---
name: "wcslen"
section: "3p"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/wcslen/3p"
---

# wcslen(3p)

get length of a fixed-sized wide-character string

## PROLOG

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.

## NAME

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

## SYNOPSIS

```
#include <wchar.h>
```

size\_t wcslen(const wchar\_t \**ws*); size\_t wcsnlen(const wchar\_t \**ws*, size\_t *maxlen*);

## DESCRIPTION

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.

## ERRORS

No errors are defined.

*The following sections are informative.*

## EXAMPLES

None.

## APPLICATION USAGE

None.

## RATIONALE

None.

## FUTURE DIRECTIONS

None.

## SEE ALSO

*strlen()*

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 .