程序代码：

#include <stdio.h>
#include <stdlib.h>
#define CNTL_Z '\032'    /* DOS 文本文件中的文件结尾标记 */
#define SLEN 50
int main (void)
{
   char file[SLEN];
   char ch;
   FILE *fp;
   long count, last;

   puts ("Enter the name of the file to be processed : ");
   gets(file);
   if ((fp = fopen(file, "rb")) == NULL)
   {      /* 只读和二进制模式 */
      printf ("reverse can't open %s \n",file);
      exit(1);
   }
   fseek(fp,0L, SEEK_END);   /* 定位文件结尾处 */
   last = ftell(fp);
   for (count = 1L; count <= last; count++)
   {
      fseek(fp,-count,SEEK_END); /* 回退 */
      ch = getc(fp);
   /* 针对 DOS, 在 UNIX 下也可工作 */
      if (ch != CNTL_Z && ch != '\r')
      putchar(ch);
    }
    putchar('\n');
    fclose(fp);
    return 0;

 }