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

# wcstok(3)

split wide-character string into tokens

## NAME

wcstok - split wide-character string into tokens

## LIBRARY

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

## SYNOPSIS

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

**wchar\_t \*wcstok(wchar\_t \*restrict** *wcs***, const wchar\_t \*restrict** *delim***,**                 **wchar\_t \*\*restrict** *ptr***);**

## DESCRIPTION

The **wcstok**() function is the wide-character equivalent of the [**strtok**(3)](/strtok/3.md) function, with an added argument to make it multithread-safe. It can be used to split a wide-character string *wcs* into tokens, where a token is defined as a substring not containing any wide-characters from *delim*.

The search starts at *wcs*, if *wcs* is not NULL, or at *\*ptr*, if *wcs* is NULL. First, any delimiter wide-characters are skipped, that is, the pointer is advanced beyond any wide-characters which occur in *delim*. If the end of the wide-character string is now reached, **wcstok**() returns NULL, to indicate that no tokens were found, and stores an appropriate value in *\*ptr*, so that subsequent calls to **wcstok**() will continue to return NULL. Otherwise, the **wcstok**() function recognizes the beginning of a token and returns a pointer to it, but before doing that, it zero-terminates the token by replacing the next wide-character which occurs in *delim* with a null wide character (L'\\0'), and it updates *\*ptr* so that subsequent calls will continue searching after the end of recognized token.

## RETURN VALUE

The **wcstok**() function returns a pointer to the next token, or NULL if no further token was found.

## ATTRIBUTES

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

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

## STANDARDS

C11, POSIX.1-2008.

## HISTORY

POSIX.1-2001, C99.

## NOTES

The original *wcs* wide-character string is destructively modified during the operation.

## EXAMPLES

The following code loops over the tokens contained in a wide-character string.

```
wchar_t *wcs = ...;
wchar_t *token;
wchar_t *state;
for (token = wcstok(wcs, L" \t\n", &state);
    token != NULL;
    token = wcstok(NULL, L" \t\n", &state)) {
    ...
}
```

## SEE ALSO

[**strtok**(3)](/strtok/3.md), [**wcschr**(3)](/wcschr/3.md)