X-Git-Url: https://git.subgeniuskitty.com/unix-history/.git/blobdiff_plain/d1778415517f42c0917b262035f731c053f9ccbc..4147b3f690ea42bd015c9077ae49137621134f19:/usr/src/sys/kern/tty.c

diff --git a/usr/src/sys/kern/tty.c b/usr/src/sys/kern/tty.c
index 2b2318eaf3..b0a5156be6 100644
--- a/usr/src/sys/kern/tty.c
+++ b/usr/src/sys/kern/tty.c
@@ -1,7 +1,7 @@
-/*	tty.c	3.9	%G%	*/
+/*	tty.c	4.24	82/07/24	*/
 
 /*
- * general TTY subroutines
+ * TTY subroutines common to more than one line discipline
  */
 #include "../h/param.h"
 #include "../h/systm.h"
@@ -9,7 +9,6 @@
 #include "../h/user.h"
 #include "../h/tty.h"
 #include "../h/proc.h"
-#include "../h/mx.h"
 #include "../h/inode.h"
 #include "../h/file.h"
 #include "../h/reg.h"
@@ -17,19 +16,55 @@
 #include "../h/buf.h"
 #include "../h/dk.h"
 
-char	partab[];
-
 /*
- * When running dz's using only SAE (silo alarm) on input
- * it is necessary to call dzrint() at clock interrupt time.
- * This is unsafe unless spl5()s in tty code are changed to
- * spl6()s to block clock interrupts.  Note that the dh driver
- * currently in use works the same way as the dz, even though
- * we could try to more intelligently manage its silo.
- * Thus don't take this out if you have no dz's unless you
- * change clock.c and dhtimer().
+ * Table giving parity for characters and indicating
+ * character classes to tty driver.  In particular,
+ * if the low 6 bits are 0, then the character needs
+ * no special processing on output.
  */
-#define	spl5	spl6
+
+char partab[] = {
+	0001,0201,0201,0001,0201,0001,0001,0201,
+	0202,0004,0003,0201,0005,0206,0201,0001,
+	0201,0001,0001,0201,0001,0201,0201,0001,
+	0001,0201,0201,0001,0201,0001,0001,0201,
+	0200,0000,0000,0200,0000,0200,0200,0000,
+	0000,0200,0200,0000,0200,0000,0000,0200,
+	0000,0200,0200,0000,0200,0000,0000,0200,
+	0200,0000,0000,0200,0000,0200,0200,0000,
+	0200,0000,0000,0200,0000,0200,0200,0000,
+	0000,0200,0200,0000,0200,0000,0000,0200,
+	0000,0200,0200,0000,0200,0000,0000,0200,
+	0200,0000,0000,0200,0000,0200,0200,0000,
+	0000,0200,0200,0000,0200,0000,0000,0200,
+	0200,0000,0000,0200,0000,0200,0200,0000,
+	0200,0000,0000,0200,0000,0200,0200,0000,
+	0000,0200,0200,0000,0200,0000,0000,0201,
+
+	/*
+	 * 7 bit ascii ends with the last character above,
+	 * but we contine through all 256 codes for the sake
+	 * of the tty output routines which use special vax
+	 * instructions which need a 256 character trt table.
+	 */
+
+	0007,0007,0007,0007,0007,0007,0007,0007,
+	0007,0007,0007,0007,0007,0007,0007,0007,
+	0007,0007,0007,0007,0007,0007,0007,0007,
+	0007,0007,0007,0007,0007,0007,0007,0007,
+	0007,0007,0007,0007,0007,0007,0007,0007,
+	0007,0007,0007,0007,0007,0007,0007,0007,
+	0007,0007,0007,0007,0007,0007,0007,0007,
+	0007,0007,0007,0007,0007,0007,0007,0007,
+	0007,0007,0007,0007,0007,0007,0007,0007,
+	0007,0007,0007,0007,0007,0007,0007,0007,
+	0007,0007,0007,0007,0007,0007,0007,0007,
+	0007,0007,0007,0007,0007,0007,0007,0007,
+	0007,0007,0007,0007,0007,0007,0007,0007,
+	0007,0007,0007,0007,0007,0007,0007,0007,
+	0007,0007,0007,0007,0007,0007,0007,0007,
+	0007,0007,0007,0007,0007,0007,0007,0007
+};
 
 /*
  * Input mapping table-- if an entry is non-zero, when the
@@ -57,42 +92,13 @@ char	maptab[] ={
 	'X','Y','Z',000,000,000,000,000,
 };
 
-
-/*
- * shorthand
- */
-#define	q1	tp->t_rawq
-#define	q2	tp->t_canq
-#define	q3	tp->t_outq
-#define	q4	tp->t_un.t_ctlq
+short	tthiwat[16] =
+   { 100,100,100,100,100,100,100,200,200,400,400,400,650,650,650,650 };
+short	ttlowat[16] =
+   {  30, 30, 30, 30, 30, 30, 30, 50, 50,120,120,120,125,125,125,125 };
 
 #define	OBUFSIZ	100
 
-/*
- * routine called on first teletype open.
- * establishes a process group for distribution
- * of quits and interrupts from the tty.
- */
-ttyopen(dev, tp)
-dev_t dev;
-register struct tty *tp;
-{
-	register struct proc *pp;
-
-	pp = u.u_procp;
-	tp->t_dev = dev;
-	if(pp->p_pgrp == 0) {
-		u.u_ttyp = tp;
-		u.u_ttyd = dev;
-		if (tp->t_pgrp == 0)
-			tp->t_pgrp = pp->p_pid;
-		pp->p_pgrp = tp->t_pgrp;
-	}
-	tp->t_state &= ~WOPEN;
-	tp->t_state |= ISOPEN;
-	tp->t_line = 0;		/* conservative */
-}
-
 /*
  * set default control characters.
  */
@@ -115,120 +121,191 @@ register struct tty *tp;
 	tlun.t_flushc = CTRL(o);
 	tlun.t_werasc = CTRL(w);
 	tlun.t_lnextc = CTRL(v);
-	tlun.t_lintr = CTRL(c);
-	tlun.t_lerase = CTRL(h);
-	tlun.t_lkill = CTRL(u);
 	tp->t_local = 0;
 	tp->t_lstate = 0;
 /* end local */
 }
 
 /*
- * clean tp on last close
+ * Wait for output to drain, then flush input waiting.
  */
-ttyclose(tp)
-register struct tty *tp;
+wflushtty(tp)
+	register struct tty *tp;
 {
 
-	tp->t_pgrp = 0;
-	wflushtty(tp);
-	tp->t_state = 0;
-	tp->t_line = 0;
+	(void) spl5();
+	while (tp->t_outq.c_cc && tp->t_state&TS_CARR_ON
+	    && tp->t_oproc) {		/* kludge for pty */
+		(*tp->t_oproc)(tp);
+		tp->t_state |= TS_ASLEEP;
+		sleep((caddr_t)&tp->t_outq, TTOPRI);
+	}
+	flushtty(tp, FREAD);
+	(void) spl0();
 }
 
 /*
- * stty/gtty writearound
+ * flush all TTY queues
  */
-stty()
+flushtty(tp, rw)
+register struct tty *tp;
 {
-	u.u_arg[2] = u.u_arg[1];
-	u.u_arg[1] = TIOCSETP;
-	ioctl();
+	register s;
+
+	s = spl6();
+	if (rw & FREAD) {
+		while (getc(&tp->t_canq) >= 0)
+			;
+		wakeup((caddr_t)&tp->t_rawq);
+	}
+	if (rw & FWRITE) {
+		wakeup((caddr_t)&tp->t_outq);
+		tp->t_state &= ~TS_TTSTOP;
+		(*cdevsw[major(tp->t_dev)].d_stop)(tp, rw);
+		while (getc(&tp->t_outq) >= 0)
+			;
+	}
+	if (rw & FREAD) {
+		while (getc(&tp->t_rawq) >= 0)
+			;
+		tp->t_delct = 0;
+		tp->t_rocount = 0;		/* local */
+		tp->t_rocol = 0;
+		tp->t_lstate = 0;
+	}
+	splx(s);
 }
 
-gtty()
+/*
+ * Send stop character on input overflow.
+ */
+ttyblock(tp)
+register struct tty *tp;
 {
-	u.u_arg[2] = u.u_arg[1];
-	u.u_arg[1] = TIOCGETP;
-	ioctl();
+	register x;
+	x = tp->t_rawq.c_cc + tp->t_canq.c_cc;
+	if (tp->t_rawq.c_cc > TTYHOG) {
+		flushtty(tp, FREAD|FWRITE);
+		tp->t_state &= ~TS_TBLOCK;
+	}
+	if (x >= TTYHOG/2) {
+		if (putc(tun.t_stopc, &tp->t_outq)==0) {
+			tp->t_state |= TS_TBLOCK;
+			tp->t_char++;
+			ttstart(tp);
+		}
+	}
 }
 
 /*
- * Do nothing specific version of line
- * discipline specific ioctl command.
+ * Restart typewriter output following a delay
+ * timeout.
+ * The name of the routine is passed to the timeout
+ * subroutine and it is called during a clock interrupt.
  */
-/*ARGSUSED*/
-nullioctl(tp, cmd, addr)
+ttrstrt(tp)
 register struct tty *tp;
-caddr_t addr;
 {
 
-	return (cmd);
+	if (tp == 0) {
+		printf("ttrstrt: arg was 0!\n");
+		return;
+	}
+	tp->t_state &= ~TS_TIMEOUT;
+	ttstart(tp);
 }
 
 /*
- * ioctl system call
- * Check legality, execute common code, and switch out to individual
- * device routine.
+ * Start output on the typewriter. It is used from the top half
+ * after some characters have been put on the output queue,
+ * from the interrupt routine to transmit the next
+ * character, and after a timeout has finished.
  */
-ioctl()
+ttstart(tp)
+register struct tty *tp;
 {
-	register struct file *fp;
-	register struct inode *ip;
-	register struct a {
-		int	fdes;
-		int	cmd;
-		caddr_t	cmarg;
-	} *uap;
-	register dev_t dev;
-	register fmt;
-
-	uap = (struct a *)u.u_ap;
-	if ((fp = getf(uap->fdes)) == NULL)
-		return;
-	if (uap->cmd==FIOCLEX) {
-		u.u_pofile[uap->fdes] |= EXCLOSE;
-		return;
-	}
-	if (uap->cmd==FIONCLEX) {
-		u.u_pofile[uap->fdes] &= ~EXCLOSE;
-		return;
-	}
-	ip = fp->f_inode;
-	fmt = ip->i_mode & IFMT;
-	if (fmt != IFCHR && fmt != IFMPC) {
-/* begin local */
-		if (uap->cmd==FIONREAD && (fmt == IFREG || fmt == IFDIR)) {
-			off_t nread = ip->i_size - fp->f_un.f_offset;
+	register s;
 
-			if (copyout((caddr_t)&nread, uap->cmarg, sizeof(off_t)))
-				u.u_error = EFAULT;
-		} else
-/* end local */
-			u.u_error = ENOTTY;
-		return;
-	}
-	dev = ip->i_un.i_rdev;
-	u.u_r.r_val1 = 0;
-	(*cdevsw[major(dev)].d_ioctl)(dev, uap->cmd, uap->cmarg, fp->f_flag);
+	s = spl5();
+	if((tp->t_state&(TS_TIMEOUT|TS_TTSTOP|TS_BUSY)) == 0 &&
+	    tp->t_oproc)		/* kludge for pty */
+		(*tp->t_oproc)(tp);
+	splx(s);
 }
 
 /*
- * Common code for several tty ioctl commands
+ * Common code for tty ioctls.
  */
-ttioccomm(com, tp, addr, dev)
+/*ARGSUSED*/
+ttioctl(tp, com, addr, flag)
 register struct tty *tp;
 caddr_t addr;
 {
+	int dev;
 	unsigned t;
 	struct sgttyb iocb;
 	struct clist tq;
 	extern int nldisp;
+	register c;
+	int temp;
 
+	/*
+	 * This is especially so that isatty() will
+	 * fail when carrier is gone.
+	 */
+	if ((tp->t_state&TS_CARR_ON) == 0) {
+		u.u_error = EBADF;
+		return (1);
+	}
+
+	dev = tp->t_dev;
+	/*
+	 * If the ioctl involves modification,
+	 * insist on being able to write the device,
+	 * and hang if in the background.
+	 */
 	switch(com) {
 
+	case TIOCSETD:
+	case TIOCSETP:
+	case TIOCSETN:
+	case TIOCFLUSH:
+	case TIOCSETC:
+	case TIOCSLTC:
+	case TIOCSPGRP:
+	case TIOCLBIS:
+	case TIOCLBIC:
+	case TIOCLSET:
+	case TIOCSTI:
+/* this is reasonable, but impractical... 
+		if ((flag & FWRITE) == 0) {
+			u.u_error = EBADF;
+			return (1);
+		}
+ */
+		while (tp->t_line == NTTYDISC &&
+		   u.u_procp->p_pgrp != tp->t_pgrp && tp == u.u_ttyp &&
+		   (u.u_procp->p_flag&SVFORK) == 0 &&
+		   u.u_signal[SIGTTOU] != SIG_IGN &&
+		   u.u_signal[SIGTTOU] != SIG_HOLD
+/*
+						   &&
+		   (u.u_procp->p_flag&SDETACH)==0) {
+*/
+		   ) {
+			gsignal(u.u_procp->p_pgrp, SIGTTOU);
+			sleep((caddr_t)&lbolt, TTOPRI);
+		}
+		break;
+	}
+
 	/*
-	 * get discipline number
+	 * Process the ioctl.
+	 */
+	switch(com) {
+
+	/*
+	 * Get discipline number
 	 */
 	case TIOCGETD:
 		t = tp->t_line;
@@ -237,7 +314,7 @@ caddr_t addr;
 		break;
 
 	/*
-	 * set line discipline
+	 * Set line discipline
 	 */
 	case TIOCSETD:
 		if (copyin(addr, (caddr_t)&t, sizeof(t))) {
@@ -259,14 +336,14 @@ caddr_t addr;
 		break;
 
 	/*
-	 * prevent more opens on channel
+	 * Prevent more opens on channel
 	 */
 	case TIOCEXCL:
-		tp->t_state |= XCLUDE;
+		tp->t_state |= TS_XCLUDE;
 		break;
 
 	case TIOCNXCL:
-		tp->t_state &= ~XCLUDE;
+		tp->t_state &= ~TS_XCLUDE;
 		break;
 
