I'm a beginner in Java and need some help with this problem. First of all let me show you my actual program.

```
import java.util.Scanner;
import java.util.Arrays;

public class IntArraySort {

        public static void main(String[] args) {

                Scanner in = new Scanner(System.in);

                System.out.println("Array-Size: ");
                int num = in.nextInt();
                int[] arr = new int[num];

                for(int i = 0; i < arr.length; i++){
                        System.out.printf("%2d-tes element: ", i+1);
                        arr[i] = in.nextInt();
                }

                System.out.printf("%nOutput before sort: ");
                System.out.println(Arrays.toString(arr));

                int minIndex, tmp;
                int n = arr.length;

                for(int i = 00; i < n - 1; i++) {
                        minIndex = i;
                        for(int j = i + 1; j < n; j++)
                                if (arr[j] < arr[minIndex])
                                        minIndex = j;
                        if (minIndex != i) {
                                tmp = arr[i];
                                arr[i] = arr[minIndex];
                                arr[minIndex] = tmp;
                        }
                        System.out.printf("%n%2d-ter Run: ", i+1);
                        System.out.println(Arrays.toString(arr));
                }
         }

}

```

It's a program to sort an Int-array from smallest to biggest number while you scan the size of the array and the numbers via keyboard input. But I want to scan my array from a .dat-file. I named it sort.dat and it looks like this:

```
0
20
12
8
16
6
10
14
2
18
4
21
4
-1
-3

```

What do I need to change in my Java-program to scan in my sort.dat file via input redirection (IntArraySort.java < sort.dat) on Unix?