Determine size of dynamically allocated memory in C

Question

Is there a way in C to find out the size of dynamically allocated memory?

For example, after

char* p = malloc (100);

Is there

Answer 1

This may work, a small update in your code:

void* inc = (void*) (++p)
size=p-inc;

But this will result 1, that is, memory associated with p if it is char*. If it is int* then result will be 4.

There is no way to find out total allocation.