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电梯直达

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发表于 2007-04-29 18:42 |只看该作者 |倒序浏览

最近，老师要我们用C语言编写一个存储、查询图书馆书记信息的程序。保存没有问题，但是即使输入一个正确的书目也查询不到。如果将书籍信息全都读取出来，得到的都是乱码。哪位高手指点、纠正一下小弟，不胜感激。先行谢过。程序如下：

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

struct booklist_info
{
char name[10];       //书籍名称
char number[9];    //书籍书目
char publisher[10];  //书籍出版社
};
typedef struct booklist_info booklist;

void writetofile(booklist *book1);
void readfromfile(booklist *book1);
void getlength(booklist *book1);

void main()
{
booklist *book1,*book2;
char ch;
FILE *fp1;
int length,i,flag = 0;

printf("what do you want to do?\n"

;
printf("1.please input 'w' if you want to save the information of the book\n"

;
printf("2.please input 'r' if you want to read the information of the book\n"

;
scanf("%c",&ch);
fflush(stdin);

switch(ch)
{
      case 'w':                   //保存书籍信息
      {
         book1 = (booklist *) malloc (sizeof(booklist));
         if(book1 == NULL)
         {
            printf("not enouh memory\n"

;
            getch();
            exit(0);
         }

         do
         {
            printf("please input the name of the book(0~9)\n"

;
            gets(book1->name);
            fflush(stdin);
            printf("please input the number of the book(0~

\n"

;
            gets(book1->number);
            fflush(stdin);
            printf("please intput the publisher of the book(0~9)\n"

;
            gets(book1->publisher);
            fflush(stdin);
            writetofile(book1);

            printf("Do you want to continue to save the booklist?Yes(y) No(n)\n"

;
            scanf("%c",&ch);
            fflush(stdin);
         }while(ch == 'y');

         break;
      }
      case 'r':             //读取书籍信息
      {
         do
         {
            printf("please input the number of the book which you what to seek.(0~

\n"

;
            book2 = (booklist *) malloc (sizeof(booklist));
            if(book2 == NULL)
            {
                  printf("not enouh memory\n"

;
                  getch();
                  exit(0);
            }
                  gets(book2->number);

            if((fp1 = fopen("d:\\book.dat","rb")) == NULL)
            {
                  printf("can not open the file\n");
                  getch();
                  exit(0);
            }

            for(i =0;i <= 2;i++)          //此处循环上限为2，因为只保存了3个书籍信息。
            {
                  fseek(fp1,i*sizeof(struct booklist_info),SEEK_SET);
                  fread(book1,sizeof(booklist),1,fp1);
                  if(book1->number == book2->number)
                  {
                     flag = 1;
                     printf("the name of the book:\n");
                     printf("%s",book1->name);
                     printf("\nthe number of the book:\n");
                     printf("%s",book1->number);
                     printf("\nthe publisher of the book:\n");
                     printf("%s",book1->publisher);
                     getch();
                  }
            }

            if(flag == 0)
            {
                  printf("can not find the book\n");
                  getch();
            }
            printf("Do you want to continue to seek the booklist?Yes(y) No(n)\n");
            scanf("%c",&ch);
            fflush(stdin);
         }while(ch == 'y');

         fclose(fp1);

         break;
      }
}

free(book1);
free(book2);
}
void writetofile(booklist *book1)
{
FILE *fp;

if((fp = fopen("d:\\book.dat","a")) == NULL)
{
      printf("can not build the file\n");
      getch();
      exit(0);
}

      fwrite(book1,sizeof(booklist),1,fp);
      fclose(fp);
}