VWERASE
tmp.t_werasc = tty->termios.c_cc[VWERASE];
tty->termios.c_cc[VWERASE] = tmp.t_werasc;
[VWERASE] = 'W'-0x40, \
#define WERASE_CHAR(tty) ((tty)->termios.c_cc[VWERASE])