and quoting work like in <option>RUN</option>.</para>
</listitem>
</varlistentry>
<varlistentry>
environment key format.</para>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><option>db</option></term>
+ <listitem>
+ <para>Import a single property specified as the assigned value from the
+ current device database. This works only if the database is already populated
+ by an earlier event.</para>
+ </listitem>
+ </varlistentry>
<varlistentry>
<term><option>parent</option></term>
<listitem>
<varlistentry>
<term><option>WAIT_FOR</option></term>
<listitem>
- <para>Wait for a file to become available.</para>
+ <para>Wait for a file to become available or until a 10
+ seconds timeout expires.</para>
</listitem>
</varlistentry>
<listitem>
<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>
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>
<term><option>watch</option></term>
<listitem>
<para>Watch the device node with inotify, when closed after being opened for
- writing, a change uevent will be synthesised.</para>
+ writing, a change uevent will be synthesised.</para>
</listitem>
</varlistentry>
</variablelist>
~ianmdlvl / elogind.git / blobdiff