USD.doc/vi.man/vi.1

.\"	$OpenBSD: vi.1,v 1.56 2012/01/17 08:18:36 jmc Exp $
.\"
.\" Copyright (c) 1994
.\"     The Regents of the University of California.  All rights reserved.
.\" Copyright (c) 1994, 1995, 1996
.\"	Keith Bostic.  All rights reserved.
.\"
.\" The vi program is freely redistributable.
.\" You are welcome to copy, modify and share it with others
.\" under the conditions listed in the LICENSE file.
.\" If any company (not individual!) finds vi sufficiently useful
.\" that you would have purchased it, or if any company wishes to
.\" redistribute it, contributions to the authors would be appreciated.
.\"
.\"     @(#)vi.1	8.51 (Berkeley) 10/10/96
.\"
.Dd $Mdocdate: January 17 2012 $
.Dt VI 1
.Os
.Sh NAME
.Nm ex , vi , view
.Nd text editors
.Sh SYNOPSIS
.Nm ex
.Op Fl FRrSsv
.Op Fl c Ar cmd
.Op Fl t Ar tag
.Op Fl w Ar size
.Op Ar
.Nm vi\ \&
.Op Fl eFRrS
.Op Fl c Ar cmd
.Op Fl t Ar tag
.Op Fl w Ar size
.Op Ar
.Nm view
.Op Fl eFrS
.Op Fl c Ar cmd
.Op Fl t Ar tag
.Op Fl w Ar size
.Op Ar
.Sh DESCRIPTION
.Nm ex
is a line-oriented text editor;
.Nm vi
is a screen-oriented text editor.
.Nm ex
and
.Nm vi
are different interfaces to the same program,
and it is possible to switch back and forth during an edit session.
.Nm view
is the equivalent of using the
.Fl R
.Pq read-only
option of
.Nm vi .
.Pp
This manual page is the one provided with the
.Nm nex Ns / Ns Nm nvi
versions of the
.Nm ex Ns / Ns Nm vi
text editors.
.Nm nex Ns / Ns Nm nvi
are intended as bug-for-bug compatible replacements for the original
Fourth Berkeley Software Distribution
.Pq 4BSD
.Nm ex
and
.Nm vi
programs.
For the rest of this manual page,
.Nm nex Ns / Ns Nm nvi
is used only when it's necessary to distinguish it from the historic
implementations of
.Nm ex Ns / Ns Nm vi .
.Pp
This manual page is intended for users already familiar with
.Nm ex Ns / Ns Nm vi .
Anyone else should almost certainly read a good tutorial on the
editor before this manual page.
If you're in an unfamiliar environment,
and you absolutely have to get work done immediately,
read the section after the options description, entitled
.Sx FAST STARTUP .
It's probably enough to get you going.
.Pp
The following options are available:
.Bl -tag -width "-w size "
.It Fl c Ar cmd
Execute
.Ar cmd
on the first file loaded.
Particularly useful for initial positioning in the file, although
.Ar cmd
is not limited to positioning commands.
This is the POSIX 1003.2 interface for the historic
.Dq +cmd
syntax.
.Nm nex Ns / Ns Nm nvi
supports both the old and new syntax.
.It Fl e
Start editing in ex mode, as if the command name were
.Nm ex .
.It Fl F
Don't copy the entire file when first starting to edit.
(The default is to make a copy in case someone else modifies
the file during your edit session.)
.\" .It Fl l
.\" Start editing with the lisp and showmatch options set.
.It Fl R
Start editing in read-only mode, as if the command name was
.Nm view ,
or the
.Cm readonly
option was set.
.It Fl r
Recover the specified files, or, if no files are specified,
list the files that could be recovered.
If no recoverable files by the specified name exist,
the file is edited as if the
.Fl r
option had not been specified.
.It Fl S
Run with the
.Cm secure
edit option set, disallowing all access to external programs.
.It Fl s
Enter batch mode; applicable only to
.Nm ex
edit sessions.
Batch mode is useful when running
.Nm ex
scripts.
Prompts, informative messages and other user oriented messages are turned off,
and no startup files or environment variables are read.
This is the POSIX 1003.2 interface for the historic
.Dq -
argument.
.Nm nex Ns / Ns Nm nvi
supports both the old and new syntax.
.It Fl t Ar tag
Start editing at the specified
.Ar tag
(see
.Xr ctags 1 ) .
.It Fl v
Start editing in vi mode, as if the command name was
.Nm vi .
.It Fl w Ar size
Set the initial window size to the specified number of lines.
.El
.Pp
Command input for
.Nm ex Ns / Ns Nm vi
is read from the standard input.
In the
.Nm vi
interface, it is an error if standard input is not a terminal.
In the
.Nm ex
interface, if standard input is not a terminal,
.Nm ex
will read commands from it regardless; however, the session will be a
batch mode session, exactly as if the
.Fl s
option had been specified.
.Sh FAST STARTUP
This section will tell you the minimum amount that you need to
do simple editing tasks using
.Nm vi .
If you've never used any screen editor before,
you're likely to have problems even with this simple introduction.
In that case you should find someone that already knows
.Nm vi
and have them walk you through this section.
.Pp
.Nm vi
is a screen editor.
This means that it takes up almost the entire screen,
displaying part of the file on each screen line,
except for the last line of the screen.
The last line of the screen is used for you to give commands to
.Nm vi ,
and for
.Nm vi
to give information to you.
.Pp
The other fact that you need to understand is that
.Nm vi
is a modeful editor,
i.e. you are either entering text or you are executing commands,
and you have to be in the right mode to do one or the other.
You will be in command mode when you first start editing a file.
There are commands that switch you into input mode.
There is only one key that takes you out of input mode,
and that is the
.Aq escape
key.
.Pp
Key names are written using less-than and greater-than signs, e.g.\&
.Aq escape
means the
.Dq escape
key, usually labeled
.Dq Esc
on your
terminal's keyboard.
If you're ever confused as to which mode you're in,
keep entering the
.Aq escape
key until
.Nm vi
beeps at you.
Generally,
.Nm vi
will beep at you if you try and do something that's not allowed.
It will also display error messages.
.Pp
To start editing a file, enter the following command:
.Pp
.Dl $ vi file
.Pp
The command you should enter as soon as you start editing is:
.Pp
.Dl :set verbose showmode
.Pp
This will make the editor give you verbose error messages and display
the current mode at the bottom of the screen.
.Pp
The commands to move around the file are:
.Bl -tag -width Ds
.It Cm h
Move the cursor left one character.
.It Cm j
Move the cursor down one line.
.It Cm k
Move the cursor up one line.
.It Cm l
Move the cursor right one character.
.It Aq Cm cursor-arrows
The cursor arrow keys should work, too.
.It Cm / Ns text
Search for the string
.Dq text
in the file,
and move the cursor to its first character.
.El
.Pp
The commands to enter new text are:
.Bl -tag -width "<escape>"
.It Cm a
Append new text, after the cursor.
.It Cm i
Insert new text, before the cursor.
.It Cm O
Open a new line above the line the cursor is on, and start entering text.
.It Cm o
Open a new line below the line the cursor is on, and start entering text.
.It Aq Cm escape
Once you've entered input mode using one of the
.Cm a ,
.Cm i ,
.Cm O
or
.Cm o
commands, use
.Aq Cm escape
to quit entering text and return to command mode.
.El
.Pp
The commands to copy text are:
.Bl -tag -width Ds
.It Cm p
Append the copied line after the line the cursor is on.
.It Cm yy
Copy the line the cursor is on.
.El
.Pp
The commands to delete text are:
.Bl -tag -width Ds
.It Cm dd
Delete the line the cursor is on.
.It Cm x
Delete the character the cursor is on.
.El
.Pp
The commands to write the file are:
.Bl -tag -width Ds
.It Cm :w
Write the file back to the file with the name that you originally used
as an argument on the
.Nm vi
command line.
.It Cm :w Ar file_name
Write the file back to the file with the name
.Ar file_name .
.El
.Pp
The commands to quit editing and exit the editor are:
.Bl -tag -width Ds
.It Cm :q
Quit editing and leave
.Nm vi
(if you've modified the file, but not saved your changes,
.Nm vi
will refuse to quit).
.It Cm :q!
Quit, discarding any modifications that you may have made.
.El
.Pp
One final caution:
Unusual characters can take up more than one column on the screen,
and long lines can take up more than a single screen line.
The above commands work on
.Dq physical
characters and lines,
i.e. they affect the entire line no matter how many screen lines it takes up
and the entire character no matter how many screen columns it takes up.
.Sh REGULAR EXPRESSIONS
.Nm ex Ns / Ns Nm vi
supports regular expressions
.Pq REs ,
as documented in
.Xr re_format 7 ,
for line addresses, as the first part of the
.Nm ex Cm substitute ,
.Cm global
and
.Cm v
commands, and in search patterns.
Basic regular expressions
.Pq BREs
are enabled by default;
extended regular expressions
.Pq EREs
are used if the
.Cm extended
option is enabled.
The use of regular expressions can be largely disabled using the
.Cm magic
option.
.Pp
The following strings have special meanings in the
.Nm ex Ns / Ns Nm vi
version of regular expressions:
.Bl -bullet -offset 6u
.It
An empty regular expression is equivalent to the last regular expression used.
.It
.Sq \e\(la
matches the beginning of the word.
.It
.Sq \e\(ra
matches the end of the word.
.It
.Sq \(a~
matches the replacement part of the last
.Cm substitute
command.
.El
.Sh BUFFERS
A buffer is an area where commands can save changed or deleted text
for later use.
.Nm vi
buffers are named with a single character preceded by a double quote,
for example
.Pf \&" Ns Aq c ;
.Nm ex
buffers are the same,
but without the double quote.
.Nm nex Ns / Ns Nm nvi
permits the use of any character without another meaning in the position where
a buffer name is expected.
.Pp
All buffers are either in
.Em line mode
or
.Em character mode .
Inserting a buffer in line mode into the text creates new lines for each of the
lines it contains, while a buffer in character mode creates new lines for any
lines
.Em other
than the first and last lines it contains.
The first and last lines are inserted at the current cursor position, becoming
part of the current line.
If there is more than one line in the buffer,
the current line itself will be split.
All
.Nm ex
commands which store text into buffers do so in line mode.
The behaviour of
.Nm vi
commands depend on their associated motion command:
.Bl -bullet -offset 6u
.It
.Aq Cm control-A ,
.Cm h ,
.Cm l ,
.Cm ,\& ,
.Cm 0 ,
.Cm B ,
.Cm E ,
.Cm F ,
.Cm T ,
.Cm W ,
.Cm ^ ,
.Cm b ,
.Cm e ,
.Cm f
and
.Cm t
make the destination buffer character-oriented.
.It
.Cm j ,
.Aq Cm control-M ,
.Cm k ,
.Cm ' ,
.Cm - ,
.Cm G ,
.Cm H ,
.Cm L ,
.Cm M ,
.Cm _
and
.Cm |\&
make the destination buffer line-oriented.
.It
.Cm $ ,
.Cm % ,
.Cm ` ,
.Cm (\& ,
.Cm )\& ,
.Cm / ,
.Cm ?\& ,
.Cm [[ ,
.Cm ]] ,
.Cm {
and
.Cm }
make the destination buffer character-oriented, unless the starting and
end positions are the first and last characters on a line.
In that case, the buffer is line-oriented.
.El
.Pp
The
.Nm ex
command
.Cm display buffers
displays the current mode for each buffer.
.Pp
Buffers named
.Sq a
through
.Sq z
may be referred to using their uppercase equivalent, in which case new content
will be appended to the buffer, instead of replacing it.
.Pp
Buffers named
.Sq 1
through
.Sq 9
are special.
A region of text modified using the
.Cm c
.Pq change
or
.Cm d
.Pq delete
commands is placed into the numeric buffer
.Sq 1
if no other buffer is specified and if it meets one of the following conditions:
.Bl -bullet -offset 6u
.It
It includes characters from more than one line.
.It
It is specified using a line-oriented motion.
.It
It is specified using one of the following motion commands:
.Aq Cm control-A ,
.Cm ` Ns Aq Cm character ,
.Cm n ,
.Cm N ,
.Cm % ,
.Cm / ,
.Cm { ,
.Cm } ,
.Cm \&( ,
.Cm \&) ,
and
.Cm \&? .
.El
.Pp
Before this copy is done, the previous contents of buffer
.Sq 1
are moved into buffer
.Sq 2 ,
.Sq 2
into buffer
.Sq 3 ,
and so on.
The contents of buffer
.Sq 9
are discarded.
Note that this rotation occurs
.Em regardless
of the user specifying another buffer.
In
.Nm vi ,
text may be explicitly stored into the numeric buffers.
In this case, the buffer rotation occurs before the replacement of the buffer's
contents.
The numeric buffers are only available in
.Nm vi
mode.
.Sh VI COMMANDS
The following section describes the commands available in the command
mode of the
.Nm vi
editor.
The following words have a special meaning in the commands
description:
.Pp
.Bl -tag -width bigword -compact -offset 3u
.It Ar bigword
A set of non-whitespace characters.
.It Ar buffer
Temporary area where commands may place text.
If not specified, the default buffer is used.
See also
.Sx BUFFERS ,
above.
.It Ar count
A positive number used to specify the desired number of iterations
of a command.
It defaults to 1 if not specified.
.It Ar motion
A cursor movement command which indicates the other end of the affected region
of text, the first being the current cursor position.
Repeating the command character makes it affect the whole
current line.
.It Ar word
A sequence of letters, digits or underscores.
.El
.Pp
.Ar buffer
and
.Ar count ,
if both present, may be specified in any order.
.Ar motion
and
.Ar count ,
if both present, are effectively multiplied together
and considered part of the motion.
.Pp
.Bl -tag -width Ds -compact
.It Xo
.Aq Cm control-A
.Xc
Search forward
for the word starting at the cursor position.
.Pp
.It Xo
.Op Ar count
.Aq Cm control-B
.Xc
Page backwards
.Ar count
screens.
Two lines of overlap are maintained, if possible.
.Pp
.It Xo
.Op Ar count
.Aq Cm control-D
.Xc
Scroll forward
.Ar count
lines.
If
.Ar count
is not given, scroll forward the number of lines specified by the last
.Aq Cm control-D
or
.Aq Cm control-U
command.
If this is the first
.Aq Cm control-D
command, scroll half the number of lines in the current screen.
.Pp
.It Xo
.Op Ar count
.Aq Cm control-E
.Xc
Scroll forward
.Ar count
lines, leaving the current line and column as is, if possible.
.Pp
.It Xo
.Op Ar count
.Aq Cm control-F
.Xc
Page forward
.Ar count
screens.
Two lines of overlap are maintained, if possible.
