###### (This is the documentation for SDL3, which is the current stable version. [SDL2](https://wiki.libsdl.org/SDL2/) was the previous version!) # SDL_utf8strnlen Count the number of codepoints in a UTF-8 string, up to n bytes. ## Header File Defined in [](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_stdinc.h) ## Syntax ```c size_t SDL_utf8strnlen(const char *str, size_t bytes); ``` ## Function Parameters | | | | | ------------ | --------- | ----------------------------------------------------------- | | const char * | **str** | The null-terminated UTF-8 string to read. Must not be NULL. | | size_t | **bytes** | The maximum amount of bytes to count. | ## Return Value (size_t) Returns The length (in codepoints, excluding the null terminator) of `src` but never more than `maxlen`. ## Remarks Counts the _codepoints_, not _bytes_, in `str`, excluding the null terminator. If you need to count the bytes in a string instead, consider using [SDL_strnlen](SDL_strnlen)(). The counting stops at `bytes` bytes (not codepoints!). This seems counterintuitive, but makes it easy to express the total size of the string's buffer. Since this handles Unicode, it expects the strings to be well-formed UTF-8 and not a null-terminated string of arbitrary bytes. Bytes that are not valid UTF-8 are treated as Unicode character U+FFFD (REPLACEMENT CHARACTER), so a malformed or incomplete UTF-8 sequence might increase the count by several replacement characters. ## Thread Safety It is safe to call this function from any thread. ## Version This function is available since SDL 3.1.3. ## See Also - [SDL_utf8strlen](SDL_utf8strlen) - [SDL_strnlen](SDL_strnlen) ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryStdinc](CategoryStdinc)