calloc - allocate and clear memory
Standard C Library (libc, -lc)
#include <stdlib.h>
void *
calloc(size_t number, size_t size);
calloc allocates number*size bytes of memory, zeros it, and returns a pointer to it. It is equivalent to calling malloc(number*size) followed by bzero.
If the product number*size overflows the range of size_t, calloc fails.
calloc returns a pointer to the memory allocated. If memory cannot be obtained, NULL is returned.