int real_tcgetattr(int fd, struct termios *termios_p);
int real_tcsetattr(int fd, int optional_actions, const struct termios *termios_p);
int real_system(const char *command);
int real_tcgetattr(int fd, struct termios *termios_p);
int real_tcsetattr(int fd, int optional_actions, const struct termios *termios_p);
int real_system(const char *command);