.Pp
.It Aq Cm control-G
Display the following file information:
the file name (as given to
.Nm vi ) ;
whether the file has been modified since it was last written;
if the file is readonly;
the current line number;
the total number of lines in the file;
and the current line number as a percentage of the total lines in the file.
.Pp
.It Xo
.Op Ar count
.Aq Cm control-H
.Xc
.It Xo
.Op Ar count
.Cm h
.Xc
Move the cursor back
.Ar count
characters in the current line.
.Pp
.It Xo
.Op Ar count
.Aq Cm control-J
.Xc
.It Xo
.Op Ar count
.Aq Cm control-N
.Xc
.It Xo
.Op Ar count
.Cm j
.Xc
Move the cursor down
.Ar count
lines without changing the current column.
.Pp
.It Aq Cm control-L
.It Aq Cm control-R
Repaint the screen.
.Pp
.It Xo
.Op Ar count
.Aq Cm control-M
.Xc
.It Xo
.Op Ar count
.Cm +
.Xc
Move the cursor down
.Ar count
lines to the first non-blank character of that line.
.Pp
.It Xo
.Op Ar count
.Aq Cm control-P
.Xc
.It Xo
.Op Ar count
.Cm k
.Xc
Move the cursor up
.Ar count
lines, without changing the current column.
.Pp
.It Aq Cm control-T
Return to the most recent tag context.
.Pp
.It Xo
.Op Ar count
.Aq Cm control-U
.Xc
Scroll backwards
.Ar count
lines.
If
.Ar count
is not given, scroll backwards the number of lines specified by the last
.Aq Cm control-D
or
.Aq Cm control-U
command.
If this is the first
.Aq Cm control-U
command, scroll half the number of lines in the current screen.
.Pp
.It Aq Cm control-W
Switch to the next lower screen in the window,
or to the first screen if there are no lower screens in the window.
.Pp
.It Xo
.Op Ar count
.Aq Cm control-Y
.Xc
Scroll backwards
.Ar count
lines, leaving the current line and column as is, if possible.
.Pp
.It Aq Cm control-Z
Suspend the current editor session.
.Pp
.It Aq Cm escape
Execute the
.Nm ex
command being entered, or cancel it if it is only partial.
.Pp
.It Aq Cm control-]
Push a tag reference onto the tag stack.
.Pp
.It Aq Cm control-^
Switch to the most recently edited file.
.Pp
.It Xo
.Op Ar count
.Aq Cm space
.Xc
.It Xo
.Op Ar count
.Cm l
.Xc
Move the cursor forward
.Ar count
characters without changing the current line.
.Pp
.It Xo
.Op Ar count
.Cm !\&
.Ar motion shell-argument(s)
.Aq Li carriage-return
.Xc
Replace the lines spanned by
.Ar count
and
.Ar motion
with the output
.Pq standard output and standard error
of the program named by the
.Cm shell
option, called with a
.Fl c
flag followed by the
.Ar shell-argument(s)
.Pq bundled into a single argument .
Within
.Ar shell-argument(s) ,
the
.Sq % ,
.Sq #
and
.Sq !\&
characters are expanded to the current file name,
the previous current file name,
and the command text of the previous
.Cm !\&
or
.Cm :!
commands, respectively.
The special meaning of
.Sq % ,
.Sq #
and
.Sq !\&
can be overridden by escaping them with a backslash.
.Pp
.It Xo
.Op Ar count
.Cm #
.Sm off
.Cm # | + | -
.Sm on
.Xc
Increment
.Pq trailing So # Sc or So + Sc
or decrement
.Pq trailing Sq -
the number under the cursor by
.Ar count ,
starting at the cursor position or at the first non-blank
character following it.
Numbers with a leading
.Sq 0x
or
.Sq 0X
are interpreted as hexadecimal numbers.
Numbers with a leading
.Sq 0
are interpreted as octal numbers unless they contain a non-octal digit.
Other numbers may be prefixed with a
.Sq +
or
.Sq -
sign.
.Pp
.It Xo
.Op Ar count
.Cm $
.Xc
Move the cursor to the end of a line.
If
.Ar count
is specified, additionally move the cursor down
.Ar count
\- 1 lines.
.Pp
.It Cm %
Move to the parenthesis, square bracket or curly brace matching
the one found at the cursor position or the closest to the right of it.
.Pp
.It Cm &
Repeat the previous substitution command on the current line.
.Pp
.It Xo
.Cm ' Ns Aq Ar character
.Xc
.It Xo
.Cm ` Ns Aq Ar character
.Xc
Return to the cursor position marked by the character
.Ar character ,
or, if
.Ar character
is
.Sq '
or
.Sq ` ,
to the position of the cursor before the last of the following commands:
.Aq Cm control-A ,
.Aq Cm control-T ,
.Aq Cm control-] ,
.Cm % ,
.Cm ' ,
.Cm ` ,
.Cm (\& ,
.Cm )\& ,
.Cm / ,
.Cm ?\& ,
.Cm G ,
.Cm H ,
.Cm L ,
.Cm [[ ,
.Cm ]] ,
.Cm { ,
.Cm } .
The first form returns to the first non-blank character of the line marked by
.Ar character .
The second form returns to the line and column marked by
.Ar character .
.Pp
.It Xo
.Op Ar count
.Cm \&(
.Xc
.It Xo
.Op Ar count
.Cm \&)
.Xc
Move
.Ar count
sentences backward or forward, respectively.
A sentence is an area of text that begins with the first nonblank character
following the previous sentence, paragraph, or section
boundary and continues until the next period, exclamation mark,
or question mark character, followed by any number of closing parentheses,
brackets, double or single quote characters, followed by
either an end-of-line or two whitespace characters.
Groups of empty lines
.Pq or lines containing only whitespace characters
are treated as a single sentence.
.Pp
.It Xo
.Op Ar count
.Cm ,\&
.Xc
Reverse find character
(i.e. the last
.Cm F ,
.Cm f ,
.Cm T
or
.Cm t
command)
.Ar count
times.
.Pp
.It Xo
.Op Ar count
.Cm -
.Xc
Move to the first non-blank character of the previous line,
.Ar count
times.
.Pp
.It Xo
.Op Ar count
.Cm .\&
.Xc
Repeat the last
.Nm vi
command that modified text.
.Ar count
replaces both the
.Ar count
argument of the repeated command and that of the associated
.Ar motion .
If the
.Cm .\&
command repeats the
.Cm u
command, the change log is rolled forward or backward, depending on the action
of the
.Cm u
command.
.Pp
.It Xo
.Pf / Ns Ar RE
.Aq Li carriage-return
.Xc
.It Xo
.Pf / Ns Ar RE Ns /
.Op Ar offset
.Op Cm z
.Aq Li carriage-return
.Xc
.It Xo
.Pf ?\& Ns Ar RE
.Aq Li carriage-return
.Xc
.It Xo
.Pf ?\& Ns Ar RE Ns ?\&
.Op Ar offset
.Op Cm z
.Aq Li carriage-return
.Xc
.It Cm N
.It Cm n
Search forward
.Pq Sq /
or backward
.Pq Sq ?\&
for a regular expression.
.Cm n
and
.Cm N
repeat the last search in the same or opposite directions, respectively.
If
.Ar RE
is empty, the last search regular expression is used.
If
.Ar offset
is specified, the cursor is placed
.Ar offset
lines before or after the matched regular expression.
If either
.Cm n
or
.Cm N
commands are used as motion components for the
.Cm !\&
command, there will be no prompt for the text of the command and the previous
.Cm !\&
will be executed.
