NAME

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

SYNOPSIS

#include <wchar.h>

size_t wcslen(const wchar_t *ws);


[CX] size_t wcsnlen(const wchar_t *ws, size_t maxlen);

DESCRIPTION

For wcslen(): ^[CX]  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.1-2024 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.

^[CX] 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.

^[CX] The wcslen() and wcsnlen() functions shall not change the setting of errno on valid input.

RETURN VALUE

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

^[CX] 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.

ERRORS

No errors are defined.

EXAMPLES

None.

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

strlen , wcslcat

XBD <wchar.h>

CHANGE HISTORY

First released in Issue 4. Derived from the MSE working draft.

Issue 7

The wcsnlen() function is added from The Open Group Technical Standard, 2006, Extended API Set Part 1.

POSIX.1-2008, Technical Corrigendum 2, XSH/TC2-2008/0390 [560] is applied.

Issue 8

Austin Group Defect 448 is applied, adding a requirement that wcslen() and wcsnlen() do not change the setting of errno on valid input.

Austin Group Defect 986 is applied, adding wcslcat() to the SEE ALSO section.