.B udev_root
Indicates where to place the device nodes in the filesystem. The default
value is
-.IR @udevdir@ .
+.IR @udevdir@/ .
.TP
.B udev_db
The name and location of the udev database. The default value is
The name of the udev rules file or directory to look for files with the suffix
.IR .rules .
All rule files are read in lexical order. The default value is
-.IR /etc/udev/udev.rules .
+.IR /etc/udev/rules.d/ .
.TP
.B udev_permissions
The name of the udev permission file or directory to look for files with the
suffix
.IR .permissions .
All permission files are read in lexical order. The default value is
-.IR /etc/udev/udev.permissions .
+.IR /etc/udev/permissions.d/ .
.TP
.B udev_log
The switch, if udev logs some information for every device handled.
.sp
.nf
# udev_root - where to place the device nodes in the filesystem
-udev_root="@udevdir@"
+udev_root="/udev"
# udev_db - The name and location of the udev database
-udev_db="@udevdir@/.udev.tdb"
+udev_db="/udev/.udev.tdb"
# udev_rules - The name of the udev rules file or directory to look
for files with the suffix .rules
udev_rules="/etc/udev/rules.d/"
-# udev_permissions - The name of the udev permission file or directry to look
- for files with the suffix .permissions
+# udev_permissions - The name of the udev permission file or directory
+ to look for files with the suffix .permissions
udev_permissions="/etc/udev/udev.permissions"
# udev_log - set to "yes" if you want logging, else "no"
default_group="root"
.fi
.P
-The rules for udev to use when naming devices may specified in
-.I /etc/udev/udev.rules
-or by the
+The rules for device naming, are read from the files located in the
+.I /etc/udev/rules.d/
+directory, or at the location specified by the
.I udev_rules
value in the
.I /etc/udev/udev.conf
file.
-.P
+.br
Every line in the rules file defines the mapping between device attributes
and the device name. One or more keys are specified to match a rule with
the current device. If all keys are matching, the rule will be applied and
.BI %s{ filename }
The content of a sysfs attribute.
.TP
+.B %e
+If a device node already exists with the name, the smallest positive
+decimal integer N is substituted such that the resulting name doesn't
+match an existing device node. Otherwise nothing is substituted. This
+can be used to create compatibility symlinks and enumerate devices of
+the same type originating from different kernel subsystems.
+.TP
.B %%
The '%' character itself.
.P
# multiple USB webcams with symlinks to be called webcam0, webcam1, ...
BUS="usb", SYSFS{model}="XV3", NAME="video%n", SYMLINK="webcam%n"
+
+# grouping of optical drives from multiple kernel subsystems
+KERNEL="sr*", NAME="%k", SYMLINK="cdrom%e"
+KERNEL="scd*", NAME="%k", SYMLINK="cdrom%e"
+KERNEL="pcd*", NAME="%k", SYMLINK="cdrom%e"
+KERNEL="hd[a-z]", PROGRAM="/bin/cat /proc/ide/%k/media", RESULT="cdrom",
+ NAME="%k", SYMLINK="cdrom%e"
+
.fi
.P
-Permissions and ownership for the created device files may specified in
-.I /etc/udev/udev.permissions
-or by the
+The permissions and ownership of the created device file is read from
+the files located in the
+.I /etc/udev/permissions.d/
+directory, or at the location specified by the
.I udev_permission
value in the
.I /etc/udev/udev.conf