#!/usr/bin/perl -s
#Assignment #1 Written by Thomas Los
#Finding Prime Number

#system("clear");

$min=100;
$max=100;

while ($min != 0 and $max != 0)
{
print "\n\n";
print "What is floor of the range of numbers you want??\n\n";
$min=<STDIN>;
chomp($min);
print "What is the ceiling of the range of numbers you want???\n\n";
$max=<STDIN>;
chomp($max);


        if (($min != 0) and ($max != 0)) 
        {
          if ($min <0 || $max<0 || $min>$max) {
            print "You are retarded!!\n";
print "Run the program again and try again! Your Min can't be greater than the maximum
Your number can't be negative either!!\n";
            exit;
            
            }

        $ret=fork();
        if ($ret == 0)
        {
        &prime($min,$max);
        }
        }
}

$prime=0;

sub prime($min,$max) {

   $beginning = (times)[0];
    # Square root for speed.
    $sqrt_max=sqrt($max);
    # Teh range
    for ($i=$min;$i<=$max;$i++) {
        # Assume it's a prime.
        $is_prime=1;
        # Skip 1, or the inner if will go wrong
        for ($j=2;$j<=$sqrt_max;$j++) {
            $y=$i%$j;
            # We only need $y = 0 and not to be the same number.
            # 2 is the only exception.
            if (($y==0 && $i!=$j) || $i==2) { 
                # Conditions met, it's not a prime.
                $is_prime=0;
                last;
            }
        }
        if ($is_prime) {
            $prime++;
        }
    }
 $end = (times)[0];
 $time_elapsed = $end - $beginning;

    print "\n\nThe child process id is $$\n";
    print "\nThe given range was from $min to $max\n";
    print "\nThe amount of prime numbers is $prime.\n";
    print "\nIt took $time_elapsed to complete your request\n";
}