calloc(3p) — Linux manual page


CALLOC(3P)                POSIX Programmer's Manual               CALLOC(3P)

PROLOG         top

       This manual page is part of the POSIX Programmer's Manual.  The Linux
       implementation of this interface may differ (consult the
       corresponding Linux manual page for details of Linux behavior), or
       the interface may not be implemented on Linux.

NAME         top

       calloc — a memory allocator

SYNOPSIS         top

       #include <stdlib.h>

       void *calloc(size_t nelem, size_t elsize);

DESCRIPTION         top

       The functionality described on this reference page is aligned with
       the ISO C standard. Any conflict between the requirements described
       here and the ISO C standard is unintentional. This volume of
       POSIX.1‐2008 defers to the ISO C standard.

       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         top

       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         top

       The calloc() function shall fail if:

       ENOMEM Insufficient memory is available.

       The following sections are informative.

EXAMPLES         top



       There is now no requirement for the implementation to support the
       inclusion of <malloc.h>.

RATIONALE         top




SEE ALSO         top

       free(3p), malloc(3p), realloc(3p)

       The Base Definitions volume of POSIX.1‐2008, stdlib.h(0p)

COPYRIGHT         top

       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1, 2013 Edition, Standard for Information
       Technology -- Portable Operating System Interface (POSIX), The Open
       Group Base Specifications Issue 7, Copyright (C) 2013 by the
       Institute of Electrical and Electronics Engineers, Inc and The Open
       Group.  (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
       applied.) 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 .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the
       source files to man page format. To report such errors, see .

IEEE/The Open Group                 2013                          CALLOC(3P)

Pages that refer to this page: stdlib.h(0p)free(3p)malloc(3p)realloc(3p)