<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>
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 consist of a list of one or more key value pairs separated by
+ <para>A rule consists 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>
<varlistentry>
<term><option>!=</option></term>
<listitem>
- <para>Compare for non-equality.</para>
+ <para>Compare for inequality.</para>
</listitem>
</varlistentry>
</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>
<varlistentry>
<term><option>ATTR{<replaceable>filename</replaceable>}</option></term>
<listitem>
- <para>Match sysfs attribute values of the event device. Up to five
- <option>ATTR</option> keys can be specified per rule. Trailing
+ <para>Match sysfs attribute values of the event device. Trailing
whitespace in the attribute values is ignored, if the specified match
- value does not contain trailing whitespace itself. Depending on the type
- of operator, this key is also used to set the value of a sysfs attribute.
+ value does not contain trailing whitespace itself.
</para>
</listitem>
</varlistentry>
<term><option>ATTRS{<replaceable>filename</replaceable>}</option></term>
<listitem>
<para>Search the devpath upwards for a device with matching sysfs attribute values.
- Up to five <option>ATTRS</option> keys can be specified per rule, but all of them
+ If multiple <option>ATTRS</option> matches are specified, all of them
must match on the same device. Trailing whitespace in the attribute values is ignored,
if the specified match value does not contain trailing whitespace itself.</para>
</listitem>
<varlistentry>
<term><option>ENV{<replaceable>key</replaceable>}</option></term>
<listitem>
- <para>Match against the value of an environment variable. Up to five <option>ENV</option>
- keys can be specified per rule. Depending on the type of operator, this key is also used
- to export a variable to the environment.</para>
+ <para>Match against a device property value.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>PROGRAM</option></term>
<listitem>
- <para>Execute external program. The key is true, if the program returns
- with exit code zero. The whole event environment is available to the
- executed program. The program's output printed to stdout, is available in
- the RESULT key.</para>
+ <para>Execute a program. The key is true, if the program returns
+ successfully. The device properties are made available to the
+ executed program in the environment. The program's output printed to
+ stdout, is available in the RESULT key.</para>
</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. Only one rule can set the node name, all later rules with
- a NAME key will be ignored.</para>
+ should be renamed to.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>SYMLINK</option></term>
<listitem>
- <para>The name of a symlink targeting the node. Every matching rule can add
+ <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>
<term><option>ATTR{<replaceable>key</replaceable>}</option></term>
<listitem>
<para>The value that should be written to a sysfs attribute of the
- event device. Depending on the type of operator, this key is also
- used to match against the value of a sysfs attribute.</para>
+ event device.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><option>ENV{<replaceable>key</replaceable>}</option></term>
<listitem>
- <para>Export a variable to the environment. Depending on the type of operator,
- this key is also to match against an environment variable.</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>
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>
- <para>If the specifiefd string starts with
+ 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 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
<varlistentry>
<term><option>IMPORT{<replaceable>type</replaceable>}</option></term>
<listitem>
- <para>Import a set of variables into the event environment,
+ <para>Import a set of variables as device properties,
depending on <replaceable>type</replaceable>:</para>
<variablelist>
<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>
with this option.</para>
</listitem>
</varlistentry>
+ <varlistentry>
+ <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>
+ </listitem>
+ </varlistentry>
</variablelist>
</listitem>
</varlistentry>
<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
+ is executed. It allows the use of device properties set by earlier matching
rules. For all other fields, substitutions are applied while the individual rule is
being processed. The available substitutions are:</para>
<variablelist>
<varlistentry>
<term><option>$env{<replaceable>key</replaceable>}</option>, <option>%E{<replaceable>key</replaceable>}</option></term>
<listitem>
- <para>The value of an environment variable.</para>
+ <para>A device property value.</para>
</listitem>
</varlistentry>
</listitem>
</varlistentry>
</variablelist>
- <para>The count of characters to be substituted may be limited by specifying
- the format length value. For example, '%3s{file}' will only
- insert the first three characters of the sysfs attribute</para>
</refsect2>
</refsect1>
~ianmdlvl / elogind.git / blobdiff