Homework & Coursework Questions

#! /bin/bash

time_diff () {
    t1=`date -d "$t_in" +%s`
    t2=`date -d "$t_out" +%s`
    t_diff=$((($t2 - $t1) / 60))
    hours=$(($t_diff / 60))
    mins=$(($t_diff % 60))
}

calc_price () {
    case $cust in
    "KID" )
        if [ $hours -gt 1 ]
        then
            if [ $mins -eq 0 ]
            then
                price=$((60 + (($hours - 1) * 2 * 20)))
            elif [ $mins -gt 0 -a $mins -le 30 ]
            then
                price=$((60 + (($hours - 1) * 2 * 20) + 20))
            elif [ $mins -gt 30 -a $mins -lt 60 ]
            then
                price=$((60 + (($hours - 1) * 2 * 20) + 40))
            fi
        else
            price=60
        fi
        ;;
    "TODDLER" )
        if [ $hours -gt 1 ]
        then
            if [ $mins -eq 0 ]
            then
                price=$((60 + (($hours - 1) * 2 * 20)))
            elif [ $mins -gt 0 -a $mins -le 30 ]
            then
                price=$((60 + (($hours - 1) * 2 * 20) + 20))
            elif [ $mins -gt 30 -a $mins -lt 60 ]
            then
                price=$((60 + (($hours - 1) * 2 * 20) + 40))
            fi
        else
            price=40
        fi
        ;;        
    esac
}

calc_discount () {
    if [ $t_diff -lt 300 ]
    then
        discount=0
    elif [ $t_diff -ge 300 -a $t_diff -le 420 ]
    then
        discount=`echo "scale=2; $price * 10 / 100" | bc`
    elif [ $t_diff -gt 420 -a $t_diff -le 480 ]
    then
        discount=`echo "scale=2; $price * 12 / 100" | bc`
    elif [ $t_diff -gt 480 ]
    then
        discount=`echo "scale=2; $price * 15 / 100" | bc`
    fi
    total=`echo "$price - $discount" | bc`
}

echo -e "Enter name: \c"
read name
echo -e "Customer Type: \c"
read cust
echo -e "Time In: \c"
read t_in
echo -e "Time Out: \c"
read t_out

time_diff
calc_price
calc_discount

echo >> PLAY.REC
echo "Name of Customer: $name" >> PLAY.REC
echo "Customer Type: $cust" >> PLAY.REC
echo "Time In: $t_in" >> PLAY.REC
echo "Time Out: $t_out" >> PLAY.REC
echo >> PLAY.REC
echo "Time Spent: $hours hours $mins minutes"
echo "Time Spent: $hours hours $mins minutes" >> PLAY.REC
echo "Charges: $price"
echo "Charges: $price" >> PLAY.REC
echo "Discount: $discount"
echo "Discount: $discount" >> PLAY.REC
echo "Amount to pay: $total"
echo "Amount to pay: $total" >> PLAY.REC
echo "-----------------------------------------------------------"
echo "-----------------------------------------------------------" >> PLAY.REC