SDL_WasInit allows you to see which SDL subsytems have been initialized. flags is a bitwise OR'd combination of the subsystems you wish to check (see SDL_Init for a list of subsystem flags).
/* Here are several ways you can use SDL_WasInit() */ /* Get init data on all the subsystems */ Uint32 subsystem_init; subsystem_init=SDL_WasInit(SDL_INIT_EVERYTHING); if(subsystem_init&SDL_INIT_VIDEO) printf("Video is initialized.\n"); else printf("Video is not initialized.\n"); /* Just check for one specfic subsystem */ if(SDL_WasInit(SDL_INIT_VIDEO)!=0) printf("Video is initialized.\n"); else printf("Video is not initialized.\n"); /* Check for two subsystems */ Uint32 subsystem_mask=SDL_INIT_VIDEO|SDL_INIT_AUDIO; if(SDL_WasInit(subsystem_mask)==subsystem_mask) printf("Video and Audio initialized.\n"); else printf("Video and Audio not initialized.\n");