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+.\" Copyright (c) 1980, 1993
+.\"	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.
+.\"
+.\"	@(#)vi.in	8.1 (Berkeley) 6/8/93
+.\"
+.EH 'USD:12-%''An Introduction to Display Editing with Vi'
+.OH 'An Introduction to Display Editing with Vi''USD:12-%'
+.bd S 3
+.if t .ds dg \(dg
+.if n .ds dg +
+.if t .ds dd \(dd
+.if n .ds dd ++
+.\".RP
+.TL
+An Introduction to Display Editing with Vi
+.AU
+William Joy
+.AU
+Mark Horton
+.AI
+Computer Science Division
+Department of Electrical Engineering and Computer Science
+University of California, Berkeley
+Berkeley, Ca.  94720
+.AB
+.PP
+.I Vi
+(visual) is a display oriented interactive text editor.
+When using
+.I vi
+the screen of your terminal acts as a window into the file which you
+are editing.  Changes which you make to the file are reflected
+in what you see.
+.PP
+Using
+.I vi
+you can insert new text any place in the file quite easily.
+Most of the commands to
+.I vi
+move the cursor around in the file.
+There are commands to move the cursor
+forward and backward in units of characters, words,
+sentences and paragraphs.
+A small set of operators, like
+.B d
+for delete and
+.B c
+for change, are combined with the motion commands to form operations
+such as delete word or change paragraph, in a simple and natural way.
+This regularity and the mnemonic assignment of commands to keys makes the
+editor command set easy to remember and to use.
+.PP
+.I Vi
+will work on a large number of display terminals,
+and new terminals are easily driven after editing a terminal description file.
+While it is advantageous to have an intelligent terminal which can locally
+insert and delete lines and characters from the display, the editor will
+function quite well on dumb terminals over slow phone lines.
+The editor makes allowance for the low bandwidth in these situations
+and uses smaller window sizes and
+different display updating algorithms to make best use of the
+limited speed available.
+.PP
+It is also possible to use the command set of
+.I vi
+on hardcopy terminals, storage tubes and ``glass tty's'' using a one line
+editing window; thus
+.I vi's
+command set is available on all terminals.
+The full command set of the more traditional, line
+oriented editor
+.I ex
+is available within
+.I vi;
+it is quite simple to switch between the two modes of editing.
+.AE
+.NH 1
+Getting started
+.PP
+.FS
+The financial support of an \s-2IBM\s0 Graduate Fellowship and the
+National Science Foundation under grants MCS74-07644-A03 and MCS78-07291
+is gratefully acknowledged.
+.FE
+This document provides a quick introduction to
+.I vi.
+(Pronounced \fIvee-eye\fP.)
+You should be running
+.I vi
+on a file you are familiar with while you are reading this.
+The first part of this document (sections 1 through 5)
+describes the basics of using
+.I vi.
+Some topics of special interest are presented in section 6, and 
+some nitty-gritty details of how the editor functions are saved for section
+7 to avoid cluttering the presentation here.
+.PP
+There is also a short appendix here, which gives for each character the
+special meanings which this character has in \fIvi\fR.  Attached to
+this document should be a quick reference card.
+This card summarizes the commands of
+.I vi
+in a very compact format.  You should have the card handy while you are
+learning
+.I vi.
+.NH 2
+Specifying terminal type
+.PP
+Before you can start
+.I vi
+you must tell the system what kind of terminal you are using.
+Here is a (necessarily incomplete) list of terminal type codes.
+If your terminal does not appear here, you should consult with one of
+the staff members on your system to find out the code for your terminal.
+If your terminal does not have a code, one can be assigned and a description
+for the terminal can be created.
+.LP
+.TS
+center;
+ab ab ab
+a a a.
+Code	Full name	Type
+_
+2621	Hewlett-Packard 2621A/P	Intelligent
+2645	Hewlett-Packard 264x	Intelligent
+act4	Microterm ACT-IV	Dumb
+act5	Microterm ACT-V	Dumb
+adm3a	Lear Siegler ADM-3a	Dumb
+adm31	Lear Siegler ADM-31	Intelligent
+c100	Human Design Concept 100	Intelligent
+dm1520	Datamedia 1520	Dumb
+dm2500	Datamedia 2500	Intelligent
+dm3025	Datamedia 3025	Intelligent
+fox	Perkin-Elmer Fox	Dumb
+h1500	Hazeltine 1500	Intelligent
+h19	Heathkit h19	Intelligent
+i100	Infoton 100	Intelligent
+mime	Imitating a smart act4	Intelligent
+t1061	Teleray 1061	Intelligent
+vt52	Dec VT-52	Dumb
+.TE
+.PP
+Suppose for example that you have a Hewlett-Packard HP2621A
+terminal.  The code used by the system for this terminal is `2621'.
+In this case you can use one of the following commands to tell the system
+the type of your terminal:
+.DS
+% \fBsetenv TERM\fP 2621
+.DE
+This command works with the
+.I csh
+shell.
+If you are using the standard Bourne shell
+.I sh
+then you should give the commands
+.DS
+$ \fBTERM=\fP2621
+$ \fBexport TERM\fP
+.DE
+.PP
+If you want to arrange to have your terminal type set up automatically
+when you log in, you can use the
+.I tset
+program.
+If you dial in on a
+.I mime ,
+but often use hardwired ports, a typical line for your
+.I .login
+file (if you use csh) would be
+.DS
+\fBsetenv TERM \(gatset\fP \- \-d mime\(ga
+.DE
+or for your
+.I .profile
+file (if you use sh)
+.DS
+\fBTERM=\(gatse\fPt \- \-d mime\(ga
+.DE
+.I Tset
+knows which terminals are hardwired to each port
+and needs only to be told that when you dial in you
+are probably on a
+.I mime .
+.I Tset
+is usually used to change the erase and kill characters, too.
+.NH 2
+Editing a file
+.PP
+After telling the system which kind of terminal you have, you should
+make a copy of a file you are familiar with, and run
+.I vi
+on this file, giving the command
+.DS
+% \fBvi\fR \fIname\fR
+.DE
+replacing \fIname\fR with the name of the copy file you just created.
+The screen should clear and the text of your file should appear on the
+screen.  If something else happens refer to the footnote.\*(dd
+.FS
+\*(dd If you gave the system an incorrect terminal type code then the
+editor may have just made a mess out of your screen.  This happens when
+it sends control codes for one kind of terminal to some other
+kind of terminal.  In this case hit
+the keys \fB:q\fR (colon and the q key) and then hit the \s-2RETURN\s0 key.
+This should get you back to the command level interpreter.
+Figure out what you did wrong (ask someone else if necessary) and try again.
+     Another thing which can go wrong is that you typed the wrong file name and
+the editor just printed an error diagnostic.  In this case you should
+follow the above procedure for getting out of the editor, and try again
+this time spelling the file name correctly.
+     If the editor doesn't seem to respond to the commands which you type
+here, try sending an interrupt to it by hitting the \s-2DEL\s0 or \s-2RUB\s0
+key on your terminal, and then hitting the \fB:q\fR command again followed
+by a carriage return.
+.sp
+.FE
+.NH 2
+The editor's copy: the buffer
+.PP
+The editor does not directly modify the file which you are editing. 
+Rather, the editor makes a copy of this file, in a place called the
+.I buffer,
+and remembers the file's
+name.  You do not affect the contents of the file unless and until you
+write the changes you make back into the original file.
+.NH 2
+Notational conventions
+.PP
+In our examples, input which must be typed as is will be presented in
+\fBbold face\fR. Text which should be replaced with appropriate input
+will be given in \fIitalics\fR.  We will represent special characters
+in \s-2SMALL CAPITALS\s0.
+.NH 2
+Arrow keys
+.PP
+The editor command set is independent of the terminal
+you are using.  On most terminals with cursor positioning keys, these keys
+will also work within the editor.
+If you don't have cursor positioning keys, or even if you do, you can use
+the \fBh j k\fR and \fBl\fR keys as cursor positioning
+keys (these are labelled with arrows on an
+.I adm3a).*
+.PP
+(Particular note for the HP2621: on this terminal the function keys
+must be \fIshifted\fR (ick) to send to the machine, otherwise they
+only act locally.  Unshifted use will leave the cursor positioned
+incorrectly.)
+.FS
+* As we will see later,
+.I h
+moves back to the left (like control-h which is a backspace),
+.I j
+moves down (in the same column),
+.I k
+moves up (in the same column),
+and
+.I l
+moves to the right.
+.FE
+.NH 2
+Special characters: \s-2ESC\s0, \s-2CR\s0 and \s-2DEL\s0
+.PP
+Several of these special characters are very important, so be sure to
+find them right now.  Look on your keyboard for a key labelled \s-2ESC\s0
+or \s-2ALT\s0.  It should be near the upper left corner of your terminal.
+Try hitting this key a few times.  The editor will ring the bell
+to indicate that it is in a quiescent state.\*(dd
+.FS
+\*(dd On smart terminals where it is possible, the editor will quietly
+flash the screen rather than ringing the bell.
+.FE
+Partially formed commands are cancelled by \s-2ESC\s0, and when you insert
+text in the file you end the text insertion
+with \s-2ESC\s0.  This key is a fairly
+harmless one to hit, so you can just hit it if you don't know
+what is going on until the editor rings the bell.
+.PP
+The \s-2CR\s0 or \s-2RETURN\s0 key is important because it is used
+to terminate certain commands.
+It is usually at the right side of the keyboard,
+and is the same command used at the end of each shell command.
+.PP
+Another very useful key is the \s-2DEL\s0 or \s-2RUB\s0 key, which generates
+an interrupt, telling the editor to stop what it is doing.
