新人求助~~~~关于 stream!=NULL的问题
求解决呀~~~~~~
#include <stdio.h>
#include <malloc.h>
#include <string.h>
#include <io.h>
#define NULL 0
#define LEN sizeof(struct employeeInfo)
#define FILE_DATA_PATH "c:\employeeInfo.txt"
struct employeeInfo
{
long int num;
char name[20];
int age;
char sex[4];
char eduLevel[10];
char address[30];
long int tel[11];
char salary[20];
struct employeeInfo *next;
};
int TOTAL_NUM = 0;
struct employeeInfo *head = NULL;
void welcome();
void mainmenu();
void record();
void insert(struct employeeInfo *stu);
void display(struct employeeInfo *stu);
void displayAll();
void query();
void query_by_num();
void query_by_name();
void readData();
void writeData();
void freeAll();
void del();
void change();
void devise(struct employeeInfo *p);
void exit();
int main()
{
char userName[9];
char userPWD[7];
int i;
welcome();
for(i = 0; i < 3; i++)
{
printf("\n管理员初始用户名和密码均为admin\n");
printf("请输入您的用户名:");
scanf("%s", userName);
printf("\n请输入您的密码:");
scanf("%s", userPWD);
if ((strcmp(userName,"admin")==0) && (strcmp(userPWD,"admin")==0))
{
//用户名和密码正确，显示主菜单
mainmenu();
break;
}
else
{
if (i < 2)
{
//用户名或密码错误，提示用户重新输入
printf("用户名或密码错误，请重新输入!");
}
else
{
//连续3次输错用户名或密码，退出系统。
printf("您已连续3次将用户名或密码输错，系统将退出!");
}
}
}
return 0;
}
//显示欢迎信息
void welcome()
{
printf("+---------------------------+\n");
printf("| |\n");
printf("| 欢迎使用职工信息管理系统 |\n");
printf("| 制作人：** ** ** |");
printf("| |\n");
printf("+---------------------------+\n");
}
//系统主菜单
void mainmenu()
{
int choice;
choice = -1;
readData();
printf("\n温馨提示：为保证您的操作得到保存，请按正常顺序退出系统^_^\n");
do
{
printf("\n\n\n");
printf("\t\t\t--------------------------------\n");
printf("\t\t\t+ 职工信息管理系统 |\n");
printf("\t\t\t--------------------------------\n");
printf("\t\t\t+ [1]----录入职工信息 |\n");
printf("\t\t\t+ [2]----浏览职工信息 |\n");
printf("\t\t\t+ [3]----查询职工信息 |\n");
printf("\t\t\t+ [4]----删除职工信息 |\n");
printf("\t\t\t+ [5]----修改职工信息 |\n");
printf("\t\t\t+ [0]----退出系统 |\n");
printf("\t\t\t+*·*·*·*·*·*·*·*·*·*·|\n");
printf("\t\t\t--------------------------------\n");
printf("请输入您的选择：");
scanf("%d", &choice);
switch(choice)
{
case 0:
writeData();
freeAll();
exit( );
case 1:
record();
break;
case 2:
displayAll();
break;
case 3:
query();
break;
case 4:
del();
break;
case 5:
change();
break;
default:
printf("\n无效选项!");
break;
}
}
while(choice != 0);
}
//录入职工信息
void record()
{
struct employeeInfo *p0;
p0 = (struct employeeInfo *)malloc(LEN);
printf("请输入职工的职工号:");
scanf("%ld",&p0->num);
printf("请输入职工的姓名:");
scanf("%s",p0->name);
printf("请输入职工的年龄:");
scanf("%d",&p0->age);
printf("请输入职工的性别:");
scanf("%s",p0->sex);
printf("请输入职工的学历:");
scanf("%s",p0->eduLevel);
printf("请输入职工的地址:");
scanf("%s",p0->address);
printf("请输入职工的电话:");
scanf("%ld",&p0->tel);
printf("请输入职工的工资:");
scanf("%s",p0->salary);
insert(p0);
printf("该职工的信息为:\n");
printf("-------------------------------------------------------------------------------");
printf("职工号\t姓名\t年龄\t性别\t学历\t\t地址\t电话\t工资\n");
display(p0);
}
void insert(struct employeeInfo *stu)
{
struct employeeInfo *p0, *p1, *p2;
p1 = head;
p0 = stu;
if(head == NULL)
{
head = p0;
p0->next = NULL;
}
else
{
while((p0->num > p1->num)&&(p1->next != NULL))
{
p2 = p1;
p1 = p1->next;
}
if(p0->num <= p1->num)
{
if(head == p1)
head = p0;
else
p2->next = p0;
p0->next = p1;
}
else
{
p1->next = p0;
p0->next = NULL;
}
}
TOTAL_NUM++;
}
void display(struct employeeInfo *p)
{
printf("%ld\t%s\t%d\t%s\t%s\t%s\t%ld\t%s\n", p->num, p->name, p->age, p->sex, p->eduLevel, p->address, p->tel, p->salary);
}
//浏览职工信息
void displayAll()
{
struct employeeInfo *p;
printf("职工总数:%d\n", TOTAL_NUM);
p = head;
if(head != NULL)
{
printf("\n职工号\t姓名\t年龄\t性别\t学历\t地址\t电话\t工资\n");
printf("-------------------------------------------------------------------------------");
do
{
display(p);
p = p->next;
}
while(p != NULL);
}
printf("\n");
}
//查询职工信息
void query()
{
int choice;
choice = -1;
do
{
printf("\n");
