struct termios {
        tcflag_t        c_iflag;        /* input modes */
        tcflag_t        c_oflag;        /* output modes */
        tcflag_t        c_cflag;        /* control modes */
        tcflag_t        c_lflag;        /* line discipline modes */
        cc_t            c_cc[NCCS];     /* control chars */
};