C语言 将结构体添加到列表并得到正确的输出

Question

我试图创建一个struct typepedef movie_t并将其添加到列表中。它包含片名、导演、等级和制作年份。我的代码只是输出标题。我不明白为什么它没有输出movie_t结构体的所有成员?

例如，我定义了:

movie_t *first_movie = {"The Outsiders","Francis Ford Coppola",'PG13',1983}

但是当我运行程序时，它只输出标题:

list[0] = The Outsiders
list[1] = The Outsiders
list[2] = The Outsiders
list[3] = The Outsiders
list[4] = The Outsiders
list[5] = The Outsiders
list[6] = The Outsiders
list[7] = The Outsiders
list[8] = The Outsiders
list[9] = The Outsiders

basiclist.h

#ifndef BASICLIST_H_
#define BASICLIST_H_
typedef struct node {
  void * data;         /* pointer to data */
  struct node * next;  /* pointer to next next node */
} node_t;
int list_add(node_t ** list, void * data);
#endif

movie.h

#ifndef MOVIE_H
#define MOVIE_H
#define SIZE_LIMIT 25
#define RATING_SIZE 5
typedef enum {G, PG, PG13, R} rating_t;
typedef struct {
    char rating;
    char title[SIZE_LIMIT];
    char director[SIZE_LIMIT];
    int year;
}movie_t;

void get_movie(movie_t * movie);
void print_movie(const movie_t * movie);
#endif /* MOVIE_H */

c

#include "movie.h"
#include <stdlib.h>
#include <stdio.h>
#include "basiclist.h"
int list_add(node_t ** list, void * data) {
  int ret = 0;
  node_t * newnode = (node_t *) malloc(sizeof(node_t));
  if (newnode == NULL) {
    ret = -1;
  }
  else {
    newnode->data = data;
    newnode->next = *list;
  }
  *list = newnode;
  return ret;
}
int main (void)
{
  int ii;
  movie_t * new_movie;
  movie_t *first_movie = {"The Outsiders","Francis Ford Coppola",'PG13',1983};
  node_t * list = NULL;
  node_t * curr;
  for(ii=0;ii<10;ii++) {
    new_movie = (movie_t *) malloc(sizeof(int));
    *new_movie = *first_movie;
    list_add(&list, new_movie);
  }
  ii = 0;
  curr = list;
  while (curr != NULL) {
    printf("list[%d] = %sn", ii, *((movie_t *) curr->data));
    ii++;
    curr = curr->next;
  }
  printf("It worked!n");
  return 0;
}

Answer 1

printf("list[%d] = %sn", ii, *((movie_t *) curr->data));: movie_t和movie_t*不适合%s。为move_t*定制打印函数(print_movie)

例如

void print_movie(FILE* fp, const movie_t *m){
    static const char *raiting[] = { "G", "PG", "PG13", "R"};
    fprintf(fp, "%st%st%st%dn", m->title, m->director, raiting[m->rating], m->year);
}

change prototype void print_movie(const movie_t * movie); to void print_movie(FILE* fp, const movie_t *m);
或更改print_movie的名称和呼叫

在主要的

change printf("list[%d] = %sn", ii, *((movie_t *) curr->data));
to print_movie(stdout, curr->data);

---

也

change movie_t *first_movie = {"The Outsiders","Francis Ford Coppola",'PG13',1983};
to movie_t first_movie = {"The Outsiders","Francis Ford Coppola", (char)PG13, 1983};

和

改变

typedef struct {
    char rating;
    char title[SIZE_LIMIT];
    char director[SIZE_LIMIT];
    int year;
}movie_t;

typedef struct {
    char title[SIZE_LIMIT];
    char director[SIZE_LIMIT];
    char rating;//or rating_t rating;
    int year;
}movie_t;

和

for(ii=0;ii<10;ii++) {
  new_movie = (movie_t *) malloc(sizeof(int));//int !!
  *new_movie = *first_movie;
  list_add(&list, new_movie);
}

for(ii=0;ii<10;ii++) {
  new_movie = malloc(sizeof(*new_movie));
  *new_movie = first_movie;
  list_add(&list, new_movie);
}