#!/usr/bin/bash 
#
# Original version from Quigley's UNIX SHELLS by EXAMPLE, #2.7

# Last revised by Brian D. Davison, 1 March 2007

# Gnu bash versions 2.x
# The Party Program--Invitations to friends from the 
# "guest" file 
guestfile=./guests
mail=/usr/ucb/mail
if [[ ! -e "$guestfile" ]] 
then
	printf "${guestfile##*/} non-existent"
	exit 1
fi
export PLACE="Packard Lab Lobby"
#declare -i Time=14
(( Time=$(date +%H)+1 ))
if (( $Time > 12 )) 
then
   (( Time = $Time - 12 ))
fi
declare -a foods=(cheese crackers shrimp drinks '"hot dogs"' sandwiches pizza)  
declare -i  n=0

for person in $(cat $guestfile) 
do
	if  [[ $person == root ]]
	then
		continue
	else 
		# Start of here document
		$mail -s "Party" $person <<- FINIS 
		Hi $person! Please join me at $PLACE for a party! 
		Meet me at $Time o'clock.
		I'll bring the ice cream. Would you please bring
		${foods[$n]} and anything else you would like to eat?
		Let me know if you can make it.
		       Hope to see you soon.
                          Your pal,
                          Prof D@$(hostname)
		FINIS

		n=n+1  

		if (( ${#foods[*]} ==  $n )) 
		then
                   n=0
		fi
	fi
done		
printf "Bye...\n"