1. Memory API

man malloc:

malloc, free, calloc, realloc - allocate and free dynamic memory

  #include <stdlib.h>

  void *malloc(size_t size); // allocate size bytes, uninitialized

  void free(void *ptr); // release ptr memory

  void *calloc(size_t nmemb, size_t size); // allocate nmemb*size bytes, initialized to zeros

  void *realloc(void *ptr, size_t size); // change allocation to new size

Others: strdup(), brk(), mmap()