+It is a forceful way of making the editor listen
+to you, or to return it to the quiescent state if you don't know or don't
+like what is going on.  Try hitting the `/' key on your terminal.  This
+key is used when you want to specify a string to be searched for.  The
+cursor should now be positioned at the bottom line of the terminal after
+a `/' printed as a prompt.  You can get the cursor back to the current
+position by hitting the \s-2DEL\s0 or \s-2RUB\s0 key; try this now.*
+.FS
+* Backspacing over the `/' will also cancel the search.
+.FE
+From now on we will simply refer to hitting the \s-2DEL\s0 or \s-2RUB\s0
+key as ``sending an interrupt.''**
+.FS
+** On some systems, this interruptibility comes at a price: you cannot type
+ahead when the editor is computing with the cursor on the bottom line.
+.FE
+.PP
+The editor often echoes your commands on the last line of the terminal.
+If the cursor is on the first position of this last line, then the editor
+is performing a computation, such as computing a new position in the
+file after a search or running a command to reformat part of the buffer.
+When this is happening you can stop the editor by
+sending an interrupt.
+.NH 2
+Getting out of the editor
+.PP
+After you have worked with this introduction for a while, and you wish
+to do something else, you can give the command \fBZZ\fP
+to the editor.
+This will write the contents of the editor's buffer back into
+the file you are editing, if you made any changes, and then quit from
+the editor.  You can also end an editor
+session by giving the command \fB:q!\fR\s-2CR\s0;\*(dg
+.FS
+\*(dg All commands which read from the last display line can also be
+terminated with a \s-2ESC\s0 as well as an \s-2CR\s0.
+.FE
+this is a dangerous but occasionally essential
+command which ends the editor session and discards all your changes.
+You need to know about this command in case you change the editor's
+copy of a file you wish only to look at.  Be very careful
+not to give this command when you really want to save
+the changes you have made.
+.NH 1
+Moving around in the file
+.NH 2
+Scrolling and paging
+.PP
+The editor has a number of commands for moving around in the file.
+The most useful of these is generated by hitting the control and D keys
+at the same time, a control-D or `^D'.  We will use this two character
+notation for referring to these control keys from now on.  You may have
+a key labelled `^' on your terminal.  This key will be represented as `\(ua'
+in this document; `^' is exclusively used as part of the `^x' notation
+for control characters.\*(dd
+.FS
+\*(dd If you don't have a `^' key on your terminal
+then there is probably a key labelled `\(ua'; in any case these characters
+are one and the same.
+.FE
+.PP
+As you know now if you tried hitting \fB^D\fR, this command scrolls down in
+the file.  The \fBD\fR thus stands for down.  Many editor commands are mnemonic
+and this makes them much easier to remember.  For instance the command
+to scroll up is \fB^U\fR.  Many dumb terminals can't scroll up at all, in which
+case hitting \fB^U\fR clears the screen and refreshes it
+with a line which is farther back in the file at the top.
+.PP
+If you want to see more of the file below where you are, you can
+hit \fB^E\fR to expose one more line at the bottom of the screen,
+leaving the cursor where it is.
+The command \fB^Y\fR (which is hopelessly non-mnemonic, but next to \fB^U\fR
+on the keyboard) exposes one more line at the top of the screen.
+.PP
+There are other ways to move around in the file; the keys \fB^F\fR and \fB^B\fR
+move forward and backward a page,
+keeping a couple of lines of continuity between screens
+so that it is possible to read through a file using these rather than
+\fB^D\fR and \fB^U\fR if you wish.
+.PP
+Notice the difference between scrolling and paging.  If you are trying
+to read the text in a file, hitting \fB^F\fR to move forward a page
+will leave you only a little context to look back at.  Scrolling on the
+other hand leaves more context, and happens more smoothly.  You can continue
+to read the text as scrolling is taking place.
+.NH 2
+Searching, goto, and previous context
+.PP
+Another way to position yourself in the file is by giving the editor a string
+to search for.  Type the character \fB/\fR followed by a string of characters
+terminated by \s-2CR\s0.  The editor will position the cursor
+at the next occurrence of this string.
+Try hitting \fBn\fR to then go to the next occurrence of this string.
+The character \fB?\fR will search backwards from where you are, and is
+otherwise like \fB/\fR.\*(dg
+.FS
+\*(dg These searches will normally wrap around the end of the file, and thus
+find the string even if it is not on a line in the direction you search
+provided it is anywhere else in the file.  You can disable this wraparound
+in scans by giving the command \fB:se nowrapscan\fR\s-2CR\s0,
+or more briefly \fB:se nows\fR\s-2CR\s0.
+.FE
+.PP
+If the search string you give the editor is not present in the
+file the editor will print
+a diagnostic on the last line of the screen, and the cursor will be returned
+to its initial position.
+.PP
+If you wish the search to match only at the beginning of a line, begin
+the search string with an \fB\(ua\fR.  To match only at the end of
+a line, end the search string with a \fB$\fR.
+Thus \fB/\(uasearch\fR\s-2CR\s0 will search for the word `search' at
+the beginning of a line, and \fB/last$\fR\s-2CR\s0 searches for the
+word `last' at the end of a line.*
+.FS
+*Actually, the string you give to search for here can be a
+.I "regular expression"
+in the sense of the editors
+.I ex (1)
+and
+.I ed (1).
+If you don't wish to learn about this yet, you can disable this more
+general facility by doing
+\fB:se\ nomagic\fR\s-2CR\s0;
+by putting this command in
+EXINIT
+in your environment, you can have this always be in effect (more
+about
+.I EXINIT
+later.)
+.FE
+.PP
+The command \fBG\fR, when preceded by a number will position the cursor
+at that line in the file.
+Thus \fB1G\fR will move the cursor to
+the first line of the file.  If you give \fBG\fR no count, then it moves
+to the end of the file.
+.PP
+If you are near the end of the file, and the last line is not at the bottom
+of the screen, the editor will place only the character `~' on each remaining
+line.  This indicates that the last line in the file is on the screen;
+that is, the `~' lines are past the end of the file.
+.PP
+You can find out the state of the file you are editing by typing a \fB^G\fR.
+The editor will show you the name of the file you are editing, the number
+of the current line, the number of lines in the buffer, and the percentage
+of the way through the buffer which you are.
+Try doing this now, and remember the number of the line you are on.
+Give a \fBG\fR command to get to the end and then another \fBG\fR command
+to get back where you were.
+.PP
+You can also get back to a previous position by using the command
+\fB\(ga\(ga\fR (two back quotes).
+This is often more convenient than \fBG\fR because it requires no advance
+preparation.
+Try giving a \fBG\fR or a search with \fB/\fR or \fB?\fR and then a
+\fB\(ga\(ga\fR to get back to where you were.  If you accidentally hit
+\fBn\fR or any command which moves you far away from a context of interest, you
+can quickly get back by hitting \fB\(ga\(ga\fR.
+.NH 2
+Moving around on the screen
+.PP
+Now try just moving the cursor around on the screen.
+If your terminal has arrow keys (4 or 5 keys with arrows
+going in each direction) try them and convince yourself
+that they work.
+If you don't have working arrow keys, you can always use
+.B h ,
+.B j ,
+.B k ,
+and
+.B l .
+Experienced users of
+.I vi
+prefer these keys to arrow keys,
+because they are usually right underneath their fingers.
+.PP
+Hit the \fB+\fR key.  Each time you do, notice that the cursor
+advances to the next line in the file, at the first non-white position
+on the line.  The \fB\-\fR key is like \fB+\fR but goes the other way.
+.PP
+These are very common keys for moving up and down lines in the file.
+Notice that if you go off the bottom or top with these keys then the
+screen will scroll down (and up if possible) to bring a line at a time
+into view.  The \s-2RETURN\s0 key has the same effect as the \fB+\fR
+key.
+.PP
+.I Vi
+also has commands to take you to the top, middle and bottom of the screen.
+\fBH\fR will take you to the top (home) line on the screen.
+Try preceding it with a
+number as in \fB3H\fR.
+This will take you to the third line on the screen.
+Many
+.I vi
+commands take preceding numbers and do interesting things with them.
+Try \fBM\fR,
+which takes you to the middle line on the screen,
+and \fBL\fR,
+which takes you to the last line on the screen.
+\fBL\fR also takes counts, thus
+\fB5L\fR will take you to the fifth line from the bottom.
+.NH 2
+Moving within a line
+.PP
+Now try picking a word on some line on the screen, not the
+first word on the line.
+move the cursor using \s-2RETURN\s0 and \fB\-\fR to be on the line where
+the word is.
+Try hitting the \fBw\fR key.  This will advance the cursor to the
+next word on the line.
+Try hitting the \fBb\fR key to back up words
+in the line.
+Also try the \fBe\fR key which advances you to the end of the current
+word rather than to the beginning of the next word.
+Also try \s-2SPACE\s0 (the space bar) which moves right one character
+and the \s-2BS\s0 (backspace or \fB^H\fR) key which moves left one character.
+The key \fBh\fR works as \fB^H\fR does and is useful if you don't have
+a \s-2BS\s0 key.
+(Also, as noted just above, \fBl\fR will move to the right.)
+.PP
+If the line had punctuation in it you may have noticed that
+that the \fBw\fR and \fBb\fR
+keys stopped at each group of punctuation.  You can also go back and
+forwards words without stopping at punctuation by using \fBW\fR and \fBB\fR
+rather than the lower case equivalents.  Think of these as bigger words.
+Try these on a few lines with punctuation to see how they differ from
+the lower case \fBw\fR and \fBb\fR.
+.PP
+The word keys wrap around the end of line,
+rather than stopping at the end.  Try moving to a word on a line below
+where you are by repeatedly hitting \fBw\fR.
