#include <stdlib.h>
void *malloc(size_t size);
malloc allocates space for an object whose size is specified by size and whose value is indeterminate.
malloc returns a null pointer if the space for the object cannot be allocated from free memory; if space for the object can be allocated, malloc returns a pointer to the start of the allocated space.
malloc conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).