MALLOC(3)

NAME
calloc, malloc, free, realloc - Allocate and free dynamic memory

SYNOPSIS
#include <stdlib.h>

void *calloc(size_t nmemb, size_t size);
void *malloc(size_t size);
void free(void *ptr);
void *realloc(void *ptr, size_t size);

DESCRIPTION
calloc() allocates memory for an array of nmemb elements of size bytes each and returns a pointer to the allocated memory. The memory is set to zero.

malloc() allocates size bytes and returns a pointer to the allocated memory. The memory is not cleared.

free() frees the memory space pointed to by ptr, which must have been returned by a previous call to malloc(), calloc() or realloc(). If ptr is NULL, no operation is performed.

realloc() changes the size of the memory block pointed to by ptr to size bytes. The contents will be unchanged to the minimum of the old an new sizes; newly allocated memory will be uninitialized. If ptr is NULL, the call is equivalent to malloc(size); if size is equal to zero, the call is equivalent to free(ptr). Unless ptr is NULL, it must have been returned by an earlier call to malloc(), calloc() or realloc().

RETURN VALUES
For calloc() and malloc(), the value returned is a pointer to the allocated memory, which is suitably aligned for any kind of variable, or NULL if the request fails.

free() returns no value.

realloc() returns a pointer to the newly allocated memory, which is suitably aligned for any kind of variable and may be different from ptr, or NULL if the request fails or if size was equal to 0. If realloc() fails the original block is left untouched - it is not freed or moved.

CONFORMING TO
ANSI-C

SEE ALSO
brk(2)