This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface

       None.

       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                                        WCSTOK(3POSIX)

       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.

       A  sequence  of calls to wcstok() shall break the wide-character string pointed to by ws1 into a sequence
       of tokens, each of which shall be delimited by a  wide-character  code  from  the  wide-character  string
       pointed  to by ws2.  The ptr argument points to a caller-provided wchar_t pointer into which the wcstok()
       function shall store information necessary for it to continue scanning the same wide-character string.

       The first call in the sequence has ws1 as its first argument, and  is  followed  by  calls  with  a  null
       pointer  as  their  first  argument. The separator string pointed to by ws2 may be different from call to
       call.

       The first call in the sequence shall search the wide-character string pointed to by  ws1  for  the  first
       wide-character  code that is not contained in the current separator string pointed to by ws2.  If no such
       wide-character code is found, then there are no tokens in the wide-character string pointed to by ws1 and
       wcstok() shall return a null pointer. If such a wide-character code is found, it shall be  the  start  of
       the first token.

       The  wcstok()  function  shall  then search from there for a wide-character code that is contained in the
       current separator string. If no such wide-character code is found, the current token extends to  the  end
       of  the  wide-character string pointed to by ws1, and subsequent searches for a token shall return a null
       pointer. If such a wide-character code is found, it shall be overwritten by a null wide character,  which
       terminates  the current token. The wcstok() function shall save a pointer to the following wide-character
       code, from which the next search for a token shall start.

       Each subsequent call, with a null pointer as the value of the first argument, shall start searching  from
       the saved pointer and behave as described above.

       The implementation shall behave as if no function calls wcstok().

       No errors are defined.

       Thefollowingsectionsareinformative.

       None.

       None.

       wcstok — split a wide-character string into tokens

       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.

       None.

       Upon successful completion, the wcstok() function shall return a pointer to the first wide-character code
       of a token. Otherwise, if there is no token, wcstok() shall return a null pointer.

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

       #include <wchar.h>

       wchar_t *wcstok(wchar_t *restrict ws1, const wchar_t *restrict ws2,
           wchar_t **restrict ptr);