图书管理系统2

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <conio.h>
#define books "f:\books.txt"
#define booksbak "f:\booksbak.txt"
struct bookinfo
{
char isbn[20];
char title[30];
char author[20];
int count;
};

struct book
{
struct bookinfo onebook;
struct book *next;
};

struct book *searchBook ( struct book *listptr,char isbn[])
{
while(listptr!=(struct book *)0)
if (strcmp(listptr->onebook.isbn,isbn)==0)
return listptr;
else
listptr=listptr->next;
return (struct book *)0;
}


void MainSearchbook(struct book *firstptr)
{
struct book *ptr;
char isbnno[20];
printf("请输入ISBN:");
scanf("%s",&isbnno);
ptr=searchBook(firstptr,isbnno);
if (ptr!=(struct book *)0)
{
printf("找到了!!! ");
printf("ISBN:%s ",ptr->onebook.isbn);
printf("Title:%s ",ptr->onebook.title);
printf("Author:%s ",ptr->onebook.author);
}
else
printf("sorry,not found!!! ");
}



int addBook(struct book *listptr,struct bookinfo note)
{
while(listptr->next!=0)
listptr=listptr->next;
listptr->next=(struct book *)malloc(sizeof(struct book));
listptr->next->onebook=note;
listptr->next->next=0;
return 0;

}

void MainAdd(struct book *listptr,FILE *fp)
{
int ok;
struct bookinfo note;
printf("请输入ISBN:");
scanf("%s",note.isbn);
printf("请输入Title:");
scanf("%s",note.title);
printf("请输入Author:");
scanf("%s",note.author);
ok=addBook(listptr,note);
if (ok==0)
{
//将加入的图书写到文件中保存
fprintf(fp," %s %s %s %d",note.isbn,note.title,note.author,0);
printf("添加图书成功!!! ");
}
else
printf("添加图书失败!!! ");
}


int removeBook(struct book *listptr,char isbn[])
{
while(listptr->next!=(struct book *)0)
{
if (strcmp(listptr->next->onebook.isbn,isbn)==0)
{
listptr->next=listptr->next->next;
return 0;
}
else
listptr=listptr->next;
}

return -1;
}

void MainRemove(struct book *listptr,FILE *fp)
/************************************************************************/
/* 删除书籍函数,通过ISBN删除链表节点,同时删除文件中对应信息 */
/* 删除文件中一行,用的是笨方法,把需要的信息写到新文件,删除旧文件,重命名..*/
/************************************************************************/
{
char isbnno[20];
int ok;
struct bookinfo onebook;
printf("请输入ISBN:");
scanf("%s",&isbnno);
ok=removeBook(listptr,isbnno);
if (!ok)
{
FILE *fpbak;
if ((fpbak=fopen(booksbak,"a+"))==NULL)
printf("文件打开失败!!! ");
fseek(fp,0,SEEK_SET); //移到文件开始
while((fscanf(fp,"%s %s %s %d ",&onebook.isbn,&onebook.title,&onebook.author,&onebook.count))!=EOF)
{
if (strcmp(onebook.isbn,isbnno)!=0)
{
fprintf(fpbak,"%s %s %s %d ",onebook.isbn,onebook.title,onebook.author,onebook.count);
}
}
fclose(fp);
fclose(fpbak);
if (remove(books)) //删除失败返回非0
{
printf("删除文件失败!!! ");
return ;
}
else
if (rename(booksbak,books)) //重命名失败返回非0值
{
printf("重命名失败!!! ");
return ;
}

printf("删除成功!!! ");
}
else
printf("查无此书!!!");
}

int choice(void)
{
int c;
printf("1.查看图书 ");
printf("2.添加图书 ");
printf("3.删除图书 ");
printf("4.退出程序 ");
printf("请选择序号:");
return c=getchar();
//return c=getche();
printf(" ");

}

int addEntry(FILE *fp,struct book *firstptr)
/************************************************************************/
/* 主要用来加载文件中存放的图书信息 */
/************************************************************************/

{
struct bookinfo onebook;
while((fscanf(fp,"%s %s %s %d ",&onebook.isbn,&onebook.title,&onebook.author,&onebook.count))!=EOF)
{
while(firstptr->next!=0)
firstptr=firstptr->next;
firstptr->next=(struct book *)malloc(sizeof(struct book));
firstptr->next->onebook=onebook;
firstptr->next->next=0;
}
return 0;

}


int main(int argc,char *argv[])
{
int ch;
struct book first;
strcpy(first.onebook.isbn,"123456");
strcpy(first.onebook.title,"Programming C");
strcpy(first.onebook.author,"yhb");
first.next=0;
struct book *firstptr=&first; //链表头指针
FILE *fp;
if ((fp=fopen(books,"a+"))==NULL)
printf("文件打开失败!!!");
addEntry(fp,firstptr);
while(1)
{
system("CLS"); //清屏
/************************************************************************/
/* 想想这里为什么要清空缓冲区? */
/*由于上一次(choice函数)的getchar(),还有一个' '留在缓冲区.... */
/*可以把这句话注释掉看看,没有这句话会遇到麻烦 */
/*如果不用fflush,可以将上面的getchar()换成getche() */
/*比较getchar(),getch(),getche()...... */
/************************************************************************/
fflush(stdin);
ch=choice()-48;
switch (ch)
{
case 1:
MainSearchbook(firstptr);
break;
case 2:
MainAdd(firstptr,fp);
break;
case 3:
MainRemove(firstptr,fp);
break;
case 4:
printf("谢谢使用... ");
exit(0);
default:
printf("请输入正确序号!");
}
system("PAUSE");
}
return 0;
}