如何將一個結構指向另一個

我需要幫助將*user_playlist指向播放列表節點。我怎樣才能做到這一點？如何將一個結構指向另一個

struct playlist_ { 
    int album; 
    int track_num; 
    struct playlist_ *next; 
}; 
typedef struct playlist_ playlists; 

struct users_ { 
    int user_ID; 
    playlists *user_playlist; 
    struct users_ *next; 
}; 
typedef struct users_ users; 

p_users = (users *)malloc(sizeof(users *)); 
p_users -> user_ID = account_number; 
head_users = p_users; 
head_users -> next = NULL; 
users_pointer = head_users; 

p_playlists = (playlists *)malloc(sizeof(playlists)); 
curr_playlists = p_playlists; 
curr_playlists -> album = NULL; 
curr_playlists -> track_num = NULL; 
curr_playlists -> next = NULL; 
curr_users -> user_playlist = curr_playlists; 

users *head_users,*curr_users,*p_users,*users_pointer; 
playlists *head_playlists,*curr_playlists,*p_playlists,*playlist_pointer;

來源

2012-04-03 Learning C

你遇到什麼問題？ – MByD 2012-04-03 11:29:04

我得到總線錯誤（核心轉儲） – 2012-04-03 11:31:40

我認爲你需要寫malloc（sizeof（users））而不是malloc（sizeof（users *））。 'sizeof（users *）'表示當你需要'users'的大小時指向'users'的指針的大小。 – Ivan 2012-04-03 11:33:23

這是一個問題：

p_users = (users *)malloc(sizeof(users *));

它僅分配一個指針的大小，而不是一個users結構的大小。更改爲：

p_users = malloc(sizeof(users));

或：

p_users = malloc(sizeof(*p_users));

Casting the return value of malloc() is unnecessary and potentially dangerous.

編輯：

解引用一個unitialised，或NULL，指針將導致段故障。這聲明但不初始化curr_users（同爲列出的其他變量）：

users *head_users,*curr_users,*p_users,*users_pointer;

試圖再製成訪問curr_users：

curr_users->user_playlist = curr_playlists; /* Segmentation fault. */

初始化curr_users使用，前一個有效的users結構或NULL並在出廠前檢查非空：

users *head_users = NULL,*curr_users = NULL, 
    *p_users = NULL,*users_pointer = NULL; 

if (curr_users) 
{ 
    curr_users->user_playlist = curr_playlists; 
}

來源

2012-04-03 11:34:33 hmjd

更不用說''p_users = malloc（sizeof（* p_users））''會完全解決問題。 – 2012-04-03 11:36:13

@DanielKozar，正確和更新。 – hmjd 2012-04-03 11:37:45

我做了更改，但仍在'curr_users - > user_playlist = curr_playlists;' – 2012-04-03 11:54:00

如何將一個結構指向另一個

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