#!/bin/sh -u
#  $0                  (no arguments)
# Prompt for a name, echo the name and a wakeup message,
# then write that wakeup message to that person.
# -IAN! idallen@ncf.ca  June 2001
#
# You need to edit this script to change the dummy names to be valid names
# of people you know on the local computer.
#
# WARNING: Many of the comments in this file are "Instructor-Type"
#   comments and are *not* appropriate for real scripts.  Do not put
#   "Instructor-Type" comments into the scripts that you submit for marking.
#   I put them in my example files because I am teaching you how to
#   write scripts; do not submit my teaching comments back to me again.
#   Read the week7.txt notes for more details on good comment style.

export PATH=/bin:/usr/bin
umask 022

# We loop until the user types one of the many "quit" keywords:
# This should be a do/while loop; but, sh doesn't have one.
#
leave=no
while [ "$leave" = "no" ] ; do
	# Get some input from stdin and echo it back to the user.
	# (It's always a good idea to echo back what the user enters,
	# just so the user sees what s/he really typed in!)
	# We always prompt a user for input on stderr, not on stdout.
	# The "tr" deletes the newline from the end of the echo output.
	# The echo of the input itself can safely go on stdout.
	#
	echo 1>&2 " "
	echo 1>&2 "Enter the name: " | tr -d '\012'
	read input
	echo "You entered: $input"

	# Select the words to write and the recipient based on the input.
	# Note how we always quote our variables to prevent glob expansion!
	#
	userid=""   # start with empty userid
	case "$input" in
	me)
		words="Wakie Wakie!"
		userid="$USER"
		;;
	a|alex)
		words="Yooo Hoooo!"
		userid=aaaa1111 # CHANGE THIS USERID
		;;
	b|bobby)
		words="Wake Up!"
		userid=bbbb2222 # CHANGE THIS USERID
		;;
	c|chris)
		words="Think Fast!"
		userid=cccc3333 # CHANGE THIS USERID
		;;
	q|quit|x|exit|bye|leave|aurevoir|schus|salut|dosvedanja)
		echo " "
		echo "Quitting the script - bye now!"
		leave=yes
		;;
	*)
		# Note how we say "unrecognized" instead of "illegal"
		# or "invalid" - the intent is to convey to the user
		# that our program wasn't smart enough to figure out
		# what the user typed, not that the user is an idiot!
		# Error messages such as these go to stderr, not stdout.
		#
		echo 1>&2 "$0: Unrecognized input \"$input\""
		echo 1>&2 "Please enter a recognized name."
		echo 1>&2 "Valid names are: me alex bobby chris"
		;;
	esac

	# If we entered a recognized name, $userid is set.
	# Echo the words and userid, then write the message.
	# Check for a good return status from the write operation.
	#
	if [ "$userid" ] ; then
		echo "Writing \"$words\" to \"$input\" (userid $userid)."
		if banner "$words" | write "$userid" ; then
			echo "Message written to $userid."
		else
			# We have to save the status to output it.
			# Error messages such as these go to stderr, not stdout.
			#
			status=$?
			echo 1>&2 " "
			echo 1>&2 "Error $status ocurred writing to $userid."
		fi
	fi
done

# Exit this script with a good return status.
#
exit 0