Memory Leak guide with Dynamic Arrays in C When Using `realloc`
I'm having trouble with I've been banging my head against this for hours. I'm working with a memory leak in my C program when using `realloc` to resize a dynamic array. I start by allocating an initial array with `malloc`, but when I call `realloc`, I seem to lose the reference to the original memory, causing a leak. Here's a simplified version of my code: ```c #include <stdio.h> #include <stdlib.h> void resize_array(int **arr, size_t *size) { size_t new_size = *size * 2; int *temp = realloc(*arr, new_size * sizeof(int)); if (temp == NULL) { fprintf(stderr, "Memory allocation failed\n"); return; } *arr = temp; *size = new_size; } int main() { size_t size = 5; int *arr = malloc(size * sizeof(int)); for (size_t i = 0; i < size; i++) { arr[i] = i + 1; } resize_array(&arr, &size); // Use `arr`... free(arr); // I free the memory, but the leak continues return 0; } ``` I notice that when I run my program with tools like Valgrind, it reports a memory leak, indicating that the original pointer was not properly freed before the call to `realloc`. I thought `realloc` took care of freeing the old memory if it had to move it, but I'm not sure if I'm missing something. Why does Valgrind still report a leak in this scenario, and how can I fix it? Am I using `realloc` correctly, or is there a better approach to handle dynamic arrays in this case? This question occurs when compiled using GCC 11.2.0 on Ubuntu 20.04. This is happening in both development and production on Linux. Any pointers in the right direction?