systemd/etc/udev/udev.rules.gentoo

# /etc/udev/udev.rules:  device naming rules for udev
# $Header: /home/cvsroot/gentoo-x86/sys-fs/udev/files/udev.rules,v 1.1 2003/12/26 23:32:44 azarah Exp $
#
# There are a number of modifiers that are allowed to be used in the NAME or PROGRAM fields.
# They provide the following subsitutions:
# %n - the "kernel number" of the device.
#      for example, 'sda3' has a "kernel number" of '3'
# %k - the kernel name for the device.
# %M - the kernel major number for the device
# %m - the kernel minor number for the device
# %b - the bus id for the device
# %c - the return value of the external PROGRAM (note, this doesn't work within
#      the PROGRAM field for the obvious reason.)
#

###########################################################
#
# Add your own rules here
#
###########################################################

# Looking for scsi bus id 42:0:0:1
BUS="scsi", PROGRAM="/bin/echo -n test-%b", RESULT="test-42:0:0:1", NAME="%c"

# A usb camera.
BUS="usb", SYSFS_vendor="FUJIFILM", SYSFS_model="M100", NAME="camera%n"

# USB Epson printer to be called lp_epson
BUS="usb", SYSFS_serial="HXOLL0012202323480", NAME="lp_epson"

# USB HP printer to be called lp_hp
BUS="usb", SYSFS_serial="W09090207101241330", NAME="lp_hp"

# sound card with PCI bus id 00:0b.0 to be the first sound card
BUS="pci", ID="00:0b.0", NAME="dsp"

# sound card with PCI bus id 00:07.1 to be the second sound card
BUS="pci", ID="00:07.1", NAME="dsp1"

# USB mouse plugged into the third port of the first hub to be called mouse0
BUS="usb", PLACE="1.3", NAME="mouse0"

# USB tablet plugged into the third port of the second hub to be called mouse1
BUS="usb", PLACE="2.3", NAME="mouse1"
BUS="usb", PLACE="2.4", NAME="mouse2"

# ttyUSB1 should always be called visor
KERNEL="ttyUSB1", NAME="visor"
KERNEL="ttyUSB0", NAME="pl2303"


###########################################################
#
# For devfs similar /dev layout (neater)
#
###########################################################

# devfs-names for ide-devices (uncomment only one)
#  /dev/ide/.../{disc,cd} and /dev/{cdroms,discs}/* type names
BUS="ide", PROGRAM="/etc/udev/scripts/ide-devfs.sh %k %b %n", RESULT="hd*", NAME="%1c", SYMLINK="%2c %3c"
 
# fb devices
KERNEL="fb[0-9]*", NAME="fb/%n", SYMLINK="%k"

# loop devices
KERNEL="loop[0-9]*", NAME="loop/%n", SYMLINK="%k"

# md block devices
KERNEL="md[0-9]*", NAME="md/%n", SYMLINK="%k"

# pty devices
KERNEL="pty[p-za-e][0-9a-f]*", NAME="pty/m%n", SYMLINK="%k"
KERNEL="tty[p-za-e][0-9a-f]*", NAME="tty/s%n", SYMLINK="%k"

# ram devices
KERNEL="ram[0-9]*", NAME="rd/%n", SYMLINK="%k"

# tty devices
KERNEL="tty[0-9]*", NAME="vc/%n", SYMLINK="%k"
KERNEL="ttyS[0-9]*", NAME="tts/%n", SYMLINK="%k"
KERNEL="ttyUSB[0-9]*", NAME="tts/USB%n"

# vc devices
KERNEL="vcs",        NAME="vcc/0", SYMLINK="%k"
KERNEL="vcs[0-9]*",  NAME="vcc/%n", SYMLINK="%k"
KERNEL="vcsa",       NAME="vcc/a0", SYMLINK="%k"
KERNEL="vcsa[0-9]*", NAME="vcc/a%n", SYMLINK="%k"

# v4l devices
KERNEL="video[0-9]*", NAME="v4l/video%n"
KERNEL="radio[0-9]*", NAME="v4l/radio%n"
KERNEL="vbi[0-9]*",   NAME="v4l/vbi%n"
KERNEL="vtx[0-9]*",   NAME="v4l/vtx%n"

# dm devices (ignore them)
KERNEL="dm-[0-9]*", NAME=""

# i2c devices
KERNEL="i2c-[0-9]*", NAME="i2c/%n", SYMLINK="%k"

# loop devices
KERNEL="loop[0-9]*", NAME="loop/%n", SYMLINK="%k"

# framebuffer devices
KERNEL="fb[0-9]*", NAME="fb/%n", SYMLINK="%k"

# misc devices
KERNEL="rtc",   NAME="misc/%k", SYMLINK="%k"
KERNEL="psaux", NAME="misc/%k", SYMLINK="%k"

# alsa devices
KERNEL="controlC[0-9]*", NAME="snd/%k"
KERNEL="hw[CD0-9]*",     NAME="snd/%k"
KERNEL="pcm[CD0-9cp]*",  NAME="snd/%k"
KERNEL="midi[CD0-9]*",   NAME="snd/%k"
KERNEL="timer",          NAME="snd/%k"
KERNEL="seq",            NAME="snd/%k"