Question

I’m new to C so please correct anything in this question, and also I might be too vague in my question as well. I have code that kind of goes like this, and I’m getting a segmentation fault. I read online that segmentation faults happen usually when u access a pointer that points to nothing

struct apple get(char* name) {
    struct apple a;
    a.name = name;
    return a;
}
struct apple* read(){
    struct apple* ap = (struct apple*)malloc(2*sizeof(struct apple));
    ap[0] = get("bob");
    return ap;
}

// loop through in another function which reads a pointer to an
// apple object in the array and then accesses apple->name

when it accesses apple->name there is a segmentation fault. I am assuming this is because the apple object was declared as a local variable and its freed later by c??? I really have no idea why I get a segmentation fault or how to fix it or how c works with freeing structs that were initialized as a local variable in a function. Can someone please tell me what’s going on, thanks!

Answer 1

Well, segmentation fault errors happen when the pointer points to something wrong, not necessarily when the pointer is empty.

There is nothing wrong in the code snippet that you posted: "bob" is a char* that stays valid for the life of the program, and the return of apple is done by value, so you are not returning a pointer to a local either. The issue is most likely in the code that iterates over apples returned from read().