Initialization Error..? Help Please

[Matt Hintzke]

I can't figure out why I am getting an error telling me that my pointer to a char in a struct is not initialized:
Here is the struct and function that is getting the error.

typedef struct song_info
{
	 char *artist;
     char *album;
     char *title;
     char *genre;
     struct song_length length;
	 int num_plays;
     int rating;
} Song_struct;

Song_struct *getInfo(void)
{
	Song_struct *newSong;
	Song_struct *pMem;
	char artist[32], album[32], title[32], genre[32];
	int min, sec, num_played, rating;
	char filler;
	printf("Please enter song information...\n");
	printf("Artist: ");
	scanf("%c");
	gets(artist);
	printf("Album: ");
	gets(album);
	printf("%s", album);
	printf("Song Title: ");
	gets(title);
	printf("Genre: ");
	gets(genre);
	printf("Song length (min:sec): ");
	scanf("%d%c%d", &min, &filler, &sec);
	printf("Number of times played: ");
	scanf("%d", &num_played);
	printf("Rating: ");
	scanf("%d", &rating);
	
	newSong->artist = (char *)malloc(sizeof(char)*strlen(artist));
	newSong->album = (char *)malloc(sizeof(char)*strlen(album));
	newSong->title = (char *)malloc(sizeof(char)*strlen(title));
	newSong->genre = (char *)malloc(sizeof(char)*strlen(genre));
	newSong->length.minutes = (int)malloc(sizeof(int));
	newSong->length.seconds = (int)malloc(sizeof(int));
	newSong->num_plays = (int)malloc(sizeof(num_played));
	newSong->rating = (int)malloc(sizeof(rating));


	strcpy(newSong->artist, artist);
	strcpy(newSong->album, album);
	strcpy(newSong->title, title);
	strcpy(newSong->genre, genre);
	newSong->length.minutes = min;
	newSong->length.seconds = sec;
	newSong->num_plays = num_played;
	newSong->rating = rating;


	return newSong;
}

The program crashes right when the first newSong->artist = ... call to malloc is started.

[stahta01]

Where do you allocate space for "newSong" or set it to a valid address?

Once you fix that remember you need to allocate space for the /0 at end of string.

malloc(sizeof(char)*(strlen(artist)+1));

Tim S.

[Matt Hintzke]

Oh thanks for the reminder, but I didn't know I have to allocate memory for newSong, I thought you only have to allocate memory for the data that is encapsulated within newSong. so to do that do I use this:

newSong = (newSong *)malloc(sizeof(newSong));

thanks

[rags_to_riches]

Arg! Why, oh why are you using gets()??? Stop immediately!

You also should not be casting the return value of malloc. If you have to because of warnings or errors, it's because you're either compiling as C++ or you've forgotten to #include <stdlib.h>

[memcpy]

Neither of the structs are being allocated, and pMem doesn't seem to be used. You don't need to allocate non-pointer variables, such as ints.

Why %c for artist? That's incorrect, it's %s like everything else.

Don't use gets(), and while you're at it, get rid of the temporary variables and just fill in the struct.

[Matt Hintzke]

what should I use instead of gets() than? If I use scanf then I can't use more than one word because the scanf stops at whitespace.

Also, memcpy, if I take out the scanf("%c"); after printf("Artist: "); then the program skips the gets() for artist and goes straight to the next printf("Album: "); without stopping to take in the string.

[memcpy]

Use fgets(), it removes all the issues with whitespace and newlines (which lets you remove the scanf %c), and you can specify the length.

[Matt Hintzke]

ok thanks a lot

[anduril462]

Note, fgets will leave the new line in the buffer, so you have to remove that by hand.