WCSTOK(3)                  POSIX Programmer's Manual                 WCSTOK(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
       wcstok -- split a wide-character string into tokens

SYNOPSIS
       #include <wchar.h>

       wchar_t *wcstok(wchar_t *restrict ws1, const wchar_t *restrict ws2,
           wchar_t **restrict 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.

       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().

RETURN VALUE
       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.

ERRORS
       No errors are defined.

       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       None.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       The Base Definitions volume of POSIX.1-2017, <wchar.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                            WCSTOK(3)
