wcslen - Man Page

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.


#include <wchar.h>

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


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.

Return Value

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.


No errors are defined.

The following sections are informative.



Application Usage




Future Directions


See Also


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

Referenced By

strlen(3p), wchar.h(0p).

2017 IEEE/The Open Group POSIX Programmer's Manual