Scanf into struct containing pointer to different struct

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this function inserts a book info into structure .. it works well but when scanning the date the program crushes..I searched a lot but couldn't fix it

typedef struct
{
    char title[10];
    char author[10];
    char publisher[10];
    char ISBN[10];
    dateStruct* date;
    int copies;
    int current;
} book;
typedef struct
{
    int day;
    int month;
    int year;
} dateStruct;

book* insert(void)
{
   book* theInserted =(book*)malloc(1*sizeof(book));
   gets(theInserted->title);
   gets(theInserted->author);
   gets(theInserted->publisher);
   gets(theInserted->ISBN);
   scanf("%d%d",&(theInserted->copies),&(theInserted->current));
   scanf("%d%d%d",&(theInserted->date->day),&(theInserted->date->month),&(theInserted->date->year));
    return theInserted;
}

What I have tried:

this is where something goes wrong:

scanf("%d%d%d",&(theInserted->date->day),&(theInserted->date->month),&(theInserted->date->year));

Posted 29-Nov-17 20:19pm

Member 13476370

Updated 29-Nov-17 21:04pm

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Jochen Arndt · Accepted Answer · 2017-11-29T21:04:00

You must allocate memory for the theInserted->date and free it when no longer used:

book* theInserted =(book*)malloc(sizeof(book));
theInserted->date = (dateStruct*)malloc(sizeof(dateStruct));

/* Use theInserted here */

/* Free memory */
free(theInserted->date);
free(theInserted);

When not doing so, the theInserted->date member points to anywhere resulting in an access violation or just a program crash.

A better solution is to make the dateStruct member a normal type member and not a pointer:

typedef struct
{
    char title[10];
    char author[10];
    char publisher[10];
    char ISBN[10];
    dateStruct date; // normal member and not pointer
    int copies;
    int current;
} book;

/* ... */

scanf("%d%d%d",&(theInserted->date.day),&(theInserted->date.month),&(theInserted->date.year));

Scanf into struct containing pointer to different struct

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Scanf into struct containing pointer to different struct

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