# SDL_WriteU8 Use this function to write a byte to an [SDL_IOStream](SDL_IOStream). ## Header File Defined in [<SDL3/SDL_iostream.h>](https://github.com/libsdl-org/SDL/blob/main/include/SDL3/SDL_iostream.h) ## Syntax ```c bool SDL_WriteU8(SDL_IOStream *dst, Uint8 value); ``` ## Function Parameters | | | | | ------------------------------ | --------- | --------------------------------------------- | | [SDL_IOStream](SDL_IOStream) * | **dst** | the [SDL_IOStream](SDL_IOStream) to write to. | | Uint8 | **value** | the byte value to write. | ## Return Value (bool) Returns true on successful write or false on failure; call [SDL_GetError](SDL_GetError)() for more information. ## Thread Safety This function is not thread safe. ## Version This function is available since SDL 3.2.0. ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryIOStream](CategoryIOStream)