#!/bin/sh 

# for every username listed on the command line, check to see if they have
# mail pending (i.e.  a non-zero /usr/spool/mail/$user file).  turn on an
# x10 device if any of them do.  turn it off if they don't.  remember
# whether the device is on or off, to avoid sending the commands _all_ the
# time, by storing its state in a file.  but remove the file at least once
# an hour, to be sure we really update the state of the device at least
# that often.
#
# invoke from cron periodically


# the alias of the device to turn on/off
WHICHX10DEVICE=email_arrived

WASMAILFILE=/tmp/x10biffwasmail

prog=`basename $0`

if [ ! "$1" ]
then
	echo "usage: $prog username username... (to turn on X10 thing)" >&2
	exit
fi

ismail=no

for user in $*
do
	if [ -s /usr/spool/mail/$user ]
	then
		ismail=yes
	fi
done


# remove the remembrance file at least once an hour.  compare the hour in
# which it was created to the current hour.
set -- `ls -l $WASMAILFILE 2>/dev/null`

washour=`expr "$8" : '\(..\):'`

set -- `date`
ishour=`expr $4 : '\(..\):'`

if [ "$washour" != "$ishour" ]
then
	rm -f $WASMAILFILE
fi

# file may not exist.  that's okay.
wasmail=`cat $WASMAILFILE 2>/dev/null`


# no change, do nothing
if [ "$wasmail" = "$ismail" ]
then
	exit
fi

if [ "$ismail" = "yes" ]
then
	cm11 turn $WHICHX10DEVICE on
else
	cm11 turn $WHICHX10DEVICE off
fi

echo $ismail >$WASMAILFILE

exit