oracular (3) malloc.3posix.gz

Provided by: manpages-posix-dev_2017a-2_all bug

PROLOG
       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
       malloc — a memory allocator


SYNOPSIS
       #include <stdlib.h>

       void *malloc(size_t size);


DESCRIPTION
       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.1‐2017 defers to the ISO C standard.

       The  malloc() function shall allocate unused space for an object whose size in bytes is specified by size
       and whose value is unspecified.

       The order and contiguity of storage allocated by successive calls to malloc() 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 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 points 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: either a null pointer shall be returned, or the behavior shall
       be as if the size were some non-zero value, except that the behavior is undefined if the returned pointer
       is used to access an object.


RETURN VALUE
       Upon successful completion with size not equal to 0, malloc() shall return a  pointer  to  the  allocated
       space. If size is 0, either:

        *  A null pointer shall be returned and errno may be set to an implementation-defined value, or

        *  A  pointer to the allocated space shall be returned. The application shall ensure that the pointer is
           not used to access an object.

       Otherwise, it shall return a null pointer and set errno to indicate the error.


ERRORS
       The malloc() function shall fail if:

       ENOMEM Insufficient storage space is available.

       The following sections are informative.


EXAMPLES
       None.


APPLICATION USAGE
       None.


RATIONALE
       None.


FUTURE DIRECTIONS
       None.


SEE ALSO
       calloc(), free(), getrlimit(), posix_memalign(), realloc()

       The Base Definitions volume of POSIX.1‐2017, <stdlib.h>


       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1-2017, Standard
       for  Information  Technology  --  Portable  Operating  System  Interface  (POSIX),  The  Open  Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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 .

       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
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .