/* Direct file I/O with fwrite() and fread(). */
#include <stdlib.h>
#include <stdio.h>

#define SIZE 20

main()
{
     int count, array1[SIZE], array2[SIZE];
     FILE *fp;

     /* Initialize array1[]. */

     for (count = 0; count < SIZE; count++)
         array1[count] = 2 * count;

     /* Open a binary mode file. */

     if ( (fp = fopen("direct.txt", "wb")) == NULL)
     {
         fprintf(stderr, "Error opening file.");
         exit(1);
     }
     /* Save array1[] to the file. */

     if (fwrite(array1, sizeof(int), SIZE, fp) != SIZE)
     {
         fprintf(stderr, "Error writing to file.");
         exit(1);
     }

     fclose(fp);

     /* Now open the same file for reading in binary mode. */

     if ( (fp = fopen("direct.txt", "rb")) == NULL)
     {
         fprintf(stderr, "Error opening file.");
         exit(1);
     }

     /* Read the data into array2[]. */

     if (fread(array2, sizeof(int), SIZE, fp) != SIZE)
     {
         fprintf(stderr, "Error reading file.");
         exit(1);
     }

     fclose(fp);

     /* Now display both arrays to show they're the same. */

     for (count = 0; count < SIZE; count++)
         printf("%d\t%d\n", array1[count], array2[count]);
     return(0);
}