Import of nvi-1.79, minus a few bits that we dont need (eg: postscript

files, curses, db, regex etc that we already have).  The other glue will
follow shortly.

Obtained from: Keith Bostic <bostic@bostic.com>

8 files changed, 3146 insertions, 0 deletions

diff --git a/contrib/nvi/cl/README.signal b/contrib/nvi/cl/README.signal
new file mode 100644
index 0000000..7faa456
--- /dev/null
+++ b/contrib/nvi/cl/README.signal
@@ -0,0 +1,174 @@
+#	@(#)README.signal	10.1 (Berkeley) 6/23/95
+
+There are six (normally) asynchronous actions about which vi cares:
+SIGHUP, SIGINT, SIGQUIT, SIGTERM, SIGTSTP and SIGWINCH.
+
+The assumptions:
+	1: The DB routines are not reentrant.
+	2: The curses routines may not be reentrant.
+	3: Neither DB nor curses will restart system calls.
+
+XXX
+Note, most C library functions don't restart system calls.  So, we should
+*probably* start blocking around any imported function that we don't know
+doesn't make a system call.  This is going to be a genuine annoyance...
+
+SIGHUP, SIGTERM
+	Used for file recovery.  The DB routines can't be reentered, nor
+	can they handle interrupted system calls, so the vi routines that
+	call DB block signals.  This means that DB routines could be
+	called at interrupt time, if necessary.
+
+SIGQUIT
+	Disabled by the signal initialization routines.  Historically, ^\
+	switched vi into ex mode, and we continue that practice.
+
+SIGWINCH:
+	The interrupt routine sets a global bit which is checked by the
+ 	key-read routine, so there are no reentrancy issues.  This means
+	that the screen will not resize until vi runs out of keys, but
+	that doesn't seem like a problem.
+
+SIGINT and SIGTSTP are a much more difficult issue to resolve.  Vi has
+to permit the user to interrupt long-running operations.  Generally, a
+search, substitution or read/write is done on a large file, or, the user
+creates a key mapping with an infinite loop.  This problem will become
+worse as more complex semantics are added to vi, especially things like
+making it a pure text widget.  There are four major solutions on the table,
+each of which have minor permutations.
+
+1:	Run in raw mode.
+
+	The up side is that there's no asynchronous behavior to worry about,
+	and obviously no reentrancy problems.  The down side is that it's easy
+	to misinterpret characters (e.g. :w big_file^Mi^V^C is going to look
+	like an interrupt) and it's easy to get into places where we won't see
+	interrupt characters (e.g. ":map a ixx^[hxxaXXX" infinitely loops in
+	historic implementations of vi).  Periodically reading the terminal
+	input buffer might solve the latter problem, but it's not going to be
+	pretty.
+
+	Also, we're going to be checking for ^C's and ^Z's both, all over
+	the place -- I hate to litter the source code with that.  For example,
+	the historic version of vi didn't permit you to suspend the screen if
+	you were on the colon command line.  This isn't right.  ^Z isn't a vi
+	command, it's a terminal event.  (Dammit.)
+
+2:	Run in cbreak mode.  There are two problems in this area.  First, the
+	current curses implementations (both System V and Berkeley) don't give
+	you clean cbreak modes. For example, the IEXTEN bit is left on, turning
+	on DISCARD and LNEXT.  To clarify, what vi WANTS is 8-bit clean, with
+	the exception that flow control and signals are turned on, and curses
+	cbreak mode doesn't give you this.
+
+	We can either set raw mode and twiddle the tty, or cbreak mode and
+	twiddle the tty.  I chose to use raw mode, on the grounds that raw
+	mode is better defined and I'm less likely to be surprised by a curses
+	implementation down the road.  The twiddling consists of setting ISIG,
+	IXON/IXOFF, and disabling some of the interrupt characters (see the
+	comments in cl_init.c).  This is all found in historic System V (SVID
+	3) and POSIX 1003.1-1992, so it should be fairly portable.
+
+	The second problem is that vi permits you to enter literal signal
+	characters, e.g. ^V^C.  There are two possible solutions.  First, you
+	can turn off signals when you get a ^V, but that means that a network
+	packet containing ^V and ^C will lose, since the ^C may take effect
+	before vi reads the ^V.  (This is particularly problematic if you're
+	talking over a protocol that recognizes signals locally and sends OOB
+	packets when it sees them.)  Second, you can turn the ^C into a literal
+	character in vi, but that means that there's a race between entering
+	^V<character>^C, i.e. the sequence may end up being ^V^C<character>.
+	Also, the second solution doesn't work for flow control characters, as
+	they aren't delivered to the program as signals.
+
+	Generally, this is what historic vi did.  (It didn't have the curses
+	problems because it didn't use curses.)  It entered signals following
+	^V characters into the input stream, (which is why there's no way to
+	enter a literal flow control character).
+
+3:	Run in mostly raw mode; turn signals on when doing an operation the
+	user might want to interrupt, but leave them off most of the time.
+
+	This works well for things like file reads and writes.  This doesn't
+	work well for trying to detect infinite maps.  The problem is that
+	you can write the code so that you don't have to turn on interrupts
+	per keystroke, but the code isn't pretty and it's hard to make sure
+	that an optimization doesn't cover up an infinite loop.  This also
+	requires interaction or state between the vi parser and the key
+	reading routines, as an infinite loop may still be returning keys
+	to the parser.
+
+	Also, if the user inserts an interrupt into the tty queue while the
+	interrupts are turned off, the key won't be treated as an interrupt,
+	and requiring the user to pound the keyboard to catch an interrupt
+	window is nasty.
+
+4:	Run in mostly raw mode, leaving signals on all of the time.  Done
+	by setting raw mode, and twiddling the tty's termios ISIG bit.
+
+	This works well for the interrupt cases, because the code only has
+	to check to see if the interrupt flag has been set, and can otherwise
+	ignore signals.  It's also less likely that we'll miss a case, and we
+	don't have to worry about synchronizing between the vi parser and the
+	key read routines.
+
+	The down side is that we have to turn signals off if the user wants
+	to enter a literal character (e.g. ^V^C).  If the user enters the
+	combination fast enough, or as part of a single network packet,
+	the text input routines will treat it as a signal instead of as a
+	literal character.  To some extent, we have this problem already,
+	since we turn off flow control so that the user can enter literal
+	XON/XOFF characters.
+
+	This is probably the easiest to code, and provides the smoothest
+	programming interface.
+
+There are a couple of other problems to consider.
+
+First, System V's curses doesn't handle SIGTSTP correctly.  If you use the
+newterm() interface, the TSTP signal will leave you in raw mode, and the
+final endwin() will leave you in the correct shell mode.  If you use the
+initscr() interface, the TSTP signal will return you to the correct shell
+mode, but the final endwin() will leave you in raw mode.  There you have
+it: proof that drug testing is not making any significant headway in the
+computer industry.  The 4BSD curses is deficient in that it does not have
+an interface to the terminal keypad.  So, regardless, we have to do our
+own SIGTSTP handling.
+
+The problem with this is that if we do our own SIGTSTP handling, in either
+models #3 or #4, we're going to have to call curses routines at interrupt
+time, which means that we might be reentering curses, which is something we
+don't want to do.
+
+Second, SIGTSTP has its own little problems.  It's broadcast to the entire
+process group, not sent to a single process.  The scenario goes something
+like this: the shell execs the mail program, which execs vi.  The user hits
+^Z, and all three programs get the signal, in some random order.  The mail
+program goes to sleep immediately (since it probably didn't have a SIGTSTP
+handler in place).  The shell gets a SIGCHLD, does a wait, and finds out
+that the only child in its foreground process group (of which it's aware)
+is asleep.  It then optionally resets the terminal (because the modes aren't
+how it left them), and starts prompting the user for input.  The problem is
+that somewhere in the middle of all of this, vi is resetting the terminal,
+and getting ready to send a SIGTSTP to the process group in order to put
+itself to sleep.  There's a solution to all of this: when vi starts, it puts
+itself into its own process group, and then only it (and possible child
+processes) receive the SIGTSTP.  This permits it to clean up the terminal
+and switch back to the original process group, where it sends that process
+group a SIGTSTP, putting everyone to sleep and waking the shell.
+
+Third, handing SIGTSTP asynchronously is further complicated by the child
+processes vi may fork off.  If vi calls ex, ex resets the terminal and
+starts running some filter, and SIGTSTP stops them both, vi has to know
+when it restarts that it can't repaint the screen until ex's child has
+finished running.  This is solveable, but it's annoying.
+
+Well, somebody had to make a decision, and this is the way it's going to be
+(unless I get talked out of it).  SIGINT is handled asynchronously, so
+that we can pretty much guarantee that the user can interrupt any operation
+at any time.  SIGTSTP is handled synchronously, so that we don't have to
+reenter curses and so that we don't have to play the process group games.
+^Z is recognized in the standard text input and command modes.  (^Z should
+also be recognized during operations that may potentially take a long time.
+The simplest solution is probably to twiddle the tty, install a handler for
+SIGTSTP, and then restore normal tty modes when the operation is complete.)
diff --git a/contrib/nvi/cl/cl.h b/contrib/nvi/cl/cl.h
new file mode 100644
index 0000000..2ef2b8d
--- /dev/null
+++ b/contrib/nvi/cl/cl.h
@@ -0,0 +1,78 @@
+/*-
+ * Copyright (c) 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1993, 1994, 1995, 1996
+ *	Keith Bostic.  All rights reserved.
+ *
+ * See the LICENSE file for redistribution information.
+ *
+ *	@(#)cl.h	10.19 (Berkeley) 9/24/96
+ */
+
+typedef struct _cl_private {
+	CHAR_T	 ibuf[256];	/* Input keys. */
+
+	int	 eof_count;	/* EOF count. */
+
+	struct termios orig;	/* Original terminal values. */
+	struct termios ex_enter;/* Terminal values to enter ex. */
+	struct termios vi_enter;/* Terminal values to enter vi. */
+
+	char	*el;		/* Clear to EOL terminal string. */
+	char	*cup;		/* Cursor movement terminal string. */
+	char	*cuu1;		/* Cursor up terminal string. */
+	char	*rmso, *smso;	/* Inverse video terminal strings. */
+	char	*smcup, *rmcup;	/* Terminal start/stop strings. */
+
+	int	 killersig;	/* Killer signal. */
+#define	INDX_HUP	0
+#define	INDX_INT	1
+#define	INDX_TERM	2
+#define	INDX_WINCH	3
+#define	INDX_MAX	4	/* Original signal information. */
+	struct sigaction oact[INDX_MAX];
+
+	enum {			/* Tty group write mode. */
+	    TGW_UNKNOWN=0, TGW_SET, TGW_UNSET } tgw;
+
+	enum {			/* Terminal initialization strings. */
+	    TE_SENT=0, TI_SENT } ti_te;
+
+#define	CL_IN_EX	0x0001	/* Currently running ex. */
+#define	CL_RENAME	0x0002	/* X11 xterm icon/window renamed. */
+#define	CL_RENAME_OK	0x0004	/* User wants the windows renamed. */
+#define	CL_SCR_EX_INIT	0x0008	/* Ex screen initialized. */
+#define	CL_SCR_VI_INIT	0x0010	/* Vi screen initialized. */
+#define	CL_SIGHUP	0x0020	/* SIGHUP arrived. */
+#define	CL_SIGINT	0x0040	/* SIGINT arrived. */
+#define	CL_SIGTERM	0x0080	/* SIGTERM arrived. */
+#define	CL_SIGWINCH	0x0100	/* SIGWINCH arrived. */
+#define	CL_STDIN_TTY	0x0200	/* Talking to a terminal. */
+	u_int32_t flags;
+} CL_PRIVATE;
+
+#define	CLP(sp)		((CL_PRIVATE *)((sp)->gp->cl_private))
+#define	GCLP(gp)	((CL_PRIVATE *)gp->cl_private)
+
+/* Return possibilities from the keyboard read routine. */
+typedef enum { INP_OK=0, INP_EOF, INP_ERR, INP_INTR, INP_TIMEOUT } input_t;
+
+/* The screen line relative to a specific window. */
+#define	RLNO(sp, lno)	(sp)->woff + (lno)
+
+/* X11 xterm escape sequence to rename the icon/window. */
+#define	XTERM_RENAME	"\033]0;%s\007"
+
+/*
+ * XXX
+ * Some implementations of curses.h don't define these for us.  Used for
+ * compatibility only.
+ */
+#ifndef TRUE
+#define	TRUE	1
+#endif
+#ifndef FALSE
+#define	FALSE	0
+#endif
+
+#include "cl_extern.h"
diff --git a/contrib/nvi/cl/cl_bsd.c b/contrib/nvi/cl/cl_bsd.c
new file mode 100644
index 0000000..4a06a54
--- /dev/null
+++ b/contrib/nvi/cl/cl_bsd.c
@@ -0,0 +1,345 @@
+/*-
+ * Copyright (c) 1995, 1996
+ *	Keith Bostic.  All rights reserved.
+ *
+ * See the LICENSE file for redistribution information.
+ */
+
+#include "config.h"
+
+#ifndef lint
+static const char sccsid[] = "@(#)cl_bsd.c	8.29 (Berkeley) 7/1/96";
+#endif /* not lint */
+
+#include <sys/types.h>
+#include <sys/queue.h>
+#include <sys/time.h>
+
+#include <bitstring.h>
+#include <ctype.h>
+#include <curses.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include "../common/common.h"
+#include "../vi/vi.h"
+#include "cl.h"
+
+static char	*ke;				/* Keypad on. */
+static char	*ks;				/* Keypad off. */
+static char	*vb;				/* Visible bell string. */
+
+/*
+ * HP's support the entire System V curses package except for the tigetstr
+ * and tigetnum functions.  Ultrix supports the BSD curses package except
+ * for the idlok function.  Cthulu only knows why.  Break things up into a
+ * minimal set of functions.
+ */
+
+#ifndef HAVE_CURSES_ADDNSTR
+/*
+ * addnstr --
+ *
+ * PUBLIC: #ifndef HAVE_CURSES_ADDNSTR
+ * PUBLIC: int addnstr __P((char *, int));
+ * PUBLIC: #endif
+ */
+int
+addnstr(s, n)
+	char *s;
+	int n;
+{
+	int ch;
+
+	while (n-- && (ch = *s++))
+		addch(ch);
+	return (OK);
+}
+#endif
+
+#ifndef	HAVE_CURSES_BEEP
+/*
+ * beep --
+ *
+ * PUBLIC: #ifndef HAVE_CURSES_BEEP
+ * PUBLIC: void beep __P((void));
+ * PUBLIC: #endif
+ */
+void
+beep()
+{
+	(void)write(1, "\007", 1);	/* '\a' */
+}
+#endif /* !HAVE_CURSES_BEEP */
+
+#ifndef	HAVE_CURSES_FLASH
+/*
+ * flash --
+ *	Flash the screen.
+ *
+ * PUBLIC: #ifndef HAVE_CURSES_FLASH
+ * PUBLIC: void flash __P((void));
+ * PUBLIC: #endif
+ */
+void
+flash()
+{
+	if (vb != NULL) {
+		(void)tputs(vb, 1, cl_putchar);
+		(void)fflush(stdout);
+	} else
+		beep();
+}
+#endif /* !HAVE_CURSES_FLASH */
+
+#ifndef	HAVE_CURSES_IDLOK
+/*
+ * idlok --
+ *	Turn on/off hardware line insert/delete.
+ *
+ * PUBLIC: #ifndef HAVE_CURSES_IDLOK
+ * PUBLIC: void idlok __P((WINDOW *, int));
+ * PUBLIC: #endif
+ */
+void
+idlok(win, bf)
+	WINDOW *win;
+	int bf;
+{
+	return;
+}
+#endif /* !HAVE_CURSES_IDLOK */
+
+#ifndef	HAVE_CURSES_KEYPAD
+/*
+ * keypad --
+ *	Put the keypad/cursor arrows into or out of application mode.
+ *
+ * PUBLIC: #ifndef HAVE_CURSES_KEYPAD
+ * PUBLIC: int keypad __P((void *, int));
+ * PUBLIC: #endif
+ */
+int
+keypad(a, on)
+	void *a;
+	int on;
+{
+	char *p;
+
+	if ((p = tigetstr(on ? "smkx" : "rmkx")) != (char *)-1) {
+		(void)tputs(p, 0, cl_putchar);
+		(void)fflush(stdout);
+	}
+	return (0);
+}
+#endif /* !HAVE_CURSES_KEYPAD */
+
+#ifndef	HAVE_CURSES_NEWTERM
+/*
+ * newterm --
+ *	Create a new curses screen.
+ *
+ * PUBLIC: #ifndef HAVE_CURSES_NEWTERM
+ * PUBLIC: void *newterm __P((const char *, FILE *, FILE *));
+ * PUBLIC: #endif
+ */
+void *
+newterm(a, b, c)
+	const char *a;
+	FILE *b, *c;
+{
+	return (initscr());
+}
+#endif /* !HAVE_CURSES_NEWTERM */
+
+#ifndef	HAVE_CURSES_SETUPTERM
+/*
+ * setupterm --
+ *	Set up terminal.
+ *
+ * PUBLIC: #ifndef HAVE_CURSES_SETUPTERM
+ * PUBLIC: void setupterm __P((char *, int, int *));
+ * PUBLIC: #endif
+ */
+void
+setupterm(ttype, fno, errp)
+	char *ttype;
+	int fno, *errp;
+{
+	static char buf[2048];
+	char *p;
+
+	if ((*errp = tgetent(buf, ttype)) > 0) {
+		if (ke != NULL)
+			free(ke);
+		ke = ((p = tigetstr("rmkx")) == (char *)-1) ?
+		    NULL : strdup(p);
+		if (ks != NULL)
+			free(ks);
+		ks = ((p = tigetstr("smkx")) == (char *)-1) ?
+		    NULL : strdup(p);
+		if (vb != NULL)
+			free(vb);
+		vb = ((p = tigetstr("flash")) == (char *)-1) ?
+		    NULL : strdup(p);
+	}
+}
+#endif /* !HAVE_CURSES_SETUPTERM */
+
+#ifndef	HAVE_CURSES_TIGETSTR
+/* Terminfo-to-termcap translation table. */
+typedef struct _tl {
+	char *terminfo;			/* Terminfo name. */
+	char *termcap;			/* Termcap name. */
+} TL;
+static const TL list[] = {
+	"cols",		"co",		/* Terminal columns. */
+	"cup",		"cm",		/* Cursor up. */
+	"cuu1",		"up",		/* Cursor up. */
+	"el",		"ce",		/* Clear to end-of-line. */
+	"flash",	"vb",		/* Visible bell. */
+	"kcub1",  	"kl",		/* Cursor left. */
+	"kcud1",	"kd",		/* Cursor down. */
+	"kcuf1",	"kr",		/* Cursor right. */
+	"kcuu1",  	"ku",		/* Cursor up. */
+	"kdch1",	"kD",		/* Delete character. */
+	"kdl1",		"kL",		/* Delete line. */
+	"ked",		"kS",		/* Delete to end of screen. */
+	"kel",		"kE",		/* Delete to eol. */
+	"khome",	"kh",		/* Go to sol. */
+	"kich1",	"kI",		/* Insert at cursor. */
+	"kil1",		"kA",		/* Insert line. */
+	"kind",		"kF",		/* Scroll down. */
+	"kll",		"kH",		/* Go to eol. */
+	"knp",		"kN",		/* Page down. */
+	"kpp",		"kP",		/* Page up. */
+	"kri",		"kR",		/* Scroll up. */
+	"lines",	"li",		/* Terminal lines. */
+	"rmcup",	"te",		/* Terminal end string. */
+	"rmkx",		"ke",		/* Exit "keypad-transmit" mode. */
+	"rmso",		"se",		/* Standout end. */
+	"smcup",	"ti",		/* Terminal initialization string. */
+	"smkx",		"ks",		/* Enter "keypad-transmit" mode. */
+	"smso",		"so",		/* Standout begin. */
+};
+
+#ifdef _AIX
+/*
+ * AIX's implementation for function keys greater than 10 is different and
+ * only goes as far as 36.
+ */
+static const char codes[] = {
+/*  0-10 */ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', ';',
+/* 11-20 */ '<', '>', '!', '@', '#', '$', '%', '^', '&', '*',
+/* 21-30 */ '(', ')', '-', '_', '+', ',', ':', '?', '[', ']',
+/* 31-36 */ '{', '}', '|', '~', '/', '='
+};
+
+#else
+
+/*
+ * !!!
+ * Historically, the 4BSD termcap code didn't support functions keys greater
+ * than 9.  This was silently enforced -- asking for key k12 would return the
+ * value for k1.  We try and get around this by using the tables specified in
+ * the terminfo(TI_ENV) man page from the 3rd Edition SVID.  This assumes the
+ * implementors of any System V compatibility code or an extended termcap used
+ * those codes.
+ */
+static const char codes[] = {
+/*  0-10 */ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', ';',
+/* 11-19 */ '1', '2', '3', '4', '5', '6', '7', '8', '9',
+/* 20-63 */ 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
+	    'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
+	    'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
+	    'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
+};
+#endif /* _AIX */
+
+/*
+ * lcmp --
+ *	list comparison routine for bsearch.
+ */
+static int
+lcmp(a, b)
+	const void *a, *b;
+{
+	return (strcmp(a, ((TL *)b)->terminfo));
+}
+
+/*
+ * tigetstr --
+ *
+ * Vendors put the prototype for tigetstr into random include files, including
+ * <term.h>, which we can't include because it makes other systems unhappy.
+ * Try and work around the problem, since we only care about the return value.
+ *
+ * PUBLIC: #ifdef HAVE_CURSES_TIGETSTR
+ * PUBLIC: char *tigetstr();
+ * PUBLIC: #else
+ * PUBLIC: char *tigetstr __P((char *));
+ * PUBLIC: #endif
+ */
+char *
+tigetstr(name)
+	char *name;
+{
+	static char sbuf[256];
+	TL *tlp;
+	int n;
+	char *p, keyname[3];
+
+	if ((tlp = bsearch(name,
+	    list, sizeof(list) / sizeof(TL), sizeof(TL), lcmp)) == NULL) {
+#ifdef _AIX
+		if (name[0] == 'k' &&
+		    name[1] == 'f' && (n = atoi(name + 2)) <= 36) {
+			keyname[0] = 'k';
+			keyname[1] = codes[n];
+			keyname[2] = '\0';
+#else
+		if (name[0] == 'k' &&
+		    name[1] == 'f' && (n = atoi(name + 2)) <= 63) {
+			keyname[0] = n <= 10 ? 'k' : 'F';
+			keyname[1] = codes[n];
+			keyname[2] = '\0';
+#endif
+			name = keyname;
+		}
+	} else
+		name = tlp->termcap;
+
+	p = sbuf;
+#ifdef _AIX
+	return ((p = tgetstr(name, &p)) == NULL ? (char *)-1 : strcpy(sbuf, p));
+#else
+	return (tgetstr(name, &p) == NULL ? (char *)-1 : sbuf);
+#endif
+}
+
+/*
+ * tigetnum --
+ *
+ * PUBLIC: #ifndef HAVE_CURSES_TIGETSTR
+ * PUBLIC: int tigetnum __P((char *));
+ * PUBLIC: #endif
+ */
+int
+tigetnum(name)
+	char *name;
+{
+	TL *tlp;
+	int val;
+
+	if ((tlp = bsearch(name,
+	    list, sizeof(list) / sizeof(TL), sizeof(TL), lcmp)) != NULL) {
+		name = tlp->termcap;
+	}
+
+	return ((val = tgetnum(name)) == -1 ? -2 : val);
+}
+#endif /* !HAVE_CURSES_TIGETSTR */
diff --git a/contrib/nvi/cl/cl_funcs.c b/contrib/nvi/cl/cl_funcs.c
new file mode 100644
index 0000000..40315ee
--- /dev/null
+++ b/contrib/nvi/cl/cl_funcs.c
@@ -0,0 +1,704 @@
+/*-
+ * Copyright (c) 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1993, 1994, 1995, 1996
+ *	Keith Bostic.  All rights reserved.
+ *
+ * See the LICENSE file for redistribution information.
+ */
+
+#include "config.h"
+
+#ifndef lint
+static const char sccsid[] = "@(#)cl_funcs.c	10.50 (Berkeley) 9/24/96";
+#endif /* not lint */
+
+#include <sys/types.h>
+#include <sys/queue.h>
+#include <sys/time.h>
+
+#include <bitstring.h>
+#include <ctype.h>
+#include <curses.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include "../common/common.h"
+#include "../vi/vi.h"
+#include "cl.h"
+
+/*
+ * cl_addstr --
+ *	Add len bytes from the string at the cursor, advancing the cursor.
+ *
+ * PUBLIC: int cl_addstr __P((SCR *, const char *, size_t));
+ */
+int
+cl_addstr(sp, str, len)
+	SCR *sp;
+	const char *str;
+	size_t len;
+{
+	CL_PRIVATE *clp;
+	size_t oldy, oldx;
+	int iv;
+
+	clp = CLP(sp);
+
+	/*
+	 * If ex isn't in control, it's the last line of the screen and
+	 * it's a split screen, use inverse video.
+	 */
+	iv = 0;
+	getyx(stdscr, oldy, oldx);
+	if (!F_ISSET(sp, SC_SCR_EXWROTE) &&
+	    oldy == RLNO(sp, LASTLINE(sp)) && IS_SPLIT(sp)) {
+		iv = 1;
+		(void)standout();
+	}
+
+	if (addnstr(str, len) == ERR)
+		return (1);
+
+	if (iv)
+		(void)standend();
+	return (0);
+}
+
+/*
+ * cl_attr --
+ *	Toggle a screen attribute on/off.
+ *
+ * PUBLIC: int cl_attr __P((SCR *, scr_attr_t, int));
+ */
+int
+cl_attr(sp, attribute, on)
+	SCR *sp;
+	scr_attr_t attribute;
+	int on;
+{
+	CL_PRIVATE *clp;
+
+	clp = CLP(sp);
+
+	switch (attribute) {
+	case SA_ALTERNATE:
+	/*
+	 * !!!
+	 * There's a major layering violation here.  The problem is that the
+	 * X11 xterm screen has what's known as an "alternate" screen.  Some
+	 * xterm termcap/terminfo entries include sequences to switch to/from
+	 * that alternate screen as part of the ti/te (smcup/rmcup) strings.
+	 * Vi runs in the alternate screen, so that you are returned to the
+	 * same screen contents on exit from vi that you had when you entered
+	 * vi.  Further, when you run :shell, or :!date or similar ex commands,
+	 * you also see the original screen contents.  This wasn't deliberate
+	 * on vi's part, it's just that it historically sent terminal init/end
+	 * sequences at those times, and the addition of the alternate screen
+	 * sequences to the strings changed the behavior of vi.  The problem
+	 * caused by this is that we don't want to switch back to the alternate
+	 * screen while getting a new command from the user, when the user is
+	 * continuing to enter ex commands, e.g.:
+	 *
+	 *	:!date				<<< switch to original screen
+	 *	[Hit return to continue]	<<< prompt user to continue
+	 *	:command			<<< get command from user
+	 *
+	 * Note that the :command input is a true vi input mode, e.g., input
+	 * maps and abbreviations are being done.  So, we need to be able to
+	 * switch back into the vi screen mode, without flashing the screen. 
+	 *
+	 * To make matters worse, the curses initscr() and endwin() calls will
+	 * do this automatically -- so, this attribute isn't as controlled by
+	 * the higher level screen as closely as one might like.
+	 */
+	if (on) {
+		if (clp->ti_te != TI_SENT) {
+			clp->ti_te = TI_SENT;
+			if (clp->smcup == NULL)
+				(void)cl_getcap(sp, "smcup", &clp->smcup);
+			if (clp->smcup != NULL)
+				(void)tputs(clp->smcup, 1, cl_putchar);
+		}
+	} else
+		if (clp->ti_te != TE_SENT) {
+			clp->ti_te = TE_SENT;
+			if (clp->rmcup == NULL)
+				(void)cl_getcap(sp, "rmcup", &clp->rmcup);
+			if (clp->rmcup != NULL)
+				(void)tputs(clp->rmcup, 1, cl_putchar);
+			(void)fflush(stdout);
+		}
+		(void)fflush(stdout);
+		break;
+	case SA_INVERSE:
+		if (F_ISSET(sp, SC_EX | SC_SCR_EXWROTE)) {
+			if (clp->smso == NULL)
+				return (1);
+			if (on)
+				(void)tputs(clp->smso, 1, cl_putchar);
+			else
+				(void)tputs(clp->rmso, 1, cl_putchar);
+			(void)fflush(stdout);
+		} else {
+			if (on)
+				(void)standout();
+			else
+				(void)standend();
+		}
+		break;
+	default:
+		abort();
+	}
+	return (0);
+}
+
+/*
+ * cl_baud --
+ *	Return the baud rate.
+ *
+ * PUBLIC: int cl_baud __P((SCR *, u_long *));
+ */
+int
+cl_baud(sp, ratep)
+	SCR *sp;
+	u_long *ratep;
+{
+	CL_PRIVATE *clp;
+
+	/*
+	 * XXX
+	 * There's no portable way to get a "baud rate" -- cfgetospeed(3)
+	 * returns the value associated with some #define, which we may
+	 * never have heard of, or which may be a purely local speed.  Vi
+	 * only cares if it's SLOW (w300), slow (w1200) or fast (w9600).
+	 * Try and detect the slow ones, and default to fast.
+	 */
+	clp = CLP(sp);
+	switch (cfgetospeed(&clp->orig)) {
+	case B50:
+	case B75:
+	case B110:
+	case B134:
+	case B150:
+	case B200:
+	case B300:
+	case B600:
+		*ratep = 600;
+		break;
+	case B1200:
+		*ratep = 1200;
+		break;
+	default:
+		*ratep = 9600;
+		break;
+	}
+	return (0);
+}
+
+/*
+ * cl_bell --
+ *	Ring the bell/flash the screen.
+ *
+ * PUBLIC: int cl_bell __P((SCR *));
+ */
+int
+cl_bell(sp)
+	SCR *sp;
+{
+	if (F_ISSET(sp, SC_EX | SC_SCR_EXWROTE))
+		(void)write(STDOUT_FILENO, "\07", 1);		/* \a */
+	else {
+		/*
+		 * Vi has an edit option which determines if the terminal
+		 * should be beeped or the screen flashed.
+		 */
+		if (O_ISSET(sp, O_FLASH))
+			(void)flash();
+		else
+			(void)beep();
+	}
+	return (0);
+}
+
+/*
+ * cl_clrtoeol --
+ *	Clear from the current cursor to the end of the line.
+ *
+ * PUBLIC: int cl_clrtoeol __P((SCR *));
+ */
+int
+cl_clrtoeol(sp)
+	SCR *sp;
+{
+	return (clrtoeol() == ERR);
+}
+
+/*
+ * cl_cursor --
+ *	Return the current cursor position.
+ *
+ * PUBLIC: int cl_cursor __P((SCR *, size_t *, size_t *));
+ */
+int
+cl_cursor(sp, yp, xp)
+	SCR *sp;
+	size_t *yp, *xp;
+{
+	/*
+	 * The curses screen support splits a single underlying curses screen
+	 * into multiple screens to support split screen semantics.  For this
+	 * reason the returned value must be adjusted to be relative to the
+	 * current screen, and not absolute.  Screens that implement the split
+	 * using physically distinct screens won't need this hack.
+	 */
+	getyx(stdscr, *yp, *xp);
+	*yp -= sp->woff;
+	return (0);
+}
+
+/*
+ * cl_deleteln --
+ *	Delete the current line, scrolling all lines below it.
+ *
+ * PUBLIC: int cl_deleteln __P((SCR *));
+ */
+int
+cl_deleteln(sp)
+	SCR *sp;
+{
+	CHAR_T ch;
+	CL_PRIVATE *clp;
+	size_t col, lno, spcnt, oldy, oldx;
+
+	clp = CLP(sp);
+
+	/*
+	 * This clause is required because the curses screen uses reverse
+	 * video to delimit split screens.  If the screen does not do this,
+	 * this code won't be necessary.
+	 *
+	 * If the bottom line was in reverse video, rewrite it in normal
+	 * video before it's scrolled.
+	 *
+	 * Check for the existence of a chgat function; XSI requires it, but
+	 * historic implementations of System V curses don't.   If it's not
+	 * a #define, we'll fall back to doing it by hand, which is slow but
+	 * acceptable.
+	 *
+	 * By hand means walking through the line, retrieving and rewriting
+	 * each character.  Curses has no EOL marker, so track strings of
+	 * spaces, and copy the trailing spaces only if there's a non-space
+	 * character following.
+	 */
+	if (!F_ISSET(sp, SC_SCR_EXWROTE) && IS_SPLIT(sp)) {
+		getyx(stdscr, oldy, oldx);
+#ifdef mvchgat
+		mvchgat(RLNO(sp, LASTLINE(sp)), 0, -1, A_NORMAL, 0, NULL);
+#else
+		for (lno = RLNO(sp, LASTLINE(sp)), col = spcnt = 0;;) {
+			(void)move(lno, col);
+			ch = winch(stdscr);
+			if (isblank(ch))
+				++spcnt;
+			else {
+				(void)move(lno, col - spcnt);
+				for (; spcnt > 0; --spcnt)
+					(void)addch(' ');
+				(void)addch(ch);
+			}
+			if (++col >= sp->cols)
+				break;
+		}
+#endif
+		(void)move(oldy, oldx);
+	}
+
+	/*
+	 * The bottom line is expected to be blank after this operation,
+	 * and other screens must support that semantic.
+	 */
+	return (deleteln() == ERR);
+}
+
+/* 
+ * cl_ex_adjust --
+ *	Adjust the screen for ex.  This routine is purely for standalone
+ *	ex programs.  All special purpose, all special case.
+ *
+ * PUBLIC: int cl_ex_adjust __P((SCR *, exadj_t));
+ */
+int
+cl_ex_adjust(sp, action)
+	SCR *sp;
+	exadj_t action;
+{
+	CL_PRIVATE *clp;
+	int cnt;
+
+	clp = CLP(sp);
+	switch (action) {
+	case EX_TERM_SCROLL:
+		/* Move the cursor up one line if that's possible. */
+		if (clp->cuu1 != NULL)
+			(void)tputs(clp->cuu1, 1, cl_putchar);
+		else if (clp->cup != NULL)
+			(void)tputs(tgoto(clp->cup,
+			    0, LINES - 2), 1, cl_putchar);
+		else
+			return (0);
+		/* FALLTHROUGH */
+	case EX_TERM_CE:
+		/* Clear the line. */
+		if (clp->el != NULL) {
+			(void)putchar('\r');
+			(void)tputs(clp->el, 1, cl_putchar);
+		} else {
+			/*
+			 * Historically, ex didn't erase the line, so, if the
+			 * displayed line was only a single glyph, and <eof>
+			 * was more than one glyph, the output would not fully
+			 * overwrite the user's input.  To fix this, output
+			 * the maxiumum character number of spaces.  Note,
+			 * this won't help if the user entered extra prompt
+			 * or <blank> characters before the command character.
+			 * We'd have to do a lot of work to make that work, and
+			 * it's almost certainly not worth the effort.
+			 */
+			for (cnt = 0; cnt < MAX_CHARACTER_COLUMNS; ++cnt)
+				(void)putchar('\b');
+			for (cnt = 0; cnt < MAX_CHARACTER_COLUMNS; ++cnt)
+				(void)putchar(' ');
+			(void)putchar('\r');
+			(void)fflush(stdout);
+		}
+		break;
+	default:
+		abort();
+	}
+	return (0);
+}
+
+/*
+ * cl_insertln --
+ *	Push down the current line, discarding the bottom line.
+ *
+ * PUBLIC: int cl_insertln __P((SCR *));
+ */
+int
+cl_insertln(sp)
+	SCR *sp;
+{
+	/*
+	 * The current line is expected to be blank after this operation,
+	 * and the screen must support that semantic.
+	 */
+	return (insertln() == ERR);
+}
+
+/*
+ * cl_keyval --
+ *	Return the value for a special key.
+ *
+ * PUBLIC: int cl_keyval __P((SCR *, scr_keyval_t, CHAR_T *, int *));
+ */
+int
+cl_keyval(sp, val, chp, dnep)
+	SCR *sp;
+	scr_keyval_t val;
+	CHAR_T *chp;
+	int *dnep;
+{
+	CL_PRIVATE *clp;
+
+	/*
+	 * VEOF, VERASE and VKILL are required by POSIX 1003.1-1990,
+	 * VWERASE is a 4BSD extension.
+	 */
+	clp = CLP(sp);
+	switch (val) {
+	case KEY_VEOF:
+		*dnep = (*chp = clp->orig.c_cc[VEOF]) == _POSIX_VDISABLE;
+		break;
+	case KEY_VERASE:
+		*dnep = (*chp = clp->orig.c_cc[VERASE]) == _POSIX_VDISABLE;
+		break;
+	case KEY_VKILL:
+		*dnep = (*chp = clp->orig.c_cc[VKILL]) == _POSIX_VDISABLE;
+		break;
+#ifdef VWERASE
+	case KEY_VWERASE:
+		*dnep = (*chp = clp->orig.c_cc[VWERASE]) == _POSIX_VDISABLE;
+		break;
+#endif
+	default:
+		*dnep = 1;
+		break;
+	}
+	return (0);
+}
+
+/*
+ * cl_move --
+ *	Move the cursor.
+ *
+ * PUBLIC: int cl_move __P((SCR *, size_t, size_t));
+ */
+int
+cl_move(sp, lno, cno)
+	SCR *sp;
+	size_t lno, cno;
+{
+	/* See the comment in cl_cursor. */
+	if (move(RLNO(sp, lno), cno) == ERR) {
+		msgq(sp, M_ERR,
+		    "Error: move: l(%u) c(%u) o(%u)", lno, cno, sp->woff);
+		return (1);
+	}
+	return (0);
+}
+
+/*
+ * cl_refresh --
+ *	Refresh the screen.
+ *
+ * PUBLIC: int cl_refresh __P((SCR *, int));
+ */
+int
+cl_refresh(sp, repaint)
+	SCR *sp;
+	int repaint;
+{
+	CL_PRIVATE *clp;
+
+	clp = CLP(sp);
+
+	/*
+	 * If we received a killer signal, we're done, there's no point
+	 * in refreshing the screen.
+	 */
+	if (clp->killersig)
+		return (0);
+
+	/*
+	 * If repaint is set, the editor is telling us that we don't know
+	 * what's on the screen, so we have to repaint from scratch.
+	 *
+	 * In the curses library, doing wrefresh(curscr) is okay, but the
+	 * screen flashes when we then apply the refresh() to bring it up
+	 * to date.  So, use clearok().
+	 */
+	if (repaint)
+		clearok(curscr, 1);
+	return (refresh() == ERR);
+}
+
+/*
+ * cl_rename --
+ *	Rename the file.
+ *
+ * PUBLIC: int cl_rename __P((SCR *, char *, int));
+ */
+int
+cl_rename(sp, name, on)
+	SCR *sp;
+	char *name;
+	int on;
+{
+	GS *gp;
+	CL_PRIVATE *clp;
+	char *ttype;
+
+	gp = sp->gp;
+	clp = CLP(sp);
+
+	ttype = OG_STR(gp, GO_TERM);
+
+	/*
+	 * XXX
+	 * We can only rename windows for xterm.
+	 */
+	if (on) {
+		if (F_ISSET(clp, CL_RENAME_OK) &&
+		    !strncmp(ttype, "xterm", sizeof("xterm") - 1)) {
+			F_SET(clp, CL_RENAME);
+			(void)printf(XTERM_RENAME, name);
+			(void)fflush(stdout);
+		}
+	} else
+		if (F_ISSET(clp, CL_RENAME)) {
+			F_CLR(clp, CL_RENAME);
+			(void)printf(XTERM_RENAME, ttype);
+			(void)fflush(stdout);
+		}
+	return (0);
+}
+
+/*
+ * cl_suspend --
+ *	Suspend a screen.
+ *
+ * PUBLIC: int cl_suspend __P((SCR *, int *));
+ */
+int
+cl_suspend(sp, allowedp)
+	SCR *sp;
+	int *allowedp;
+{
+	struct termios t;
+	CL_PRIVATE *clp;
+	GS *gp;
+	size_t oldy, oldx;
+	int changed;
+
+	gp = sp->gp;
+	clp = CLP(sp);
+	*allowedp = 1;
+
+	/*
+	 * The ex implementation of this function isn't needed by screens not
+	 * supporting ex commands that require full terminal canonical mode
+	 * (e.g. :suspend).
+	 *
+	 * The vi implementation of this function isn't needed by screens not
+	 * supporting vi process suspension, i.e. any screen that isn't backed
+	 * by a UNIX shell.
+	 *
+	 * Setting allowedp to 0 will cause the editor to reject the command.
+	 */
+	if (F_ISSET(sp, SC_EX)) { 
+		/* Save the terminal settings, and restore the original ones. */
+		if (F_ISSET(clp, CL_STDIN_TTY)) {
+			(void)tcgetattr(STDIN_FILENO, &t);
+			(void)tcsetattr(STDIN_FILENO,
+			    TCSASOFT | TCSADRAIN, &clp->orig);
+		}
+
+		/* Stop the process group. */
+		(void)kill(0, SIGTSTP);
+
+		/* Time passes ... */
+
+		/* Restore terminal settings. */
+		if (F_ISSET(clp, CL_STDIN_TTY))
+			(void)tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &t);
+		return (0);
+	}
+
+	/*
+	 * Move to the lower left-hand corner of the screen.
+	 *
+	 * XXX
+	 * Not sure this is necessary in System V implementations, but it
+	 * shouldn't hurt.
+	 */
+	getyx(stdscr, oldy, oldx);
+	(void)move(LINES - 1, 0);
+	(void)refresh();
+
+	/*
+	 * Temporarily end the screen.  System V introduced a semantic where
+	 * endwin() could be restarted.  We use it because restarting curses
+	 * from scratch often fails in System V.  4BSD curses didn't support
+	 * restarting after endwin(), so we have to do what clean up we can
+	 * without calling it.
+	 */
+#ifdef HAVE_BSD_CURSES
+	/* Save the terminal settings. */
+	(void)tcgetattr(STDIN_FILENO, &t);
+#endif
+
+	/* Restore the cursor keys to normal mode. */
+	(void)keypad(stdscr, FALSE);
+
+	/* Restore the window name. */
+	(void)cl_rename(sp, NULL, 0);
+
+#ifdef HAVE_BSD_CURSES
+	(void)cl_attr(sp, SA_ALTERNATE, 0);
+#else
+	(void)endwin();
+#endif
+	/*
+	 * XXX
+	 * Restore the original terminal settings.  This is bad -- the
+	 * reset can cause character loss from the tty queue.  However,
+	 * we can't call endwin() in BSD curses implementations, and too
+	 * many System V curses implementations don't get it right.
+	 */
+	(void)tcsetattr(STDIN_FILENO, TCSADRAIN | TCSASOFT, &clp->orig);
+
+	/* Stop the process group. */
+	(void)kill(0, SIGTSTP);
+
+	/* Time passes ... */
+
+	/*
+	 * If we received a killer signal, we're done.  Leave everything
+	 * unchanged.  In addition, the terminal has already been reset
+	 * correctly, so leave it alone.
+	 */
+	if (clp->killersig) {
+		F_CLR(clp, CL_SCR_EX_INIT | CL_SCR_VI_INIT);
+		return (0);
+	}
+
+#ifdef HAVE_BSD_CURSES
+	/* Restore terminal settings. */
+	if (F_ISSET(clp, CL_STDIN_TTY))
+		(void)tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &t);
+
+	(void)cl_attr(sp, SA_ALTERNATE, 1);
+#endif
+
+	/* Set the window name. */
+	(void)cl_rename(sp, sp->frp->name, 1);
+
+	/* Put the cursor keys into application mode. */
+	(void)keypad(stdscr, TRUE);
+
+	/* Refresh and repaint the screen. */
+	(void)move(oldy, oldx);
+	(void)cl_refresh(sp, 1);
+
+	/* If the screen changed size, set the SIGWINCH bit. */
+	if (cl_ssize(sp, 1, NULL, NULL, &changed))
+		return (1);
+	if (changed)
+		F_SET(CLP(sp), CL_SIGWINCH);
+
+	return (0);
+}
+
+/*
+ * cl_usage --
+ *	Print out the curses usage messages.
+ * 
+ * PUBLIC: void cl_usage __P((void));
+ */
+void
+cl_usage()
+{
+#define	USAGE "\
+usage: ex [-eFRrSsv] [-c command] [-t tag] [-w size] [file ...]\n\
+usage: vi [-eFlRrSv] [-c command] [-t tag] [-w size] [file ...]\n"
+	(void)fprintf(stderr, "%s", USAGE);
+#undef	USAGE
+}
+
+#ifdef DEBUG
+/*
+ * gdbrefresh --
+ *	Stub routine so can flush out curses screen changes using gdb.
+ */
+int
+gdbrefresh()
+{
+	refresh();
+	return (0);		/* XXX Convince gdb to run it. */
+}
+#endif
diff --git a/contrib/nvi/cl/cl_main.c b/contrib/nvi/cl/cl_main.c
new file mode 100644
index 0000000..2889f70
--- /dev/null
+++ b/contrib/nvi/cl/cl_main.c
@@ -0,0 +1,471 @@
+/*-
+ * Copyright (c) 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1993, 1994, 1995, 1996
+ *	Keith Bostic.  All rights reserved.
+ *
+ * See the LICENSE file for redistribution information.
+ */
+
+#include "config.h"
+
+#ifndef lint
+static const char sccsid[] = "@(#)cl_main.c	10.36 (Berkeley) 10/14/96";
+#endif /* not lint */
+
+#include <sys/types.h>
+#include <sys/queue.h>
+
+#include <bitstring.h>
+#include <curses.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include "../common/common.h"
+#ifdef RUNNING_IP
+#include "../ip/ip.h"
+#endif
+#include "cl.h"
+#include "pathnames.h"
+
+GS *__global_list;				/* GLOBAL: List of screens. */
+sigset_t __sigblockset;				/* GLOBAL: Blocked signals. */
+
+static void	   cl_func_std __P((GS *));
+static CL_PRIVATE *cl_init __P((GS *));
+static GS	  *gs_init __P((char *));
+static void	   perr __P((char *, char *));
+static int	   setsig __P((int, struct sigaction *, void (*)(int)));
+static void	   sig_end __P((GS *));
+static void	   term_init __P((char *, char *));
+
+/*
+ * main --
+ *	This is the main loop for the standalone curses editor.
+ */
+int
+main(argc, argv)
+	int argc;
+	char *argv[];
+{
+	static int reenter;
+	CL_PRIVATE *clp;
+	GS *gp;
+	size_t rows, cols;
+	int rval;
+	char *ip_arg, **p_av, **t_av, *ttype;
+
+	/* If loaded at 0 and jumping through a NULL pointer, stop. */
+	if (reenter++)
+		abort();
+
+	/* Create and initialize the global structure. */
+	__global_list = gp = gs_init(argv[0]);
+
+	/*
+	 * Strip out any arguments that vi isn't going to understand.  There's
+	 * no way to portably call getopt twice, so arguments parsed here must
+	 * be removed from the argument list.
+	 */
+#ifdef RUNNING_IP
+	ip_arg = NULL;
+	for (p_av = t_av = argv;;) {
+		if (*t_av == NULL) {
+			*p_av = NULL;
+			break;
+		}
+		if (!strcmp(*t_av, "--")) {
+			while ((*p_av++ = *t_av++) != NULL);
+			break;
+		}
+		if (!memcmp(*t_av, "-I", sizeof("-I") - 1)) {
+			if (t_av[0][2] != '\0') {
+				ip_arg = t_av[0] + 2;
+				++t_av;
+				--argc;
+				continue;
+			}
+			if (t_av[1] != NULL) {
+				ip_arg = t_av[1];
+				t_av += 2;
+				argc -= 2;
+				continue;
+			}
+		}
+		*p_av++ = *t_av++;
+	}
+
+	/*
+	 * If we're being called as an editor library, we're done here, we
+	 * get loaded with the curses screen, we don't share much code.
+	 */
+	if (ip_arg != NULL)
+		exit (ip_main(argc, argv, gp, ip_arg));
+#else
+	ip_arg = argv[0];
+#endif
+		
+	/* Create and initialize the CL_PRIVATE structure. */
+	clp = cl_init(gp);
+
+	/*
+	 * Initialize the terminal information.
+	 *
+	 * We have to know what terminal it is from the start, since we may
+	 * have to use termcap/terminfo to find out how big the screen is.
+	 */
+	if ((ttype = getenv("TERM")) == NULL)
+		ttype = "unknown";
+	term_init(gp->progname, ttype);
+
+	/* Add the terminal type to the global structure. */
+	if ((OG_D_STR(gp, GO_TERM) =
+	    OG_STR(gp, GO_TERM) = strdup(ttype)) == NULL)
+		perr(gp->progname, NULL);
+
+	/* Figure out how big the screen is. */
+	if (cl_ssize(NULL, 0, &rows, &cols, NULL))
+		exit (1);
+
+	/* Add the rows and columns to the global structure. */
+	OG_VAL(gp, GO_LINES) = OG_D_VAL(gp, GO_LINES) = rows;
+	OG_VAL(gp, GO_COLUMNS) = OG_D_VAL(gp, GO_COLUMNS) = cols;
+
+	/* Ex wants stdout to be buffered. */
+	(void)setvbuf(stdout, NULL, _IOFBF, 0);
+
+	/* Start catching signals. */
+	if (sig_init(gp, NULL))
+		exit (1);
+
+	/* Run ex/vi. */
+	rval = editor(gp, argc, argv);
+
+	/* Clean up signals. */
+	sig_end(gp);
+
+	/* Clean up the terminal. */
+	(void)cl_quit(gp);
+
+	/*
+	 * XXX
+	 * Reset the O_MESG option.
+	 */
+	if (clp->tgw != TGW_UNKNOWN)
+		(void)cl_omesg(NULL, clp, clp->tgw == TGW_SET);
+
+	/*
+	 * XXX
+	 * Reset the X11 xterm icon/window name.
+	 */
+	if (F_ISSET(clp, CL_RENAME)) {
+		(void)printf(XTERM_RENAME, ttype);
+		(void)fflush(stdout);
+	}
+
+	/* If a killer signal arrived, pretend we just got it. */
+	if (clp->killersig) {
+		(void)signal(clp->killersig, SIG_DFL);
+		(void)kill(getpid(), clp->killersig);
+		/* NOTREACHED */
+	}
+
+	/* Free the global and CL private areas. */
+#if defined(DEBUG) || defined(PURIFY) || defined(LIBRARY)
+	free(clp);
+	free(gp);
+#endif
+
+	exit (rval);
+}
+
+/*
+ * gs_init --
+ *	Create and partially initialize the GS structure.
+ */
+static GS *
+gs_init(name)
+	char *name;
+{
+	CL_PRIVATE *clp;
+	GS *gp;
+	char *p;
+
+	/* Figure out what our name is. */
+	if ((p = strrchr(name, '/')) != NULL)
+		name = p + 1;
+
+	/* Allocate the global structure. */
+	CALLOC_NOMSG(NULL, gp, GS *, 1, sizeof(GS));
+	if (gp == NULL)
+		perr(name, NULL);
+
+
+	gp->progname = name;
+	return (gp);
+}
+
+/*
+ * cl_init --
+ *	Create and partially initialize the CL structure.
+ */
+static CL_PRIVATE *
+cl_init(gp)
+	GS *gp;
+{
+	CL_PRIVATE *clp;
+	int fd;
+
+	/* Allocate the CL private structure. */
+	CALLOC_NOMSG(NULL, clp, CL_PRIVATE *, 1, sizeof(CL_PRIVATE));
+	if (clp == NULL)
+		perr(gp->progname, NULL);
+	gp->cl_private = clp;
+
+	/*
+	 * Set the CL_STDIN_TTY flag.  It's purpose is to avoid setting
+	 * and resetting the tty if the input isn't from there.  We also
+	 * use the same test to determine if we're running a script or
+	 * not.
+	 */
+	if (isatty(STDIN_FILENO))
+		F_SET(clp, CL_STDIN_TTY);
+	else
+		F_SET(gp, G_SCRIPTED);
+
+	/*
+	 * We expect that if we've lost our controlling terminal that the
+	 * open() (but not the tcgetattr()) will fail.
+	 */
+	if (F_ISSET(clp, CL_STDIN_TTY)) {
+		if (tcgetattr(STDIN_FILENO, &clp->orig) == -1)
+			goto tcfail;
+	} else if ((fd = open(_PATH_TTY, O_RDONLY, 0)) != -1) {
+		if (tcgetattr(fd, &clp->orig) == -1) {
+tcfail:			perr(gp->progname, "tcgetattr");
+			exit (1);
+		}
+		(void)close(fd);
+	}
+
+	/* Initialize the list of curses functions. */
+	cl_func_std(gp);
+
+	return (clp);
+}
+
+/*
+ * term_init --
+ *	Initialize terminal information.
+ */
+static void
+term_init(name, ttype)
+	char *name, *ttype;
+{
+	int err;
+
+	/* Set up the terminal database information. */
+	setupterm(ttype, STDOUT_FILENO, &err);
+	switch (err) {
+	case -1:
+		(void)fprintf(stderr,
+		    "%s: No terminal database found\n", name);
+		exit (1);
+	case 0:
+		(void)fprintf(stderr,
+		    "%s: %s: unknown terminal type\n", name, ttype);
+		exit (1);
+	}
+}
+
+#define	GLOBAL_CLP \
+	CL_PRIVATE *clp = GCLP(__global_list);
+static void
+h_hup(signo)
+	int signo;
+{
+	GLOBAL_CLP;
+
+	F_SET(clp, CL_SIGHUP);
+	clp->killersig = SIGHUP;
+}
+
+static void
+h_int(signo)
+	int signo;
+{
+	GLOBAL_CLP;
+
+	F_SET(clp, CL_SIGINT);
+}
+
+static void
+h_term(signo)
+	int signo;
+{
+	GLOBAL_CLP;
+
+	F_SET(clp, CL_SIGTERM);
+	clp->killersig = SIGTERM;
+}
+
+static void
+h_winch(signo)
+	int signo;
+{
+	GLOBAL_CLP;
+
+	F_SET(clp, CL_SIGWINCH);
+}
+#undef	GLOBAL_CLP
+
+/*
+ * sig_init --
+ *	Initialize signals.
+ *
+ * PUBLIC: int sig_init __P((GS *, SCR *));
+ */
+int
+sig_init(gp, sp)
+	GS *gp;
+	SCR *sp;
+{
+	CL_PRIVATE *clp;
+
+	clp = GCLP(gp);
+
+	if (sp == NULL) {
+		(void)sigemptyset(&__sigblockset);
+		if (sigaddset(&__sigblockset, SIGHUP) ||
+		    setsig(SIGHUP, &clp->oact[INDX_HUP], h_hup) ||
+		    sigaddset(&__sigblockset, SIGINT) ||
+		    setsig(SIGINT, &clp->oact[INDX_INT], h_int) ||
+		    sigaddset(&__sigblockset, SIGTERM) ||
+		    setsig(SIGTERM, &clp->oact[INDX_TERM], h_term)
+#ifdef SIGWINCH
+		    ||
+		    sigaddset(&__sigblockset, SIGWINCH) ||
+		    setsig(SIGWINCH, &clp->oact[INDX_WINCH], h_winch)
+#endif
+		    ) {
+			perr(gp->progname, NULL);
+			return (1);
+		}
+	} else
+		if (setsig(SIGHUP, NULL, h_hup) ||
+		    setsig(SIGINT, NULL, h_int) ||
+		    setsig(SIGTERM, NULL, h_term)
+#ifdef SIGWINCH
+		    ||
+		    setsig(SIGWINCH, NULL, h_winch)
+#endif
+		    ) {
+			msgq(sp, M_SYSERR, "signal-reset");
+		}
+	return (0);
+}
+
+/*
+ * setsig --
+ *	Set a signal handler.
+ */
+static int
+setsig(signo, oactp, handler)
+	int signo;
+	struct sigaction *oactp;
+	void (*handler) __P((int));
+{
+	struct sigaction act;
+
+	/*
+	 * Use sigaction(2), not signal(3), since we don't always want to
+	 * restart system calls.  The example is when waiting for a command
+	 * mode keystroke and SIGWINCH arrives.  Besides, you can't portably
+	 * restart system calls (thanks, POSIX!).  On the other hand, you
+	 * can't portably NOT restart system calls (thanks, Sun!).  SunOS
+	 * used SA_INTERRUPT as their extension to NOT restart read calls.
+	 * We sure hope nobody else used it for anything else.  Mom told me
+	 * there'd be days like this.  She just never told me that there'd
+	 * be so many.
+	 */
+	act.sa_handler = handler;
+	sigemptyset(&act.sa_mask);
+
+#ifdef SA_INTERRUPT
+	act.sa_flags = SA_INTERRUPT;
+#else
+	act.sa_flags = 0;
+#endif
+	return (sigaction(signo, &act, oactp));
+}
+
+/*
+ * sig_end --
+ *	End signal setup.
+ */
+static void
+sig_end(gp)
+	GS *gp;
+{
+	CL_PRIVATE *clp;
+
+	clp = GCLP(gp);
+	(void)sigaction(SIGHUP, NULL, &clp->oact[INDX_HUP]);
+	(void)sigaction(SIGINT, NULL, &clp->oact[INDX_INT]);
+	(void)sigaction(SIGTERM, NULL, &clp->oact[INDX_TERM]);
+#ifdef SIGWINCH
+	(void)sigaction(SIGWINCH, NULL, &clp->oact[INDX_WINCH]);
+#endif
+}
+
+/*
+ * cl_func_std --
+ *	Initialize the standard curses functions.
+ */
+static void
+cl_func_std(gp)
+	GS *gp;
+{
+	gp->scr_addstr = cl_addstr;
+	gp->scr_attr = cl_attr;
+	gp->scr_baud = cl_baud;
+	gp->scr_bell = cl_bell;
+	gp->scr_busy = NULL;
+	gp->scr_clrtoeol = cl_clrtoeol;
+	gp->scr_cursor = cl_cursor;
+	gp->scr_deleteln = cl_deleteln;
+	gp->scr_event = cl_event;
+	gp->scr_ex_adjust = cl_ex_adjust;
+	gp->scr_fmap = cl_fmap;
+	gp->scr_insertln = cl_insertln;
+	gp->scr_keyval = cl_keyval;
+	gp->scr_move = cl_move;
+	gp->scr_msg = NULL;
+	gp->scr_optchange = cl_optchange;
+	gp->scr_refresh = cl_refresh;
+	gp->scr_rename = cl_rename;
+	gp->scr_screen = cl_screen;
+	gp->scr_suspend = cl_suspend;
+	gp->scr_usage = cl_usage;
+}
+
+/*
+ * perr --
+ *	Print system error.
+ */
+static void
+perr(name, msg)
+	char *name, *msg;
+{
+	(void)fprintf(stderr, "%s:", name);
+	if (msg != NULL)
+		(void)fprintf(stderr, "%s:", msg);
+	(void)fprintf(stderr, "%s\n", strerror(errno));
+	exit(1);
+}
diff --git a/contrib/nvi/cl/cl_read.c b/contrib/nvi/cl/cl_read.c
new file mode 100644
index 0000000..8a95a77
--- /dev/null
+++ b/contrib/nvi/cl/cl_read.c
@@ -0,0 +1,334 @@
+/*-
+ * Copyright (c) 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1993, 1994, 1995, 1996
+ *	Keith Bostic.  All rights reserved.
+ *
+ * See the LICENSE file for redistribution information.
+ */
+
+#include "config.h"
+
+#ifndef lint
+static const char sccsid[] = "@(#)cl_read.c	10.15 (Berkeley) 9/24/96";
+#endif /* not lint */
+
+#include <sys/types.h>
+#include <sys/queue.h>
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+#include <sys/time.h>
+
+#include <bitstring.h>
+#include <curses.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include "../common/common.h"
+#include "../ex/script.h"
+#include "cl.h"
+
+static input_t	cl_read __P((SCR *,
+    u_int32_t, CHAR_T *, size_t, int *, struct timeval *));
+static int	cl_resize __P((SCR *, size_t, size_t));
+
+/*
+ * cl_event --
+ *	Return a single event.
+ *
+ * PUBLIC: int cl_event __P((SCR *, EVENT *, u_int32_t, int));
+ */
+int
+cl_event(sp, evp, flags, ms)
+	SCR *sp;
+	EVENT *evp;
+	u_int32_t flags;
+	int ms;
+{
+	struct timeval t, *tp;
+	CL_PRIVATE *clp;
+	size_t lines, columns;
+	int changed, nr;
+
+	/*
+	 * Queue signal based events.  We never clear SIGHUP or SIGTERM events,
+	 * so that we just keep returning them until the editor dies.
+	 */
+	clp = CLP(sp);
+retest:	if (LF_ISSET(EC_INTERRUPT) || F_ISSET(clp, CL_SIGINT)) {
+		if (F_ISSET(clp, CL_SIGINT)) {
+			F_CLR(clp, CL_SIGINT);
+			evp->e_event = E_INTERRUPT;
+		} else
+			evp->e_event = E_TIMEOUT;
+		return (0);
+	}
+	if (F_ISSET(clp, CL_SIGHUP | CL_SIGTERM | CL_SIGWINCH)) {
+		if (F_ISSET(clp, CL_SIGHUP)) {
+			evp->e_event = E_SIGHUP;
+			return (0);
+		}
+		if (F_ISSET(clp, CL_SIGTERM)) {
+			evp->e_event = E_SIGTERM;
+			return (0);
+		}
+		if (F_ISSET(clp, CL_SIGWINCH)) {
+			F_CLR(clp, CL_SIGWINCH);
+			if (cl_ssize(sp, 1, &lines, &columns, &changed))
+				return (1);
+			if (changed) {
+				(void)cl_resize(sp, lines, columns);
+				evp->e_event = E_WRESIZE;
+				return (0);
+			}
+			/* No real change, ignore the signal. */
+		}
+	}
+
+	/* Set timer. */
+	if (ms == 0)
+		tp = NULL;
+	else {
+		t.tv_sec = ms / 1000;
+		t.tv_usec = (ms % 1000) * 1000;
+		tp = &t;
+	}
+
+	/* Read input characters. */
+	switch (cl_read(sp, LF_ISSET(EC_QUOTED | EC_RAW),
+	    clp->ibuf, sizeof(clp->ibuf), &nr, tp)) {
+	case INP_OK:
+		evp->e_csp = clp->ibuf;
+		evp->e_len = nr;
+		evp->e_event = E_STRING;
+		break;
+	case INP_EOF:
+		evp->e_event = E_EOF;
+		break;
+	case INP_ERR:
+		evp->e_event = E_ERR;
+		break;
+	case INP_INTR:
+		goto retest;
+	case INP_TIMEOUT:
+		evp->e_event = E_TIMEOUT;
+		break;
+	default:
+		abort();
+	}
+	return (0);
+}
+
+/*
+ * cl_read --
+ *	Read characters from the input.
+ */
+static input_t
+cl_read(sp, flags, bp, blen, nrp, tp)
+	SCR *sp;
+	u_int32_t flags;
+	CHAR_T *bp;
+	size_t blen;
+	int *nrp;
+	struct timeval *tp;
+{
+	struct termios term1, term2;
+	struct timeval poll;
+	CL_PRIVATE *clp;
+	GS *gp;
+	SCR *tsp;
+	fd_set rdfd;
+	input_t rval;
+	int maxfd, nr, term_reset;
+
+	gp = sp->gp;
+	clp = CLP(sp);
+	term_reset = 0;
+
+	/*
+	 * 1: A read from a file or a pipe.  In this case, the reads
+	 *    never timeout regardless.  This means that we can hang
+	 *    when trying to complete a map, but we're going to hang
+	 *    on the next read anyway.
+	 */
+	if (!F_ISSET(clp, CL_STDIN_TTY)) {
+		switch (nr = read(STDIN_FILENO, bp, blen)) {
+		case 0:
+			return (INP_EOF);
+		case -1:
+			goto err;
+		default:
+			*nrp = nr;
+			return (INP_OK);
+		}
+		/* NOTREACHED */
+	}
+
+	/*
+	 * 2: A read with an associated timeout, e.g., trying to complete
+	 *    a map sequence.  If input exists, we fall into #3.
+	 */
+	FD_ZERO(&rdfd);
+	poll.tv_sec = 0;
+	poll.tv_usec = 0;
+	if (tp != NULL) {
+		FD_SET(STDIN_FILENO, &rdfd);
+		switch (select(STDIN_FILENO + 1,
+		    &rdfd, NULL, NULL, tp == NULL ? &poll : tp)) {
+		case 0:
+			return (INP_TIMEOUT);
+		case -1:
+			goto err;
+		default:
+			break;
+		}
+	}
+	
+	/*
+	 * The user can enter a key in the editor to quote a character.  If we
+	 * get here and the next key is supposed to be quoted, do what we can.
+	 * Reset the tty so that the user can enter a ^C, ^Q, ^S.  There's an
+	 * obvious race here, when the key has already been entered, but there's
+	 * nothing that we can do to fix that problem.
+	 *
+	 * The editor can ask for the next literal character even thought it's
+	 * generally running in line-at-a-time mode.  Do what we can.
+	 */
+	if (LF_ISSET(EC_QUOTED | EC_RAW) && !tcgetattr(STDIN_FILENO, &term1)) {
+		term_reset = 1;
+		if (LF_ISSET(EC_QUOTED)) {
+			term2 = term1;
+			term2.c_lflag &= ~ISIG;
+			term2.c_iflag &= ~(IXON | IXOFF);
+			(void)tcsetattr(STDIN_FILENO,
+			    TCSASOFT | TCSADRAIN, &term2);
+		} else
+			(void)tcsetattr(STDIN_FILENO,
+			    TCSASOFT | TCSADRAIN, &clp->vi_enter);
+	}
+
+	/*
+	 * 3: Wait for input.
+	 *
+	 * Select on the command input and scripting window file descriptors.
+	 * It's ugly that we wait on scripting file descriptors here, but it's
+	 * the only way to keep from locking out scripting windows.
+	 */
+	if (F_ISSET(gp, G_SCRWIN)) {
+loop:		FD_ZERO(&rdfd);
+		FD_SET(STDIN_FILENO, &rdfd);
+		maxfd = STDIN_FILENO;
+		for (tsp = gp->dq.cqh_first;
+		    tsp != (void *)&gp->dq; tsp = tsp->q.cqe_next)
+			if (F_ISSET(sp, SC_SCRIPT)) {
+				FD_SET(sp->script->sh_master, &rdfd);
+				if (sp->script->sh_master > maxfd)
+					maxfd = sp->script->sh_master;
+			}
+		switch (select(maxfd + 1, &rdfd, NULL, NULL, NULL)) {
+		case 0:
+			abort();
+		case -1:
+			goto err;
+		default:
+			break;
+		}
+		if (!FD_ISSET(STDIN_FILENO, &rdfd)) {
+			if (sscr_input(sp))
+				return (INP_ERR);
+			goto loop;
+		}
+	}
+
+	/*
+	 * 4: Read the input.
+	 *
+	 * !!!
+	 * What's going on here is some scary stuff.  Ex runs the terminal in
+	 * canonical mode.  So, the <newline> character terminating a line of
+	 * input is returned in the buffer, but a trailing <EOF> character is
+	 * not similarly included.  As ex uses 0<EOF> and ^<EOF> as autoindent
+	 * commands, it has to see the trailing <EOF> characters to determine
+	 * the difference between the user entering "0ab" and "0<EOF>ab".  We
+	 * leave an extra slot in the buffer, so that we can add a trailing
+	 * <EOF> character if the buffer isn't terminated by a <newline>.  We
+	 * lose if the buffer is too small for the line and exactly N characters
+	 * are entered followed by an <EOF> character.
+	 */
+#define	ONE_FOR_EOF	1
+	switch (nr = read(STDIN_FILENO, bp, blen - ONE_FOR_EOF)) {
+	case  0:				/* EOF. */
+		/*
+		 * ^D in canonical mode returns a read of 0, i.e. EOF.  EOF is
+		 * a valid command, but we don't want to loop forever because
+		 * the terminal driver is returning EOF because the user has
+		 * disconnected. The editor will almost certainly try to write
+		 * something before this fires, which should kill us, but You
+		 * Never Know.
+		 */
+		if (++clp->eof_count < 50) {
+			bp[0] = clp->orig.c_cc[VEOF];
+			*nrp = 1;
+			rval = INP_OK;
+
+		} else
+			rval = INP_EOF;
+		break;
+	case -1:				/* Error or interrupt. */
+err:		if (errno == EINTR)
+			rval = INP_INTR;
+		else {
+			rval = INP_ERR;
+			msgq(sp, M_SYSERR, "input");
+		}
+		break;
+	default:				/* Input characters. */
+		if (F_ISSET(sp, SC_EX) && bp[nr - 1] != '\n')
+			bp[nr++] = clp->orig.c_cc[VEOF];
+		*nrp = nr;
+		clp->eof_count = 0;
+		rval = INP_OK;
+		break;
+	}
+
+	/* Restore the terminal state if it was modified. */
+	if (term_reset)
+		(void)tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &term1);
+	return (rval);
+}
+
+/* 
+ * cl_resize --
+ *	Reset the options for a resize event.
+ */
+static int
+cl_resize(sp, lines, columns)
+	SCR *sp;
+	size_t lines, columns;
+{
+	ARGS *argv[2], a, b;
+	char b1[1024];
+
+	a.bp = b1;
+	b.bp = NULL;
+	a.len = b.len = 0;
+	argv[0] = &a;
+	argv[1] = &b;
+
+	(void)snprintf(b1, sizeof(b1), "lines=%lu", (u_long)lines);
+	a.len = strlen(b1);
+	if (opts_set(sp, argv, NULL))
+		return (1);
+	(void)snprintf(b1, sizeof(b1), "columns=%lu", (u_long)columns);
+	a.len = strlen(b1);
+	if (opts_set(sp, argv, NULL))
+		return (1);
+	return (0);
+}
diff --git a/contrib/nvi/cl/cl_screen.c b/contrib/nvi/cl/cl_screen.c
new file mode 100644
index 0000000..2ce58e8
--- /dev/null
+++ b/contrib/nvi/cl/cl_screen.c
@@ -0,0 +1,581 @@
+/*-
+ * Copyright (c) 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1993, 1994, 1995, 1996
+ *	Keith Bostic.  All rights reserved.
+ *
+ * See the LICENSE file for redistribution information.
+ */
+
+#include "config.h"
+
+#ifndef lint
+static const char sccsid[] = "@(#)cl_screen.c	10.49 (Berkeley) 9/24/96";
+#endif /* not lint */
+
+#include <sys/types.h>
+#include <sys/queue.h>
+
+#include <bitstring.h>
+#include <curses.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include "../common/common.h"
+#include "cl.h"
+
+static int	cl_ex_end __P((GS *));
+static int	cl_ex_init __P((SCR *));
+static void	cl_freecap __P((CL_PRIVATE *));
+static int	cl_vi_end __P((GS *));
+static int	cl_vi_init __P((SCR *));
+static int	cl_putenv __P((char *, char *, u_long));
+
+/*
+ * cl_screen --
+ *	Switch screen types.
+ *
+ * PUBLIC: int cl_screen __P((SCR *, u_int32_t));
+ */
+int
+cl_screen(sp, flags)
+	SCR *sp;
+	u_int32_t flags;
+{
+	CL_PRIVATE *clp;
+	GS *gp;
+
+	gp = sp->gp;
+	clp = CLP(sp);
+
+	/* See if the current information is incorrect. */
+	if (F_ISSET(gp, G_SRESTART)) {
+		if (cl_quit(gp))
+			return (1);
+		F_CLR(gp, G_SRESTART);
+	}
+	
+	/* See if we're already in the right mode. */
+	if (LF_ISSET(SC_EX) && F_ISSET(sp, SC_SCR_EX) ||
+	    LF_ISSET(SC_VI) && F_ISSET(sp, SC_SCR_VI))
+		return (0);
+
+	/*
+	 * Fake leaving ex mode.
+	 *
+	 * We don't actually exit ex or vi mode unless forced (e.g. by a window
+	 * size change).  This is because many curses implementations can't be
+	 * called twice in a single program.  Plus, it's faster.  If the editor
+	 * "leaves" vi to enter ex, when it exits ex we'll just fall back into
+	 * vi.
+	 */
+	if (F_ISSET(sp, SC_SCR_EX))
+		F_CLR(sp, SC_SCR_EX);
+
+	/*
+	 * Fake leaving vi mode.
+	 *
+	 * Clear out the rest of the screen if we're in the middle of a split
+	 * screen.  Move to the last line in the current screen -- this makes
+	 * terminal scrolling happen naturally.  Note: *don't* move past the
+	 * end of the screen, as there are ex commands (e.g., :read ! cat file)
+	 * that don't want to.  Don't clear the info line, its contents may be
+	 * valid, e.g. :file|append.
+	 */
+	if (F_ISSET(sp, SC_SCR_VI)) {
+		F_CLR(sp, SC_SCR_VI);
+
+		if (sp->q.cqe_next != (void *)&gp->dq) {
+			(void)move(RLNO(sp, sp->rows), 0);
+			clrtobot();
+		}
+		(void)move(RLNO(sp, sp->rows) - 1, 0);
+		refresh();
+	}
+
+	/* Enter the requested mode. */
+	if (LF_ISSET(SC_EX)) {
+		if (cl_ex_init(sp))
+			return (1);
+		F_SET(clp, CL_IN_EX | CL_SCR_EX_INIT);
+
+		/*
+		 * If doing an ex screen for ex mode, move to the last line
+		 * on the screen.
+		 */
+		if (F_ISSET(sp, SC_EX) && clp->cup != NULL)
+			tputs(tgoto(clp->cup,
+			    0, O_VAL(sp, O_LINES) - 1), 1, cl_putchar);
+	} else {
+		if (cl_vi_init(sp))
+			return (1);
+		F_CLR(clp, CL_IN_EX);
+		F_SET(clp, CL_SCR_VI_INIT);
+	}
+	return (0);
+}
+
+/*
+ * cl_quit --
+ *	Shutdown the screens.
+ *
+ * PUBLIC: int cl_quit __P((GS *));
+ */
+int
+cl_quit(gp)
+	GS *gp;
+{
+	CL_PRIVATE *clp;
+	int rval;
+
+	rval = 0;
+	clp = GCLP(gp);
+
+	/*
+	 * If we weren't really running, ignore it.  This happens if the
+	 * screen changes size before we've called curses.
+	 */
+	if (!F_ISSET(clp, CL_SCR_EX_INIT | CL_SCR_VI_INIT))
+		return (0);
+
+	/* Clean up the terminal mappings. */
+	if (cl_term_end(gp))
+		rval = 1;
+
+	/* Really leave vi mode. */
+	if (F_ISSET(clp, CL_STDIN_TTY) &&
+	    F_ISSET(clp, CL_SCR_VI_INIT) && cl_vi_end(gp))
+		rval = 1;
+
+	/* Really leave ex mode. */
+	if (F_ISSET(clp, CL_STDIN_TTY) &&
+	    F_ISSET(clp, CL_SCR_EX_INIT) && cl_ex_end(gp))
+		rval = 1;
+
+	/*
+	 * If we were running ex when we quit, or we're using an implementation
+	 * of curses where endwin() doesn't get this right, restore the original
+	 * terminal modes.
+	 *
+	 * XXX
+	 * We always do this because it's too hard to figure out what curses
+	 * implementations get it wrong.  It may discard type-ahead characters
+	 * from the tty queue.
+	 */
+	(void)tcsetattr(STDIN_FILENO, TCSADRAIN | TCSASOFT, &clp->orig);
+
+	F_CLR(clp, CL_SCR_EX_INIT | CL_SCR_VI_INIT);
+	return (rval);
+}
+
+/*
+ * cl_vi_init --
+ *	Initialize the curses vi screen.
+ */
+static int
+cl_vi_init(sp)
+	SCR *sp;
+{
+	CL_PRIVATE *clp;
+	GS *gp;
+	char *o_cols, *o_lines, *o_term, *ttype;
+
+	gp = sp->gp;
+	clp = CLP(sp);
+
+	/* If already initialized, just set the terminal modes. */
+	if (F_ISSET(clp, CL_SCR_VI_INIT))
+		goto fast;
+
+	/* Curses vi always reads from (and writes to) a terminal. */
+	if (!F_ISSET(clp, CL_STDIN_TTY) || !isatty(STDOUT_FILENO)) {
+		msgq(sp, M_ERR,
+		    "016|Vi's standard input and output must be a terminal");
+		return (1);
+	}
+
+	/* We'll need a terminal type. */
+	if (opts_empty(sp, O_TERM, 0))
+		return (1);
+	ttype = O_STR(sp, O_TERM);
+
+	/*
+	 * XXX
+	 * Changing the row/column and terminal values is done by putting them
+	 * into the environment, which is then read by curses.  What this loses
+	 * in ugliness, it makes up for in stupidity.  We can't simply put the
+	 * values into the environment ourselves, because in the presence of a
+	 * kernel mechanism for returning the window size, entering values into
+	 * the environment will screw up future screen resizing events, e.g. if
+	 * the user enters a :shell command and then resizes their window.  So,
+	 * if they weren't already in the environment, we make sure to delete
+	 * them immediately after setting them.
+	 *
+	 * XXX
+	 * Putting the TERM variable into the environment is necessary, even
+	 * though we're using newterm() here.  We may be using initscr() as
+	 * the underlying function.
+	 */
+	o_term = getenv("TERM");
+	cl_putenv("TERM", ttype, 0);
+	o_lines = getenv("LINES");
+	cl_putenv("LINES", NULL, (u_long)O_VAL(sp, O_LINES));
+	o_cols = getenv("COLUMNS");
+	cl_putenv("COLUMNS", NULL, (u_long)O_VAL(sp, O_COLUMNS));
+
+	/*
+	 * We don't care about the SCREEN reference returned by newterm, we
+	 * never have more than one SCREEN at a time.
+	 *
+	 * XXX
+	 * The SunOS initscr() can't be called twice.  Don't even think about
+	 * using it.  It fails in subtle ways (e.g. select(2) on fileno(stdin)
+	 * stops working).  (The SVID notes that applications should only call
+	 * initscr() once.)
+	 *
+	 * XXX
+	 * The HP/UX newterm doesn't support the NULL first argument, so we
+	 * have to specify the terminal type.
+	 */
+	errno = 0;
+	if (newterm(ttype, stdout, stdin) == NULL) {
+		if (errno)
+			msgq(sp, M_SYSERR, "%s", ttype);
+		else
+			msgq(sp, M_ERR, "%s: unknown terminal type", ttype);
+		return (1);
+	}
+
+	if (o_term == NULL)
+		unsetenv("TERM");
+	if (o_lines == NULL)
+		unsetenv("LINES");
+	if (o_cols == NULL)
+		unsetenv("COLUMNS");
+
+	/*
+	 * XXX
+	 * Someone got let out alone without adult supervision -- the SunOS
+	 * newterm resets the signal handlers.  There's a race, but it's not
+	 * worth closing.
+	 */
+	(void)sig_init(sp->gp, sp);
+
+	/*
+	 * We use raw mode.  What we want is 8-bit clean, however, signals
+	 * and flow control should continue to work.  Admittedly, it sounds
+	 * like cbreak, but it isn't.  Using cbreak() can get you additional
+	 * things like IEXTEN, which turns on flags like DISCARD and LNEXT.
+	 *
+	 * !!!
+	 * If raw isn't turning off echo and newlines, something's wrong.
+	 * However, it shouldn't hurt.
+	 */
+	noecho();			/* No character echo. */
+	nonl();				/* No CR/NL translation. */
+	raw();				/* 8-bit clean. */
+	idlok(stdscr, 1);		/* Use hardware insert/delete line. */
+
+	/* Put the cursor keys into application mode. */
+	(void)keypad(stdscr, TRUE);
+
+	/*
+	 * XXX
+	 * The screen TI sequence just got sent.  See the comment in
+	 * cl_funcs.c:cl_attr().
+	 */
+	clp->ti_te = TI_SENT;
+
+	/*
+	 * XXX
+	 * Historic implementations of curses handled SIGTSTP signals
+	 * in one of three ways.  They either:
+	 *
+	 *	1: Set their own handler, regardless.
+	 *	2: Did not set a handler if a handler was already installed.
+	 *	3: Set their own handler, but then called any previously set
+	 *	   handler after completing their own cleanup.
+	 *
+	 * We don't try and figure out which behavior is in place, we force
+	 * it to SIG_DFL after initializing the curses interface, which means
+	 * that curses isn't going to take the signal.  Since curses isn't
+	 * reentrant (i.e., the whole curses SIGTSTP interface is a fantasy),
+	 * we're doing The Right Thing.
+	 */
+	(void)signal(SIGTSTP, SIG_DFL);
+
+	/*
+	 * If flow control was on, turn it back on.  Turn signals on.  ISIG
+	 * turns on VINTR, VQUIT, VDSUSP and VSUSP.   The main curses code
+	 * already installed a handler for VINTR.  We're going to disable the
+	 * other three.
+	 *
+	 * XXX
+	 * We want to use ^Y as a vi scrolling command.  If the user has the
+	 * DSUSP character set to ^Y (common practice) clean it up.  As it's
+	 * equally possible that the user has VDSUSP set to 'a', we disable
+	 * it regardless.  It doesn't make much sense to suspend vi at read,
+	 * so I don't think anyone will care.  Alternatively, we could look
+	 * it up in the table of legal command characters and turn it off if
+	 * it matches one.  VDSUSP wasn't in POSIX 1003.1-1990, so we test for
+	 * it.
+	 *
+	 * XXX
+	 * We don't check to see if the user had signals enabled originally.
+	 * If they didn't, it's unclear what we're supposed to do here, but
+	 * it's also pretty unlikely.
+	 */
+	if (tcgetattr(STDIN_FILENO, &clp->vi_enter)) {
+		msgq(sp, M_SYSERR, "tcgetattr");
+		goto err;
+	}
+	if (clp->orig.c_iflag & IXON)
+		clp->vi_enter.c_iflag |= IXON;
+	if (clp->orig.c_iflag & IXOFF)
+		clp->vi_enter.c_iflag |= IXOFF;
+
+	clp->vi_enter.c_lflag |= ISIG;
+#ifdef VDSUSP
+	clp->vi_enter.c_cc[VDSUSP] = _POSIX_VDISABLE;
+#endif
+	clp->vi_enter.c_cc[VQUIT] = _POSIX_VDISABLE;
+	clp->vi_enter.c_cc[VSUSP] = _POSIX_VDISABLE;
+
+	/*
+	 * XXX
+	 * OSF/1 doesn't turn off the <discard>, <literal-next> or <status>
+	 * characters when curses switches into raw mode.  It should be OK
+	 * to do it explicitly for everyone.
+	 */
+#ifdef VDISCARD
+	clp->vi_enter.c_cc[VDISCARD] = _POSIX_VDISABLE;
+#endif
+#ifdef VLNEXT
+	clp->vi_enter.c_cc[VLNEXT] = _POSIX_VDISABLE;
+#endif
+#ifdef VSTATUS
+	clp->vi_enter.c_cc[VSTATUS] = _POSIX_VDISABLE;
+#endif
+
+	/* Initialize terminal based information. */
+	if (cl_term_init(sp))
+		goto err;
+
+fast:	/* Set the terminal modes. */
+	if (tcsetattr(STDIN_FILENO, TCSASOFT | TCSADRAIN, &clp->vi_enter)) {
+		msgq(sp, M_SYSERR, "tcsetattr");
+err:		(void)cl_vi_end(sp->gp);
+		return (1);
+	}
+	return (0);
+}
+
+/*
+ * cl_vi_end --
+ *	Shutdown the vi screen.
+ */
+static int
+cl_vi_end(gp)
+	GS *gp;
+{
+	CL_PRIVATE *clp;
+
+	clp = GCLP(gp);
+
+	/* Restore the cursor keys to normal mode. */
+	(void)keypad(stdscr, FALSE);
+
+	/*
+	 * If we were running vi when we quit, scroll the screen up a single
+	 * line so we don't lose any information.
+	 *
+	 * Move to the bottom of the window (some endwin implementations don't
+	 * do this for you).
+	 */
+	if (!F_ISSET(clp, CL_IN_EX)) {
+		(void)move(0, 0);
+		(void)deleteln();
+		(void)move(LINES - 1, 0);
+		(void)refresh();
+	}
+
+	cl_freecap(clp);
+
+	/* End curses window. */
+	(void)endwin();
+
+	/*
+	 * XXX
+	 * The screen TE sequence just got sent.  See the comment in
+	 * cl_funcs.c:cl_attr().
+	 */
+	clp->ti_te = TE_SENT;
+
+	return (0);
+}
+
+/*
+ * cl_ex_init --
+ *	Initialize the ex screen.
+ */
+static int
+cl_ex_init(sp)
+	SCR *sp;
+{
+	CL_PRIVATE *clp;
+
+	clp = CLP(sp);
+
+	/* If already initialized, just set the terminal modes. */
+	if (F_ISSET(clp, CL_SCR_EX_INIT))
+		goto fast;
+
+	/* If not reading from a file, we're done. */
+	if (!F_ISSET(clp, CL_STDIN_TTY))
+		return (0);
+
+	/* Get the ex termcap/terminfo strings. */
+	(void)cl_getcap(sp, "cup", &clp->cup);
+	(void)cl_getcap(sp, "smso", &clp->smso);
+	(void)cl_getcap(sp, "rmso", &clp->rmso);
+	(void)cl_getcap(sp, "el", &clp->el);
+	(void)cl_getcap(sp, "cuu1", &clp->cuu1);
+
+	/* Enter_standout_mode and exit_standout_mode are paired. */
+	if (clp->smso == NULL || clp->rmso == NULL) {
+		if (clp->smso != NULL) {
+			free(clp->smso);
+			clp->smso = NULL;
+		}
+		if (clp->rmso != NULL) {
+			free(clp->rmso);
+			clp->rmso = NULL;
+		}
+	}
+
+	/*
+	 * Turn on canonical mode, with normal input and output processing.
+	 * Start with the original terminal settings as the user probably
+	 * had them (including any local extensions) set correctly for the
+	 * current terminal.
+	 *
+	 * !!!
+	 * We can't get everything that we need portably; for example, ONLCR,
+	 * mapping <newline> to <carriage-return> on output isn't required
+	 * by POSIX 1003.1b-1993.  If this turns out to be a problem, then
+	 * we'll either have to play some games on the mapping, or we'll have
+	 * to make all ex printf's output \r\n instead of \n.
+	 */
+	clp->ex_enter = clp->orig;
+	clp->ex_enter.c_lflag  |= ECHO | ECHOE | ECHOK | ICANON | IEXTEN | ISIG;
+#ifdef ECHOCTL
+	clp->ex_enter.c_lflag |= ECHOCTL;
+#endif
+#ifdef ECHOKE
+	clp->ex_enter.c_lflag |= ECHOKE;
+#endif
+	clp->ex_enter.c_iflag |= ICRNL;
+	clp->ex_enter.c_oflag |= OPOST;
+#ifdef ONLCR
+	clp->ex_enter.c_oflag |= ONLCR;
+#endif
+
+fast:	if (tcsetattr(STDIN_FILENO, TCSADRAIN | TCSASOFT, &clp->ex_enter)) {
+		msgq(sp, M_SYSERR, "tcsetattr");
+		return (1);
+	}
+	return (0);
+}
+
+/*
+ * cl_ex_end --
+ *	Shutdown the ex screen.
+ */
+static int
+cl_ex_end(gp)
+	GS *gp;
+{
+	CL_PRIVATE *clp;
+
+	clp = GCLP(gp);
+
+	cl_freecap(clp);
+
+	return (0);
+}
+
+/*
+ * cl_getcap --
+ *	Retrieve termcap/terminfo strings.
+ *
+ * PUBLIC: int cl_getcap __P((SCR *, char *, char **));
+ */
+int
+cl_getcap(sp, name, elementp)
+	SCR *sp;
+	char *name, **elementp;
+{
+	size_t len;
+	char *t;
+
+	if ((t = tigetstr(name)) != NULL &&
+	    t != (char *)-1 && (len = strlen(t)) != 0) {
+		MALLOC_RET(sp, *elementp, char *, len + 1);
+		memmove(*elementp, t, len + 1);
+	}
+	return (0);
+}
+
+/*
+ * cl_freecap --
+ *	Free any allocated termcap/terminfo strings.
+ */
+static void
+cl_freecap(clp)
+	CL_PRIVATE *clp;
+{
+	if (clp->el != NULL) {
+		free(clp->el);
+		clp->el = NULL;
+	}
+	if (clp->cup != NULL) {
+		free(clp->cup);
+		clp->cup = NULL;
+	}
+	if (clp->cuu1 != NULL) {
+		free(clp->cuu1);
+		clp->cuu1 = NULL;
+	}
+	if (clp->rmso != NULL) {
+		free(clp->rmso);
+		clp->rmso = NULL;
+	}
+	if (clp->smso != NULL) {
+		free(clp->smso);
+		clp->smso = NULL;
+	}
+}
+
+/*
+ * cl_putenv --
+ *	Put a value into the environment.
+ */
+static int
+cl_putenv(name, str, value)
+	char *name, *str;
+	u_long value;
+
+{
+	char buf[40];
+
+	if (str == NULL) {
+		(void)snprintf(buf, sizeof(buf), "%lu", value);
+		return (setenv(name, buf, 1));
+	} else
+		return (setenv(name, str, 1));
+}
diff --git a/contrib/nvi/cl/cl_term.c b/contrib/nvi/cl/cl_term.c
new file mode 100644
index 0000000..e400740
--- /dev/null
+++ b/contrib/nvi/cl/cl_term.c
@@ -0,0 +1,459 @@
+/*-
+ * Copyright (c) 1993, 1994
+ *	The Regents of the University of California.  All rights reserved.
+ * Copyright (c) 1993, 1994, 1995, 1996
+ *	Keith Bostic.  All rights reserved.
+ *
+ * See the LICENSE file for redistribution information.
+ */
+
+#include "config.h"
+
+#ifndef lint
+static const char sccsid[] = "@(#)cl_term.c	10.22 (Berkeley) 9/15/96";
+#endif /* not lint */
+
+#include <sys/types.h>
+#include <sys/ioctl.h>
+#include <sys/queue.h>
+#include <sys/stat.h>
+
+#include <bitstring.h>
+#include <curses.h>
+#include <errno.h>
+#include <limits.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include "../common/common.h"
+#include "cl.h"
+
+static int cl_pfmap __P((SCR *, seq_t, CHAR_T *, size_t, CHAR_T *, size_t));
+
+/*
+ * XXX
+ * THIS REQUIRES THAT ALL SCREENS SHARE A TERMINAL TYPE.
+ */
+typedef struct _tklist {
+	char	*ts;			/* Key's termcap string. */
+	char	*output;		/* Corresponding vi command. */
+	char	*name;			/* Name. */
+	u_char	 value;			/* Special value (for lookup). */
+} TKLIST;
+static TKLIST const c_tklist[] = {	/* Command mappings. */
+	{"kil1",	"O",	"insert line"},
+	{"kdch1",	"x",	"delete character"},
+	{"kcud1",	"j",	"cursor down"},
+	{"kel",		"D",	"delete to eol"},
+	{"kind",     "\004",	"scroll down"},			/* ^D */
+	{"kll",		"$",	"go to eol"},
+	{"khome",	"^",	"go to sol"},
+	{"kich1",	"i",	"insert at cursor"},
+	{"kdl1",       "dd",	"delete line"},
+	{"kcub1",	"h",	"cursor left"},
+	{"knp",	     "\006",	"page down"},			/* ^F */
+	{"kpp",	     "\002",	"page up"},			/* ^B */
+	{"kri",	     "\025",	"scroll up"},			/* ^U */
+	{"ked",	       "dG",	"delete to end of screen"},
+	{"kcuf1",	"l",	"cursor right"},
+	{"kcuu1",	"k",	"cursor up"},
+	{NULL},
+};
+static TKLIST const m1_tklist[] = {	/* Input mappings (lookup). */
+	{NULL},
+};
+static TKLIST const m2_tklist[] = {	/* Input mappings (set or delete). */
+	{"kcud1",  "\033ja",	"cursor down"},			/* ^[ja */
+	{"kcub1",  "\033ha",	"cursor left"},			/* ^[ha */
+	{"kcuu1",  "\033ka",	"cursor up"},			/* ^[ka */
+	{"kcuf1",  "\033la",	"cursor right"},		/* ^[la */
+	{NULL},
+};
+
+/*
+ * cl_term_init --
+ *	Initialize the special keys defined by the termcap/terminfo entry.
+ *
+ * PUBLIC: int cl_term_init __P((SCR *));
+ */
+int
+cl_term_init(sp)
+	SCR *sp;
+{
+	KEYLIST *kp;
+	SEQ *qp;
+	TKLIST const *tkp;
+	char *t;
+
+	/* Command mappings. */
+	for (tkp = c_tklist; tkp->name != NULL; ++tkp) {
+		if ((t = tigetstr(tkp->ts)) == NULL || t == (char *)-1)
+			continue;
+		if (seq_set(sp, tkp->name, strlen(tkp->name), t, strlen(t),
+		    tkp->output, strlen(tkp->output), SEQ_COMMAND,
+		    SEQ_NOOVERWRITE | SEQ_SCREEN))
+			return (1);
+	}
+
+	/* Input mappings needing to be looked up. */
+	for (tkp = m1_tklist; tkp->name != NULL; ++tkp) {
+		if ((t = tigetstr(tkp->ts)) == NULL || t == (char *)-1)
+			continue;
+		for (kp = keylist;; ++kp)
+			if (kp->value == tkp->value)
+				break;
+		if (kp == NULL)
+			continue;
+		if (seq_set(sp, tkp->name, strlen(tkp->name), t, strlen(t),
+		    &kp->ch, 1, SEQ_INPUT, SEQ_NOOVERWRITE | SEQ_SCREEN))
+			return (1);
+	}
+
+	/* Input mappings that are already set or are text deletions. */
+	for (tkp = m2_tklist; tkp->name != NULL; ++tkp) {
+		if ((t = tigetstr(tkp->ts)) == NULL || t == (char *)-1)
+			continue;
+		/*
+		 * !!!
+		 * Some terminals' <cursor_left> keys send single <backspace>
+		 * characters.  This is okay in command mapping, but not okay
+		 * in input mapping.  That combination is the only one we'll
+		 * ever see, hopefully, so kluge it here for now.
+		 */
+		if (!strcmp(t, "\b"))
+			continue;
+		if (tkp->output == NULL) {
+			if (seq_set(sp, tkp->name, strlen(tkp->name),
+			    t, strlen(t), NULL, 0,
+			    SEQ_INPUT, SEQ_NOOVERWRITE | SEQ_SCREEN))
+				return (1);
+		} else
+			if (seq_set(sp, tkp->name, strlen(tkp->name),
+			    t, strlen(t), tkp->output, strlen(tkp->output),
+			    SEQ_INPUT, SEQ_NOOVERWRITE | SEQ_SCREEN))
+				return (1);
+	}
+
+	/*
+	 * Rework any function key mappings that were set before the
+	 * screen was initialized.
+	 */
+	for (qp = sp->gp->seqq.lh_first; qp != NULL; qp = qp->q.le_next)
+		if (F_ISSET(qp, SEQ_FUNCMAP))
+			(void)cl_pfmap(sp, qp->stype,
+			    qp->input, qp->ilen, qp->output, qp->olen);
+	return (0);
+}
+
+/*
+ * cl_term_end --
+ *	End the special keys defined by the termcap/terminfo entry.
+ *
+ * PUBLIC: int cl_term_end __P((GS *));
+ */
+int
+cl_term_end(gp)
+	GS *gp;
+{
+	SEQ *qp, *nqp;
+
+	/* Delete screen specific mappings. */
+	for (qp = gp->seqq.lh_first; qp != NULL; qp = nqp) {
+		nqp = qp->q.le_next;
+		if (F_ISSET(qp, SEQ_SCREEN))
+			(void)seq_mdel(qp);
+	}
+	return (0);
+}
+
+/*
+ * cl_fmap --
+ *	Map a function key.
+ *
+ * PUBLIC: int cl_fmap __P((SCR *, seq_t, CHAR_T *, size_t, CHAR_T *, size_t));
+ */
+int
+cl_fmap(sp, stype, from, flen, to, tlen)
+	SCR *sp;
+	seq_t stype;
+	CHAR_T *from, *to;
+	size_t flen, tlen;
+{
+	/* Ignore until the screen is running, do the real work then. */
+	if (F_ISSET(sp, SC_VI) && !F_ISSET(sp, SC_SCR_VI))
+		return (0);
+	if (F_ISSET(sp, SC_EX) && !F_ISSET(sp, SC_SCR_EX))
+		return (0);
+
+	return (cl_pfmap(sp, stype, from, flen, to, tlen));
+}
+
+/*
+ * cl_pfmap --
+ *	Map a function key (private version).
+ */
+static int
+cl_pfmap(sp, stype, from, flen, to, tlen)
+	SCR *sp;
+	seq_t stype;
+	CHAR_T *from, *to;
+	size_t flen, tlen;
+{
+	size_t nlen;
+	char *p, keyname[64];
+
+	(void)snprintf(keyname, sizeof(keyname), "kf%d", atoi(from + 1));
+	if ((p = tigetstr(keyname)) == NULL ||
+	    p == (char *)-1 || strlen(p) == 0)
+		p = NULL;
+	if (p == NULL) {
+		msgq_str(sp, M_ERR, from, "233|This terminal has no %s key");
+		return (1);
+	}
+
+	nlen = snprintf(keyname,
+	    sizeof(keyname), "function key %d", atoi(from + 1));
+	return (seq_set(sp, keyname, nlen,
+	    p, strlen(p), to, tlen, stype, SEQ_NOOVERWRITE | SEQ_SCREEN));
+}
+
+/*
+ * cl_optchange --
+ *	Curses screen specific "option changed" routine.
+ *
+ * PUBLIC: int cl_optchange __P((SCR *, int, char *, u_long *));
+ */
+int
+cl_optchange(sp, opt, str, valp)
+	SCR *sp;
+	int opt;
+	char *str;
+	u_long *valp;
+{
+	CL_PRIVATE *clp;
+
+	clp = CLP(sp);
+
+	switch (opt) {
+	case O_COLUMNS:
+	case O_LINES:
+	case O_TERM:
+		/*
+		 * Changing the columns, lines or terminal require that
+		 * we restart the screen.
+		 */
+		F_SET(sp->gp, G_SRESTART);
+		F_CLR(sp, SC_SCR_EX | SC_SCR_VI);
+		break;
+	case O_MESG:
+		(void)cl_omesg(sp, clp, !*valp);
+		break;
+	case O_WINDOWNAME:
+		if (*valp) {
+			F_CLR(clp, CL_RENAME_OK);
+
+			(void)cl_rename(sp, NULL, 0);
+		} else {
+			F_SET(clp, CL_RENAME_OK);
+
+			/*
+			 * If the screen is live, i.e. we're not reading the
+			 * .exrc file, update the window.
+			 */
+			if (sp->frp != NULL && sp->frp->name != NULL)
+				(void)cl_rename(sp, sp->frp->name, 1);
+		}
+		break;
+	}
+	return (0);
+}
+
+/*
+ * cl_omesg --
+ *	Turn the tty write permission on or off.
+ *
+ * PUBLIC: int cl_omesg __P((SCR *, CL_PRIVATE *, int));
+ */
+int
+cl_omesg(sp, clp, on)
+	SCR *sp;
+	CL_PRIVATE *clp;
+	int on;
+{
+	struct stat sb;
+	char *tty;
+
+	/* Find the tty, get the current permissions. */
+	if ((tty = ttyname(STDERR_FILENO)) == NULL) {
+		if (sp != NULL)
+			msgq(sp, M_SYSERR, "stderr");
+		return (1);
+	}
+	if (stat(tty, &sb) < 0) {
+		if (sp != NULL)
+			msgq(sp, M_SYSERR, "%s", tty);
+		return (1);
+	}
+
+	/* Save the original status if it's unknown. */
+	if (clp->tgw == TGW_UNKNOWN)
+		clp->tgw = sb.st_mode & S_IWGRP ? TGW_SET : TGW_UNSET;
+
+	/* Toggle the permissions. */
+	if (on) {
+		if (chmod(tty, sb.st_mode | S_IWGRP) < 0) {
+			if (sp != NULL)
+				msgq(sp, M_SYSERR,
+				    "046|messages not turned on: %s", tty);
+			return (1);
+		}
+	} else
+		if (chmod(tty, sb.st_mode & ~S_IWGRP) < 0) {
+			if (sp != NULL)
+				msgq(sp, M_SYSERR,
+				    "045|messages not turned off: %s", tty);
+			return (1);
+		}
+	return (0);
+}
+
+/*
+ * cl_ssize --
+ *	Return the terminal size.
+ *
+ * PUBLIC: int cl_ssize __P((SCR *, int, size_t *, size_t *, int *));
+ */
+int
+cl_ssize(sp, sigwinch, rowp, colp, changedp)
+	SCR *sp;
+	int sigwinch;
+	size_t *rowp, *colp;
+	int *changedp;
+{
+#ifdef TIOCGWINSZ
+	struct winsize win;
+#endif
+	size_t col, row;
+	int rval;
+	char *p;
+
+	/* Assume it's changed. */
+	if (changedp != NULL)
+		*changedp = 1;
+
+	/*
+	 * !!!
+	 * sp may be NULL.
+	 *
+	 * Get the screen rows and columns.  If the values are wrong, it's
+	 * not a big deal -- as soon as the user sets them explicitly the
+	 * environment will be set and the screen package will use the new
+	 * values.
+	 *
+	 * Try TIOCGWINSZ.
+	 */
+	row = col = 0;
+#ifdef TIOCGWINSZ
+	if (ioctl(STDERR_FILENO, TIOCGWINSZ, &win) != -1) {
+		row = win.ws_row;
+		col = win.ws_col;
+	}
+#endif
+	/* If here because of suspend or a signal, only trust TIOCGWINSZ. */
+	if (sigwinch) {
+		/*
+		 * Somebody didn't get TIOCGWINSZ right, or has suspend
+		 * without window resizing support.  The user just lost,
+		 * but there's nothing we can do.
+		 */
+		if (row == 0 || col == 0) {
+			if (changedp != NULL)
+				*changedp = 0;
+			return (0);
+		}
+
+		/*
+		 * SunOS systems deliver SIGWINCH when windows are uncovered
+		 * as well as when they change size.  In addition, we call
+		 * here when continuing after being suspended since the window
+		 * may have changed size.  Since we don't want to background
+		 * all of the screens just because the window was uncovered,
+		 * ignore the signal if there's no change.
+		 */
+		if (sp != NULL &&
+		    row == O_VAL(sp, O_LINES) && col == O_VAL(sp, O_COLUMNS)) {
+			if (changedp != NULL)
+				*changedp = 0;
+			return (0);
+		}
+
+		if (rowp != NULL)
+			*rowp = row;
+		if (colp != NULL)
+			*colp = col;
+		return (0);
+	}
+
+	/*
+	 * !!!
+	 * If TIOCGWINSZ failed, or had entries of 0, try termcap.  This
+	 * routine is called before any termcap or terminal information
+	 * has been set up.  If there's no TERM environmental variable set,
+	 * let it go, at least ex can run.
+	 */
+	if (row == 0 || col == 0) {
+		if ((p = getenv("TERM")) == NULL)
+			goto noterm;
+		if (row == 0)
+			if ((rval = tigetnum("lines")) < 0)
+				msgq(sp, M_SYSERR, "tigetnum: lines");
+			else
+				row = rval;
+		if (col == 0)
+			if ((rval = tigetnum("cols")) < 0)
+				msgq(sp, M_SYSERR, "tigetnum: cols");
+			else
+				col = rval;
+	}
+
+	/* If nothing else, well, it's probably a VT100. */
+noterm:	if (row == 0)
+		row = 24;
+	if (col == 0)
+		col = 80;
+
+	/*
+	 * !!!
+	 * POSIX 1003.2 requires the environment to override everything.
+	 * Often, people can get nvi to stop messing up their screen by
+	 * deleting the LINES and COLUMNS environment variables from their
+	 * dot-files.
+	 */
+	if ((p = getenv("LINES")) != NULL)
+		row = strtol(p, NULL, 10);
+	if ((p = getenv("COLUMNS")) != NULL)
+		col = strtol(p, NULL, 10);
+
+	if (rowp != NULL)
+		*rowp = row;
+	if (colp != NULL)
+		*colp = col;
+	return (0);
+}
+
+/*
+ * cl_putchar --
+ *	Function version of putchar, for tputs.
+ *
+ * PUBLIC: int cl_putchar __P((int));
+ */
+int
+cl_putchar(ch)
+	int ch;
+{
+	return (putchar(ch));
+}