#!/bin/sh

D_TEST=/usr/local/sbin/disk-test
D_LOGDIR=/var/log/diskwatch
MAIL_TO="root"

[ -x ${D_TEST} ] || { echo "ERROR: cannot execute ${D_TEST}" >&2 ; exit 1 ; }

[ -d ${D_LOGDIR} ] || \
	mkdir -p ${D_LOGDIR} || \
		{ echo "ERROR: cannot create ${D_LOGDIR}" >&2 ; exit 1 ; }

cd ${D_LOGDIR} || { echo "ERROR: cannot cd ${D_LOGDIR}" >&2 ; exit 1 ; }

rm -f previous

[ -L latest ] && mv latest previous

NOW=$(date "+%F-%T")

${D_TEST} >${NOW}

ln -s "${NOW}" latest

DIFF=''

[ -r previous ] && DIFF=$(diff -u previous latest)

[ -z "${DIFF}" ] && exit 0

mailx -s "$(hostname): SMART DISK WARNING" ${MAIL_TO} <<+++
Disk status change:
${DIFF}

Recent results:
$(cat latest)
+++