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NAME
calloc - a memory allocator
SYNOPSIS
#include <stdlib.h> void *calloc(size_t nelem, size_t elsize);
DESCRIPTION
The calloc() function shall allocate unused space for an array of nelem elements each of whose size in
bytes is elsize. The space shall be initialized to all bits 0.
The order and contiguity of storage allocated by successive calls to calloc() is unspecified. The pointer
returned if the allocation succeeds shall be suitably aligned so that it may be assigned to a pointer to
any type of object and then used to access such an object or an array of such objects in the space
allocated (until the space is explicitly freed or reallocated). Each such allocation shall yield a
pointer to an object disjoint from any other object. The pointer returned shall point to the start
(lowest byte address) of the allocated space. If the space cannot be allocated, a null pointer shall be
returned. If the size of the space requested is 0, the behavior is implementation-defined: the value
returned shall be either a null pointer or a unique pointer.
RETURN VALUE
Upon successful completion with both nelem and elsize non-zero, calloc() shall return a pointer to the
allocated space. If either nelem or elsize is 0, then either a null pointer or a unique pointer value
that can be successfully passed to free() shall be returned. Otherwise, it shall return a null pointer
and set errno to indicate the error.
ERRORS
The calloc() function shall fail if:
ENOMEM Insufficient memory is available.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
There is now no requirement for the implementation to support the inclusion of <malloc.h>.
RATIONALE
None.
FUTURE DIRECTIONS
None.
SEE ALSO
free() , malloc() , realloc() , the Base Definitions volume of IEEE Std 1003.1-2001, <stdlib.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition,
Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers,
Inc and The Open Group. In the event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The
original Standard can be obtained online at http://www.opengroup.org/unix/online.html .