:

[ "$#" -gt 1 -o \( "$#" -eq 1 -a "$1" != "-i" \) ] && echo "Usage:  $(basename $0) [-i]" 1>&2 && exit 1

# change this to a safe directory
TMP="$HOME"

dmesg -T |
egrep -v '\<(mounted filesystem with ordered data mode|MSI/MSI-X|lowering kernel.perf_event_max_sample_rate|promiscuous mode|bad checksum|fragment too large|short packet)\>' > $TMP/0

if [ "$1" != "-i" -a -e /u/dmesg.log ]
then	diff /u/dmesg.log $TMP/0 | sed -n 's/^> //p' > $TMP/1
	[ -s $TMP/1 ] && cat $TMP/1 | mail -s 'changed dmesg output' root
fi

[ -s $TMP/1 -o "$1" = "-i" ] && cp $TMP/0 /u/dmesg.log