#include <stdlib.h>
void *calloc(size_t nmemb, size_t size);
calloc allocates space for an array of nmemb objects, each of whose size is size. The space is initialized to all zero bits.
calloc returns a null pointer if the space for the array of object cannot be allocated from free memory; if space for the array can be allocated, calloc returns a pointer to the start of the allocated space.
calloc conforms to ISO/IEC 9899:1990 (C90) and ISO/IEC 9899:1999 (C99).