direct.c

来自「c21Examples.rar」· C语言 代码 · 共 59 行

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

#define SIZE 20

int main( void )
{
   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;
}