# SDL_wcsnstr

Search a wide string, up to n wide chars, for the first instance of a specific substring.

## Header File

Defined in [<SDL3/SDL_stdinc.h>](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_stdinc.h)

## Syntax

```c
wchar_t * SDL_wcsnstr(const wchar_t *haystack, const wchar_t *needle, size_t maxlen);
```

## Function Parameters

|                 |              |                                                                |
| --------------- | ------------ | -------------------------------------------------------------- |
| const wchar_t * | **haystack** | the wide string to search. Must not be NULL.                   |
| const wchar_t * | **needle**   | the wide string to search for. Must not be NULL.               |
| size_t          | **maxlen**   | the maximum number of wide characters to search in `haystack`. |

## Return Value

(wchar_t *) Returns a pointer to the first instance of `needle` in the
string, or NULL if not found.

## Remarks

The search ends once it finds the requested substring, or a null terminator
value to end the string, or `maxlen` wide character have been examined. It
is possible to use this function on a wide string without a null
terminator.

Note that this looks for strings of _wide characters_, not _codepoints_, so
it's legal to search for malformed and incomplete UTF-16 sequences.

## Thread Safety

It is safe to call this function from any thread.

## Version

This function is available since SDL 3.2.0.

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[CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryStdinc](CategoryStdinc)