---
name: "wcsncmp"
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/wcsncmp"
---

# wcsncmp(3)

compare two fixed-size wide-character strings

## NAME

wcsncmp - compare two fixed-size wide-character strings

## LIBRARY

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

## SYNOPSIS

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

**int wcsncmp(const wchar\_t** s1**\[\], const wchar\_t** s2**\[\], size\_t** n**);**

## DESCRIPTION

The **wcsncmp**() function is the wide-character equivalent of the [**strncmp**(3)](/strncmp/3.md) function. It compares the wide-character string pointed to by *s1* and the wide-character string pointed to by *s2*, but at most *n* wide characters from each string. In each string, the comparison extends only up to the first occurrence of a null wide character (L'\\0'), if any.

## RETURN VALUE

The **wcsncmp**() function returns zero if the wide-character strings at *s1* and *s2*, truncated to at most length *n*, are equal. It returns an integer greater than zero if at the first differing position *i* (*i* \< *n*), the corresponding wide-character *s1\[i\]* is greater than *s2\[i\]*. It returns an integer less than zero if at the first differing position *i* (*i* \< *n*), the corresponding wide-character *s1\[i\]* is less than *s2\[i\]*.

## ATTRIBUTES

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

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

## STANDARDS

C11, POSIX.1-2008.

## HISTORY

POSIX.1-2001, C99.

## SEE ALSO

[**strncmp**(3)](/strncmp/3.md), [**wcsncasecmp**(3)](/wcsncasecmp/3.md)