Multiple search patterns may be grouped together by delimiting them with
semicolons and zero or more whitespace characters.
These patterns are evaluated from left to right with the final cursor position
determined by the last search pattern.
A
.Cm z
command may be appended to the closed search expressions to reposition the
result line.
.Pp
.It Cm 0
Move to the first character in the current line.
.Pp
.It Cm :\&
Execute an
.Nm ex
command.
.Pp
.It Xo
.Op Ar count
.Cm ;\&
.Xc
Repeat the last character find
(i.e. the last
.Cm F ,
.Cm f ,
.Cm T
or
.Cm t
command)
.Ar count
times.
.Pp
.It Xo
.Op Ar count
.Cm <
.Ar motion
.Xc
.It Xo
.Op Ar count
.Cm >
.Ar motion
.Xc
Shift
.Ar count
lines left or right, respectively, by an amount of
.Cm shiftwidth .
.Pp
.It Cm @ Ar buffer
Execute a named
.Ar buffer
as
.Nm vi
commands.
The buffer may include
.Nm ex
commands too, but they must be expressed as a
.Cm \&:
command.
If
.Ar buffer
is
.Sq @
or
.Sq * ,
then the last buffer executed shall be used.
.Pp
.It Xo
.Op Ar count
.Cm A
.Xc
Enter input mode, appending the text after the end of the line.
If a
.Ar count
argument is given,
the characters input are repeated
.Ar count
\- 1 times after input mode is exited.
.Pp
.It Xo
.Op Ar count
.Cm B
.Xc
Move backwards
.Ar count
bigwords.
.Pp
.It Xo
.Op Ar buffer
.Cm C
.Xc
Change text from the current position to the end-of-line.
If
.Ar buffer
is specified,
.Dq yank
the deleted text into
.Ar buffer .
.Pp
.It Xo
.Op Ar buffer
.Cm D
.Xc
Delete text from the current position to the end-of-line.
If
.Ar buffer
is specified,
.Dq yank
the deleted text into
.Ar buffer .
.Pp
.It Xo
.Op Ar count
.Cm E
.Xc
Move forward
.Ar count
end-of-bigwords.
.Pp
.It Xo
.Op Ar count
.Cm F Aq Ar character
.Xc
Search
.Ar count
times backward through the current line for
.Ar character .
.Pp
.It Xo
.Op Ar count
.Cm G
.Xc
Move to line
.Ar count ,
or the last line of the file if
.Ar count
is not specified.
.Pp
.It Xo
.Op Ar count
.Cm H
.Xc
Move to the screen line
.Ar count
\- 1 lines below the top of the screen.
.Pp
.It Xo
.Op Ar count
.Cm I
.Xc
Enter input mode, inserting the text at the beginning of the line.
If a
.Ar count
argument is given,
the characters input are repeated
.Ar count
\- 1 more times.
.Pp
.It Xo
.Op Ar count
.Cm J
.Xc
Join
.Ar count
lines with the current line.
The spacing between two joined lines is set to two whitespace characters if the
former ends with a question mark, a period or an exclamation mark.
It is set to one whitespace character otherwise.
.Pp
.It Xo
.Op Ar count
.Cm L
.Xc
Move to the screen line
.Ar count
\- 1 lines above the bottom of the screen.
.Pp
.It Cm M
Move to the screen line in the middle of the screen.
.Pp
.It Xo
.Op Ar count
.Cm O
.Xc
Enter input mode, appending text in a new line above the current line.
If a
.Ar count
argument is given,
the characters input are repeated
.Ar count
\- 1 more times.
.Pp
.It Xo
.Op Ar buffer
.Cm P
.Xc
Insert text from
.Ar buffer
before the current column if
.Ar buffer
is character-oriented or before the current line if it is line-oriented.
.Pp
.It Cm Q
Exit
.Nm vi
.Pq or visual
mode and switch to
.Nm ex
mode.
.Pp
.It Xo
.Op Ar count
.Cm R
.Xc
Enter input mode, replacing the characters in the current line.
If a
.Ar count
argument is given,
the characters input are repeated
.Ar count
\- 1 more times upon exit from insert mode.
.Pp
.It Xo
.Op Ar buffer
.Op Ar count
.Cm S
.Xc
Substitute
.Ar count
lines.
If
.Ar buffer
is specified,
.Dq yank
the deleted text into
.Ar buffer .
.Pp
.It Xo
.Op Ar count
.Cm T
.Aq Ar character
.Xc
Search backwards,
.Ar count
times, through the current line for the character after the specified
.Ar character .
.Pp
.It Cm U
Restore the current line to its state before the cursor last moved to it.
.Pp
.It Xo
.Op Ar count
.Cm W
.Xc
Move forward
.Ar count
bigwords.
.Pp
.It Xo
.Op Ar buffer
.Op Ar count
.Cm X
.Xc
Delete
.Ar count
characters before the cursor, on the current line.
If
.Ar buffer
is specified,
.Dq yank
the deleted text into
.Ar buffer .
.Pp
.It Xo
.Op Ar buffer
.Op Ar count
.Cm Y
.Xc
Copy (or
.Dq yank )
.Ar count
lines into
.Ar buffer .
.Pp
.It Cm ZZ
Write the file and exit
.Nm vi
if there are no more files to edit.
Entering two
.Dq quit
commands in a row ignores any remaining file to edit.
.Pp
.It Xo
.Op Ar count
.Cm [[
.Xc
Back up
.Ar count
section boundaries.
.Pp
.It Xo
.Op Ar count
.Cm ]]
.Xc
Move forward
.Ar count
section boundaries.
.Pp
.It Cm ^
Move to the first non-blank character on the current line.
.Pp
.It Xo
.Op Ar count
.Cm _
.Xc
Move down
.Ar count
\- 1 lines, to the first non-blank character.
.Pp
.It Xo
.Op Ar count
.Cm a
.Xc
Enter input mode, appending the text after the cursor.
If a
.Ar count
argument is given,
the characters input are repeated
.Ar count
\-1 more times.
.Pp
.It Xo
.Op Ar count
.Cm b
.Xc
Move backwards
.Ar count
words.
.Pp
.It Xo
.Op Ar buffer
.Op Ar count
.Cm c
.Ar motion
.Xc
Change the region of text described by
.Ar count
and
.Ar motion .
If
.Ar buffer
is specified,
.Dq yank
the changed text into
.Ar buffer .
.Pp
.It Xo
.Op Ar buffer
.Op Ar count
.Cm d
.Ar motion
.Xc
Delete the region of text described by
.Ar count
and
.Ar motion .
If
.Ar buffer
is specified,
.Dq yank
the deleted text into
.Ar buffer .
.Pp
.It Xo
.Op Ar count
.Cm e
.Xc
Move forward
.Ar count
end-of-words.
.Pp
.It Xo
.Op Ar count
.Cm f Aq Ar character
.Xc
Search forward,
.Ar count
times, through the rest of the current line for
.Aq Ar character .
.Pp
.It Xo
.Op Ar count
.Cm i
.Xc
Enter input mode, inserting the text before the cursor.
If a
.Ar count
argument is given,
the characters input are repeated
.Ar count
\-1 more times.
.Pp
.It Xo
.Cm m
.Aq Ar character
.Xc
Save the current context
.Pq line and column
as
.Aq Ar character .
.Pp
.It Xo
.Op Ar count
.Cm o
.Xc
Enter input mode, appending text in a new line under the current line.
If a
.Ar count
argument is given,
the characters input are repeated
.Ar count
\- 1 more times.
