ledfifo_load

#!/bin/bash
# REF: https://lwn.net/images/pdf/LDD3/ch03.pdf - Page 47

module="LEDfifo" 
device="ledfifo" 
mode="666"

# invoke insmod with all arguments we got
# and use a pathname, as newer modutils don't look in . by default 
(set -x;/sbin/insmod ./$module.ko $* || exit 1)
# remove stale nodes
(set -x;rm -f /dev/${device}[0-3])

#major=$(awk "\$2==\"$module\" {print \$1}" /proc/devices)
major=$(cat /proc/devices | grep ${device} | cut -d' ' -f1 | sort -n | tail -1)
if [ -n "${major}" ]; then
(set -x;mknod /dev/${device}0 c ${major} 0)
#mknod /dev/${device}1 c $major 1
#mknod /dev/${device}2 c $major 2
#mknod /dev/${device}3 c $major 3
     
# give appropriate group/permissions, and change the group.
# Not all distributions have staff, some have "wheel" instead. 
group="staff"
grep -q '^staff:' /etc/group || group="wheel"
(set -x;chgrp $group /dev/${device}[0-3]; chmod $mode /dev/${device}[0-3])
else
echo "$0: failed to grab major node id"
fi