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                                        WCSLEN(3POSIX)

       For  wcslen(): 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  wcslen()  function  shall compute the number of wide-character codes in the wide-character string to
       which ws points, not including the terminating null wide-character code.

       The wcsnlen() function shall compute the smaller of the number of wide characters in the array  to  which
       ws  points,  not  including  any  terminating  null  wide-character  code,  and the value of maxlen.  The
       wcsnlen() function shall never examine more than the first maxlen characters of the wide-character  array
       pointed to by ws.

       No errors are defined.

       Thefollowingsectionsareinformative.

       None.

       None.

       wcslen, wcsnlen — get length of a fixed-sized wide-character string

       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.

       The wcslen() function shall return the length of ws.

       The wcsnlen() function shall return the number of wide characters preceding the first null wide-character
       code  in  the array to which ws points, if ws contains a null wide-character code within the first maxlen
       wide characters; otherwise, it shall return maxlen.

       No return values are reserved to indicate an error.

strlen()

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

       #include <wchar.h>

       size_t wcslen(const wchar_t *ws);
       size_t wcsnlen(const wchar_t *ws, size_t maxlen);