Exception thrown: read access violation. **head** was 0xCCCCCCCC. occurred - c

Question

I am writing a Linked list in C. This is my code. I cannot really see any logic error here but when printing in while loop, after the last node is printed it does not jump out of the loop but keep looping then give me this error "Exception thrown: read access violation. head was 0xCCCCCCCC. occurred" on the "head" pointer in the loop.
// ass0.c
#define _CRT_SECURE_NO_WARNINGS
#define _CRTDBG_MAP_ALLOC // need this to get the line identification
//_CrtSetDbgFlag(_CRTDBG_ALLOC_MEM_DF|_CRTDBG_LEAK_CHECK_DF); // in main, after local declarations
//NB must be in debug build
#include <crtdbg.h>
#include <stdio.h>
#include <string.h>
typedef enum { FALSE = 0, TRUE } BOOL;
struct Frame {
char* frameName;
struct Frame* pNext;
};
typedef struct {
char* animationName;
struct Frame* frames;
}Animation;
// Forward declarations
void InitAnimation(Animation*);
void InsertFrame(Animation*);
//void DeleteFrame(Animation*);
//void EditFrame(Animation*);
void ReportAnimation(Animation*);
//void CleanUp(Animation*);
int main(void)
{
char response;
BOOL RUNNING = TRUE;
Animation RG;
_CrtSetDbgFlag(_CRTDBG_ALLOC_MEM_DF | _CRTDBG_LEAK_CHECK_DF);
InitAnimation(&RG);
while (RUNNING)
{
printf("MENU\n 1. Insert a Frame at the front\n 2. Delete last Frame\n 3. Edit a Frame\n 4. Report the Animation\n 5. Quit\n");
scanf("%c", &response);
switch (response)
{
case '1':InsertFrame(&RG); break;
//case '2':DeleteFrame(&RG); break;
//case '3':EditFrame(&RG); break;
case '4':ReportAnimation(&RG); break;
//case '5':RUNNING = FALSE; CleanUp(&RG); break;
default:printf("Please enter a valid option\n");
}
}
return 0;
}
void InitAnimation(Animation* newAnimation) {
newAnimation = malloc(sizeof(Animation));
newAnimation->animationName = "Animation_1";
newAnimation->frames = NULL;
}
void InsertFrame(Animation* animation) {
printf("Insert a Frame in the Animation\n");
char fName[50];
printf("Please enter the Frame Name: ");
scanf("%s", fName);
struct Frame *newFrame;
newFrame = malloc(sizeof(struct Frame));
int nameSize = strlen(fName);
newFrame->frameName = malloc(nameSize + 1);
strcpy(newFrame->frameName, fName);
newFrame->pNext = 0;
//struct Frame* head;
if (animation->frames == NULL)
animation->frames = newFrame;
//head = animation->frames;
//head->pNext = NULL;
//head = animation->frames;
else {
//head = animation->frames;
newFrame->pNext = animation->frames;
animation->frames = newFrame;
/*while (head != NULL) {
newFrame->pNext = *head;
animation->frames = newFrame;
printf("%s", *head->frameName);
head = head->pNext;
}*/
//head = animation->frames;
printf("\n");
}
}
void ReportAnimation(Animation* animation) {
printf("Animation name is Animation_1\n");
printf("Report the Animation\n");
struct Frame* head = animation->frames;
//printf("%s\n", head->frameName);
while (head) {
printf("%s\n", head->frameName);
head = head->pNext;
}
//printf("%d", count);
}

Answer 1

At least the function InitAnimation does not make sense
void InitAnimation(Animation* newAnimation) {
newAnimation = malloc(sizeof(Animation));
newAnimation->animationName = "Animation_1";
newAnimation->frames = NULL;
}
and hence the program in whole is incorrect.
The original object
Animation RG;
//...
InitAnimation(&RG);
is not initialized. The parameter of the function is just overwritten.
The object of the type Animation is already created in main due to the definition
Animation RG;
You need only to initialize its data members.
Remove the statement with the malloc call
void InitAnimation(Animation* newAnimation) {
newAnimation->animationName = "Animation_1";
newAnimation->frames = NULL;
}
And in general you should allocate dynamically memory for the string that will be pointed to by the data member animationName.
The function cam look the following way
int InitAnimation( Animation *newAnimation, const char *name )
{
newAnimation->animationName = malloc( strlen( name ) + 1 );
int success = newAnimation->animationName !+ NULL;
if ( success )
{
strcpy( newAnimation->animationName, name );
newAnimation->frames = NULL;
}
return success;
}
and called like
Animation RG;
//...
InitAnimation(&RG, "Animation_1" );
Pay attention to that you need to include the header <stdlib.h> where the functions malloc and free are declared.