NetBSD/usr.bin/vi/docs/README

#	@(#)README	8.42 (Berkeley) 1/23/94

This is the README for version 1.03 of nvi, a freely redistributable
replacement for the vi and ex text editors.  It can be retrieved via
anonymous ftp from ftp.uu.net, or from ftp.cs.berkeley.edu.  In the
latter, it is in the directory ucb/4bsd, and is named nvi.tar.Z.

If you have any questions or problems with nvi, please send them to
me by electronic mail at one of the following addresses:

	uunet!bostic
	bostic@cs.berkeley.edu

Keith Bostic

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o Redistribution:

Nvi is copyrighted by the The Regents of the University of California,
but may be freely redistributed (or used to line your birdcage) under
the following conditions:

/*-
 * Copyright (c) 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

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o Credit where it's due:

	This software was originally derived from software contributed
	to the University of California, Berkeley by Steve Kirkendall,
	the author of the vi clone elvis.  Without his work, this work
	would have been far more difficult.

	POSIX 1003.2 style regular expression support is courtesy of
	Henry Spencer, for which I am *very* grateful.

	The curses library was originally done by Ken Arnold.  Scrolling
	and general reworking for 4.4BSD was done by Elan Amir.

o From the original vi acknowledgements, by William Joy and Mark Horton:

	Bruce Englar encouraged the early development of this display
	editor.  Peter Kessler helped bring sanity to version 2's
	command layout.  Bill Joy wrote versions 1 and 2.0 through 2.7,
	and created the framework that users see in the present editor.
	Mark Horton added macros and other features and made the editor
	work on a large number of terminals and Unix systems.

o And...

	The financial support of UUNET Communications Services is gratefully
	acknowledged.

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o Comments:

This software is beta software, although it's pretty stable.  Almost
of the necessary functionality for ex/vi is in it, the only missing
pieces are fairly obscure.

Code fixes are very much appreciated, of course, but if you can't
provide them, please send me as much information as you can as to how
to reproduce the bug, and I'll try to fix it here.  In particular, the
screen routines are nasty stuff, and you probably don't want to mess
with them.  Stack traces of core dumps are sometimes helpful, but an
example file with a set of keystrokes that causes the problem is far
better.

Nvi is mostly 8-bit clean.  This isn't difficult to fix, and was left in
during initial development to make things easier.  Wide character support
will be integrated at the same time it is made fully 8-bit clean.

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o New features:

There aren't a lot of new features in nex/nvi, but there are a few things
you might like:

	o 8-bit clean data, practically infinite lines/files.
		^Vx[0-9A-Fa-f]* in input mode will insert any
		legal character value.
	o Split screens:
		:sp[lit] [file ...] splits the screen.
		^W switches between screens.
		:resize count grows/shrinks the current screen.
	o Background/foreground screens
		:bg backgrounds the current screen.
		:di[splay] s[creens] lists the hidden screens.
		:fg [file] foregrounds the specified (or next) screen.
	o Shell screens:
		:sc[ript] [file ...] runs a shell in the screen.
		Carriage return sends a line to the shell.
	o Buffer, screens, tags display:
		:di[splay] b[uffers] displays the current cut buffers.
		:di[splay] s[creens] displays the hidden screen names.
		:di[splay] t[ags] displays the current tags stack.
	o Tag stacks:
		^T returns to previous tag location.
		:tagpop [number | file] returns to previous tag location,
		     or, optionally tag #N, or the tag in a specific file.
		:tagtop returns to first tag location.
	o Infinite undo:
		A '.' command immediately after a 'u' command continues
		either forward or backward depending on whether the 'u'
		command was an undo or a redo.
	o Usage information:
		:exu[sage] [cmd] for ex commands.
		:viu[sage] [key] for vi commands.
		:help
	o Extended RE expressions:
		:set extended turns on extended RE's, so you can
		    do "/in|or" and search for the next occurrence of
		    more than one expression.
	o Word search:
		^A searches for the word referenced by the cursor.
	o Number increment:
		# increments the number referenced by the cursor.
	o Previous file:
		:prev[ious][!] edits the previous file from the
		argument list.

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o Porting information:

The directory PORT has directories per machine/OS combination, with
V7-style Makefiles which build nvi.  See the file PORT/README for
more detailed information.

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o Directories:

The main directory, nvi, contains source files for pieces of code that
are shared by all the editors, like searching and logging code or code
translating line numbers into requests to the dbopen(3) database code.
It also has the code for adding, deleting, and changing "records" in
the underlying database.

nvi/docs:
	The nvi/docs directory has technical information about data
	structures and some of the trickier parts of vi like quoting,
	key mapping, input queues, and executing buffers, and a
	description of how nvi does edit session recovery.

nvi/ex:
	The nvi/ex directory is the ex source code.  Because vi has the
	colon command, lots of this code is used by vi.  Generally, if
	functionality is shared by both ex and vi, it's in nvi/ex, if
	it's vi only, it's in nvi/vi.  Files are generally named by the
	command(s) they support, but occasionally with a name that
	describes their functionality.

nvi/sex:
	The nvi/sex directory is the screen support for the ex editor.

nvi/svi:
	The nvi/svi directory is the screen support for a curses based
	vi editor.

nvi/vi:
	The nvi/vi directory is the vi source code.

nvi/xaw:
	Place reserved for an X11 (Athena Widget) screen.