+.NH 2
+Summary
+.IP
+.TS
+lw(.50i)b a.
+\fR\s-2SPACE\s0\fP	advance the cursor one position
+^B	backwards to previous page
+^D	scrolls down in the file
+^E	exposes another line at the bottom
+^F	forward to next page
+^G	tell what is going on
+^H	backspace the cursor
+^N	next line, same column
+^P	previous line, same column
+^U	scrolls up in the file
+^Y	exposes another line at the top
++	next line, at the beginning
+\-	previous line, at the beginning
+/	scan for a following string forwards
+?	scan backwards
+B	back a word, ignoring punctuation
+G	go to specified line, last default
+H	home screen line
+M	middle screen line
+L	last screen line
+W	forward a word, ignoring punctuation
+b	back a word
+e	end of current word
+n	scan for next instance of \fB/\fR or \fB?\fR pattern
+w	word after this word
+.TE
+.NH 2
+View
+.PP
+If you want to use the editor to look at a file,
+rather than to make changes,
+invoke it as
+.I view
+instead of
+.I vi .
+This will set the
+.I readonly
+option which will prevent you from
+accidently overwriting the file.
+.NH 1
+Making simple changes
+.NH 2
+Inserting
+.PP
+One of the most useful commands is the
+\fBi\fR (insert) command.
+After you type \fBi\fR, everything you type until you hit \s-2ESC\s0
+is inserted into the file.
+Try this now; position yourself to some word in the file and try inserting
+text before this word.
+If you are on an dumb terminal it will seem, for a minute,
+that some of the characters in your line have been overwritten, but they will
+reappear when you hit \s-2ESC\s0.
+.PP
+Now try finding a word which can, but does not, end in an `s'.
+Position yourself at this word and type \fBe\fR (move to end of word), then
+\fBa\fR for append and then `s\s-2ESC\s0' to terminate the textual insert.
+This sequence of commands can be used to easily pluralize a word.
+.PP
+Try inserting and appending a few times to make sure you understand how
+this works; \fBi\fR placing text to the left of the cursor, \fBa\fR to
+the right.
+.PP
+It is often the case that you want to add new lines to the file you are
+editing, before or after some specific line in the file.  Find a line
+where this makes sense and then give the command \fBo\fR to create a
+new line after the line you are on, or the command \fBO\fR to create
+a new line before the line you are on.  After you create a new line in
+this way, text you type up to an \s-2ESC\s0 is inserted on the new line.
+.PP
+Many related editor commands
+are invoked by the same letter key and differ only in that one is given
+by a lower
+case key and the other is given by
+an upper case key.  In these cases, the
+upper case key often differs from the lower case key in its sense of
+direction, with
+the upper case key working backward and/or up, while the lower case
+key moves forward and/or down.
+.PP
+Whenever you are typing in text, you can give many lines of input or
+just a few characters.
+To type in more than one line of text,
+hit a \s-2RETURN\s0 at the middle of your input.  A new line will be created
+for text, and you can continue to type.  If you are on a slow
+and dumb terminal the editor may choose to wait to redraw the
+tail of the screen, and will let you type over the existing screen lines.
+This avoids the lengthy delay which would occur if the editor attempted
+to keep the tail of the screen always up to date.  The tail of the screen will
+be fixed up, and the missing lines will reappear, when you hit \s-2ESC\s0.
+.PP
+While you are inserting new text, you can use the characters you normally use
+at the system command level (usually \fB^H\fR or \fB#\fR) to backspace
+over the last
+character which you typed, and the character which you use to kill input lines
+(usually \fB@\fR, \fB^X\fR, or \fB^U\fR)
+to erase the input you have typed on the current line.\*(dg
+.FS
+\*(dg In fact, the character \fB^H\fR (backspace) always works to erase the
+last input character here, regardless of what your erase character is.
+.FE
+The character \fB^W\fR
+will erase a whole word and leave you after the space after the previous
+word; it is useful for quickly backing up in an insert.
+.PP
+Notice that when you backspace during an insertion the characters you
+backspace over are not erased; the cursor moves backwards, and the characters
+remain on the display.  This is often useful if you are planning to type
+in something similar.  In any case the characters disappear when when
+you hit \s-2ESC\s0; if you want to get rid of them immediately, hit an
+\s-2ESC\s0 and then \fBa\fR again.
+.PP
+Notice also that you can't erase characters which you didn't insert, and that
+you can't backspace around the end of a line.  If you need to back up
+to the previous line to make a correction, just hit \s-2ESC\s0 and move
+the cursor back to the previous line.  After making the correction you
+can return to where you were and use the insert or append command again.
+.NH 2
+Making small corrections
+.PP
+You can make small corrections in existing text quite easily.
+Find a single character which is wrong or just pick any character.
+Use the arrow keys to find the character, or
+get near the character with the word motion keys and then either
+backspace (hit the \s-2BS\s0 key or \fB^H\fR or even just \fBh\fR) or 
+\s-2SPACE\s0 (using the space bar)
+until the cursor is on the character which is wrong.
+If the character is not needed then hit the \fBx\fP key; this deletes
+the character from the file.  It is analogous to the way you \fBx\fP
+out characters when you make mistakes on a typewriter (except it's not
+as messy).
+.PP
+If the character
+is incorrect, you can replace it with the correct character by giving
+the command \fBr\fR\fIc\fR,
+where \fIc\fR is replaced by the correct character.
+Finally if the character which is incorrect should be replaced
+by more than one character, give the command \fBs\fR which substitutes
+a string of characters, ending with \s-2ESC\s0, for it.
+If there are a small number of characters
+which are wrong you can precede \fBs\fR with a count of the number of
+characters to be replaced.  Counts are also useful with \fBx\fR to specify
+the number of characters to be deleted.
+.NH 2
+More corrections: operators
+.PP
+You already know almost enough to make changes at a higher level.
+All you need to know now is that the 
+.B d
+key acts as a delete operator.  Try the command
+.B dw
+to delete a word.
+Try hitting \fB.\fR a few times.  Notice that this repeats the effect
+of the \fBdw\fR.  The command \fB.\fR repeats the last command which
+made a change.  You can remember it by analogy with an ellipsis `\fB...\fR'.
+.PP
+Now try
+\fBdb\fR.
+This deletes a word backwards, namely the preceding word.
+Try 
+\fBd\fR\s-2SPACE\s0.  This deletes a single character, and is equivalent
+to the \fBx\fR command.
+.PP
+Another very useful operator is
+.B c
+or change.  The command 
+.B cw
+thus changes the text of a single word.
+You follow it by the replacement text ending with an \s-2ESC\s0.
+Find a word which you can change to another, and try this
+now.
+Notice that the end of the text to be changed was marked with the character
+`$' so that you can see this as you are typing in the new material.
+.NH 2
+Operating on lines
+.PP
+It is often the case that you want to operate on lines.
+Find a line which you want to delete, and type 
+\fBdd\fR,
+the
+.B d
+operator twice.  This will delete the line.
+If you are on a dumb terminal, the editor may just erase the line on
+the screen, replacing it with a line with only an @ on it.  This line
+does not correspond to any line in your file, but only acts as a place
+holder.  It helps to avoid a lengthy redraw of the rest of the screen
+which would be necessary to close up the hole created by the deletion
+on a terminal without a delete line capability.
+.PP
+Try repeating the
+.B c
+operator twice; this will change a whole line, erasing its previous contents and
+replacing them with text you type up to an \s-2ESC\s0.\*(dg
+.FS
+\*(dg The command \fBS\fR is a convenient synonym for for \fBcc\fR, by
+analogy with \fBs\fR.  Think of \fBS\fR as a substitute on lines, while
+\fBs\fR is a substitute on characters.
+.FE
+.PP
+You can delete or change more than one line by preceding the
+.B dd
+or
+.B cc
+with a count, i.e. \fB5dd\fR deletes 5 lines.
+You can also give a command like \fBdL\fR to delete all the lines up to
+and including
+the last line on the screen, or \fBd3L\fR to delete through the third from
+the bottom line.  Try some commands like this now.*
+.FS
+* One subtle point here involves using the \fB/\fR search after a \fBd\fR.
+This will normally delete characters from the current position to the
+point of the match.  If what is desired is to delete whole lines
+including the two points, give the pattern as \fB/pat/+0\fR, a line address.
+.FE
+Notice that the editor lets you know when you change a large number of
+lines so that you can see the extent of the change.
+The editor will also always tell you when a change you make affects text which
+you cannot see.
+.NH 2
+Undoing
+.PP
+Now suppose that the last change which you made was incorrect;
+you could use the insert, delete and append commands to put the correct
+material back.  However, since it is often the case that we regret a
+change or make a change incorrectly, the editor provides a
+.B u
+(undo) command to reverse the last change which you made.
+Try this a few times, and give it twice in a row to notice that an
+.B u
+also undoes a
+.B u.
+.PP
+The undo command lets you reverse only a single change.  After you make
+a number of changes to a line, you may decide that you would rather have
+the original state of the line back.  The
+.B U
+command restores the current line to the state before you started changing
+it.
+.PP
+You can recover text which you delete, even if
+undo will not bring it back; see the section on recovering lost text
+below.
+.NH 2
+Summary
+.IP
+.TS
+lw(.50i)b a.
