tc28.c

关于学习C语言的电子书籍

/******************
	  tc28.c
   文件的随机访问
******************/

#include <stdio.h>
struct student
{  
	char name[10];
	int score;
};
void main()
{
    FILE *fp;
	struct student st,stud[5];
    int i;
	printf("        文件的随机访问\n\n");
    if ((fp=fopen("studbk.dat","rb"))==NULL)
    {
       printf("不能打开studbk.dat文件\n");
       exit(1);
    }
    for (i=1; i<=2; i++) {
       fseek(fp,-(long)sizeof(struct student)*i,SEEK_END);		/*设置文件指针位置*/
       fread(&st,sizeof(struct student),1,fp);
       printf("姓名: %s  成绩: %d\n",st.name,st.score);
    }
    printf("\n");
	rewind(fp);										/*文件指针重置*/
	fread(stud,sizeof(struct student),5,fp);		
    printf("姓名\t成绩\n");
    printf("----\t----\n");
    for(i=0; i<5; i++)
      printf("%s\t%d\n",stud[i].name,stud[i].score);
    printf("\n");
    fclose(fp);
}