.Pp
.It Xo
.Op Ar buffer
.Cm p
.Xc
Append text from
.Ar buffer .
Text is appended after the current column if
.Ar buffer
is character oriented, or the after current line otherwise.
.Pp
.It Xo
.Op Ar count
.Cm r
.Aq Ar character
.Xc
Replace
.Ar count
characters by
.Ar character .
.Pp
.It Xo
.Op Ar buffer
.Op Ar count
.Cm s
.Xc
Substitute
.Ar count
characters in the current line starting with the current character.
If
.Ar buffer
is specified,
.Dq yank
the substituted text into
.Ar buffer .
.Pp
.It Xo
.Op Ar count
.Cm t
.Aq Ar character
.Xc
Search forward,
.Ar count
times, through the current line for the character immediately before
.Aq Ar character .
.Pp
.It Cm u
Undo the last change made to the file.
If repeated, the
.Cm u
command alternates between these two states.
The
.Cm .\&
command, when used immediately after
.Cm u ,
causes the change log to be rolled forward or backward, depending on the action
of the
.Cm u
command.
.Pp
.It Xo
.Op Ar count
.Cm w
.Xc
Move forward
.Ar count
words.
.Pp
.It Xo
.Op Ar buffer
.Op Ar count
.Cm x
.Xc
Delete
.Ar count
characters at the current cursor position, but no more than there are till the
end of the line.
.Pp
.It Xo
.Op Ar buffer
.Op Ar count
.Cm y
.Ar motion
.Xc
Copy (or
.Dq yank )
a text region specified by
.Ar count
and
.Ar motion
into a buffer.
.Pp
.It Xo
.Op Ar count1
.Cm z
.Op Ar count2
.Cm type
.Xc
Redraw, optionally repositioning and resizing the screen.
If
.Ar count2
is specified, limit the screen size to
.Ar count2
lines.
The following
.Cm type
characters may be used:
.Bl -tag -width Ds
.It Cm +
If
.Ar count1
is specified, place the line
.Ar count1
at the top of the screen.
Otherwise, display the screen after the current screen.
.It Aq Cm carriage-return
Place the line
.Ar count1
at the top of the screen.
.It Cm .\&
Place the line
.Ar count1
in the center of the screen.
.It Cm -
Place the line
.Ar count1
at the bottom of the screen.
.It Cm ^
If
.Ar count1
is given,
display the screen before the screen before
.Ar count1
.Pq i.e. 2 screens before .
Otherwise, display the screen before the current screen.
.El
.Pp
.It Xo
.Op Ar count
.Cm {\&
.Xc
Move backward
.Ar count
paragraphs.
.Pp
.It Xo
.Op Ar column
.Cm |\&
.Xc
Move to a specific
.Ar column
position on the current line.
If
.Ar column
is omitted,
move to the start of the current line.
.Pp
.It Xo
.Op Ar count
.Cm }\&
.Xc
Move forward
.Ar count
paragraphs.
.Pp
.It Xo
.Op Ar count
.Cm ~
.Ar motion
.Xc
If the
.Cm tildeop
option is not set, reverse the case of the next
.Ar count
character(s) and no
.Ar motion
can be specified.
Otherwise
.Ar motion
is mandatory and
.Cm ~
reverses the case of the characters in a text region specified by the
.Ar count
and
.Ar motion .
.Pp
.It Aq Cm interrupt
Interrupt the current operation.
The
.Aq interrupt
character is usually
.Aq control-C .
.El
.Sh VI TEXT INPUT COMMANDS
The following section describes the commands available in the text input mode
of the
.Nm vi
editor.
.Pp
.Bl -tag -width Ds -compact
.It Aq Cm nul
Replay the previous input.
.Pp
.It Aq Cm control-D
Erase to the previous
.Ar shiftwidth
column boundary.
.Pp
.It Cm ^ Ns Aq Cm control-D
Erase all of the autoindent characters, and reset the autoindent level.
.Pp
.It Cm 0 Ns Aq Cm control-D
Erase all of the autoindent characters.
.Pp
.It Aq Cm control-T
Insert sufficient
.Aq tab
and
.Aq space
characters to move forward to the next
.Ar shiftwidth
column boundary.
.Pp
.It Aq Cm erase
.It Aq Cm control-H
Erase the last character.
.Pp
.It Aq Cm literal next
Escape the next character from any special meaning.
The
.Aq literal\ \&next
character is usually
.Aq control-V .
.Pp
.It Aq Cm escape
Resolve all text input into the file, and return to command mode.
.Pp
.It Aq Cm line erase
Erase the current line.
.Pp
.It Aq Cm control-W
.It Aq Cm word erase
Erase the last word.
The definition of word is dependent on the
.Cm altwerase
and
.Cm ttywerase
options.
.Pp
.Sm off
.It Xo
.Aq Cm control-X
.Bq Cm 0-9A-Fa-f
.Cm +
.Xc
.Sm on
Insert a character with the specified hexadecimal value into the text.
.Pp
.It Aq Cm interrupt
Interrupt text input mode, returning to command mode.
The
.Aq interrupt
character is usually
.Aq control-C .
.El
.Sh EX COMMANDS
The following section describes the commands available in the
.Nm ex
editor.
In each entry below, the tag line is a usage synopsis for the command.
.Pp
.Bl -tag -width Ds -compact
.It Aq Cm end-of-file
Scroll the screen.
.Pp
.It Cm !\& Ar argument(s)
.It Xo
.Op Ar range
.Cm !\&
.Ar argument(s)
.Xc
Execute a shell command, or filter lines through a shell command.
.Pp
.It Cm \&"
A comment.
.Pp
.It Xo
.Op Ar range
.Cm nu Ns Op Cm mber
.Op Ar count
.Op Ar flags
.Xc
.It Xo
.Op Ar range
.Cm #
.Op Ar count
.Op Ar flags
.Xc
Display the selected lines, each preceded with its line number.
.Pp
.It Cm @ Ar buffer
.It Cm * Ar buffer
Execute a buffer.
.Pp
.It Xo
.Op Ar range
.Cm < Ns Op Cm < ...
.Op Ar count
.Op Ar flags
.Xc
Shift lines left.
.Pp
.It Xo
.Op Ar line
.Cm =
.Op Ar flags
.Xc
Display the line number of
.Ar line .
If
.Ar line
is not specified, display the line number of the last line in the file.
.Pp
.It Xo
.Op Ar range
.Cm > Ns Op Cm > ...
.Op Ar count
.Op Ar flags
.Xc
Shift lines right.
.Pp
.It Xo
.Cm ab Ns Op Cm breviate
.Ar lhs rhs
.Xc
.Nm vi
only.
Add
.Ar lhs
as an abbreviation for
.Ar rhs
to the abbreviation list.
.Pp
.It Xo
.Op Ar line
.Cm a Ns Op Cm ppend Ns
.Op Cm !\&
.Xc
The input text is appended after the specified line.
.Pp
.It Cm ar Ns Op Cm gs
Display the argument list.
.Pp
.It Cm bg
.Nm vi
only.
Background the current screen.
.Pp
.It Xo
.Op Ar range
.Cm c Ns Op Cm hange Ns
.Op Cm !\&
.Op Ar count
.Xc
The input text replaces the specified range.
.Pp
.It Xo
.Cm chd Ns Op Cm ir Ns
.Op Cm !\&
.Op Ar directory
.Xc
.It Xo
.Cm cd Ns Op Cm !\&
.Op Ar directory
.Xc
Change the current working directory.
