###### (This is the legacy documentation for SDL2, the previous stable version; [SDL3](https://wiki.libsdl.org/SDL3/) is the current stable version.) # SDL_hid_set_nonblocking Set the device handle to be non-blocking. ## Header File Defined in [SDL_hidapi.h](https://github.com/libsdl-org/SDL/blob/SDL2/include/SDL_hidapi.h) ## Syntax ```c int SDL_hid_set_nonblocking(SDL_hid_device *dev, int nonblock); ``` ## Function Parameters | | | | | ---------------------------------- | ------------ | ----------------------------------------------------------------------------------------- | | [SDL_hid_device](SDL_hid_device) * | **dev** | A device handle returned from [SDL_hid_open](SDL_hid_open)(). | | int | **nonblock** | enable or not the nonblocking reads - 1 to enable nonblocking - 0 to disable nonblocking. | ## Return Value (int) Returns 0 on success and -1 on error. ## Remarks In non-blocking mode calls to [SDL_hid_read](SDL_hid_read)() will return immediately with a value of 0 if there is no data to be read. In blocking mode, [SDL_hid_read](SDL_hid_read)() will wait (block) until there is data to read before returning. Nonblocking can be turned on and off at any time. ## Version This function is available since SDL 2.0.18. ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryHIDAPI](CategoryHIDAPI)