我有一个函数，它返回一个指向该函数内分配的书籍的指针，数据来自一个名为 book_saved.dat 的文件。我可以编译这段代码，但它给我发送垃圾，为什么？
book_saved 是一个已经存在的文件
*我的原始代码中有该结构。
#include <stdio.h>
#include <stdlib.h>
book_t *book_load(){
book_t *book;// book_t is a struct
book = (book_t*)malloc(sizeof(book_t));
if (book == NULL)
exit(1);
FILE*fp = fopen ("book_saved.dat", "rb");
fread (book, sizeof(book_t), 1, fp);
return book;
}
void print_book (book_t *book) {
printf("\n");
printf ("Book \nTitle: %s\nWriter: %s\nPublishing: %s\nYear: %d\nWeight %.1f\n", book->title, book->writer, book->publishing_house, book->year, book->weight);
}
int main (int argc, char *argv[]){
book_t *pontaux = book_load();
print_book (pontaux);
free (pontaux);
return 0;
}
最佳答案
你能提供一下你的写作功能吗？我做了一个相当基本的，它似乎工作正常。我建议将 struct 粘贴在共享头文件中，以确保使用的结构完全相同，并在十六进制编辑器中打开 book_saved.dat 以使确保其中的格式正确。
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
typedef struct book_t {
char title[75];
char writer [50];
char publishing[30];
int year;
float weight; // kg.
} book_t;
void book_make(){
book_t *book;// book_t is a struct
book = (book_t*)malloc(sizeof(book_t));
if (book == NULL)
exit(1);
strcpy(book->title, "Harry Potter: World\'s End");
strcpy(book->writer, "JK Rowlingbatman");
strcpy(book->publishing, "Publisherguy inc.");
book->year = 3000;
book->weight = 14.6;
FILE*fp = fopen ("book_saved.dat", "wb");
fwrite(book, sizeof(book_t), 1, fp);
fclose(fp);
}
book_t *book_load(){
book_t *book;// book_t is a struct
book = (book_t*)malloc(sizeof(book_t));
if (book == NULL)
exit(1);
FILE*fp = fopen ("book_saved.dat", "rb");
fread (book, sizeof(book_t), 1, fp);
return book;
}
void print_book (book_t *book) {
printf("\n");
printf ("Book \nTitle: %s\nWriter: %s\nPublishing: %s\nYear: %d\nWeight %.1f\n", book->title, book->writer, book->publishing, book->year, book->weight);
}
int main (int argc, char *argv[]){
book_make();
book_t *pontaux = book_load();
print_book (pontaux);
free (pontaux);
return 0;
}
关于c - C 读取文件并返回指针，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/21642274/