.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
The permissions and ownership of the created device file is read from