dahdi-linux-extra/build_tools/genudevrules

#!/bin/sh

ver=`udevinfo -V | cut -f3 -d" "`

if [ -z "${ver}" ]; then
   # Not found - try udevadm
   ver=`udevadm info -V | cut -f3 -d" "`

   if [ -z "${ver}" ]; then
      # nobody has that old version, anyway.
      ver=54
   fi
fi

# udev versions prior to 055 use a single '=' for matching key values
# udev versions 055 and later support '==' for that purpose, and versions
# beyond 092 will probably make it mandatory
#
# very old versions of udev required naming rules and permissions rules to be
# in separate files, but it's not clear at what version number that changed

if [ ${ver} -gt 54 ]; then
    match="=="
else
    match="="
fi

cat <<EOF
# udev rules to generate the /dev/dahdi device files (if not yet provided 
# by your distribution):
KERNEL${match}"dahdictl", NAME="dahdi/ctl"
KERNEL${match}"dahditranscode", NAME="dahdi/transcode"
KERNEL${match}"dahditimer", NAME="dahdi/timer"
KERNEL${match}"dahdichannel", NAME="dahdi/channel"
KERNEL${match}"dahdipseudo", NAME="dahdi/pseudo"
KERNEL${match}"dahdi[0-9]*", NAME="dahdi/%n"

# DAHDI devices with ownership/permissions for running as non-root
SUBSYSTEM${match}"dahdi",  OWNER="asterisk", GROUP="asterisk", MODE="0660"
EOF