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



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

NAME
       free -- free allocated memory

SYNOPSIS
       #include <stdlib.h>

       void free(void *ptr);

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 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
       The free() function shall not return a value.

ERRORS
       No errors are defined.

       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
       calloc(), malloc(), posix__memalign(), realloc()

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

COPYRIGHT
       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(3)
