Novell LINUX ENTERPRISE SERVER 11 - ADMINISTRATION Administration Manual page 151

• udev rules support substitutions.
11.6.1 Using Operators in udev Rules
Creating keys you can choose from several different operators, depending on the type
of key you want to create. Match keys will normally just be used to find a value that
either matches or explicitly mismatches the search value. Match keys contain either of
the following operators:
==
Compare for equality. If the key contains a search pattern, all results matching this
pattern are valid.
!=
Compare for non-equality. If the key contains a search pattern, all results matching
this pattern are valid.
Any of the following operators can be used with assign keys:
=
Assign a value to a key. If the key previously consisted of a list of values, the key
resets and only the single value is assigned.
+=
Add a value to a key that contains a list of entries.
:=
Assign a final value. Disallow any later change by later rules.
11.6.2 Using Substitutions in udev Rules
udev rules support the use of placeholders and substitutions. Use them in a similar
fashion as you would do in any other scripts. The following substitutions can be used
with udev rules:
%r, $root
The device directory, /dev by default.
Dynamic Kernel Device Management with udev 137