+\fR\s-2SPACE\s0\fP	advance the cursor one position
+^H	backspace the cursor
+^W	erase a word during an insert
+\fRerase\fP	your erase (usually ^H or #), erases a character during an insert
+\fRkill\fP	your kill (usually @, ^X, or ^U), kills the insert on this line
+\&\fB.\fP	repeats the changing command
+O	opens and inputs new lines, above the current
+U	undoes the changes you made to the current line
+a	appends text after the cursor
+c	changes the object you specify to the following text
+d	deletes the object you specify
+i	inserts text before the cursor
+o	opens and inputs new lines, below the current
+u	undoes the last change
+.TE
+.NH 1
+Moving about; rearranging and duplicating text
+.NH 2
+Low level character motions
+.PP
+Now move the cursor to a line where there is a punctuation or a bracketing
+character such as a parenthesis or a comma or period.  Try the command
+\fBf\fR\fIx\fR where \fIx\fR is this character.  This command finds
+the next \fIx\fR character to the right of the cursor in the current
+line.  Try then hitting a \fB;\fR, which finds the next instance of the
+same character.  By using the \fBf\fR command and then a sequence of
+\fB;\fR's you can often
+get to a particular place in a line much faster than with a sequence
+of word motions or \s-2SPACE\s0s.
+There is also a \fBF\fR command, which is like \fBf\fR, but searches 
+backward.  The \fB;\fR command repeats \fBF\fR also.
+.PP
+When you are operating on the text in a line it is often desirable to
+deal with the characters up to, but not including, the first instance of
+a character.  Try \fBdf\fR\fIx\fR for some \fIx\fR now and
+notice that the \fIx\fR character is deleted.  Undo this with \fBu\fR
+and then try \fBdt\fR\fIx\fR;  the \fBt\fR here stands for to, i.e.
+delete up to the next \fIx\fR, but not the \fIx\fR.  The command \fBT\fR
+is the reverse of \fBt\fR.
+.PP
+When working with the text of a single line, an \fB\(ua\fR moves the
+cursor to the first non-white position on the line, and a
+\fB$\fR moves it to the end of the line.  Thus \fB$a\fR will append new
+text at the end of the current line.
+.PP
+Your file may have tab (\fB^I\fR) characters in it.  These
+characters are represented as a number of spaces expanding to a tab stop,
+where tab stops are every 8 positions.*
+.FS
+* This is settable by a command of the form \fB:se ts=\fR\fIx\fR\s-2CR\s0,
+where \fIx\fR is 4 to set tabstops every four columns.  This has
+effect on the screen representation within the editor.
+.FE
+When the cursor is at a tab, it sits on the last of the several spaces
+which represent that tab.  Try moving the cursor back and forth over
+tabs so you understand how this works.
+.PP
+On rare occasions, your file may have nonprinting characters in it. 
+These characters are displayed in the same way they are represented in
+this document, that is with a two character code, the first character
+of which is `^'.  On the screen non-printing characters resemble a `^'
+character adjacent to another, but spacing or backspacing over the character
+will reveal that the two characters are, like the spaces representing
+a tab character, a single character.
+.PP
+The editor sometimes discards control characters,
+depending on the character and the setting of the
+.I beautify
+option,
+if you attempt to insert them in your file.
+You can get a control character in the file by beginning
+an insert and then typing a \fB^V\fR before the control
+character.  The
+\fB^V\fR quotes the following character, causing it to be
+inserted directly into the file.
+.PP
+.NH 2
+Higher level text objects
+.PP
+In working with a document it is often advantageous to work in terms
+of sentences, paragraphs, and sections.  The operations \fB(\fR and \fB)\fR
+move to the beginning of the previous and next sentences respectively.
+Thus the command \fBd)\fR will delete the rest of the current sentence;
+likewise \fBd(\fR will delete the previous sentence if you are at the
+beginning of the current sentence, or the current sentence up to where
+you are if you are not at the beginning of the current sentence.
+.PP
+A sentence is defined to end at a `.', `!' or `?' which is followed by
+either the end of a line, or by two spaces.  Any number of closing `)',
+`]', `"' and `\(aa' characters may appear after the `.', `!' or `?' before
+the spaces or end of line.
+.PP
+The operations \fB{\fR and \fB}\fR move over paragraphs and the operations
+\fB[[\fR and \fB]]\fR move over sections.\*(dg
+.FS
+\*(dg The \fB[[\fR and \fB]]\fR operations
+require the operation character to be doubled because they can move the
+cursor far from where it currently is.  While it is easy to get back
+with the command \fB\(ga\(ga\fP,
+these commands would still be frustrating
+if they were easy to hit accidentally.
+.FE
+.PP
+A paragraph begins after each empty line, and also
+at each of a set of paragraph macros, specified by the pairs of characters
+in the definition of the string valued option \fIparagraphs\fR.
+The default setting for this option defines the paragraph macros of the
+\fI\-ms\fR and \fI\-mm\fR macro packages, i.e. the `.IP', `.LP', `.PP'
+and `.QP', `.P' and `.LI' macros.\*(dd
+.FS
+\*(dd You can easily change or extend this set of macros by assigning a
+different string to the \fIparagraphs\fR option in your EXINIT.
+See section 6.2 for details.
+The `.bp' directive is also considered to start a paragraph.
+.FE
+Each paragraph boundary is also a sentence boundary.  The sentence
+and paragraph commands can
+be given counts to operate over groups of sentences and paragraphs.
+.PP
+Sections in the editor begin after each macro in the \fIsections\fR option,
+normally `.NH', `.SH', `.H' and `.HU', and each line with a formfeed \fB^L\fR
+in the first column.
+Section boundaries are always line and paragraph boundaries also.
+.PP
+Try experimenting with the sentence and paragraph commands until you are
+sure how they work.  If you have a large document, try looking through
+it using the section commands.
+The section commands interpret a preceding count as a different window size in
+which to redraw the screen at the new location, and this window size
+is the base size for newly drawn windows until another size is specified.
+This is very useful
+if you are on a slow terminal and are looking for a particular section. 
+You can give the first section command a small count to then see each successive
+section heading in a small window.
+.NH 2
+Rearranging and duplicating text
+.PP
+The editor has a single unnamed buffer where the last deleted or
+changed away text is saved, and a set of named buffers \fBa\fR\-\fBz\fR
+which you can use to save copies of text and to move text around in
+your file and between files.
+.PP
+The operator
+.B y
+yanks a copy of the object which follows into the unnamed buffer.
+If preceded by a buffer name, \fB"\fR\fIx\fR\|\fBy\fR, where
+\fIx\fR here is replaced by a letter \fBa\-z\fR, it places the text in the named
+buffer.  The text can then be put back in the file with the commands
+.B p
+and
+.B P;
+\fBp\fR puts the text after or below the cursor, while \fBP\fR puts the text
+before or above the cursor.
+.PP
+If the text which you
+yank forms a part of a line, or is an object such as a sentence which
+partially spans more than one line, then when you put the text back,
+it will be placed after the cursor (or before if you
+use \fBP\fR).  If the yanked text forms whole lines, they will be put
+back as whole lines, without changing the current line.  In this case,
+the put acts much like a \fBo\fR or \fBO\fR command.
+.PP
+Try the command \fBYP\fR.  This makes a copy of the current line and
+leaves you on this copy, which is placed before the current line.
+The command \fBY\fR is a convenient abbreviation for \fByy\fR.
+The command \fBYp\fR will also make a copy of the current line, and place
+it after the current line.  You can give \fBY\fR a count of lines to
+yank, and thus duplicate several lines; try \fB3YP\fR.
+.PP
+To move text within the buffer, you need to delete it in one place, and
+put it back in another.  You can precede a delete operation by the
+name of a buffer in which the text is to be stored as in \fB"a5dd\fR
+deleting 5 lines into the named buffer \fIa\fR.  You can then move the
+cursor to the eventual resting place of the these lines and do a \fB"ap\fR
+or \fB"aP\fR to put them back.
+In fact, you can switch and edit another file before you put the lines
+back, by giving a command of the form \fB:e \fR\fIname\fR\s-2CR\s0 where
+\fIname\fR is the name of the other file you want to edit.  You will
+have to write back the contents of the current editor buffer (or discard
+them) if you have made changes before the editor will let you switch
+to the other file.
+An ordinary delete command saves the text in the unnamed buffer,
+so that an ordinary put can move it elsewhere.
+However, the unnamed buffer is lost when you change files,
+so to move text from one file to another you should use an unnamed buffer.
+.NH 2
+Summary.
+.IP
+.TS
+lw(.50i)b a.
+\(ua	first non-white on line
+$	end of line
+)	forward sentence
+}	forward paragraph
+]]	forward section
+(	backward sentence
+{	backward paragraph
+[[	backward section
+f\fIx\fR	find \fIx\fR forward in line
+p	put text back, after cursor or below current line
+y	yank operator, for copies and moves
+t\fIx\fR	up to \fIx\fR forward, for operators
+F\fIx\fR	f backward in line
+P	put text back, before cursor or above current line
+T\fIx\fR	t backward in line
+.TE
+.NH 1
+High level commands
+.NH 2
+Writing, quitting, editing new files
+.PP
+So far we have seen how to enter
+.I vi
+and to write out our file using either
+\fBZZ\fR or \fB:w\fR\s-2CR\s0. The first exits from
+the editor,
+(writing if changes were made),
+the second writes and stays in the editor.
+.PP
+If you have changed the editor's copy of the file but do not wish to
+save your changes, either because you messed up the file or decided that the
+changes are not an improvement to the file, then you can give the command
+\fB:q!\fR\s-2CR\s0 to quit from the editor without writing the changes.
+You can also reedit the same file (starting over) by giving the command
+\fB:e!\fR\s-2CR\s0.  These commands should be used only rarely, and with
+caution, as it is not possible to recover the changes you have made after
+you discard them in this manner.
+.PP
+You can edit a different file without leaving the editor by giving the
+command \fB:e\fR\ \fIname\fR\s-2CR\s0.  If you have not written out
+your file before you try to do this, then the editor will tell you this,
+and delay editing the other file.  You can then give the command
+\fB:w\fR\s-2CR\s0 to save your work and then the \fB:e\fR\ \fIname\fR\s-2CR\s0
+command again, or carefully give the command \fB:e!\fR\ \fIname\fR\s-2CR\s0,
+which edits the other file discarding the changes you have made to the
+current file.
