Unexpected Segmentation Fault When Accessing Struct Members in C After Dynamic Memory Allocation
I've looked through the documentation and I'm still confused about I'm testing a new approach and I'm working with a segmentation fault when attempting to access members of a struct after dynamically allocating memory for it. I'm using GCC version 10.2 on Ubuntu 20.04. Here's a snippet of my code: ```c #include <stdio.h> #include <stdlib.h> typedef struct { int id; char name[50]; } Person; int main() { Person *p = malloc(sizeof(Person)); if (!p) { perror("Failed to allocate memory"); return EXIT_FAILURE; } p->id = 1; snprintf(p->name, sizeof(p->name), "Alice"); // Trying to access struct members printf("ID: %d, Name: %s\n", p->id, p->name); // Freeing memory free(p); // Accessing freed memory printf("After free: ID: %d, Name: %s\n", p->id, p->name); return EXIT_SUCCESS; } ``` The line that prints the struct members after freeing the memory seems to cause a segmentation fault. From what I've read, accessing memory after it has been freed is undefined behavior, but I thought it was more of a warning than an immediate crash. I was expecting to see garbage values or potentially a crash later in the program, but I didn't expect it to crash right away when attempting to access it. I have tried commenting out the printf statements after the `free(p);` line, and the program runs fine without crashing. Is my understanding of accessing freed memory incorrect? Shouldn't the program continue to work until the memory is reused by something else? Any insights into the behavior I'm observing would be greatly appreciated! Is there a better approach?