Segmentation fault when using pointers in struct array with function callbacks in C
After trying multiple solutions online, I still can't figure this out. I'm working on a project and hit a roadblock. After trying multiple solutions online, I still can't figure this out. I'm encountering a segmentation fault when trying to implement a callback function that processes an array of structs in C. The structs contain a pointer to a dynamically allocated string, and I'm using a function pointer to apply a transformation to each element of the array. Here's the relevant portion of my code: ```c #include <stdio.h> #include <stdlib.h> #include <string.h> typedef struct { char *name; } Item; void transform(Item *item) { if (item && item->name) { strcat(item->name, "_processed"); // Dynamically modifying the string } } void processItems(Item *items, size_t count, void (*callback)(Item *)) { for (size_t i = 0; i < count; i++) { callback(&items[i]); } } int main() { size_t count = 3; Item *items = malloc(count * sizeof(Item)); for (size_t i = 0; i < count; i++) { items[i].name = malloc(20); snprintf(items[i].name, 20, "Item%d", i); } processItems(items, count, transform); // Free the allocated memory for (size_t i = 0; i < count; i++) { free(items[i].name); } free(items); return 0; } ``` When I run this code, I get a segmentation fault during the execution of `strcat(item->name, "_processed");`. I suspect that the memory for `item->name` might not be sufficient after the concatenation. I've tried increasing the size allocated for `name`, but it still crashes. I also checked for NULL pointers, and they seem to be fine. Can anyone help me understand why this is happening and how to fix it? I am using GCC version 11.2.0 on Ubuntu 20.04. Has anyone else encountered this? For context: I'm using C on Ubuntu 20.04. Am I approaching this the right way? Hoping someone can shed some light on this.