#include"stdafx.h"
#include"stdlib.h"



struct student                /* 学生成绩结构体*/
{
int number;
float english;
float math;
struct student *p_next;
};
FILE *fp1,*fp2;
struct student *head;



struct student *create()     /*创建学生成绩链表的函数*/
{
struct student *end,*NEW;
int i=1;
head=(struct student *)malloc(sizeof(struct student));
end=(struct student *)malloc(sizeof(struct student));
fp1=fopen("C:\\Documents and Settings\\Administrator\\桌面\\新建 文本文档","r");
fscanf(fp1,"%d%f%f",&head->number,&head->english,&head->math);   /*从文件中读取数据*/
fscanf(fp1,"%d%f%f",&end->number,&end->english,&end->math);
while(&end->number!=NULL)
{
NEW=(struct student *)malloc(sizeof(struct student));
NEW->p_next=NULL;
end->p_next=NEW;
end=NEW;
fp1=fopen("C:\\Documents and Settings\\Administrator\\桌面\\新建 文本文档","r");
fscanf(fp1,"%d%f%f",&NEW->number,&NEW->english,&NEW->math);
fscanf(fp1,"%d%f%f",&end->number,&end->english,&end->math);
}
free(NEW);
return(head);           /*返回链表的头地址*/
}


void print(struct student *head)        /*将链表输出的函数*/
{
while(head->p_next!=NULL)
{
printf("%d%f%f",head->number,head->english,head->math);
head=head->p_next;
}
}
 void main()
{
struct student *create();           /*创建链表*/
void print(struct student *head);   /*输出链表*/
struct student *p;         /*在链表中搜索number，并将对应于number的成绩输出到文件中*/
int j=0;
p=head;
while(p->number!=3)
{
head=head->p_next;
p=head;
j++;
}
fp2=fopen("C:\\Documents and Settings\\Administrator\\桌面\\新建 文本文档2","w");
fprintf(fp2,"%d%f%f",p->number,p->english,p->math);
}

高手指点一下！！
1 80 90
2 85 91
3 78 79
4 69 84
这是上面程序读取的文件中的数据！！

帮你改了一下,你试试看看:

#include<stdio.h>
#include<stdlib.h>



struct student                /* 学生成绩结构体*/
{
    int number;
    float english;
    float math;
    struct student *p_next;
};
FILE *fp1,*fp2;
struct student *head;



struct student *create()     /*创建学生成绩链表的函数*/
{
    struct student *p,*pr;
    //int i=1;
    p=pr=head=(struct student *)malloc(sizeof(struct student));
    //end=(struct student *)malloc(sizeof(struct student));
    p->p_next=NULL;
    fp1=fopen("C:\\Documents and Settings\\Administrator\\桌面\\新建 文本文档","r");
    //fscanf(fp1,"%d%f%f",&head->number,&head->english,&head->math);   /*从文件中读取数据*/
    //fscanf(fp1,"%d%f%f",&end->number,&end->english,&end->math);
    while(fscanf(fp1,"%d%f%f",&p->number,&p->english,&p->math)!=EOF)
    {
        p=(struct student *)malloc(sizeof(struct student));
        p->p_next=NULL;
        pr->p_next=p;
        pr=p;
        //fp1=fopen("d:\\a.txt","r");
        //fscanf(fp1,"%d%f%f",&p->number,&p->english,&p->math);
        //fscanf(fp1,"%d%f%f",&end->number,&end->english,&end->math);
    }
    free(p);
    return(head);           /*返回链表的头地址*/
}


void print(struct student *head)        /*将链表输出的函数*/
{
    while(head->p_next!=NULL)
    {
        printf("NO. %d : english= %f  math= %f\n",head->number,head->english,head->math);
        head=head->p_next;
    }
}
int main(void)
{
    //struct student *create();           /*创建链表*/
    //void print(struct student *head);   /*输出链表*/
    struct student *p;         /*在链表中搜索number，并将对应于number的成绩输出到文件中*/
    //int j=0;
    p=head=create();
    /*while(p->number!=3)
    {
        head=head->p_next;
        p=head;
        j++;
    }
    fp2=fopen("C:\\Documents and Settings\\Administrator\\桌面\\新建 文本文档2","w");
    fprintf(fp2,"%d%f%f",p->number,p->english,p->math);*/
    print(head);

    return 0;
}