#include <stdio.h>

#include <stdlib.h>

#define MAXTLEN 70

#define MAXALEN 70

#define MAXBKS 10

struct book{

        char title[MAXTLEN];

        char author[MAXALEN];

        float value;

};

int main(){

        struct book library[MAXBKS];    //图书馆

        int count = , index, filecount;

        int size = sizeof(struct book); //这点值得注意

        FILE *pbooks;

        if((pbooks = fopen("book.dat","a+b")) == NULL){

                fputs("Can not open book.dat file\n", stderr);

                exit();

        }

        rewind(pbooks);

        while(count < MAXBKS && fread(&library[count],size,,pbooks) == ){

                if(count == ){

                        puts("Current contents of book.dat: ");

                }

                printf("%s by %s: $%.2f\n",library[count].title,library[count].author,library[count].value);

                count++;

        }

        filecount = count;

        if(count == MAXBKS){

                fputs("The book.dat file is full",stderr);

                exit();

        }

        puts("please add the new book, title:");

        while(count < MAXBKS && gets(library[count].title) != NULL && library[count].title[] != '\0'){

                puts("the author:");

                gets(library[count].author);

                puts("the value:");

                scanf("%f",&library[count++].value);

                while(getchar() != '\n'){

                        continue;

                }

                if(count < MAXBKS){

                        puts("---continue---");

                }

        }

        if(count > ){

                puts("Here is the list of your books:");

                for(index = ; index<count; index++){

                        printf("%s by %s: $%.2f\n",library[index].title,library[index].author,library[index].value);

                }

                fwrite(&library[filecount],size,count-filecount,pbooks);

        }else{

                puts("No books? Too bad\n");

        }

        puts("Bye\n");

        fclose(pbooks);

        return ;

}

Current contents of book.dat:

C语言权威指南 by jimmy: $68.00

PHP项目大全 by jimmy: $99.90

please add the new book, title: