/* *	indirect driver for controlling tty. */#include "../h/param.h"#include "../h/conf.h"#include "../h/dir.h"#include "../h/user.h"#include "../h/tty.h"#include "../h/proc.h"syopen(dev, flag){	if(u.u_ttyp == NULL) {		u.u_error = ENXIO;		return;	}	(*cdevsw[major(u.u_ttyd)].d_open)(u.u_ttyd, flag);}syread(dev){	(*cdevsw[major(u.u_ttyd)].d_read)(u.u_ttyd);}sywrite(dev){	(*cdevsw[major(u.u_ttyd)].d_write)(u.u_ttyd);}sysioctl(dev, cmd, addr, flag)caddr_t addr;{	(*cdevsw[major(u.u_ttyd)].d_ioctl)(u.u_ttyd, cmd, addr, flag);}