#!/bin/sh -u
# Demonstrate a "while" loop
# Syntax:   $0 number
# Purpose: loop reading input until the user types the number
#
# NOTE: This script fragment is incomplete - it does not follow all
# the script guidelines set out in "script_style.txt".
#
# -IAN! idallen@idallen.ca

# missing step: should validate input first

# This is a value that we hope never matches the argument number.
# It is used as a dummy value just to get the loop started the first time.
#
random=2845736

number="$1"
guess="$random"

count=0
while [ "$guess" -ne "$number" ] ; do
    let count=count+1

    # Complain about previous guess; prompt and get next guess.
    # Don't complain the first time through the loop.
    #
    if [ "$count" -gt 1 ] ; then
	echo "$count. guess '$guess' does not match the number"
    fi
    echo 1>&2 "Try $count. Enter a guess for the number:"
    read guess || exit 1

    # Do some minimal validation of the input.
    # Missing step: should validate that input is an integer.
    #
    if [ -z "$guess" ] ; then
	echo 1>&2 "$0: Blank line - no guess - program exits"
	exit 0
    fi

done

echo "You guesed the number: $number"
echo "Tries: $count"

# script exits with the return status of the last command