###### (This is the legacy documentation for SDL2, the previous stable version; [SDL3](https://wiki.libsdl.org/SDL3/) is the current stable version.) # SDL_AllocRW Use this function to allocate an empty, unpopulated [SDL_RWops](SDL_RWops) structure. ## Header File Defined in [SDL_rwops.h](https://github.com/libsdl-org/SDL/blob/SDL2/include/SDL_rwops.h) ## Syntax ```c SDL_RWops* SDL_AllocRW(void); ``` ## Return Value ([SDL_RWops](SDL_RWops) *) Returns a pointer to the allocated memory on success, or NULL on failure; call [SDL_GetError](SDL_GetError)() for more information. ## Remarks Applications do not need to use this function unless they are providing their own [SDL_RWops](SDL_RWops) implementation. If you just need a [SDL_RWops](SDL_RWops) to read/write a common data source, you should use the built-in implementations in SDL, like [SDL_RWFromFile](SDL_RWFromFile)() or [SDL_RWFromMem](SDL_RWFromMem)(), etc. You must free the returned pointer with [SDL_FreeRW](SDL_FreeRW)(). Depending on your operating system and compiler, there may be a difference between the malloc() and free() your program uses and the versions SDL calls internally. Trying to mix the two can cause crashing such as segmentation faults. Since all [SDL_RWops](SDL_RWops) must free themselves when their **close** method is called, all [SDL_RWops](SDL_RWops) must be allocated through this function, so they can all be freed correctly with [SDL_FreeRW](SDL_FreeRW)(). ## Version This function is available since SDL 2.0.0. ## See Also - [SDL_FreeRW](SDL_FreeRW) ---- [CategoryAPI](CategoryAPI), [CategoryAPIFunction](CategoryAPIFunction), [CategoryRWOPS](CategoryRWOPS)