This function must be called to terminate use of a backend. The function will first close all device handles that still might be open (it is recommended to close device handles explicitly through a call to sane_close(), but backends are required to release all resources upon a call to this function). After this function returns, no function other than sane_init() may be called (regardless of the status value returned by sane_exit(). Neglecting to call this function may result in some resources not being released properly.
void sane_exit (void);