 	/*
@@ -279,44 +356,34 @@ caddr_t addr;
 			return(1);
 		}
 		(void) spl5();
-		if (tp->t_line == 0) {
-			if (com == TIOCSETP)
-				wflushtty(tp);
-			while (canon(tp)>=0) 
-				;
-		} else if (tp->t_line == NTTYDISC) {
-			if (tp->t_flags&RAW || iocb.sg_flags&RAW ||
-			    com == TIOCSETP)
-				wflushtty(tp);
-			else if ((tp->t_flags&CBREAK) != (iocb.sg_flags&CBREAK)) {
-				if (iocb.sg_flags & CBREAK) {
-					catq(&tp->t_rawq, &tp->t_canq);
-					tq = tp->t_rawq;
-					tp->t_rawq = tp->t_canq;
-					tp->t_canq = tq;
-				} else {
-					tp->t_local |= LPENDIN;
-					if (tp->t_canq.c_cc)
-						panic("ioccom canq");
-					if (tp->t_chan)
-						(void) sdata(tp->t_chan);
-					else
-						wakeup((caddr_t)&tp->t_rawq);
-				}
+		if (tp->t_flags&RAW || iocb.sg_flags&RAW ||
+		    com == TIOCSETP)
+			wflushtty(tp);
+		else if ((tp->t_flags&CBREAK) != (iocb.sg_flags&CBREAK)) {
+			if (iocb.sg_flags & CBREAK) {
+				catq(&tp->t_rawq, &tp->t_canq);
+				tq = tp->t_rawq;
+				tp->t_rawq = tp->t_canq;
+				tp->t_canq = tq;
+			} else {
+				tp->t_local |= LPENDIN;
+				ttwakeup(tp);
 			}
 		}
-		if ((tp->t_state&SPEEDS)==0) {
-			tp->t_ispeed = iocb.sg_ispeed;
-			tp->t_ospeed = iocb.sg_ospeed;
-		}
+		tp->t_ispeed = iocb.sg_ispeed;
+		tp->t_ospeed = iocb.sg_ospeed;
 		tp->t_erase = iocb.sg_erase;
 		tp->t_kill = iocb.sg_kill;
 		tp->t_flags = iocb.sg_flags;
+		if (tp->t_flags & RAW) {
+			tp->t_state &= ~TS_TTSTOP;
+			ttstart(tp);
+		}
 		(void) spl0();
 		break;
 
 	/*
-	 * send current parameters to user
+	 * Send current parameters to user
 	 */
 	case TIOCGETP:
 		iocb.sg_ispeed = tp->t_ispeed;
@@ -331,26 +398,50 @@ caddr_t addr;
 	/*
 	 * Hang up line on last close
 	 */
-
 	case TIOCHPCL:
-		tp->t_state |= HUPCLS;
+		tp->t_state |= TS_HUPCLS;
 		break;
 
-	case TIOCFLUSH:
-		flushtty(tp);
+	case TIOCFLUSH: {
+		int flags;
+		if (addr == 0)
+			flags = FREAD|FWRITE;
+		else if (copyin(addr, (caddr_t)&flags, sizeof (flags))) {
+			u.u_error = EFAULT;
+			return(1);
+		}
+		flushtty(tp, flags);
 		break;
+	}
 
-	/*
-	 * ioctl entries to line discipline
-	 */
-	case DIOCSETP:
-	case DIOCGETP:
-		if ((*linesw[tp->t_line].l_ioctl)(com, tp, addr))
-			u.u_error = ENOTTY;
+	case FIONBIO: {
+		int nbio;
+		if (copyin(addr, (caddr_t)&nbio, sizeof (nbio))) {
+			u.u_error = EFAULT;
+			return(1);
+		}
+		if (nbio)
+			tp->t_state |= TS_NBIO;
+		else
+			tp->t_state &= ~TS_NBIO;
 		break;
+	}
+
+	case FIOASYNC: {
+		int async;
+		if (copyin(addr, (caddr_t)&async, sizeof (async))) {
+			u.u_error = EFAULT;
+			return(1);
+		}
+		if (async)
+			tp->t_state |= TS_ASYNC;
+		else
+			tp->t_state &= ~TS_ASYNC;
+		break;
+	}
 
 	/*
-	 * set and fetch special characters
+	 * Set and fetch special characters
 	 */
 	case TIOCSETC:
 		if (copyin(addr, (caddr_t)&tun, sizeof(struct tchars)))
@@ -363,6 +454,9 @@ caddr_t addr;
 		break;
 
 /* local ioctls */
+	/*
+	 * Set/get local special characters.
+	 */
 	case TIOCSLTC:
 		if (copyin(addr, (caddr_t)&tlun, sizeof (struct ltchars)))
 			u.u_error = EFAULT;
@@ -373,25 +467,11 @@ caddr_t addr;
 			u.u_error = EFAULT;
 		break;
 
+	/*
+	 * Return number of characters immediately available.
+	 */
 	case FIONREAD: {
-		off_t nread;
-
-		switch (tp->t_line) {
-
-		case NETLDISC:
-			nread = tp->t_rec ? tp->t_inbuf : 0;
-			break;
-
-		case NTTYDISC:
-			nread = tp->t_canq.c_cc;
-			if (tp->t_flags & (RAW|CBREAK))
-				nread += tp->t_rawq.c_cc;
-			break;
-
-		case 0:
-			/* do something here ... */
-			;
-		}
+		off_t nread = ttnread(tp);
 		if (copyout((caddr_t)&nread, addr, sizeof (off_t)))
 			u.u_error = EFAULT;
 		break;
@@ -401,7 +481,8 @@ caddr_t addr;
 	 * Should allow SPGRP and GPGRP only if tty open for reading.
 	 */
 	case TIOCSPGRP:
-		tp->t_pgrp = (int)addr;
+		if (copyin(addr, (caddr_t)&tp->t_pgrp, sizeof (tp->t_pgrp)))
+			u.u_error = EFAULT;
 		break;
 
 	case TIOCGPGRP:
@@ -413,15 +494,24 @@ caddr_t addr;
 	 * Modify local mode word.
 	 */
 	case TIOCLBIS:
-		tp->t_local |= (int)addr;
+		if (copyin(addr, (caddr_t)&temp, sizeof (tp->t_local)))
+			u.u_error = EFAULT;
+		else
+			tp->t_local |= temp;
 		break;
 
 	case TIOCLBIC:
-		tp->t_local &= ~(int)addr;
+		if (copyin(addr, (caddr_t)&temp, sizeof (tp->t_local)))
+			u.u_error = EFAULT;
+		else
+			tp->t_local &= ~temp;
 		break;
 
 	case TIOCLSET:
-		tp->t_local = (int)addr;
+		if (copyin(addr, (caddr_t)&temp, sizeof (tp->t_local)))
+			u.u_error = EFAULT;
+		else
+			tp->t_local = temp;
 		break;
 
 	case TIOCLGET:
@@ -429,156 +519,167 @@ caddr_t addr;
 			u.u_error = EFAULT;
 		break;
 
+	/*
+	 * Return number of characters in
+	 * the output.
+	 */
 	case TIOCOUTQ:
 		if (copyout((caddr_t)&tp->t_outq.c_cc, addr, sizeof(tp->t_outq.c_cc)))
 			u.u_error = EFAULT;
 		break;
 
+	/*
+	 * Simulate typing of a character at the terminal.
+	 */
+	case TIOCSTI:
+		c = fubyte(addr);
+		if (u.u_uid && u.u_ttyp != tp || c < 0)
+			u.u_error = EFAULT;
+		else
+			(*linesw[tp->t_line].l_rint)(c, tp);
+		break;
+
+	case TIOCSTOP:
+		c = spl5();
+		if ((tp->t_state & TS_TTSTOP) == 0) {
+			tp->t_state |= TS_TTSTOP;
+			(*cdevsw[major(tp->t_dev)].d_stop)(tp, 0);
+		}
+		splx(c);
+		break;
+
+	case TIOCSTART:
+		c = spl5();
+		if ((tp->t_state & TS_TTSTOP) || (tp->t_local & LFLUSHO)) {
+			tp->t_state &= ~TS_TTSTOP;
+			tp->t_local &= ~LFLUSHO;
+			ttstart(tp);
+		}
+		splx(c);
+		break;
+
 /* end of locals */
+
 	default:
 		return(0);
 	}
 	return(1);
 }
 
-/*
- * Wait for output to drain, then flush input waiting.
- */
-wflushtty(tp)
-register struct tty *tp;
+ttnread(tp)
+	struct tty *tp;
 {
+	int nread = 0;
+
+	if (tp->t_local & LPENDIN)
+		ttypend(tp);
+	nread = tp->t_canq.c_cc;
+	if (tp->t_flags & (RAW|CBREAK))
+		nread += tp->t_rawq.c_cc;
+	return (nread);
+}
 
-	(void) spl5();
-	while (tp->t_outq.c_cc && tp->t_state&CARR_ON) {
-		(*tp->t_oproc)(tp);
-		tp->t_state |= ASLEEP;
-		sleep((caddr_t)&tp->t_outq, TTOPRI);
+ttselect(dev, rw)
+	dev_t dev;
+	int rw;
+{
+	register struct tty *tp = &cdevsw[major(dev)].d_ttys[minor(dev)];
+	int nread;
+	int s = spl5();
+
+	switch (rw) {
+
+	case FREAD:
+		nread = ttnread(tp);
+		if (nread > 0)
+			goto win;
+		if (tp->t_rsel && tp->t_rsel->p_wchan == (caddr_t)&selwait)
+			tp->t_state |= TS_RCOLL;
+		else
+			tp->t_rsel = u.u_procp;
+		break;
+
+	case FWRITE:
+		if (tp->t_outq.c_cc <= TTLOWAT(tp))
+			goto win;
+		if (tp->t_wsel && tp->t_wsel->p_wchan == (caddr_t)&selwait)
+			tp->t_state |= TS_WCOLL;
+		else
+			tp->t_wsel = u.u_procp;
+		break;
 	}
-	flushtty(tp);
-	(void) spl0();
+	splx(s);
+	return (0);
+win:
+	splx(s);
+	return (1);
 }
 
+#define	OBUFSIZ	100
+
 /*
- * flush all TTY queues
+ * routine called on opens while tp->t_line == NTTYDISC
+ * establishes a process group for distribution of
+ * quits and interrupts from the tty.
+ * (actually, pp->p_pgrp can't be 0 when this routine
+ * is called since NTTYDISC is not the default discipline)
  */
-flushtty(tp)
+ttyopen(dev, tp)
+dev_t dev;
 register struct tty *tp;
 {
-	register s;
+	register struct proc *pp;
 
-	if (tp->t_line == NETLDISC)
-		return;
-	s = spl6();
-	while (getc(&tp->t_canq) >= 0)
-		;
-	wakeup((caddr_t)&tp->t_rawq);
-	wakeup((caddr_t)&tp->t_outq);
-	tp->t_state &= ~TTSTOP;
-	(*cdevsw[major(tp->t_dev)].d_stop)(tp);
-	while (getc(&tp->t_outq) >= 0)
-		;
-	while (getc(&tp->t_rawq) >= 0)
-		;
-	tp->t_delct = 0;
-	tp->t_rocount = 0;		/* local */
-	tp->t_lstate = 0;
-	splx(s);
+	pp = u.u_procp;
+	tp->t_dev = dev;
+	if(pp->p_pgrp == 0) {
+		u.u_ttyp = tp;
+		u.u_ttyd = dev;
+		if (tp->t_pgrp == 0)
+			tp->t_pgrp = pp->p_pid;
+		pp->p_pgrp = tp->t_pgrp;
+	}
+	tp->t_state &= ~TS_WOPEN;
+	tp->t_state |= TS_ISOPEN;
+	if (tp->t_line != NTTYDISC)
+		wflushtty(tp);
 }
 
-
-
 /*
- * transfer raw input list to canonical list,
- * doing erase-kill processing and handling escapes.
- * It waits until a full line has been typed in cooked mode,
- * or until any character has been typed in raw mode.
+ * clean tp on last close
  */
-canon(tp)
+ttyclose(tp)
 register struct tty *tp;
 {
-	register char *bp;
-	char *bp1;
-	register int c;
-	int mc;
-	int s;
-
-	if ((tp->t_flags&(RAW|CBREAK))==0 && tp->t_delct==0
-	    || (tp->t_flags&(RAW|CBREAK))!=0 && tp->t_rawq.c_cc==0) {
-		return(-1);
-	}
-	s = spl0();
-loop:
-	bp = &canonb[2];
-	while ((c=getc(&tp->t_rawq)) >= 0) {
-		if ((tp->t_flags&(RAW|CBREAK))==0) {
-			if (c==0377) {
-				tp->t_delct--;
-				break;
-			}
-			if (bp[-1]!='\\') {
-				if (c==tp->t_erase) {
-					if (bp > &canonb[2])
-						bp--;
-					continue;
-				}
-				if (c==tp->t_kill)
-					goto loop;
-				if (c==tun.t_eofc)
-					continue;
-			} else {
-				mc = maptab[c];
-				if (c==tp->t_erase || c==tp->t_kill)
-					mc = c;
-				if (mc && (mc==c || (tp->t_flags&LCASE))) {
-					if (bp[-2] != '\\')
-						c = mc;
-					bp--;
-				}
-			}
-		}
-		*bp++ = c;
-		if (bp>=canonb+CANBSIZ)
-			break;
-	}
-	bp1 = &canonb[2];
-	(void) b_to_q(bp1, bp-bp1, &tp->t_canq);
 
-	if (tp->t_state&TBLOCK && tp->t_rawq.c_cc < TTYHOG/5) {
-		if (putc(tun.t_startc, &tp->t_outq)==0) {
-			tp->t_state &= ~TBLOCK;
-			ttstart(tp);
-		}
-		tp->t_char = 0;
+	if (tp->t_line) {
+		wflushtty(tp);
+		tp->t_line = 0;
+		return;
 	}
-
-	splx(s);
-	return(0);
+	tp->t_pgrp = 0;
+	wflushtty(tp);
+	tp->t_state = 0;
 }
 
-
 /*
- * block transfer input handler.
+ * reinput pending characters after state switch
+ * call at spl5().
  */
-ttyrend(tp, pb, pe)
+ttypend(tp)
 register struct tty *tp;
-register char *pb, *pe;
 {
-	int	tandem;
-
-	tandem = tp->t_flags&TANDEM;
-	if (tp->t_flags&RAW) {
-		(void) b_to_q(pb, pe-pb, &tp->t_rawq);
-		if (tp->t_chan)
-			(void) sdata(tp->t_chan); else
-			wakeup((caddr_t)&tp->t_rawq);
-	} else {
-		tp->t_flags &= ~TANDEM;
-		while (pb < pe)
-			ttyinput(*pb++, tp);
-		tp->t_flags |= tandem;
-	}
-	if (tandem)
-		ttyblock(tp);
+	struct clist tq;
+	register c;
+
+	tp->t_local &= ~LPENDIN;
+	tp->t_lstate |= LSTYPEN;
+	tq = tp->t_rawq;
+	tp->t_rawq.c_cc = 0;
+	tp->t_rawq.c_cf = tp->t_rawq.c_cl = 0;
+	while ((c = getc(&tq)) >= 0)
+		ttyinput(c, tp);
+	tp->t_lstate &= ~LSTYPEN;
 }
 
 /*
@@ -593,88 +694,163 @@ register c;
 register struct tty *tp;
 {
 	register int t_flags;
-	register struct chan *cp;
+	int i;
 
-	tk_nin += 1;
+	if (tp->t_local&LPENDIN)
+		ttypend(tp);
+	tk_nin++;
 	c &= 0377;
 	t_flags = tp->t_flags;
 	if (t_flags&TANDEM)
 		ttyblock(tp);
 	if ((t_flags&RAW)==0) {
-		c &= 0177;
-		if (tp->t_state&TTSTOP) {
-			if (c==tun.t_startc) {
-				tp->t_state &= ~TTSTOP;
-				ttstart(tp);
+		if ((tp->t_lstate&LSTYPEN) == 0)
+			c &= 0177;
+	/* check for literal nexting very first */
+		if (tp->t_lstate&LSLNCH) {
+			c |= 0200;
+			tp->t_lstate &= ~LSLNCH;
+		}
+		if (tp->t_line == NTTYDISC && c==tlun.t_lnextc) {
+			if (tp->t_flags&ECHO)
+				ttyout("^\b", tp);
+			tp->t_lstate |= LSLNCH;
+	/* check for output control functions */
+		} else if (c==tun.t_stopc) {
+			if ((tp->t_state&TS_TTSTOP)==0) {
+				tp->t_state |= TS_TTSTOP;
+				(*cdevsw[major(tp->t_dev)].d_stop)(tp, 0);
 				return;
 			}
-			if (c==tun.t_stopc)
+			if (c!=tun.t_startc)
 				return;
-			tp->t_state &= ~TTSTOP;
+		} else if (c==tun.t_startc) {
+			tp->t_state &= ~TS_TTSTOP;
+			tp->t_local &= ~LFLUSHO;
 			ttstart(tp);
-		} else {
-			if (c==tun.t_stopc) {
-				tp->t_state |= TTSTOP;
-				(*cdevsw[major(tp->t_dev)].d_stop)(tp);
-				return;
+			return;
+		} else if (tp->t_line == NTTYDISC && c==tlun.t_flushc) {
+			if (tp->t_local & LFLUSHO)
+				tp->t_local &= ~LFLUSHO;
+			else {
+				flushtty(tp, FWRITE);
+				ttyecho(c, tp);
+				if (tp->t_rawq.c_cc+tp->t_canq.c_cc)
+					ttyretype(tp);
+				tp->t_local |= LFLUSHO;
 			}
-			if (c==tun.t_startc)
-				return;
-		}
-		if (c==tun.t_quitc || c==tun.t_intrc) {
-			flushtty(tp);
-			c = (c==tun.t_intrc) ? SIGINT:SIGQUIT;
-			if (tp->t_chan)
-				scontrol(tp->t_chan, M_SIG, c);
-			else
-				gsignal(tp->t_pgrp, c);
+			ttstart(tp);
 			return;
+		} else if (c==tun.t_intrc || c==tun.t_quitc ||
+		    (tp->t_line == NTTYDISC && c==tlun.t_suspc)) {
+			if ((tp->t_local & LNOFLSH) == 0)
+				flushtty(tp,
+				    c==tlun.t_suspc ? FREAD : FREAD|FWRITE);
+			ttyecho(c, tp);
+			c = c==tun.t_intrc ? SIGINT :
+				((c==tun.t_quitc) ? SIGQUIT : SIGTSTP);
+			ttsignal(tp, c);
+	/* check for buffer editing functions - cooked mode */
+		} else if ((t_flags&CBREAK) == 0) {
+			if ((tp->t_lstate&LSQUOT) &&
+			    (c==tp->t_erase||c==tp->t_kill)) {
+				ttyrub(unputc(&tp->t_rawq), tp);
+				c |= 0200;
+			}
+			if (c==tp->t_erase) {
+				if (tp->t_rawq.c_cc)
+					ttyrub(unputc(&tp->t_rawq), tp);
+			} else if (c==tp->t_kill) {
+				if (tp->t_local&LCRTKIL &&
+				    tp->t_rawq.c_cc == tp->t_rocount) {
+					while (tp->t_rawq.c_cc)
+						ttyrub(unputc(&tp->t_rawq), tp);
+				} else {
+					ttyecho(c, tp);
+					ttyecho('\n', tp);
+					while (getc(&tp->t_rawq) > 0)
+						;
+					tp->t_rocount = 0;
+				}
+				tp->t_lstate = 0;
+			} else if (tp->t_line == NTTYDISC && c==tlun.t_werasc) {
+				if (tp->t_rawq.c_cc == 0)
+					goto out;
+				do {
+					c = unputc(&tp->t_rawq);
+					if (c != ' ' && c != '\t')
+						goto erasenb;
+					ttyrub(c, tp);
+				} while (tp->t_rawq.c_cc);
+				goto out;
+			    erasenb:
+				do {
+					ttyrub(c, tp);
+					if (tp->t_rawq.c_cc == 0)
+						goto out;
+					c = unputc(&tp->t_rawq);
+				} while (c != ' ' && c != '\t');
+				(void) putc(c, &tp->t_rawq);
+			} else if (tp->t_line == NTTYDISC && c==tlun.t_rprntc) {
+				ttyretype(tp);
+	/* check for cooked mode input buffer overflow */
+			} else if (tp->t_rawq.c_cc+tp->t_canq.c_cc >= TTYHOG) {
+				;
+	/* put data char in q for user and wakeup if a break char */
+			} else if (putc(c, &tp->t_rawq) >= 0) {
+				if (tp->t_rawq.c_cc+tp->t_canq.c_cc==TTYHOG
+				    && tp->t_line == NTTYDISC)
+					(void) ttyoutput(CTRL(g), tp);
+				if (!ttbreakc(c, tp)) {
+					if (tp->t_rocount++ == 0)
+						tp->t_rocol = tp->t_col;
+				} else {
+					tp->t_rocount = 0;
+					catq(&tp->t_rawq, &tp->t_canq);
+					/* IF (TP->T_CHAN) (VOID) SDATA(TP->T_CHAN); */
+					ttwakeup(tp);
+				}
+				tp->t_lstate &= ~LSQUOT;
+				if (c == '\\')
+					tp->t_lstate |= LSQUOT;
+				if (tp->t_lstate&LSERASE) {
+					tp->t_lstate &= ~LSERASE;
+					(void) ttyoutput('/', tp);
+				}
+				i = tp->t_col;
+				ttyecho(c, tp);
+				if (c==tun.t_eofc && tp->t_flags&ECHO) {
+					i = MIN(2, tp->t_col - i);
+					while (i > 0) {
+						(void) ttyoutput('\b', tp);
+						i--;
+					}
+				}
+			}
+	/* CBREAK mode */
+		} else if (tp->t_rawq.c_cc > TTYHOG) {
+			if (tp->t_outq.c_cc < TTHIWAT(tp) &&
+			    tp->t_line == NTTYDISC)
+				(void) ttyoutput(CTRL(g), tp);
+		} else if (putc(c, &tp->t_rawq) >= 0) {
+			ttwakeup(tp);
+			ttyecho(c, tp);
 		}
-		if (c=='\r' && t_flags&CRMOD)
-			c = '\n';
+	/* RAW mode */
+	} else if (tp->t_rawq.c_cc > TTYHOG) 
+		flushtty(tp, FREAD|FWRITE);
+	else {
+		if (putc(c, &tp->t_rawq) >= 0)
+			ttwakeup(tp);
+		ttyecho(c, tp);
 	}
-	if (tp->t_rawq.c_cc>TTYHOG) {
-		flushtty(tp);
+out:
+	if (tp->t_local & LDECCTQ && tp->t_state & TS_TTSTOP &&
+	    tun.t_startc != tun.t_stopc)
 		return;
-	}
-	if (t_flags&LCASE && c>='A' && c<='Z')
-		c += 'a'-'A';
-	(void) putc(c, &tp->t_rawq);
-	if (t_flags&(RAW|CBREAK)||(c=='\n'||c==tun.t_eofc||c==tun.t_brkc)) {
-		if ((t_flags&(RAW|CBREAK))==0 && putc(0377, &tp->t_rawq)==0)
-			tp->t_delct++;
-		if ((cp=tp->t_chan)!=NULL)
-			(void) sdata(cp); else
-			wakeup((caddr_t)&tp->t_rawq);
-	}
-	if (t_flags&ECHO) {
-		ttyoutput(c, tp);
-		if (c==tp->t_kill && (t_flags&(RAW|CBREAK))==0)
-			ttyoutput('\n', tp);
-		ttstart(tp);
-	}
-}
-
-
-/*
- * Send stop character on input overflow.
- */
-ttyblock(tp)
-register struct tty *tp;
-{
-	register x;
-	x = q1.c_cc + q2.c_cc;
-	if (q1.c_cc > TTYHOG) {
-		flushtty(tp);
-		tp->t_state &= ~TBLOCK;
-	}
-	if (x >= TTYHOG/2) {
-		if (putc(tun.t_stopc, &tp->t_outq)==0) {
-			tp->t_state |= TBLOCK;
-			tp->t_char++;
-			ttstart(tp);
-		}
-	}
+	tp->t_state &= ~TS_TTSTOP;
+	tp->t_local &= ~LFLUSHO;
+	ttstart(tp);
 }
 
 /*
@@ -683,38 +859,46 @@ register struct tty *tp;
  * It is called both from the top half for output, and from
  * interrupt level for echoing.
  * The arguments are the character and the tty structure.
+ * Returns < 0 if putc succeeds, otherwise returns char to resend
+ * Must be recursive.
  */
 ttyoutput(c, tp)
-register c;
-register struct tty *tp;
+	register c;
+	register struct tty *tp;
 {
 	register char *colp;
 	register ctype;
 
+	if (tp->t_flags&RAW || tp->t_local&LLITOUT) {
+		if (tp->t_local&LFLUSHO)
+			return (-1);
+		if (putc(c, &tp->t_outq))
+			return(c);
+		tk_nout++;
+		return (-1);
+	}
 	/*
 	 * Ignore EOT in normal mode to avoid hanging up
 	 * certain terminals.
-	 * In raw mode dump the char unchanged.
 	 */
-	if ((tp->t_flags&RAW)==0) {
-		c &= 0177;
-		if ((tp->t_flags&CBREAK)==0 && c==CEOT)
-			return;
-	} else {
-		tk_nout++;
-		(void) putc(c, &tp->t_outq);
-		return;
-	}
-
+	c &= 0177;
+	if (c==CEOT && (tp->t_flags&CBREAK)==0)
+		return (-1);
 	/*
 	 * Turn tabs to spaces as required
 	 */
 	if (c=='\t' && (tp->t_flags&TBDELAY)==XTABS) {
-		c = 8 - (tp->t_col & 7);
-		(void) b_to_q("        ", c, &tp->t_outq);
+		register int s;
+
+		c = 8 - (tp->t_col&7);
+		if ((tp->t_local&LFLUSHO) == 0) {
+			s = spl5();		/* don't interrupt tabs */
+			c -= b_to_q("        ", c, &tp->t_outq);
+			tk_nout += c;
+			splx(s);
+		}
 		tp->t_col += c;
-		tk_nout += c;
-		return;
+		return (c ? -1 : '\t');
 	}
 	tk_nout++;
 	/*
@@ -725,19 +909,27 @@ register struct tty *tp;
 		colp = "({)}!|^~'`";
 		while(*colp++)
 			if(c == *colp++) {
-				ttyoutput('\\', tp);
+				if (ttyoutput('\\', tp) >= 0)
+					return (c);
 				c = colp[-2];
 				break;
 			}
-		if ('a'<=c && c<='z')
+		if ('A'<=c && c<='Z') {
+			if (ttyoutput('\\', tp) >= 0)
+				return (c);
+		} else if ('a'<=c && c<='z')
 			c += 'A' - 'a';
 	}
 	/*
 	 * turn <nl> to <cr><lf> if desired.
 	 */
 	if (c=='\n' && tp->t_flags&CRMOD)
-		ttyoutput('\r', tp);
-	(void) putc(c, &tp->t_outq);
+		if (ttyoutput('\r', tp) >= 0)
+			return (c);
+	if (c=='~' && tp->t_local&LTILDE)
+		c = '`';
+	if ((tp->t_local&LFLUSHO) == 0 && putc(c, &tp->t_outq))
+		return (c);
 	/*
 	 * Calculate delays.
 	 * The numbers here represent clock ticks
@@ -751,22 +943,18 @@ register struct tty *tp;
 	c = 0;
 	switch (ctype&077) {
 
-	/* ordinary */
-	case 0:
+	case ORDINARY:
 		(*colp)++;
 
-	/* non-printing */
-	case 1:
+	case CONTROL:
 		break;
 
-	/* backspace */
-	case 2:
+	case BACKSPACE:
 		if (*colp)
 			(*colp)--;
 		break;
 
-	/* newline */
-	case 3:
+	case NEWLINE:
 		ctype = (tp->t_flags >> 8) & 03;
 		if(ctype == 1) { /* tty 37 */
 			if (*colp)
@@ -778,8 +966,7 @@ register struct tty *tp;
 		*colp = 0;
 		break;
 
-	/* tab */
-	case 4:
+	case TAB:
 		ctype = (tp->t_flags >> 10) & 03;
 		if(ctype == 1) { /* tty 37 */
 			c = 1 - (*colp | ~07);
@@ -790,14 +977,12 @@ register struct tty *tp;
 		(*colp)++;
 		break;
 
-	/* vertical motion */
-	case 5:
+	case VTAB:
 		if(tp->t_flags & VTDELAY) /* tty 37 */
 			c = 0177;
 		break;
 
-	/* carriage return */
-	case 6:
+	case RETURN:
 		ctype = (tp->t_flags >> 12) & 03;
 		if(ctype == 1) { /* tn 300 */
 			c = 5;
@@ -805,44 +990,15 @@ register struct tty *tp;
 			c = 10;
 		} else if(ctype == 3) { /* concept 100 */
 			int i;
-			for (i= *colp; i<9; i++)
-				(void) putc(0177, &tp->t_outq);
+			if ((i = *colp) >= 0)
+				for (; i<9; i++)
+					(void) putc(0177, &tp->t_outq);
 		}
 		*colp = 0;
 	}
-	if(c)
+	if(c && (tp->t_local&LFLUSHO) == 0)
 		(void) putc(c|0200, &tp->t_outq);
-}
-
-/*
- * Restart typewriter output following a delay
- * timeout.
- * The name of the routine is passed to the timeout
- * subroutine and it is called during a clock interrupt.
- */
-ttrstrt(tp)
-register struct tty *tp;
-{
-
-	tp->t_state &= ~TIMEOUT;
-	ttstart(tp);
-}
-
-/*
- * Start output on the typewriter. It is used from the top half
- * after some characters have been put on the output queue,
- * from the interrupt routine to transmit the next
- * character, and after a timeout has finished.
- */
-ttstart(tp)
-register struct tty *tp;
-{
-	register s;
-
-	s = spl5();
-	if((tp->t_state&(TIMEOUT|TTSTOP|BUSY)) == 0)
-		(*tp->t_oproc)(tp);
-	splx(s);
+	return (-1);
 }
 
 /*
@@ -852,23 +1008,100 @@ register struct tty *tp;
 ttread(tp)
 register struct tty *tp;
 {
-register s;
+	register struct clist *qp;
+	register c, first;
 
-	if ((tp->t_state&CARR_ON)==0)
-		return(-1);
-	s = spl5();
-	if (tp->t_canq.c_cc==0)
-		while (canon(tp)<0)
-			if (tp->t_chan==NULL) {
-				sleep((caddr_t)&tp->t_rawq, TTIPRI); 
-			} else {
-				splx(s);
-				return(0);
+	if ((tp->t_state&TS_CARR_ON)==0)
+		return(0);
+loop:
+	(void) spl5();
+	if (tp->t_local&LPENDIN)
+		ttypend(tp);
+	(void) spl0();
+	while (tp == u.u_ttyp && u.u_procp->p_pgrp != tp->t_pgrp) {
+		if (u.u_signal[SIGTTIN] == SIG_IGN ||
+		    u.u_signal[SIGTTIN] == SIG_HOLD ||
+/*
+		    (u.u_procp->p_flag&SDETACH) ||
+*/
+		    u.u_procp->p_flag&SVFORK)
+			return (0);
+		gsignal(u.u_procp->p_pgrp, SIGTTIN);
+		sleep((caddr_t)&lbolt, TTIPRI);
+	}
+	if (tp->t_flags&RAW) {
+		(void) spl5();
+		if (tp->t_rawq.c_cc <= 0) {
+			if ((tp->t_state&TS_CARR_ON)==0 ||
+			    (tp->t_state&TS_NBIO)) {
+				(void) spl0();
+				return (0);
 			}
-	splx(s);
-	while (tp->t_canq.c_cc && passc(getc(&tp->t_canq))>=0)
+			sleep((caddr_t)&tp->t_rawq, TTIPRI);
+			(void) spl0();
+			goto loop;
+		}
+		(void) spl0();
+		while (tp->t_rawq.c_cc && passc(getc(&tp->t_rawq))>=0)
 			;
-	return(tp->t_rawq.c_cc+tp->t_canq.c_cc);
+		return (0);
+	} else {
+		qp = tp->t_flags & CBREAK ? &tp->t_rawq : &tp->t_canq;
+		(void) spl5();
+		if (qp->c_cc <= 0) {
+			if ((tp->t_state&TS_CARR_ON)==0 ||
+			    (tp->t_state&TS_NBIO)) {
+				(void) spl0();
+				return (0);
+			}
+			sleep((caddr_t)&tp->t_rawq, TTIPRI);
+			(void) spl0();
+			goto loop;
+		}
+		(void) spl0();
+		first = 1;
+		while ((c = getc(qp)) >= 0) {
+			if (tp->t_flags&CRMOD && c == '\r')
+				c = '\n';
+			if (tp->t_flags&LCASE && c <= 0177)
+				if (tp->t_lstate&LSBKSL) {
+					if (maptab[c])
+						c = maptab[c];
+					tp->t_lstate &= ~LSBKSL;
+				} else if (c >= 'A' && c <= 'Z')
+					c += 'a' - 'A';
+				else if (c == '\\') {
+					tp->t_lstate |= LSBKSL;
+					continue;
+				}
+			if (c == tlun.t_dsuspc) {
+				ttsignal(tp, SIGTSTP);
+				if (first) {
+					sleep((caddr_t)&lbolt, TTIPRI);
+					goto loop;
+				}
+				break;
+			}
+			if (c == tun.t_eofc && (tp->t_flags&CBREAK)==0)
+				break;
+			if (passc(c & 0177) < 0)
+				break;
+			if ((tp->t_flags&CBREAK)==0 && ttbreakc(c, tp))
+				break;
+			first = 0;
+		}
+		tp->t_lstate &= ~LSBKSL;
+	}
+
+	if (tp->t_state&TS_TBLOCK && tp->t_rawq.c_cc < TTYHOG/5) {
+		if (putc(tun.t_startc, &tp->t_outq)==0) {
+			tp->t_state &= ~TS_TBLOCK;
+			ttstart(tp);
+		}
+		tp->t_char = 0;
+	}
+
+	return (tp->t_rawq.c_cc + tp->t_canq.c_cc);
 }
 
 /*
@@ -879,79 +1112,324 @@ caddr_t
 ttwrite(tp)
 register struct tty *tp;
 {
+#ifdef vax
 	/*
 	 * THE POSITIONING OF CP, CC, AND CE ARE CRITICAL
 	 * AND MUST NOT BE CHANGED WITHOUT PATCHING
 	 * THE 'ASM' INLINES BELOW.  WATCH OUT.
 	 */
+#endif
 	register char *cp;
 	register int cc, ce;
 	register i;
 	char obuf[OBUFSIZ];
+	register c;
+	int hiwat = TTHIWAT(tp);
+	int cnt = u.u_count;
 
-	if ((tp->t_state&CARR_ON)==0)
-		return(NULL);
+	if ((tp->t_state&TS_CARR_ON)==0)
+		return (NULL);
+loop:
+	while (u.u_procp->p_pgrp != tp->t_pgrp && tp == u.u_ttyp &&
+	    (tp->t_local&LTOSTOP) && (u.u_procp->p_flag&SVFORK)==0 &&
+	    u.u_signal[SIGTTOU] != SIG_IGN &&
+	    u.u_signal[SIGTTOU] != SIG_HOLD
+/*
+					     &&
+	    (u.u_procp->p_flag&SDETACH)==0) {
+*/
+	    ) {
+		gsignal(u.u_procp->p_pgrp, SIGTTOU);
+		sleep((caddr_t)&lbolt, TTIPRI);
+	}
 	while (u.u_count) {
 		cc = MIN(u.u_count, OBUFSIZ);
 		cp = obuf;
 		iomove(cp, (unsigned)cc, B_WRITE);
 		if (u.u_error)
 			break;
-		(void) spl5();
-		while (tp->t_outq.c_cc > TTHIWAT) {
-			ttstart(tp);
-			tp->t_state |= ASLEEP;
-			if (tp->t_chan) {
-				u.u_base -= cc;
-				u.u_offset -= cc;
-				u.u_count += cc;
-				(void) spl0();
-				return((caddr_t)&tp->t_outq);
+		if (tp->t_outq.c_cc > hiwat)
+			goto ovhiwat;
+		if (tp->t_local&LFLUSHO)
+			continue;
+		if (tp->t_flags&LCASE || tp->t_local&LTILDE) {
+			while (cc) {
+				c = *cp++;
+				tp->t_rocount = 0;
+				while((c = ttyoutput(c, tp)) >= 0) {
+					/* out of clists, wait a bit */
+					ttstart(tp);
+					sleep((caddr_t)&lbolt, TTOPRI);
+					tp->t_rocount = 0;
+				}
+				--cc;
+				if (tp->t_outq.c_cc > hiwat)
+					goto ovhiwat;
 			}
-			sleep((caddr_t)&tp->t_outq, TTOPRI);
-		}
-		(void) spl0();
-		if (tp->t_flags&LCASE) {
-			while (cc--)
-				ttyoutput(*cp++,tp);
 			continue;
 		}
 		while (cc) {
-			if (tp->t_flags&RAW)
-				ce=cc;
+			if (tp->t_flags&RAW || tp->t_local&LLITOUT)
+				ce = cc;
 			else {
-#ifdef VAX
+#ifdef vax
 				asm("	scanc	r9,(r10),_partab,$077");
 				asm("	subl3	r0,r9,r8");
 #else
 				ce=0;
-				while(((partab[*(cp+ce)]&077)==0)&&(ce<cc))
+				while(((partab[*(unsigned char *)(cp+ce)]&077)==0)&&(ce<cc))
 					ce++;
 #endif
 				if (ce==0) {
-					ttyoutput(*cp++,tp);
+					tp->t_rocount = 0;
+					if (ttyoutput(*cp, tp) >= 0) {
+						ttstart(tp);
+						sleep((caddr_t)&lbolt, TTOPRI);
+						continue;
+					}
+					cp++;
 					cc--;
-					goto check;
+					if (tp->t_outq.c_cc > hiwat)
+						goto ovhiwat;
 				}
 			}
+			tp->t_rocount = 0;
 			i=b_to_q(cp,ce,&tp->t_outq);
 			ce-=i;
 			tk_nout+=ce;
 			tp->t_col+=ce;
 			cp+=ce;
 			cc-=ce;
-check:
-			if (tp->t_outq.c_cc > TTHIWAT) {
-				(void) spl5();
-				while (tp->t_outq.c_cc > TTHIWAT) {
-					ttstart(tp);
-					tp->t_state |= ASLEEP;
-					sleep((caddr_t)&tp->t_outq, TTOPRI);
-				}
-				(void) spl0();
+			if (i) {
+				ttstart(tp);
+				sleep((caddr_t)&lbolt, TTOPRI);
 			}
+			if (ce || tp->t_outq.c_cc > hiwat)
+				goto ovhiwat;
 		}
 	}
 	ttstart(tp);
 	return(NULL);
+
+ovhiwat:
+	(void) spl5();
+	u.u_base -= cc;
+	u.u_offset -= cc;
+	u.u_count += cc;
+	if (tp->t_outq.c_cc <= hiwat) {
+		(void) spl0();
+		goto loop;
+	}
+	ttstart(tp);
+	if (tp->t_state & TS_NBIO) {
+		if (u.u_count == cnt)
+			u.u_error = EWOULDBLOCK;
+		return (NULL);
+	}
+	tp->t_state |= TS_ASLEEP;
+	sleep((caddr_t)&tp->t_outq, TTOPRI);
+	(void) spl0();
+	goto loop;
+}
+
+/*
+ * Rubout one character from the rawq of tp
+ * as cleanly as possible.
+ */
+ttyrub(c, tp)
+register c;
+register struct tty *tp;
+{
+	register char *cp;
+	register int savecol;
+	int s;
+	char *nextc();
+
+	if ((tp->t_flags&ECHO)==0)
+		return;
+	tp->t_local &= ~LFLUSHO;
+	c &= 0377;
+	if (tp->t_local&LCRTBS) {
+		if (tp->t_rocount == 0) {
+			/*
+			 * Screwed by ttwrite; retype
+			 */
+			ttyretype(tp);
+			return;
+		}
+		if (c==('\t'|0200) || c==('\n'|0200))
+			ttyrubo(tp, 2);
+		else switch(partab[c&=0177] & 0177) {
+
+		case ORDINARY:
+			if (tp->t_flags&LCASE && c >= 'A' && c <= 'Z')
+				ttyrubo(tp, 2);
+			else
+				ttyrubo(tp, 1);
+			break;
+
+		case VTAB:
+		case BACKSPACE:
+		case CONTROL:
+		case RETURN:
+			if (tp->t_local & LCTLECH)
+				ttyrubo(tp, 2);
+			break;
+
+		case TAB:
+			if (tp->t_rocount < tp->t_rawq.c_cc) {
+				ttyretype(tp);
+				return;
+			}
+			s = spl5();
+			savecol = tp->t_col;
+			tp->t_lstate |= LSCNTTB;
+			tp->t_local |= LFLUSHO;
+			tp->t_col = tp->t_rocol;
+			for (cp = tp->t_rawq.c_cf; cp; cp = nextc(&tp->t_rawq, cp))
+				ttyecho(*cp, tp);
+			tp->t_local &= ~LFLUSHO;
+			tp->t_lstate &= ~LSCNTTB;
+			splx(s);
+			/*
+			 * savecol will now be length of the tab
+			 */
+			savecol -= tp->t_col;
+			tp->t_col += savecol;
+			if (savecol > 8)
+				savecol = 8;		/* overflow screw */
+			while (--savecol >= 0)
+				(void) ttyoutput('\b', tp);
+			break;
+
+		default:
+			panic("ttyrub");
+		}
+	} else if (tp->t_local&LPRTERA) {
+		if ((tp->t_lstate&LSERASE) == 0) {
+			(void) ttyoutput('\\', tp);
+			tp->t_lstate |= LSERASE;
+		}
+		ttyecho(c, tp);
+	} else
+		ttyecho(tp->t_erase, tp);
+	tp->t_rocount--;
+}
+
+/*
+ * Crt back over cnt chars perhaps
+ * erasing them.
+ */
+ttyrubo(tp, cnt)
+register struct tty *tp;
+int cnt;
+{
+
+	while (--cnt >= 0)
+		ttyout(tp->t_local&LCRTERA ? "\b \b" : "\b", tp);
+}
+
+/*
+ * Reprint the rawq line.
+ * We assume c_cc has already been checked.
+ */
+ttyretype(tp)
+register struct tty *tp;
+{
+	register char *cp;
+	char *nextc();
+	int s;
+
+	if (tlun.t_rprntc != 0377)
+		ttyecho(tlun.t_rprntc, tp);
+	(void) ttyoutput('\n', tp);
+	s = spl5();
+	for (cp = tp->t_canq.c_cf; cp; cp = nextc(&tp->t_canq, cp))
+		ttyecho(*cp, tp);
+	for (cp = tp->t_rawq.c_cf; cp; cp = nextc(&tp->t_rawq, cp))
+		ttyecho(*cp, tp);
+	tp->t_lstate &= ~LSERASE;
+	splx(s);
+	tp->t_rocount = tp->t_rawq.c_cc;
+	tp->t_rocol = 0;
+}
+
+/*
+ * Echo a typed character to the terminal
+ */
+ttyecho(c, tp)
+register c;
+register struct tty *tp;
+{
+
+	if ((tp->t_lstate & LSCNTTB) == 0)
+		tp->t_local &= ~LFLUSHO;
+	if ((tp->t_flags&ECHO) == 0)
+		return;
+	c &= 0377;
+	if (tp->t_flags&RAW) {
+		(void) ttyoutput(c, tp);
+		return;
+	}
+	if (c == '\r' && tp->t_flags&CRMOD)
+		c = '\n';
+	if (tp->t_local&LCTLECH) {
+		if ((c&0177) <= 037 && c!='\t' && c!='\n' || (c&0177)==0177) {
+			(void) ttyoutput('^', tp);
+			c &= 0177;
+			if (c == 0177)
+				c = '?';
+			else if (tp->t_flags&LCASE)
+				c += 'a' - 1;
+			else
+				c += 'A' - 1;
+		}
+	}
+	if ((tp->t_flags&LCASE) && (c >= 'A' && c <= 'Z'))
+		c += 'a' - 'A';
+	(void) ttyoutput(c & 0177, tp);
+}
+
+/*
+ * Is c a break char for tp?
+ */
+ttbreakc(c, tp)
+register c;
+register struct tty *tp;
+{
+	return (c == '\n' || c == tun.t_eofc || c == tun.t_brkc ||
+		c == '\r' && (tp->t_flags&CRMOD));
+}
+
+/*
+ * send string cp to tp
+ */
+ttyout(cp, tp)
+register char *cp;
+register struct tty *tp;
+{
+	register char c;
+
+	while (c = *cp++)
+		(void) ttyoutput(c, tp);
+}
+
+ttwakeup(tp)
+	struct tty *tp;
+{
+
+	if (tp->t_rsel) {
+		selwakeup(tp->t_rsel, tp->t_state&TS_RCOLL);
+		tp->t_state &= ~TS_RCOLL;
+		tp->t_rsel = 0;
+	}
+	wakeup((caddr_t)&tp->t_rawq);
+}
+
+ttsignal(tp, signo)
+	struct tty *tp;
+	int signo;
+{
+
+	gsignal(tp->t_pgrp, signo);
 }