书上的范例,居然会出现文件写入错误,奇葩!!!!求大神给看看

#include<stdio.h>struct student_type{char name[10];int num;int age;char addr[15];} stud[2];
void save(){FILE *fp;int i;if(fp=fopen("stu_list","w")==NULL){printf("can not open file\n");return ;}for(i=0;i<2;i++){if(fwrite(&stud[i],sizeof(struct student_type),1,fp)!=1)printf("%d file write error \n",fwrite(&stud[i],sizeof(struct student_type),1,fp));}fclose(fp);}
void main(){int i;for(i=0;i<2;i++)scanf("%s%d%d%s",stud[i].name,&stud[i].num,&stud[i].age,stud[i].addr);save();for(i=0;i<2;i++)printf("%s %d %d %s\n",stud[i].name,stud[i].num,stud[i].age,stud[i].addr);}