#!/bin/sh
# Bart Trojanowski (c) 2003
# bart@jukie.net

# Use this script from cron, or run regularly, to get emails on new
# kernel releases.
#
# Example crontab:
#   USER=bart
#   HOME=/home/bart
#   1 * * * * $HOME/bin/finger-kernel-org

# NOTE that ~/tmp must exist for this script to function
DIR=${HOME}/tmp
FILE=${DIR}/last-finger-kernel-org
TMP=${FILE}.$$
DIFF=${FILE}.diff
EMAIL=${FILE}.email

# make sure that we have ${DIR}
if ! [ -d ${DIR} ] ; then
	echo "create ${DIR} or configure the script" >&2
	exit 1
fi
# ${DIR} must be writable
if ! [ -w ${DIR} ] ; then
	echo "make ${DIR} writable or configure the script" >&2
	exit 1
fi
# ${MAILTO} must be defined
if [ -z "${MAILTO}" ] ; then
	# in that case ${USER} must be defined
	if [ -z "${USER}" ] ; then
		echo "either MAILTO or USER must be set in your environment" >&2
		exit 1
	fi
	MAILTO="${USER}"
fi

# nuke stale files
rm -f ${FILE}.*

# can we get a new list?
if ! ( finger @www.kernel.org > ${TMP} ) ; then
	exit $?
fi

# are there any kernels, need at least 3 lines
lines=$(wc -l < ${TMP})
if [ $lines -lt 2 ] ; then
	exit 1
fi

# is this the first one?
newvers=""
if [ -f ${FILE} ] ; then

	# are there any diffs?
	if ( diff -u ${FILE} ${TMP} > ${DIFF} ) ; then
		exit 0
	fi

	# compose email
	echo "" > $EMAIL
	echo "Changes" >> $EMAIL
	echo "" >> $EMAIL
	cat $DIFF >> $EMAIL

	newvers=$(grep "^+The latest" < $DIFF | cut -d : -f 2- | xargs echo)
	newvers="($newvers)"
fi

echo "" >> $EMAIL
echo "Complete output of finger @www.kernel.org" >> $EMAIL
echo "" >> $EMAIL
cat $TMP >> $EMAIL

mv -f $TMP $FILE

mail -s "new kernel release $newvers" ${MAILTO} < $EMAIL