+To have the editor automatically save changes,
+include
+.I "set autowrite"
+in your EXINIT,
+and use \fB:n\fP instead of \fB:e\fP.
+.NH 2
+Escaping to a shell
+.PP
+You can get to a shell to execute a single command by giving a
+.I vi
+command of the form \fB:!\fIcmd\fR\s-2CR\s0.
+The system will run the single command
+.I cmd
+and when the command finishes, the editor will ask you to hit a \s-2RETURN\s0
+to continue.  When you have finished looking at the output on the screen,
+you should hit \s-2RETURN\s0 and the editor will clear the screen and
+redraw it.  You can then continue editing.
+You can also give another \fB:\fR command when it asks you for a \s-2RETURN\s0;
+in this case the screen will not be redrawn.
+.PP
+If you wish to execute more than one command in the shell, then you can
+give the command \fB:sh\fR\s-2CR\s0.
+This will give you a new shell, and when you finish with the shell, ending
+it by typing a \fB^D\fR, the editor will clear the screen and continue.
+.PP
+On systems which support it, \fB^Z\fP will suspend the editor
+and return to the (top level) shell.
+When the editor is resumed, the screen will be redrawn.
+.NH 2
+Marking and returning
+.PP
+The command \fB\(ga\(ga\fR returned to the previous place
+after a motion of the cursor by a command such as \fB/\fR, \fB?\fR or
+\fBG\fR.  You can also mark lines in the file with single letter tags
+and return to these marks later by naming the tags.  Try marking the
+current line with the command \fBm\fR\fIx\fR, where you should pick some
+letter for \fIx\fR, say `a'.  Then move the cursor to a different line
+(any way you like) and hit \fB\(gaa\fR.  The cursor will return to the
+place which you marked.
+Marks last only until you edit another file.
+.PP
+When using operators such as
+.B d
+and referring to marked lines, it is often desirable to delete whole lines
+rather than deleting to the exact position in the line marked by \fBm\fR.
+In this case you can use the form \fB\(aa\fR\fIx\fR rather than
+\fB\(ga\fR\fIx\fR.  Used without an operator, \fB\(aa\fR\fIx\fR will move to
+the first non-white character of the marked line; similarly \fB\(aa\(aa\fR
+moves to the first non-white character of the line containing the previous
+context mark \fB\(ga\(ga\fR.
+.NH 2
+Adjusting the screen
+.PP
+If the screen image is messed up because of a transmission error to your
+terminal, or because some program other than the editor wrote output
+to your terminal, you can hit a \fB^L\fR, the \s-2ASCII\s0 form-feed
+character, to cause the screen to be refreshed.
+.PP
+On a dumb terminal, if there are @ lines in the middle of the screen
+as a result of line deletion, you may get rid of these lines by typing
+\fB^R\fR to cause the editor to retype the screen, closing up these holes.
+.PP
+Finally, if you wish to place a certain line on the screen at the top
+middle or bottom of the screen, you can position the cursor to that line,
+and then give a \fBz\fR command.
+You should follow the \fBz\fR command with a \s-2RETURN\s0 if you want
+the line to appear at the top of the window, a \fB.\fR if you want it
+at the center, or a \fB\-\fR if you want it at the bottom.
+.NH 1
+Special topics
+.NH 2
+Editing on slow terminals
+.PP
+When you are on a slow terminal, it is important to limit the amount
+of output which is generated to your screen so that you will not suffer
+long delays, waiting for the screen to be refreshed.  We have already
+pointed out how the editor optimizes the updating of the screen during
+insertions on dumb terminals to limit the delays, and how the editor erases
+lines to @ when they are deleted on dumb terminals.
+.PP
+The use of the slow terminal insertion mode is controlled by the
+.I slowopen
+option.  You can force the editor to use this mode even on faster terminals
+by giving the command \fB:se slow\fR\s-2CR\s0.  If your system is sluggish
+this helps lessen the amount of output coming to your terminal.
+You can disable this option by \fB:se noslow\fR\s-2CR\s0.
+.PP
+The editor can simulate an intelligent terminal on a dumb one.  Try
+giving the command \fB:se redraw\fR\s-2CR\s0.  This simulation generates
+a great deal of output and is generally tolerable only on lightly loaded
+systems and fast terminals.  You can disable this by giving the command
+ \fB:se noredraw\fR\s-2CR\s0.
+.PP
+The editor also makes editing more pleasant at low speed by starting
+editing in a small window, and letting the window expand as you edit.
+This works particularly well on intelligent terminals.  The editor can
+expand the window easily when you insert in the middle of the screen
+on these terminals.  If possible, try the editor on an intelligent terminal
+to see how this works.
+.PP
+You can control the size of the window which is redrawn each time the
+screen is cleared by giving window sizes as argument to the commands
+which cause large screen motions:
+.DS
+.B ":  /  ?  [[  ]]  \(ga  \(aa"
+.DE
+Thus if you are searching for a particular instance of a common string
+in a file you can precede the first search command by a small number,
+say 3, and the editor will draw three line windows around each instance
+of the string which it locates.
+.PP
+You can easily expand or contract the window, placing the current line
+as you choose, by giving a number on a \fBz\fR command, after the \fBz\fR
+and before the following \s-2RETURN\s0, \fB.\fR or \fB\-\fR.  Thus the
+command \fBz5.\fR redraws the screen with the current line in the center
+of a five line window.\*(dg
+.FS
+\*(dg Note that the command \fB5z.\fR has an entirely different effect,
+placing line 5 in the center of a new window.
+.FE
+.PP
+If the editor is redrawing or otherwise updating large portions of the
+display, you can interrupt this updating by hitting a \s-2DEL\s0 or \s-2RUB\s0
+as usual.  If you do this you may partially confuse the editor about
+what is displayed on the screen.  You can still edit the text on
+the screen if you wish; clear up the confusion
+by hitting a \fB^L\fR; or move or search again, ignoring the
+current state of the display.
+.PP
+See section 7.8 on \fIopen\fR mode for another way to use the
+.I vi
+command set on slow terminals.
+.NH 2
+Options, set, and editor startup files
+.PP
+The editor has a set of options, some of which have been mentioned above.
+The most useful options are given in the following table.
+.KF
+.TS
+lb lb lb lb
+l l l a.
+Name	Default	Description
+_
+autoindent	noai	Supply indentation automatically
+autowrite	noaw	Automatic write before \fB:n\fR, \fB:ta\fR, \fB^\(ua\fR, \fB!\fR
+ignorecase	noic	Ignore case in searching
+lisp	nolisp	\fB( { ) }\fR commands deal with S-expressions
+list	nolist	Tabs print as ^I; end of lines marked with $
+magic	nomagic	The characters . [ and * are special in scans
+number	nonu	Lines are displayed prefixed with line numbers
+paragraphs	para=IPLPPPQPbpP LI	Macro names which start paragraphs
+redraw	nore	Simulate a smart terminal on a dumb one
+sections	sect=NHSHH HU	Macro names which start new sections
+shiftwidth	sw=8	Shift distance for <, > and input \fB^D\fP and \fB^T\fR
+showmatch	nosm	Show matching \fB(\fP or \fB{\fP as \fB)\fP or \fB}\fR is typed
+slowopen	slow	Postpone display updates during inserts
+term	dumb	The kind of terminal you are using.
+.TE
+.KE
+.PP
+The options are of three kinds:  numeric options, string options, and
+toggle options.  You can set numeric and string options by a statement
+of the form
+.DS
+\fBset\fR \fIopt\fR\fB=\fR\fIval\fR
+.DE
+and toggle options can be set or unset by statements of one of the forms
+.DS
+\fBset\fR \fIopt\fR
+\fBset\fR \fBno\fR\fIopt\fR
+.DE
+These statements can be placed in your EXINIT in your environment,
+or given while you are running
+.I vi
+by preceding them with a \fB:\fR and following them with a \s-2CR\s0.
+.PP
+You can get a list of all options which you have changed by the
+command \fB:set\fR\s-2CR\s0, or the value of a single option by the
+command \fB:set\fR \fIopt\fR\fB?\fR\s-2CR\s0.
+A list of all possible options and their values is generated by
+\fB:set all\fP\s-2CR\s0.
+Set can be abbreviated \fBse\fP.
+Multiple options can be placed on one line, e.g.
+\fB:se ai aw nu\fP\s-2CR\s0.
+.PP
+Options set by the \fBset\fP command only last
+while you stay in the editor.
+It is common to want to have certain options set whenever you
+use the editor.
+This can be accomplished by creating a list of \fIex\fP commands\*(dg
+.FS
+\*(dg
+All commands which start with
+.B :
+are \fIex\fP commands.
+.FE
+which are to be run every time you start up \fIex\fP, \fIedit\fP,
+or \fIvi\fP.
+A typical list includes a \fBset\fP command, and possibly a few
+\fBmap\fP commands.
+Since it is advisable to get these commands on one line, they can
+be separated with the | character, for example:
+.DS
+\fBset\fP ai aw terse|\fBmap\fP @ dd|\fBmap\fP # x
+.DE
+which sets the options \fIautoindent\fP, \fIautowrite\fP, \fIterse\fP,
+(the
+.B set
+command),
+makes @ delete a line,
+(the first
+.B map ),
+and makes # delete a character,
+(the second
+.B map ).
+(See section 6.9 for a description of the \fBmap\fP command)
+This string should be placed in the variable EXINIT in your environment.
+If you use the shell \fIcsh\fP,
+put this line in the file
+.I .login
+in your home directory:
+.DS
+setenv EXINIT \(aa\fBset\fP ai aw terse|\fBmap\fP @ dd|\fBmap\fP # x\(aa
+.DE
+If you use the standard shell \fIsh\fP,
+put these lines in the file
+.I .profile
+in your home directory:
+.DS
+EXINIT=\(aa\fBset\fP ai aw terse|\fBmap\fP @ dd|\fBmap\fP # x\(aa
+export EXINIT
+.DE
+Of course, the particulars of the line would depend on which options
+you wanted to set.
+.NH 2
+Recovering lost lines
+.PP
+You might have a serious problem if you delete a number of lines and then
+regret that they were deleted.  Despair not, the editor saves the last
+9 deleted blocks of text in a set of numbered registers 1\-9.
+You can get the \fIn\fR'th previous deleted text back in your file by
+the command
+"\fR\fIn\fR\|\fBp\fR.
+The "\fR here says that a buffer name is to follow,
+\fIn\fR is the number of the buffer you wish to try
+(use the number 1 for now),
+and
+.B p
+is the put command, which puts text in the buffer after the cursor.
+If this doesn't bring back the text you wanted, hit
+.B u
+to undo this and then
+\fB\&.\fR
+(period)
+to repeat the put command.
+In general the
+\fB\&.\fR
+command will repeat the last change you made.
+As a special case, when the last command refers to a numbered text buffer,
+the \fB.\fR command increments the number of the buffer before repeating
+the command.  Thus a sequence of the form
+.DS
+\fB"1pu.u.u.\fR
+.DE
+will, if repeated long enough, show you all the deleted text which has
+been saved for you.
+You can omit the
+.B u
+commands here to gather up all this text in the buffer, or stop after any
+\fB\&.\fR command to keep just the then recovered text.
+The command
+.B P
+can also be used rather than
+.B p
+to put the recovered text before rather than after the cursor.
+.NH 2
+Recovering lost files
+.PP
+If the system crashes, you can recover the work you were doing
+to within a few changes.  You will normally receive mail when you next
+login giving you the name of the file which has been saved for you. 
+You should then change to the directory where you were when the system
+crashed and give a command of the form:
+.DS
+% \fBvi \-r\fR \fIname\fR
+.DE
+replacing \fIname\fR with the name of the file which you were editing.
+This will recover your work to a point near where you left off.\*(dg
+.FS
+\*(dg In rare cases, some of the lines of the file may be lost.  The
+editor will give you the numbers of these lines and the text of the lines
+will be replaced by the string `LOST'.  These lines will almost always
+be among the last few which you changed.  You can either choose to discard
+the changes which you made (if they are easy to remake) or to replace
+the few lost lines by hand.
+.FE
+.PP
+You can get a listing of the files which are saved for you by giving
+the command:
+.DS
+% \fBvi \-r\fR
+.DE
+If there is more than one instance of a particular file saved, the editor
+gives you the newest instance each time you recover it.  You can thus
+get an older saved copy back by first recovering the newer copies.
+.PP
+For this feature to work,
+.I vi
+must be correctly installed by a super user on your system,
+and the
+.I mail
+program must exist to receive mail.
+The invocation ``\fIvi -r\fP'' will not always list all saved files,
+but they can be recovered even if they are not listed.
+.NH 2
+Continuous text input
+.PP
+When you are typing in large amounts of text it is convenient to have
+lines broken near the right margin automatically.  You can cause this
+to happen by giving the command
+\fB:se wm=10\fR\s-2CR\s0.
+This causes all lines to be broken at a space at least 10 columns
+from the right hand edge of the screen.
+.PP
+If the editor breaks an input line and you wish to put it back together
+you can tell it to join the lines with \fBJ\fR.  You can give \fBJ\fR
+a count of the number of lines to be joined as in \fB3J\fR to join 3
+lines.  The editor supplies white space, if appropriate,
+at the juncture of the joined
+lines, and leaves the cursor at this white space.
+You can kill the white space with \fBx\fR if you don't want it.
+.NH 2
+Features for editing programs
+.PP
+The editor has a number of commands for editing programs.
+The thing that most distinguishes editing of programs from editing of text
+is the desirability of maintaining an indented structure to the body of
+the program.  The editor has a
+.I autoindent
+facility for helping you generate correctly indented programs.
+.PP
+To enable this facility you can give the command \fB:se ai\fR\s-2CR\s0.
+Now try opening a new line with \fBo\fR and type some characters on the
+line after a few tabs.  If you now start another line, notice that the
+editor supplies white space at the beginning of the line to line it up
+with the previous line.  You cannot backspace over this indentation,
+but you can use \fB^D\fR key to backtab over the supplied indentation.
+.PP
+Each time you type \fB^D\fR you back up one position, normally to an
+8 column boundary.  This amount is settable; the editor has an option
+called
+.I shiftwidth
+which you can set to change this value.
+Try giving the command \fB:se sw=4\fR\s-2CR\s0
+and then experimenting with autoindent again.
+.PP
+For shifting lines in the program left and right, there are operators
+.B <
+and
+.B >.
+These shift the lines you specify right or left by one
+.I shiftwidth.
+Try
+.B <<
+and
+.B >>
+which shift one line left or right, and
+.B <L
+and
+.B >L
+shifting the rest of the display left and right.
+.PP
+If you have a complicated expression and wish to see how the parentheses
+match, put the cursor at a left or right parenthesis and hit \fB%\fR.
+This will show you the matching parenthesis.
+This works also for braces { and }, and brackets [ and ].
+.PP
+If you are editing C programs, you can use the \fB[[\fR and \fB]]\fR keys
+to advance or retreat to a line starting with a \fB{\fR, i.e. a function
+declaration at a time.  When \fB]]\fR is used with an operator it stops
+after a line which starts with \fB}\fR; this is sometimes useful with
+\fBy]]\fR.
+.NH 2
+Filtering portions of the buffer
+.PP
+You can run system commands over portions of the buffer using the operator
+\fB!\fR.
+You can use this to sort lines in the buffer, or to reformat portions
+of the buffer with a pretty-printer.
+Try typing in a list of random words, one per line and ending them
+with a blank line.  Back up to the beginning of the list, and then give
+the command \fB!}sort\fR\s-2CR\s0.  This says to sort the next paragraph
+of material, and the blank line ends a paragraph.
+.NH 2
+Commands for editing \s-2LISP\s0
+.PP
+If you are editing a \s-2LISP\s0 program you should set the option
+.I lisp
+by doing
+\fB:se\ lisp\fR\s-2CR\s0.
+This changes the \fB(\fR and \fB)\fR commands to move backward and forward
+over s-expressions.
+The \fB{\fR and \fB}\fR commands are like \fB(\fR and \fB)\fR but don't
+stop at atoms.  These can be used to skip to the next list, or through
+a comment quickly.
+.PP
+The
+.I autoindent
+option works differently for \s-2LISP\s0, supplying indent to align at
+the first argument to the last open list.  If there is no such argument
+then the indent is two spaces more than the last level.
+.PP
+There is another option which is useful for typing in \s-2LISP\s0, the
+.I showmatch
+option.
+Try setting it with
+\fB:se sm\fR\s-2CR\s0
+and then try typing a `(' some words and then a `)'.  Notice that the
+cursor shows the position of the `(' which matches the `)' briefly. 
+This happens only if the matching `(' is on the screen, and the cursor
+stays there for at most one second.
+.PP
+The editor also has an operator to realign existing lines as though they
+had been typed in with
+.I lisp
+and
+.I autoindent
+set.  This is the \fB=\fR operator.
+Try the command \fB=%\fR at the beginning of a function.  This will realign
+all the lines of the function declaration.
+.PP
+When you are editing \s-2LISP\s0,, the \fB[[\fR and \fR]]\fR advance
+and retreat to lines beginning with a \fB(\fR, and are useful for dealing
+with entire function definitions.
+.NH 2
+Macros
+.PP
+.I Vi
+has a parameterless macro facility, which lets you set it up so that
+when you hit a single keystroke, the editor will act as though
+you had hit some longer sequence of keys.  You can set this up if
+you find yourself typing the same sequence of commands repeatedly.
+.PP
+Briefly, there are two flavors of macros:
+.IP a)
+Ones where you put the macro body in a buffer register, say \fIx\fR.
+You can then type \fB@x\fR to invoke the macro.  The \fB@\fR may be followed
+by another \fB@\fR to repeat the last macro.
+.IP b)
+You can use the
+.I map
+command from
+.I vi
+(typically in your
+.I EXINIT )
+with a command of the form:
+.DS
+:map \fIlhs\fR \fIrhs\fR\s-2CR\f0
+.DE
+mapping
+.I lhs
+into
+.I rhs.
+There are restrictions:
+.I lhs
+should be one keystroke (either 1 character or one function key)
+since it must be entered within one second
+(unless
+.I notimeout
+is set, in which case you can type it as slowly as you wish,
+and
+.I vi
+will wait for you to finish it before it echoes anything).
+The
+.I lhs
+can be no longer than 10 characters, the
+.I rhs
+no longer than 100.
+To get a space, tab or newline into
+.I lhs
+or
+.I rhs
+you should escape them with a \fB^V\fR.
+(It may be necessary to double the \fB^V\fR if the map
+command is given inside
+.I vi,
+rather than in
+.I ex.)
+Spaces and tabs inside the
+.I rhs
+need not be escaped.
+.PP
+Thus to make the \fBq\fR key write and exit the editor, you can give
+the command
+.DS
+:map q :wq\fB^V^V\fP\s-2CR CR\s0
+.DE
+which means that whenever you type \fBq\fR, it will be as though you
+had typed the four characters \fB:wq\fR\s-2CR\s0.
+A \fB^V\fR's is needed because without it the \s-2CR\s0 would end the
+\fB:\fR command, rather than becoming part of the
+.I map
+definition.
+There are two
+.B ^V 's
+because from within
+.I vi ,
+two
+.B ^V 's
+must be typed to get one.
+The first \s-2CR\s0 is part of the
+.I rhs ,
+the second terminates the : command.
+.PP
+Macros can be deleted with
+.DS
+unmap lhs
+.DE
+.PP
+If the
+.I lhs
+of a macro is ``#0'' through ``#9'', this maps the particular function key
+instead of the 2 character ``#'' sequence.  So that terminals without
+function keys can access such definitions, the form ``#x'' will mean function
+key
+.I x
+on all terminals (and need not be typed within one second.)
+The character ``#'' can be changed by using a macro in the usual way:
+.DS
+:map \fB^V^V^I\fP #
+.DE
+to use tab, for example.  (This won't affect the
+.I map
+command, which still uses
+.B #,
+but just the invocation from visual mode.
+.PP
+The undo command reverses an entire macro call as a unit,
+if it made any changes.
+.PP
+Placing a `!' after the word
+.B map
+causes the mapping to apply
+to input mode, rather than command mode.
+Thus, to arrange for \fB^T\fP to be the same as 4 spaces in input mode,
+you can type:
+.DS
+:map \fB^T\fP \fB^V\fP\o'b/'\o'b/'\o'b/'\o'b/'
+.DE
+where
+.B \o'b/'
+is a blank.
+The \fB^V\fP is necessary to prevent the blanks from being taken as
+white space between the
+.I lhs
+and
+.I rhs .
+.NH
+Word Abbreviations
+.PP
+A feature similar to macros in input mode is word abbreviation.
+This allows you to type a short word and have it expanded into
+a longer word or words.
+The commands are
+.B :abbreviate
+and
+.B :unabbreviate
+(\fB:ab\fP
+and
+.B :una )
+and have the same syntax as
+.B :map .
+For example:
+.DS
+:ab eecs Electrical Engineering and Computer Sciences
+.DE
+causes the word `eecs' to always be changed into the
+phrase `Electrical Engineering and Computer Sciences'.
+Word abbreviation is different from macros in that
+only whole words are affected.
+If `eecs' were typed as part of a larger word, it would
+be left alone.
+Also, the partial word is echoed as it is typed.
+There is no need for an abbreviation to be a single keystroke,
+as it should be with a macro.
+.NH 2
+Abbreviations
+.PP
+The editor has a number of short
+commands which abbreviate longer commands which we
+have introduced here.  You can find these commands easily
+on the quick reference card.
+They often save a bit of typing and you can learn them as convenient.
+.NH 1
+Nitty-gritty details
+.NH 2
+Line representation in the display
+.PP
+The editor folds long logical lines onto many physical lines in the display.
+Commands which advance lines advance logical lines and will skip
+over all the segments of a line in one motion.  The command \fB|\fR moves
+the cursor to a specific column, and may be useful for getting near the
+middle of a long line to split it in half.  Try \fB80|\fR on a line which
+is more than 80 columns long.\*(dg
+.FS
+\*(dg You can make long lines very easily by using \fBJ\fR to join together
+short lines.
+.FE
+.PP
+The editor only puts full lines on the display; if there is not enough
+room on the display to fit a logical line, the editor leaves the physical
+line empty, placing only an @ on the line as a place holder.  When you
+delete lines on a dumb terminal, the editor will often just clear the
+lines to @ to save time (rather than rewriting the rest of the screen.)
+You can always maximize the information on the screen by giving the \fB^R\fR
+command.
+.PP
+If you wish, you can have the editor place line numbers before each line
+on the display.  Give the command \fB:se nu\fR\s-2CR\s0 to enable
+this, and the command \fB:se nonu\fR\s-2CR\s0 to turn it off.
+You can have tabs represented as \fB^I\fR and the ends of lines indicated
+with `$' by giving the command \fB:se list\fR\s-2CR\s0;
+\fB:se nolist\fR\s-2CR\s0 turns this off.
+.PP
+Finally, lines consisting of only the character `~' are displayed when
+the last line in the file is in the middle of the screen.  These represent
+physical lines which are past the logical end of file.
+.NH 2
+Counts
+.PP
+Most
+.I vi
+commands will use a preceding count to affect their behavior in some way.
+The following table gives the common ways in which the counts are used:
+.DS
+.TS
+l lb.
+new window size	:  /  ?  [[  ]]  \`  \'
+scroll amount	^D  ^U
+line/column number	z  G  |
+repeat effect	\fRmost of the rest\fP
+.TE
+.DE
+.PP
+The editor maintains a notion of the current default window size.
+On terminals which run at speeds greater than 1200 baud
+the editor uses the full terminal screen.
+On terminals which are slower than 1200 baud
+(most dialup lines are in this group)
+the editor uses 8 lines as the default window size.
+At 1200 baud the default is 16 lines.
+.PP
+This size is the size used when the editor clears and refills the screen
+after a search or other motion moves far from the edge of the current window.
+The commands which take a new window size as count all often cause the
+screen to be redrawn.  If you anticipate this, but do not need as large
+a window as you are currently using, you may wish to change the screen
+size by specifying the new size before these commands.
+In any case, the number of lines used on the screen will expand if you
+move off the top with a \fB\-\fR or similar command or off the bottom
+with a command such as \s-2RETURN\s0 or \fB^D\fR.
+The window will revert to the last specified size the next time it is
+cleared and refilled.\*(dg
+.FS
+\*(dg But not by a \fB^L\fR which just redraws the screen as it is.
+.FE
+.PP
+The scroll commands \fB^D\fR and \fB^U\fR likewise remember the amount
+of scroll last specified, using half the basic window size initially.
+The simple insert commands use a count to specify a repetition of the
+inserted text.  Thus \fB10a+\-\-\-\-\fR\s-2ESC\s0 will insert a grid-like
+string of text.
+A few commands also use a preceding count as a line or column number.
+.PP
+Except for a few commands which ignore any counts (such as \fB^R\fR),
+the rest of the editor commands use a count to indicate a simple repetition
+of their effect.  Thus \fB5w\fR advances five words on the current line,
+while \fB5\fR\s-2RETURN\s0 advances five lines.  A very useful instance
+of a count as a repetition is a count given to the \fB.\fR command, which
+repeats the last changing command.  If you do \fBdw\fR and then \fB3.\fR,
+you will delete first one and then three words.  You can then delete
+two more words with \fB2.\fR.
+.NH 2
+More file manipulation commands
+.PP
+The following table lists the file manipulation commands which you can
+use when you are in
+.I vi.
+.KF
+.DS
+.TS
+lb l.
+:w	write back changes
+:wq	write and quit
+:x	write (if necessary) and quit (same as ZZ).
+:e \fIname\fP	edit file \fIname\fR
+:e!	reedit, discarding changes
+:e + \fIname\fP	edit, starting at end
+:e +\fIn\fP	edit, starting at line \fIn\fP
+:e #	edit alternate file
+:w \fIname\fP	write file \fIname\fP
+:w! \fIname\fP	overwrite file \fIname\fP
+:\fIx,y\fPw \fIname\fP	write lines \fIx\fP through \fIy\fP to \fIname\fP
+:r \fIname\fP	read file \fIname\fP into buffer
+:r !\fIcmd\fP	read output of \fIcmd\fP into buffer
+:n	edit next file in argument list
+:n!	edit next file, discarding changes to current
+:n \fIargs\fP	specify new argument list
+:ta \fItag\fP	edit file containing tag \fItag\fP, at \fItag\fP
+.TE
+.DE
+.KE
+All of these commands are followed by a \s-2CR\s0 or \s-2ESC\s0.
+The most basic commands are \fB:w\fR and \fB:e\fR.
+A normal editing session on a single file will end with a \fBZZ\fR command.
+If you are editing for a long period of time you can give \fB:w\fR commands
+occasionally after major amounts of editing, and then finish
+with a \fBZZ\fR.   When you edit more than one file, you can finish
+with one with a \fB:w\fR and start editing a new file by giving a \fB:e\fR
+command,
+or set
+.I autowrite
+and use \fB:n\fP <file>.
+.PP
+If you make changes to the editor's copy of a file, but do not wish to
+write them back, then you must give an \fB!\fR after the command you
+would otherwise use; this forces the editor to discard any changes
+you have made.  Use this carefully.
+.PP
+The \fB:e\fR command can be given a \fB+\fR argument to start at the
+end of the file, or a \fB+\fR\fIn\fR argument to start at line \fIn\fR\^.
+In actuality, \fIn\fR may be any editor command not containing a space,
+usefully a scan like \fB+/\fIpat\fR or \fB+?\fIpat\fR.
+In forming new names to the \fBe\fR command, you can use the character
+\fB%\fR which is replaced by the current file name, or the character
+\fB#\fR which is replaced by the alternate file name.
+The alternate file name is generally the last name you typed other than
+the current file.  Thus if you try to do a \fB:e\fR and get a diagnostic
+that you haven't written the file, you can give a \fB:w\fR command and
+then a \fB:e #\fR command to redo the previous \fB:e\fR.
+.PP
+You can write part of the buffer to a file by finding out the lines
+that bound the range to be written using \fB^G\fR, and giving these
+numbers after the \fB:\fR
+and before the \fBw\fP, separated by \fB,\fR's.
+You can also mark these lines with \fBm\fR and
+then use an address of the form \fB\(aa\fR\fIx\fR\fB,\fB\(aa\fR\fIy\fR
+on the \fBw\fR command here.
+.PP
+You can read another file into the buffer after the current line by using
+the \fB:r\fR command.
