Does every malloc call have to be freed

Question

From what I understand because malloc dynamically assigns mem , you need to free that mem so that it can be used again.

1. What happens if you return a char* that

Answer 1

Yes, every call to malloc() has to be matched with a call to free().

To answer your specific questions:

1. You have to explicitly document your API telling the user whether the returned pointer has to be free()'d
2. The OS will free all memory allocated to the process.