text: #include <stdio.h>
  #include <string.h>
  #include <stdlib.h>
  #include <time.h>
  #include <unistd.h>
  
  int main() {
  
      int arr[] = {1, 2, 3, 4, 5, 6, 7, 8, 9};
      srand((unsigned) time(NULL));
      int len = (sizeof (arr) / sizeof (int));
  
      for (int i = 0; i < len; i++) {
  
          long int a = rand() % len;
          int tmp = arr[a];
          long int b = rand() % len;
          arr[a] = arr[b];
          arr[b] = tmp;
      }
  
      for (int i = 0; i < len; i++) {
          printf("arr[%d] = %d \n", i, arr[i]);
      }
  
      return 0;
  }
  