在ubuntu下用C语言编写一个学生管理系统，编译时出错，紧急求救！！！

/*
* 已经将错误改正.
* 建议 id 为字符串型, 加入检测是否惟一. 可以加入很多功能, 希望能做得更好.
* 最好是图形界面的.
* Welcome to mysite http://www.
*/
#include "stdio.h"
#include "stdlib.h"
#include "string.h"

#define N 2

struct stu_info{
int id; /*学号*/
char name[20]; /*姓名*/
char major[20]; /*专业*/
float score; /*分数*/
};

struct stu_info student[20];
struct stu_info *p;
struct stu_info temp;


FILE *fp;

/*输入模块*/

int save(){

if((fp=fopen("student.dat","w+"))==NULL){
printf("文件打开失败!\n");
exit(0);
}
printf("请依次输入 %d 个同学的信息:\n",N);
printf("学号\t姓名\t专业\t分数\n");
for(p=student;p<student+N;p++){
scanf(" %d %s %s %f",&(p->id),p->name,p->major,&(p->score));
fwrite(p,sizeof(struct stu_info),1,fp);
}
printf("输入结束!\n");
fclose(fp);
return 0;
}

/*输出模块*/

int show(){
if((fp=fopen("student.dat","r"))==NULL){
printf("文件打开失败!\n");
exit(0);
}
printf("文件已经打开，现在显示所有同学的信息.\n");
p=student;
printf("学号\t姓名\t专业\t分数\n");
while(fread(p,sizeof(struct stu_info),1,fp)!=0){
printf("%d\t%s\t%s\t%f\n",p->id,p->name,p->major,p->score);
p++;
}
fclose(fp);
return 0;
}

/*建立文件模块*/

int select_id(int sid){
int flag=0;
struct stu_info temp;

if((fp=fopen("student.dat","r"))==NULL){
printf("文件打开失败!\n");
exit(0);
}

while(fread(&temp,sizeof(struct stu_info),1,fp)!=0 && flag==0){
if(sid==temp.id){
printf("%d\t%s\t%s\t\t%.2f\n",temp.id,temp.name,temp.major,temp.score);
flag=1;
break;
}
}
if(flag==0){
printf("这里没有学号为 %d 的记录.\n", sid);
}
fclose(fp);
return 0;
}

int select_major(char smajor[]){
int flag=0;
struct stu_info temp;

if((fp=fopen("student.dat","r"))==NULL){
printf("文件打开失败!\n");
exit(0);
}

while(fread(&temp,sizeof(struct stu_info),1,fp)!=0){
if (strcmp(smajor,temp.major)==0){
printf("%d\t%s\t%s\t%f\n",temp.id,temp.name,temp.major,temp.score);
flag=1;
}
}
if(flag==0){
printf("这里没有专业为 %s 的有关记录.\n", smajor);
}
fclose(fp);
return 0;
}

/*查询模块*/

int search(){
int k,sid;
char smajor[20];
printf("选择查询方式:\n");
printf("1.通过学生的学号查询.\n");
printf("2.通过学生的专业查询.\n");
printf("请输入1或2进行查询:\n");
scanf("%d",&k);
switch(k){
case 1: printf("请输入学号:\n");
scanf("%d",&sid);
select_id(sid);
break;

case 2: printf("请输入专业:\n");
scanf("%s",smajor);
select_major(smajor);
break;

default: printf("输入有误.\n");
exit(0);
}
return 0;
}

/*添加模块*/

int append(){
struct stu_info temp;
printf("请输入添加的学生记录信息.\n");
scanf("%d\t%s\t%s\t%f",&(temp.id),temp.name,temp.major,&(temp.score));
if((fp=fopen("student.dat","a+"))==NULL){
printf("文件打开失败!\n");
exit(0);
}
fseek(fp,sizeof(struct stu_info),1);
fwrite(&temp,sizeof(struct stu_info),1,fp);
printf("记录已经被添加.\n");
fclose(fp);
return 0;
}

/*修改模块*/

int amend(){
int flag=0;
struct stu_info temp;
int sid;
char smajor[15];
float newscore;
if((fp=fopen("student.dat","r+"))==NULL){
printf("文件打开失败!\n");
exit(0);
}
printf("请输入要修改的学生的学号:\n");
scanf("%d",&sid);

while(fread(&temp,sizeof(struct stu_info),1,fp)!=0 && flag==0)
if(sid==temp.id){
printf("原来的记录是 %d\t%s\t%s\t%.2f\n",temp.id,temp.name,temp.major,temp.score);
printf("请输入正确的专业:\n");
scanf("%s",smajor);
printf("请输入正确的分数:\n");
scanf("%f",&newscore);
strcpy(temp.major,smajor);
temp.score=newscore;
printf("现在的记录是 %d\t%s\t%s\t%.2f\n",temp.id,temp.name,temp.major,temp.score);
fseek(fp,-sizeof(struct stu_info),1);
fwrite(&temp,sizeof(struct stu_info),1,fp);
flag=1;
printf("记录已经被修改.\n");
break;
}
if(flag==0)
printf("这里没有需要添加的信息.\n");
fclose(fp);
return 0;
}

/*删除模块*/

int deleted(){
int sid;
//int del_id=0;
int i=0,j;
int number=0;
printf("请输入需要删除的学生的学号:\n");
scanf("%d",&sid);
if((fp=fopen("student.dat","r+"))==NULL){
printf("文件打开失败!\n");
exit(0);
}
p=student;
while(fread(p,sizeof(struct stu_info),1,fp)!=0){
if(sid==p->id){
printf("以下记录将被删除:\n%d\t%s\t%s\t%.2f\n",p->id,p->name,p->major,p->score);
i--;
}
i++;
number++;
}
if(i==number)
printf("这里没有需要添加的信息.\n");
else{
printf("最新的文件有 %d 记录.\n",i);
rewind(fp);
for(j=0;j<i;j++){
printf("%d\t%s\t%s\t%.2f\n",student[j].id,student[j].name,student[j].major,student[j].score);
fwrite(&student[j],sizeof(struct stu_info),1,fp);
}
printf("记录已经被删除.\n");

}
fclose(fp);
return 0;
}

/* main program */
int main(){
p=student;
int choice;
while(1){
printf(" ***************学生管理系统***************\n\n\n");
printf(" 1.输入 %d 个学生信息.\n\n", N);
printf(" 2.显示学生的信息.\n\n");
printf(" 3.寻找学生的信息.\n\n");
printf(" 4.修改学生的信息.\n\n");
printf(" 5.添加学生的信息.\n\n");
printf(" 6.删除学生的信息.\n\n");
printf(" 0.退出学生管理系统.\n\n");
printf(" 请选择(0-6):\n");
scanf("%d",&choice);
switch(choice){
case 1: save();break; /*输入模块*/
case 2: show();break; /*输出模块*/
case 3: search();break; /*查询模块*/
case 4: amend();break; /*修改模块*/
case 5: append();break; /*添加模块*/
case 6: deleted();break; /*删除模块*/
case 0: exit(0);
default:printf("输入的数字有误.\n");
}
}
return 0;
}