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

# wcscspn(3)

search a wide-character string for any of a set of wide characters

## NAME

wcscspn - search a wide-character string for any of a set of wide characters

## LIBRARY

Standard C library (*libc*, *-lc*)

## SYNOPSIS

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

**size\_t wcscspn(const wchar\_t \****wcs***, const wchar\_t \****reject***);**

## DESCRIPTION

The **wcscspn**() function is the wide-character equivalent of the [**strcspn**(3)](/strcspn/3.md) function. It determines the length of the longest initial segment of *wcs* which consists entirely of wide-characters not listed in *reject*. In other words, it searches for the first occurrence in the wide-character string *wcs* of any of the characters in the wide-character string *reject*.

## RETURN VALUE

The **wcscspn**() function returns the number of wide characters in the longest initial segment of *wcs* which consists entirely of wide-characters not listed in *reject*. In other words, it returns the position of the first occurrence in the wide-character string *wcs* of any of the characters in the wide-character string *reject*, or *wcslen(wcs)* if there is none.

## ATTRIBUTES

For an explanation of the terms used in this section, see [**attributes**(7)](/attributes/7.md).

| | | |
| --- | --- | --- |
| **Interface** | **Attribute** | **Value** |
| **wcscspn**() | Thread safety | MT-Safe |

## STANDARDS

C11, POSIX.1-2008.

## HISTORY

POSIX.1-2001, C99.

## SEE ALSO

[**strcspn**(3)](/strcspn/3.md), [**wcspbrk**(3)](/wcspbrk/3.md), [**wcsspn**(3)](/wcsspn/3.md)