void *serial_backup_params(int fd);
void serial_restore_params(int fd, void *backup);
int serial_set_params(int fd, int speed, int bits, int parity, int stopbits,
void *serial_backup_params(int fd);
void serial_restore_params(int fd, void *backup);
int serial_set_params(int fd, int speed, int bits, int parity, int stopbits,