+You can similarly read in the output from a command, just use \fB!\fR\fIcmd\fR
+instead of a file name.
+.PP
+If you wish to edit a set of files in succession, you can give all the
+names on the command line, and then edit each one in turn using the command
+\fB:n\fR.  It is also possible to respecify the list of files to be edited
+by giving the \fB:n\fR command a list of file names, or a pattern to
+be expanded as you would have given it on the initial
+.I vi
+command.
+.PP
+If you are editing large programs, you will find the \fB:ta\fR command
+very useful.  It utilizes a data base of function names and their locations,
+which can be created by programs such as
+.I ctags,
+to quickly find a function whose name you give.
+If the \fB:ta\fR command will require the editor to switch files, then
+you must \fB:w\fR or abandon any changes before switching.  You can repeat
+the \fB:ta\fR command without any arguments to look for the same tag
+again.
+.NH 2
+More about searching for strings
+.PP
+When you are searching for strings in the file with \fB/\fR and \fB?\fR,
+the editor normally places you at the next or previous occurrence
+of the string.  If you are using an operator such as \fBd\fR,
+\fBc\fR or \fBy\fR, then you may well wish to affect lines up to the
+line before the line containing the pattern.  You can give a search of
+the form \fB/\fR\fIpat\fR\fB/\-\fR\fIn\fR to refer to the \fIn\fR'th line
+before the next line containing \fIpat\fR, or you can use \fB\+\fR instead
+of \fB\-\fR to refer to the lines after the one containing \fIpat\fR.
+If you don't give a line offset, then the editor will affect characters
+up to the match place, rather than whole lines; thus use ``+0'' to affect
+to the line which matches.
+.PP
+You can have the editor ignore the case of words in the searches it does
+by giving the command \fB:se ic\fR\s-2CR\s0.
+The command \fB:se noic\fR\s-2CR\s0 turns this off.
+.PP
+Strings given to searches may actually be regular expressions.
+If you do not want or need this facility, you should
+.DS
+set nomagic
+.DE
+in your EXINIT.
+In this case, 
+only the characters \fB\(ua\fR and \fB$\fR are special in patterns.
+The character \fB\e\fR is also then special (as it is most everywhere in
+the system), and may be used to get at the
+an extended pattern matching facility.
+It is also necessary to use a \e before a
+\fB/\fR in a forward scan or a \fB?\fR in a backward scan, in any case.
+The following table gives the extended forms when \fBmagic\fR is set.
+.DS
+.TS
+bl l.
+\(ua	at beginning of pattern, matches beginning of line
+$	at end of pattern, matches end of line
+\fB\&.\fR	matches any character
+\e<	matches the beginning of a word
+\e>	matches the end of a word
+[\fIstr\fP]	matches any single character in \fIstr\fP
+[\(ua\fIstr\fP]	matches any single character not in \fIstr\fP
+[\fIx\fP\-\fIy\fP]	matches any character between \fIx\fP and \fIy\fP
+*	matches any number of the preceding pattern
+.TE
+.DE
+If you use \fBnomagic\fR mode, then
+the \fB. [\fR and \fB*\fR primitives are given with a preceding
+\e.
+.NH 2
+More about input mode
+.PP
+There are a number of characters which you can use to make corrections
+during input mode.  These are summarized in the following table.
+.DS
+.TS
+lb l.
+^H	deletes the last input character
+^W	deletes the last input word, defined as by \fBb\fR
+erase	your erase character, same as \fB^H\fP
+kill	your kill character, deletes the input on this line
+\e	escapes a following \fB^H\fP and your erase and kill
+\s-2ESC\s0	ends an insertion
+\s-2DEL\s0	interrupts an insertion, terminating it abnormally
+\s-2CR\s0	starts a new line
+^D	backtabs over \fIautoindent\fP
+0^D	kills all the \fIautoindent\fP
+\(ua^D	same as \fB0^D\fP, but restores indent next line
+^V	quotes the next non-printing character into the file
+.TE
+.DE
+.PP
+The most usual way of making corrections to input is by typing \fB^H\fR
+to correct a single character, or by typing one or more \fB^W\fR's to
+back over incorrect words.  If you use \fB#\fR as your erase character
+in the normal system, it will work like \fB^H\fR.
+.PP
+Your system kill character, normally \fB@\fR, \fB^X\fP or \fB^U\fR,
+will erase all
+the input you have given on the current line.
+In general, you can neither
+erase input back around a line boundary nor can you erase characters
+which you did not insert with this insertion command.  To make corrections
+on the previous line after a new line has been started you can hit \s-2ESC\s0
+to end the insertion, move over and make the correction, and then return
+to where you were to continue.  The command \fBA\fR which appends at the
+end of the current line is often useful for continuing.
+.PP
+If you wish to type in your erase or kill character (say # or @) then
+you must precede it with a \fB\e\fR, just as you would do at the normal
+system command level.  A more general way of typing non-printing characters
+into the file is to precede them with a \fB^V\fR.  The \fB^V\fR echoes
+as a \fB\(ua\fR character on which the cursor rests.  This indicates that
+the editor expects you to type a control character.  In fact you may
+type any character and it will be inserted into the file at that point.*
+.FS
+* This is not quite true.  The implementation of the editor does
+not allow the \s-2NULL\s0 (\fB^@\fR) character to appear in files.  Also
+the \s-2LF\s0 (linefeed or \fB^J\fR) character is used by the editor
+to separate lines in the file, so it cannot appear in the middle of a
+line.  You can insert any other character, however, if you wait for the
+editor to echo the \fB\(ua\fR before you type the character.  In fact,
+the editor will treat a following letter as a request for the corresponding
+control character.  This is the only way to type \fB^S\fR or \fB^Q\fP,
+since the system normally uses them to suspend and resume output
+and never gives them to the editor to process.
+.FE
+.PP
+If you are using \fIautoindent\fR you can backtab over the indent which
+it supplies by typing a \fB^D\fR.  This backs up to a \fIshiftwidth\fR
+boundary.
+This only works immediately after the supplied \fIautoindent\fR.
+.PP
+When you are using \fIautoindent\fR you may wish to place a label at
+the left margin of a line.  The way to do this easily is to type \fB\(ua\fR
+and then \fB^D\fR.  The editor will move the cursor to the left margin
+for one line, and restore the previous indent on the next.  You can also
+type a \fB0\fR followed immediately by a \fB^D\fR if you wish to kill
+all the indent and not have it come back on the next line.
+.NH 2
+Upper case only terminals
+.PP
+If your terminal has only upper case, you can still use
+.I vi
+by using the normal
+system convention for typing on such a terminal.
+Characters which you normally type are converted to lower case, and you
+can type upper case letters by preceding them with a \e.
+The characters { ~ } | \(ga are not available on such terminals, but you
+can escape them as \e( \e\(ua \e) \e! \e\(aa.
+These characters are represented on the display in the same way they
+are typed.\*(dd
+.FS
+\*(dd The \e character you give will not echo until you type another
+key.
+.FE
+.NH 2
+Vi and ex
+.PP
+.I Vi
+is actually one mode of editing within the editor
+.I ex.
+When you are running
+.I vi
+you can escape to the line oriented editor of
+.I ex
+by giving the command
+\fBQ\fR.
+All of the
+.B :
+commands which were introduced above are available in
+.I ex.
+Likewise, most
+.I ex
+commands can be invoked from
+.I vi
+using :.
+Just give them without the \fB:\fR and follow them with a \s-2CR\s0.
+.PP
+In rare instances, an internal error may occur in
+.I vi.
+In this case you will get a diagnostic and be left in the command mode of
+.I ex.
+You can then save your work and quit if you wish by giving a command
+\fBx\fR after the \fB:\fR which \fIex\fR prompts you with, or you can
+reenter \fIvi\fR by giving
+.I ex
+a
+.I vi
+command.
+.PP
+There are a number of things which you can do more easily in
+.I ex
+than in
+.I vi.
+Systematic changes in line oriented material are particularly easy.
+You can read the advanced editing documents for the editor
+.I ed
+to find out a lot more about this style of editing.
+Experienced
+users often mix their use of
+.I ex
+command mode and
+.I vi
+command mode to speed the work they are doing.
+.NH 2
+Open mode: vi on hardcopy terminals and ``glass tty's''
+\(dd
+.PP
+If you are on a hardcopy terminal or a terminal which does not have a cursor
+which can move off the bottom line, you can still use the command set of
+.I vi,
+but in a different mode.
+When you give a
+.I vi
+command, the editor will tell you that it is using
+.I open
+mode.
+This name comes from the
+.I open
+command in
+.I ex,
+which is used to get into the same mode.
+.PP
+The only difference between
+.I visual
+mode
+and
+.I open
+mode is the way in which the text is displayed.
+.PP
+In
+.I open
+mode the editor uses a single line window into the file, and moving backward
+and forward in the file causes new lines to be displayed, always below the
+current line.
+Two commands of
+.I vi
+work differently in
+.I open:
+.B z
+and
+\fB^R\fR.
+The
+.B z
+command does not take parameters, but rather draws a window of context around
+the current line and then returns you to the current line.
+.PP
+If you are on a hardcopy terminal,
+the
+.B ^R
+command will retype the current line.
+On such terminals, the editor normally uses two lines to represent the
+current line.
+The first line is a copy of the line as you started to edit it, and you work
+on the line below this line.
+When you delete characters, the editor types a number of \e's to show
+you the characters which are deleted.  The editor also reprints the current
+line soon after such changes so that you can see what the line looks
+like again.
+.PP
+It is sometimes useful to use this mode on very slow terminals which
+can support
+.I vi
+in the full screen mode.
+You can do this by entering
+.I ex
+and using an
+.I open
+command.
+.LP
+.SH
+Acknowledgements
+.PP
+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.