.Pp
.It Xo
.Op Ar range
.Cm co Ns Op Cm py
.Ar line
.Op Ar flags
.Xc
.It Xo
.Op Ar range
.Cm t
.Ar line
.Op Ar flags
.Xc
Copy the specified lines after the destination
.Ar line .
.Pp
.It Xo
.Cm cs Ns Op Cm cope
.Cm add | find | help | kill | reset
.Xc
Execute a Cscope command.
.Pp
.It Xo
.Op Ar range
.Cm d Ns Op Cm elete
.Op Ar buffer
.Op Ar count
.Op Ar flags
.Xc
Delete the lines from the file.
.Pp
.It Xo
.Cm di Ns Op Cm splay
.Cm b Ns Oo Cm uffers Oc |
.Cm c Ns Oo Cm onnections Oc |
.Cm s Ns Oo Cm creens Oc |
.Cm t Ns Op Cm ags
.Xc
Display buffers, Cscope connections, screens or tags.
.Pp
.It Xo
.Op Cm Ee Ns
.Op Cm dit Ns
.Op Cm !\&
.Op Ar +cmd
.Op Ar file
.Xc
.It Xo
.Op Cm Ee Ns
.Cm x Ns Op Cm !\&
.Op Ar +cmd
.Op Ar file
.Xc
Edit a different file.
.Pp
.It Xo
.Cm exu Ns Op Cm sage
.Op Ar command
.Xc
Display usage for an
.Nm ex
command.
.Pp
.It Xo
.Cm f Ns Op Cm ile
.Op Ar file
.Xc
Display and optionally change the file name.
.Pp
.It Xo
.Op Cm Ff Ns
.Cm g
.Op Ar name
.Xc
.Nm vi
mode only.
Foreground the specified screen.
.Pp
.It Xo
.Op Ar range
.Cm g Ns Op Cm lobal
.No / Ns Ar pattern Ns /
.Op Ar commands
.Xc
.It Xo
.Op Ar range
.Cm v
.No / Ns Ar pattern Ns /
.Op Ar commands
.Xc
Apply commands to lines matching
.Pq Sq global
or not matching
.Pq Sq v
a pattern.
.Pp
.It Cm he Ns Op Cm lp
Display a help message.
.Pp
.It Xo
.Op Ar line
.Cm i Ns Op Cm nsert Ns
.Op Cm !\&
.Xc
The input text is inserted before the specified line.
.Pp
.It Xo
.Op Ar range
.Cm j Ns Op Cm oin Ns
.Op Cm !\&
.Op Ar count
.Op Ar flags
.Xc
Join lines of text together.
.Pp
.It Xo
.Op Ar range
.Cm l Ns Op Cm ist
.Op Ar count
.Op Ar flags
.Xc
Display the lines unambiguously.
.Pp
.It Xo
.Cm map Ns Op Cm !\&
.Op Ar lhs rhs
.Xc
Define or display maps (for
.Nm vi
only).
.Pp
.It Xo
.Op Ar line
.Cm ma Ns Op Cm rk
.Aq Ar character
.Xc
.It Xo
.Op Ar line
.Cm k Aq Ar character
.Xc
Mark the line with the mark
.Aq Ar character .
.Pp
.It Xo
.Op Ar range
.Cm m Ns Op Cm ove
.Ar line
.Xc
Move the specified lines after the target line.
.Pp
.It Xo
.Cm mk Ns Op Cm exrc Ns
.Op Cm !\&
.Ar file
.Xc
Write the abbreviations, editor options and maps to the specified
.Ar file .
.Pp
.It Xo
.Op Cm Nn Ns
.Op Cm ext Ns
.Op Cm !\&
.Op Ar file ...
.Xc
Edit the next file from the argument list.
.\" .Pp
.\" .It Xo
.\" .Op Ar line
.\" .Cm o Ns Op Cm pen
.\" .No / Ns Ar pattern Ns /
.\" .Op Ar flags
.\" .Xc
.\" Enter open mode.
.Pp
.It Cm pre Ns Op Cm serve
Save the file in a form that can later be recovered using the
.Nm ex
.Fl r
option.
.Pp
.It Xo
.Op Cm \&Pp Ns
.Cm rev Ns Op Cm ious Ns
.Op Cm !\&
.Xc
Edit the previous file from the argument list.
.Pp
.It Xo
.Op Ar range
.Cm p Ns Op Cm rint
.Op Ar count
.Op Ar flags
.Xc
Display the specified lines.
.Pp
.It Xo
.Op Ar line
.Cm pu Ns Op Cm t
.Op Ar buffer
.Xc
Append buffer contents to the current line.
.Pp
.It Xo
.Cm q Ns Op Cm uit Ns
.Op Cm !\&
.Xc
End the editing session.
.Pp
.It Xo
.Op Ar line
.Cm r Ns Op Cm ead Ns
.Op Cm !\&
.Op Ar file
.Xc
Read a file.
.Pp
.It Xo
.Cm rec Ns Op Cm over
.Ar file
.Xc
Recover
.Ar file
if it was previously saved.
.Pp
.It Xo
.Cm res Ns Op Cm ize
.Op Cm + Ns | Ns Cm - Ns
.Ar size
.Xc
.Nm vi
mode only.
Grow or shrink the current screen.
.Pp
.It Xo
.Cm rew Ns Op Cm ind Ns
.Op Cm !\&
.Xc
Rewind the argument list.
.Pp
.It Xo
.Cm se Ns Op Cm t
.Sm off
.Op option Oo = Oo value Oc Oc \ \&...
.Sm on
.Pf \ \& Op nooption ...
.Op option? ...
.Op Ar all
.Xc
Display or set editor options.
.Pp
.It Cm sh Ns Op Cm ell
Run a shell program.
.Pp
.It Xo
.Cm so Ns Op Cm urce
.Ar file
.Xc
Read and execute
.Nm ex
commands from a file.
.Pp
.It Xo
.Op Ar range
.Cm s Ns Op Cm ubstitute
.Sm off
.Op / Ar pattern No / Ar replace  No /
.Sm on
.Pf \ \& Op Ar options
.Op Ar count
.Op Ar flags
.Xc
.It Xo
.Op Ar range
.Cm &
.Op Ar options
.Op Ar count
.Op Ar flags
.Xc
.It Xo
.Op Ar range
.Cm ~
.Op Ar options
.Op Ar count
.Op Ar flags
.Xc
Make substitutions.
The
.Ar replace
field may contain any of the following sequences:
.Bl -tag -width Ds
.It Sq \*(Am
The text matched by
.Ar pattern .
.It Sq \(a~
The replacement part of the previous
.Cm substitute
command.
.It Sq %
If this is the entire
.Ar replace
pattern, the replacement part of the previous
.Cm substitute
command.
.It Sq \e\(sh
Where
.Sq \(sh
is an integer from 1 to 9, the text matched by the #'th subexpression in
.Ar pattern .
.It Sq \eL
Causes the characters up to the end of the line of the next occurrence of
.Sq \eE
or
.Sq \ee
to be converted to lowercase.
.It Sq \el
Causes the next character to be converted to lowercase.
.It Sq \eU
Causes the characters up to the end of the line of the next occurrence of
.Sq \eE
or
.Sq \ee
to be converted to uppercase.
.It Sq \eu
Causes the next character to be converted to uppercase.
.El
.Pp
.It Xo
.Cm su Ns Op Cm spend Ns
.Op Cm !\&
.Xc
.It Xo
.Cm st Ns Op Cm op Ns
.Op Cm !\&
.Xc
.It Aq Cm suspend
Suspend the edit session.
