SDL_VideoDriverName (3) - Linux Manuals
SDL_VideoDriverName: Obtain the name of the video driver
NAME
SDL_VideoDriverName - Obtain the name of the video driverSYNOPSIS
#include "SDL.h"
char *SDL_VideoDriverName(char *namebuf, int maxlen);
DESCRIPTION
The buffer pointed to by namebuf is filled up to a maximum of maxlen characters (include the NULL terminator) with the name of the initialised video driver. The driver name is a simple one word identifier like "x11" or "windib".
RETURN VALUE
Returns NULL if video has not been initialised with SDL_Init or a pointer to namebuf otherwise.
SEE ALSO
SDL_Init SDL_InitSubSystem