free(3p) — Linux manual page

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

       free — free allocated memory

SYNOPSIS         top

       #include <stdlib.h>

       void free(void *ptr);

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.1‐2017 defers to the ISO C standard.

       The free() function shall cause the space pointed to by ptr to be
       deallocated; that is, made available for further allocation. If
       ptr is a null pointer, no action shall occur. Otherwise, if the
       argument does not match a pointer earlier returned by a function
       in POSIX.1‐2008 that allocates memory as if by malloc(), or if
       the space has been deallocated by a call to free() or realloc(),
       the behavior is undefined.

       Any use of a pointer that refers to freed space results in
       undefined behavior.

RETURN VALUE         top

       The free() function shall not return a value.

ERRORS         top

       No errors are defined.

       The following sections are informative.

EXAMPLES         top

       None.

APPLICATION USAGE         top

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

RATIONALE         top

       None.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       calloc(3p), malloc(3p), posix_memalign(3p), realloc(3p)

       The Base Definitions volume of POSIX.1‐2017, stdlib.h(0p)

COPYRIGHT         top

       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 .

IEEE/The Open Group               2017                          FREE(3P)

Pages that refer to this page: stdlib.h(0p),  calloc(3p),  getdelim(3p),  malloc(3p),  open_memstream(3p),  posix_memalign(3p),  putenv(3p),  realloc(3p),  realpath(3p),  strdup(3p),  tempnam(3p),  wcsdup(3p)

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