The
.Aq suspend
character is usually
.Aq control-Z .
.Pp
.It Xo
.Op Cm Tt Ns
.Cm a Ns Op Cm g Ns
.Op Cm !\&
.Ar tagstring
.Xc
Edit the file containing the specified tag.
.Pp
.It Xo
.Cm tagn Ns Op Cm ext Ns
.Op Cm !\&
.Xc
Edit the file containing the next context for the current tag.
.Pp
.It Xo
.Cm tagp Ns Op Cm op Ns
.Op Cm !\&
.Op Ar file | number
.Xc
Pop to the specified tag in the tags stack.
.Pp
.It Xo
.Cm tagpr Ns Op Cm ev Ns
.Op Cm !\&
.Xc
Edit the file containing the previous context for the current tag.
.Pp
.It Xo
.Cm tagt Ns Op Cm op Ns
.Op Cm !\&
.Xc
Pop to the least recent tag on the tags stack, clearing the stack.
.Pp
.It Xo
.Cm una Ns Op Cm bbreviate
.Ar lhs
.Xc
.Nm vi
only.
Delete an abbreviation.
.Pp
.It Cm u Ns Op Cm ndo
Undo the last change made to the file.
.Pp
.It Xo
.Cm unm Ns Op Cm ap Ns
.Op Cm !\&
.Ar lhs
.Xc
Unmap a mapped string.
.Pp
.It Cm ve Ns Op Cm rsion
Display the version of the
.Nm ex Ns / Ns Nm vi
editor.
.Pp
.It Xo
.Op Ar line
.Cm vi Ns Op Cm sual
.Op Ar type
.Op Ar count
.Op Ar flags
.Xc
.Nm ex
mode only.
Enter
.Nm vi .
.Pp
.It Xo
.Op Cm Vi Ns
.Cm i Ns Op Cm sual Ns
.Op Cm !\&
.Op Ar +cmd
.Op Ar file
.Xc
.Nm vi
mode only.
Edit a new file.
.Pp
.It Xo
.Cm viu Ns Op Cm sage
.Op Ar command
.Xc
Display usage for a
.Nm vi
command.
.Pp
.It Xo
.Op Ar range
.Cm w Ns Op Cm rite Ns
.Op Cm !\&
.Op >>
.Op Ar file
.Xc
.It Xo
.Op Ar range
.Cm w Ns Op Cm rite
.Op Cm !\&
.Op Ar file
.Xc
.It Xo
.Op Ar range
.Cm wn Ns Op Cm !\&
.Op >>
.Op Ar file
.Xc
.It Xo
.Op Ar range
.Cm wq Ns Op Cm !\&
.Op >>
.Op Ar file
.Xc
Write the file.
.Pp
.It Xo
.Op Ar range
.Cm x Ns Op Cm it Ns
.Op Cm !\&
.Op Ar file
.Xc
Exit the editor,
writing the file if it has been modified.
.Pp
.It Xo
.Op Ar range
.Cm ya Ns Op Cm nk
.Op Ar buffer
.Op Ar count
.Xc
Copy the specified lines to a buffer.
.Pp
.It Xo
.Op Ar line
.Cm z
.Op Ar type
.Op Ar count
.Op Ar flags
.Xc
Adjust the window.
.El
.Sh SET OPTIONS
There are a large number of options that may be set
.Pq or unset
to change the editor's behavior.
This section describes the options, their abbreviations and their
default values.
.Pp
In each entry below, the first part of the tag line is the full name
of the option, followed by any equivalent abbreviations.
The part in square brackets is the default value of the option.
Most of the options are boolean, i.e. they are either on or off,
and do not have an associated value.
.Pp
Options apply to both
.Nm ex
and
.Nm vi
modes, unless otherwise specified.
.Bl -tag -width Ds
.It Cm altwerase Bq off
.Nm vi
only.
Select an alternate word erase algorithm.
.It Cm autoindent , ai Bq off
Automatically indent new lines.
.It Cm autoprint , ap Bq on
.Nm ex
only.
Display the current line automatically.
.It Cm autowrite , aw Bq off
Write modified files automatically when changing files or suspending the editor
session.
.It Cm backup Bq \&"\&"
Back up files before they are overwritten.
.It Cm beautify , bf Bq off
Discard control characters.
.It Cm cdpath Bq "environment variable CDPATH, or current directory"
The directory paths used as path prefixes for the
.Cm cd
command.
.It Cm cedit Bq no default
Set the character to edit the colon command-line history.
.It Cm columns , co Bq 80
Set the number of columns in the screen.
.It Cm comment Bq off
.Nm vi
only.
Skip leading comments in shell, C and C++ language files.
.It Cm directory , dir Bq "environment variable TMPDIR, or /tmp"
The directory where temporary files are created.
.It Cm edcompatible , ed Bq off
Remember the values of the
.Sq c
and
.Sq g
suffixes to the
.Cm substitute
commands, instead of initializing them as unset for each new command.
.It Cm escapetime Bq 1
The 10th's of a second
.Nm ex Ns / Ns Nm vi
waits for a subsequent key to complete an
.Aq escape
key mapping.
.It Cm errorbells , eb Bq off
.Nm ex
only.
Announce error messages with a bell.
.It Cm exrc , ex Bq off
Read the startup files in the local directory.
.It Cm extended Bq off
Use extended regular expressions
.Pq EREs
rather than basic regular expressions
.Pq BREs .
See
.Xr re_format 7
for more information on regular expressions.
.It Cm filec Bq no default
Set the character to perform file path completion on the colon command line.
.It Cm flash Bq off
Flash the screen instead of beeping the keyboard on error.
.It Cm hardtabs , ht Bq 0
Set the spacing between hardware tab settings.
This option currently has no effect.
.It Cm iclower Bq off
Makes all regular expressions case-insensitive,
as long as an upper-case letter does not appear in the search string.
.It Cm ignorecase , ic Bq off
Ignore case differences in regular expressions.
.It Cm keytime Bq 6
The 10th's of a second
.Nm ex Ns / Ns Nm vi
waits for a subsequent key to complete a key mapping.
.It Cm leftright Bq off
.Nm vi
only.
Do left-right scrolling.
.It Cm lines , li Bq 24
.Nm vi
only.
Set the number of lines in the screen.
.It Cm lisp Bq off
.Nm vi
only.
Modify various search commands and options to work with Lisp.
This option is not yet implemented.
.It Cm list Bq off
Display lines in an unambiguous fashion.
.It Cm lock Bq on
Attempt to get an exclusive lock on any file being edited, read or written.
.It Cm magic Bq on
When turned off, all regular expression characters except for
.Sq \(ha
and
.Sq \(Do
are treated as ordinary characters.
Preceding individual characters by
.Sq \e
re-enables them.
.It Cm matchtime Bq 7
.Nm vi
only.
The 10th's of a second
.Nm ex Ns / Ns Nm vi
pauses on the matching character when the
.Cm showmatch
option is set.
.It Cm mesg Bq on
Permit messages from other users.
.It Cm msgcat Bq /usr/share/vi/catalog/
Selects a message catalog to be used to display error and informational
messages in a specified language.
.It Cm modelines , modeline Bq off
Read the first and last few lines of each file for
.Nm ex
commands.
This option will never be implemented.
.It Cm noprint Bq \&"\&"
Characters that are never handled as printable characters.
.It Cm number, nu Bq off
Precede each line displayed with its current line number.
