#!/usr/bin/perl

# program to calculate payment schedule for a credit card

use strict;

my $principle;
my $interestRate;
my $interestPay;
my $payment;
my $month=1;
my $totalInterest=0;

# prompt user for amount borrowed (principle), annual interest 
#      rate, and month payment amount

print "Enter amount borrowed ";
$principle=<STDIN>;
chomp($principle);

print "Enter annual interest rate ";
$interestRate=<STDIN>;
chomp($interestRate);
$interestRate=($interestRate/12)/100;

print "Enter month payment amount ";
$payment=<STDIN>;
chomp($payment);

# do the calculations

print "Month    Interest  Payment  Principle \n";
print "------------------------------------- \n";

while( ($principle*(1+$interestRate))>=$payment )
{
    $interestPay=$interestRate*$principle;
    $totalInterest=$totalInterest+$interestPay;
    printf("%-9d%10.2f%10.2f%10.2f\n",$month,$interestPay,$payment ,$principle+$interestPay-$payment);
    $principle=$principle+$interestPay-$payment;
    $month++;
}
$interestPay=$interestRate*$principle;
$totalInterest=$totalInterest+$interestPay;
$payment=$principle+$interestPay;
printf("%-9d%10.2f%10.2f%10.2f\n",$month,$interestPay,$payment ,0);

printf ("\n\nThe total interest paid is %-10.2f\n",$totalInterest);