#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include  <malloc.h>
#define N 1000
FILE*stu_information;
struct student
{
    int numble;char name[50] ;char sex[50];int age; struct student *next;
}   stu[N];
struct student *head,*operation,*test;
void input_first();
void show();
int main ()
{
    input_first();
    show(); 

return 0;
}
void input_first ()
{
    int num,i;
    stu_information=fopen("stu_information.txt","w");
    printf("input zhe numble you want :\n");
    scanf("%d",&num);
    fprintf(stu_information,"xue_hao name sex age\n");
    if(num==0)
    {
        head=NULL;
        printf("wrong!\n");return ;
    }
    for(i=0;i<num;i++)
    {  
        test=(struct student*)malloc(sizeof(struct student));
        if(i==0)
            head=operation=test;
        else
           operation->next=test;
           operation=test;
           printf("input numble,name,sex,and age:\n");
           scanf("%d%s%s%d",&test->numble,test->name,test->sex ,&test->age );
    
    }
       operation->next=NULL;
       operation = head;
       while(operation!=NULL)
       {
        fprintf(stu_information,"%3d%s%6s%6d\n",operation->numble,operation->name,operation->sex,operation->age);
        operation=operation->next;
    
       }
    fclose(stu_information);
}
void show()
{
    int num=1;
    int i;
    char kong_bai[20];
    stu_information=fopen("stu_information.txt","r");
    for(i=0;i<4;i++)
    {
     fscanf(stu_information,"%s",kong_bai);
    }

while(!feof(stu_information))
{
 test=(struct student*)malloc(sizeof(struct student));
 if(num==1)
  head=operation=test;
 else 
  operation->next=test;
  operation=test;
  fscanf(stu_information,"%d%s%s%d",&operation->numble,operation->name,operation->sex,&operation->age);
  num++;
 
}
 // printf("%d\n",num);
  operation->next=NULL;
  operation=head;
 // test=test->next;
 // operation=test;
  while(operation!=NULL)
  {
    printf("%d  %s  %s  %d\n",operation->numble,operation->name,operation->sex,operation->age);
    operation=operation->next;
    
  }
    fclose(stu_information);
}
这里只是部分功能，但是在show函数里出现了问题就是他会多循环了一次，就是如果文件里有两组结构体的数据，但是show中会读取三组导致最后一次读取的内容是空的，为什么胡出现多读取一次呢就是多循环一次，及求解啊