如何解决电脑上C语言中strcpy函数与strcmp函数没有标识符的问题 下面是代码第一次能运行，过了一天就不能用了。
源代码
#include<stdio.h>
#include<stdlib.h>
#include<string.h>
typedef struct//定义结构体
{
char number[10];//书号
char name[20];//书名
char author[20];//作者
char publish[50];//出版社
char time[20];//出版时间
float price;
}mbook;
typedef struct//定义结构体
{
int count;//书的本数
mbook book[100];//最大可有100本书
}mlibrary;
mlibrary library;
void save()//保存图书信息。
{
FILE *fp;
if((fp=fopen("library.doc","w"))==NULL)
{
printf("\n不能保存图书信息\n");
return;
}
fwrite(&library.count,sizeof(int),1,fp);
fwrite(library.book,sizeof(library.book[0]),library.count,fp);
}
void putin() /*定义录入函数*/
{
int y=1;
system("cls");
while(y)
{
printf("\t请输入您的书籍的书号:");
scanf("%s",library.book[library.count].number);
printf("\t请输入书名:");
scanf("%s",library.book[library.count].name);
printf("\t请输入作者名:");
scanf("%s",library.book[library.count].author);
printf("\t请输入出版社:");
scanf("%s",library.book[library.count].publish);
printf("\t请输入出版时间:");
scanf("%s",library.book[library.count].time);
printf("\t请输入该书的价格:");
fflush(stdin);
scanf("%f",&library.book[library.count].price);
library.count++;
printf("\n是否继续录入(1.继续;0,退出录入):");
fflush(stdin);
scanf("%d",&y);
if (y!=1)
{
y=0;
break;
}
}
save();
}
void lookup()
{
int i ;
system("cls");
printf("图书号\t图书名\t作者名\t出版社\t出版日期\t图书价格\n");
for ( i=0;i<library.count;i++)
{
printf("%s\t%s\t%s\t%s\t%s\t%6.2f\n",library.book[i].number,library.book[i].name,library.book[i].author,library.book[i].publish,library.book[i].time,library.book[i].price);
}
fflush(stdin);
getchar();
}
void search_by_name() /*定义按书名查询*/
{
int i ;
char s2[20];
int flag=1;
printf("\n请输入要查询的书名: ");
fflush(stdin);
scanf("%s",s2);
printf("图书号\t图书名\t作者名\t出版社\t出版日期\t图书价格\n");
for( i=0;i<library.count;i++ )
if(strcmp(s2,library.book[i].name)==0)
{
flag=0;
printf("%s\t%s\t%s\t%s\t%s\t%6.2f\n",library.book[i].number,library.book[i].name,library.book[i].author,library.book[i].publish,library.book[i].time,library.book[i].price);
}
if (flag)
{
printf("cannot found!");
}
fflush(stdin);
getchar();
}
void search_by_author() /*定义按作者名查询*/
{
int i ;
char s3[20];
int flag=1;
printf("请输入要查询的书的作者: ");
fflush(stdin);
scanf("%s",s3);
printf("图书号\t图书名\t作者名\t出版社\t出版日期\t图书价格\n");
for( i=0;i<library.count;i++ )
if(strcmp(s3,library.book[i].author)==0)
{
flag=0;
printf("%s\t%s\t%s\t%s\t%s\t%6.2f\n",library.book[i].number,library.book[i].name,library.book[i].author,library.book[i].publish,library.book[i].time,library.book[i].price);
}
if (flag)
{
printf("cannot found!");
}
fflush(stdin);
getchar();
}
void search() /*定义查询函数*/
{
int a;
system("cls"); /*进行清屏*/
printf("\t\t******************************\n");
printf("开始查询\n");
printf("\t\t\t1---------------search_by_name\n");
printf("\t\t\t2---------------search_by_writer\n");
printf("\t\t\t0---------------exit\n");
printf("\t\t******************************\n") ;
printf("\t\t请选择你想要的查询方式:");
flush(stdin);
scanf("%d",&a);
switch(a)
{
case 1:
search_by_name();
break;
case 2:
search_by_author();
break;
case 0:
return;
}
}
void del() /*定义删除函数*/
{
int i;
char number[10];
system("cls"); /*清屏*/
printf("\n Please type in the number of the book you want to delete:");
fflush(stdin);
scanf("%s",number);
for (i=0;i<library.count;i++)
{
if(strcmp(number,library.book[i].number)==0)break;
}
if (i!=library.count)
{
for(;i<library.count-1;i++)
break;
}
}
if (i!=library.count)
{
mbook book;
printf("\n\t\t请输入修改后此图书的信息\n");
printf("\t请输入图书号:");
scanf("%s",book.number);
printf("\t请输入图书名:");
scanf("%s",book.name);
printf("\t请输入作者名:");
scanf("%s",book.author);
printf("\t请输入出版社:");
scanf("%s",book.publish);
printf("\t请输入出版时间:");
scanf("%s",book.time);
printf("\t请输入该书的价格:");
fflush(stdin);
scanf("%f",&book.price);
strcpy(library.book[i].name,book.name);
strcpy(library.book[i].number,book.number); strcpy(library.book[i].publish,book.publish);
strcpy(library.book[i].author,book.author);
strcpy(library.book[i].time,book.time);
library.book[i].price=book.price;
save();
}
else
printf("\n cannot found!\n");
fflush(stdin);//清空输入缓冲区
getchar();
}
void main()
{
int a;
FILE *fp;//定义一个指向文件流的指针，通过操作这个指针你就能进行文件读写，打开关闭
if((fp=fopen("library.doc","r"))==NULL)//fopen函数打开文件
{
printf("\n不能打开图书信息库\n");
fp=fopen("library.doc","w+");
printf("\n初始化图书信息库,初始化之后要重启程序\n");
library.count=0;
fwrite(&library.count,sizeof(int),1,fp);//fwrite()函数常用语将一块内存区域中的数据写入到本地文本
fclose(fp);//关闭
return;
}
fread(&library.count,sizeof(int),1,fp);//fread()函数：1. 作用：从一个文件流中读取数据
fread(library.book,sizeof(library.book[0]),library.count,fp);
fclose(fp);
do
{
system("cls");
printf("\n\n\n\n\n\t\t\t\t图书信息管理系统\t\t\t\t\n");
printf("\t\t*********************************************\n");
printf("\t\t\t1 ------------------图书信息录入\n");
printf("\t\t\t2 ------------------图书信息浏览\n");
printf("\t\t\t3 ------------------图书信息查询\n");
printf("\t\t\t4 ------------------图书信息删除\n");
printf("\t\t\t5 ------------------图书信息修改\n");
printf("\t\t\t0 -----------------退出图书管理系统\n");
printf("\t\t*********************************************\n");
printf("\t\tPlease Enter Choose: ");
fflush(stdin);//清空缓存区
scanf("%d",&a);
switch(a)
{
case 1:
putin();
break;
case 2:
lookup();
break;
case 3:
search();
break;
case 4:
del();
break;
case 5:
update();
break;
case 0:
printf("\n\n退出\n\n");
break;
default:
printf("\n序号不对\n");
}
}while(a!=0);
save();
}
