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

       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 .