printf("+--------------------+\n");
printf("| 按职工号查询 请按 1 |\n");
printf("| 按姓名查询 请按 2 |\n");
printf("| 取消 请按 0 |\n");
printf("+--------------------+\n");
printf("请输入您的选择：");
scanf("%d", &choice);
switch(choice)
{
case 0:
return;
case 1:
query_by_num();
break;
case 2:
query_by_name();
break;
default:
printf("\n无效选项!");
break;
}
}
while(choice != 0);
}
//按职工号查询职工信息
void query_by_num()
{
int num;
struct employeeInfo *p1;
printf("请输入职工的职工号：");
scanf("%ld", &num);
if(head==NULL)
{
printf("无职工记录！\n");
return;
}
p1=head;
while(num!=p1->num && p1->next!=NULL)
p1=p1->next;
if(num == p1->num)
{
printf("\n职工号\t姓名\t年龄\t性别\t学历\t地址\t电话\t工资\n");
printf("-------------------------------------------------------------------------------");
display(p1);
}
else
printf("没有该职工记录，请核对！");
}
//按姓名查询职工信息
void query_by_name()
{
char name[20];
struct employeeInfo *p1;
printf("请输入职工的姓名：");
scanf("%s", name);
if(head==NULL)
{
printf("无职工记录！\n");
return;
}
p1=head;
while(strcmp(name, p1->name) && p1->next!=NULL)
p1=p1->next;
if(!strcmp(name, p1->name))
{
printf("\n职工号\t姓名\t年龄\t性别\t学历\t地址\t电话\t工资\n");
printf("-------------------------------------------------------------------------------");
display(p1);
}
else
printf("没有该职工记录，请核对！");
}
//写入文件
void writeData()
{
FILE* fp;//文件指针
struct employeeInfo *p;
fp = fopen(FILE_DATA_PATH, "w");
if (!fp)
{
printf("文件打开错误！");
}
fprintf(fp,"%d\n", TOTAL_NUM);
for(p = head; p!= NULL; p= p->next)
{
fprintf(fp,"%ld\t%s\t%d\t%s\t%s\t%s\t%ld\t%s\n",
p->num, p->name, p->age, p->sex, p->eduLevel, p->address, p->tel, p->salary);
}
fclose(fp);
}
void freeAll()
{
struct employeeInfo *p1, *p2;
p1=p2=head;
while(p1)
{
p2=p1->next;
free(p1);
p1=p2;
}
}
//读取文件
void readData()
{
FILE* fp;//文件指针
struct employeeInfo *p1, *p2;
fp = fopen(FILE_DATA_PATH, "r");
if (!fp)
{
printf("文件打开错误！");
}
fscanf(fp,"%d\n", &TOTAL_NUM);
head = p1 = p2 = (struct employeeInfo *)malloc(LEN);
fscanf(fp,"%ld\t%s\t%d\t%s\t%s\t%s\t%ld\t%s\n",
&p1->num, p1->name, &p1->age, p1->sex, p1->eduLevel, p1->address, &p1->tel, p1->salary);
while(!feof(fp))
{
p1 = (struct employeeInfo *)malloc(LEN);
fscanf(fp,"%ld\t%s\t%d\t%s\t%s\t%s\t%ld\t%s\n",
&p1->num, p1->name, &p1->age, p1->sex, p1->eduLevel, p1->address, &p1->tel, p1->salary);
p2->next = p1;
p2 = p1;
}
p2->next = NULL;
fclose(fp);
}
//删除职工信息
void del()
{
struct employeeInfo *p1, *p2;
long int num;
if(head == NULL)
{
printf("无职工记录！\n");
return;
}
printf("请输入您要删除的职工的职工号：");
scanf("%ld", &num);
p1 = head;
while(num != p1->num && p1->next != NULL)
{
p2 = p1;
p1 = p1->next;
}
if(num == p1->num)
{
if(p1 == head)
head = p1->next;
else p2->next = p1->next;
free(p1);
TOTAL_NUM--;
}
else
printf("没有该职工记录，请核对！\n");
}
//修改职工信息
void change()
{
struct employeeInfo *p1, *p2;
long int num;
if(head == NULL)
{
printf("无职工记录！\n");
return;
}
printf("请输入您要修改的职工的职工号：");
scanf("%ld", &num);
p1 = head;
while(num != p1->num && p1->next != NULL)
{
p2 = p1;
p1 = p1->next;
}
if(num == p1->num)
devise(p1);
else
printf("没有该职工记录，请核对！\n");
}
void devise(struct employeeInfo *p)
{
int choice;
choice = -1;
do
{
printf("请选择您要修改的职工的信息内容：\n");
printf("+----------------------+\n");
printf("| 姓名 请按 1 |\n");
printf("| 年龄 请按 2 |\n");
printf("| 性别 请按 3 |\n");
printf("| 学历 请按 4 |\n");
printf("| 地址 请按 5 |\n");
printf("| 电话 请按 6 |\n");
printf("| 工资 请按 7 |\n");
printf("| 取消 请按 0 |\n");
printf("+----------------------+\n");
printf("请输入您的选择：");
scanf("%d", &choice);
switch(choice)
{
case 0:
return;
case 1:
printf("请输入新姓名：");
scanf("%s", p->name);
break;
case 2:
printf("请输入新年龄：");
scanf("%d", &p->age);
break;
case 3:
printf("请输入新性别：");
scanf("%s", p->sex);
break;
case 4:
printf("请输入新学历：");
scanf("%s", p->eduLevel);
break;
case 5:
printf("请输入新地址：");
scanf("%s", p->address);
break;
case 6:
printf("请输入新电话：");
scanf("%ld", &p->tel);
break;
case 7:
printf("请输入新工资：");
scanf("%s", p->salary);
break;
default:
printf("\n无效选项!");
break;
}
}
while(choice != 0);
}
void exit()
{
}
程序代码：