.It Cm octal Bq off
Display unknown characters as octal numbers, instead of the default
hexadecimal.
.It Cm open Bq on
.Nm ex
only.
If this option is not set, the
.Cm open
and
.Cm visual
commands are disallowed.
.It Cm optimize , opt Bq on
.Nm vi
only.
Optimize text throughput to dumb terminals.
This option is not yet implemented
.It Cm paragraphs , para Bq "IPLPPPQPP LIpplpipbp"
.Nm vi
only.
Define additional paragraph boundaries for the
.Cm {\&
and
.Cm }\&
commands.
.It Cm path Bq \&"\&"
Define additional directories to search for files being edited.
.It Cm print Bq \&"\&"
Characters that are always handled as printable characters.
.It Cm prompt Bq on
.Nm ex
only.
Display a command prompt.
.It Cm readonly , ro Bq off
Mark the file and session as read-only.
.It Cm recdir Bq /var/tmp/vi.recover
The directory where recovery files are stored.
.It Cm redraw , re Bq off
.Nm vi
only.
Simulate an intelligent terminal on a dumb one.
This option is not yet implemented.
.It Cm remap Bq on
Remap keys until resolved.
.It Cm report Bq 5
Set the number of lines about which the editor reports changes or yanks.
.It Cm ruler Bq off
.Nm vi
only.
Display a row/column ruler on the colon command line.
.It Cm scroll , scr Bq "($LINES \- 1) / 2"
Set the number of lines scrolled.
.It Cm searchincr Bq off
Makes the
.Cm /
and
.Cm ?\&
commands incremental.
.It Cm sections , sect Bq "NHSHH HUnhsh"
.Nm vi
only.
Define additional section boundaries for the
.Cm [[
and
.Cm ]]
commands.
.It Cm secure Bq off
Turns off all access to external programs.
.It Cm shell , sh Bq "environment variable SHELL, or /bin/sh"
Select the shell used by the editor.
.It Cm shellmeta Bq ~{[*?$`'\&"\e
Set the meta characters checked to determine if file name expansion
is necessary.
.It Cm shiftwidth , sw Bq 8
Set the autoindent and shift command indentation width.
.It Cm showmatch , sm Bq off
.Nm vi
only.
Note matching
.Sq {
and
.Sq \&(
for
.Sq }
and
.Sq )\&
characters.
.It Cm showmode , smd Bq off
.Nm vi
only.
Display the current editor mode and a
.Dq modified
flag.
.It Cm sidescroll Bq 16
.Nm vi
only.
Set the amount a left-right scroll will shift.
.It Cm slowopen , slow Bq off
Delay display updating during text input.
This option is not yet implemented.
.It Cm sourceany Bq off
Read startup files not owned by the current user.
This option will never be implemented.
.It Cm tabstop , ts Bq 8
This option sets tab widths for the editor display.
.It Cm taglength , tl Bq 0
Set the number of significant characters in tag names.
.It Cm tags, tag Bq tags
Set the list of tags files.
.It Xo
.Cm term , ttytype , tty
.Bq "environment variable TERM"
.Xc
Set the terminal type.
.It Cm terse Bq off
This option has historically made editor messages less verbose.
It has no effect in this implementation.
.It Cm tildeop Bq off
Modify the
.Cm ~
command to take an associated motion.
.It Cm timeout , to Bq on
Time out on keys which may be mapped.
.It Cm ttywerase Bq off
.Nm vi
only.
Select an alternate erase algorithm.
.It Cm verbose Bq off
.Nm vi
only.
Display an error message for every error.
.It Cm w300 Bq no default
.Nm vi
only.
Set the window size if the baud rate is less than 1200 baud.
.It Cm w1200 Bq no default
.Nm vi
only.
Set the window size if the baud rate is equal to 1200 baud.
.It Cm w9600 Bq no default
.Nm vi
only.
Set the window size if the baud rate is greater than 1200 baud.
.It Cm warn Bq on
.Nm ex
only.
This option causes a warning message to be printed on the terminal
if the file has been modified since it was last written, before a
.Cm !\&
command.
.It Xo
.Cm window , w , wi
.Bq "environment variable LINES \- 1"
.Xc
Set the window size for the screen.
.It Cm windowname Bq off
Change the icon/window name to the current file name even if it can't
be restored on editor exit.
.It Cm wraplen , wl Bq 0
.Nm vi
only.
Break lines automatically,
the specified number of columns from the left-hand margin.
If both the
.Cm wraplen
and
.Cm wrapmargin
edit options are set, the
.Cm wrapmargin
value is used.
.It Cm wrapmargin , wm Bq 0
.Nm vi
only.
Break lines automatically,
the specified number of columns from the right-hand margin.
If both the
.Cm wraplen
and
.Cm wrapmargin
edit options are set, the
.Cm wrapmargin
value is used.
.It Cm wrapscan , ws Bq on
Set searches to wrap around the end or beginning of the file.
.It Cm writeany , wa Bq off
Turn off file-overwriting checks.
.El
.Sh ENVIRONMENT
.Bl -tag -width "COLUMNS"
.It Ev COLUMNS
The number of columns on the screen.
This value overrides any system or terminal specific values.
If the
.Ev COLUMNS
environment variable is not set when
.Nm ex Ns / Ns Nm vi
runs, or the
.Cm columns
option is explicitly reset by the user,
.Nm ex Ns / Ns Nm vi
enters the value into the environment.
.It Ev EXINIT
A list of
.Nm ex
startup commands, read after
.Pa /etc/vi.exrc
unless the variable
.Ev NEXINIT
is also set.
.It Ev HOME
The user's home directory, used as the initial directory path for the startup
.Pa $HOME/.nexrc
and
.Pa $HOME/.exrc
files.
This value is also used as the default directory for the
.Nm vi
.Cm cd
command.
.It Ev LINES
The number of rows on the screen.
This value overrides any system or terminal specific values.
If the
.Ev LINES
environment variable is not set when
.Nm ex Ns / Ns Nm vi
runs, or the
.Cm lines
option is explicitly reset by the user,
.Nm ex Ns / Ns Nm vi
enters the value into the environment.
.It Ev NEXINIT
A list of
.Nm ex
startup commands, read after
.Pa /etc/vi.exrc .
.It Ev SHELL
The user's shell of choice (see also the
.Cm shell
option).
.It Ev TERM
The user's terminal type.
The default is the type
.Dq unknown .
If the
.Ev TERM
environment variable is not set when
.Nm ex Ns / Ns Nm vi
runs, or the
.Cm term
option is explicitly reset by the user,
.Nm ex Ns / Ns Nm vi
enters the value into the environment.
.It Ev TMPDIR
The location used to stored temporary files (see also the
.Cm directory
edit option).
.El
.Sh ASYNCHRONOUS EVENTS
.Bl -tag -width "SIGWINCH" -compact
.It Dv SIGALRM
.Nm vi Ns / Ns Nm ex
uses this signal for periodic backups of file modifications and to display
.Dq busy
messages when operations are likely to take a long time.
.Pp
.It Dv SIGHUP
.It Dv SIGTERM
If the current buffer has changed since it was last written in its entirety,
the editor attempts to save the modified file so it can be later recovered.
See the
.Nm vi Ns / Ns Nm ex
reference manual section
.Sx Recovery
for more information.
.Pp
.It Dv SIGINT
When an interrupt occurs, the current operation is halted
and the editor returns to the command level.
If interrupted during text input,
the text already input is resolved into the file as if the text
input had been normally terminated.
.Pp
.It Dv SIGWINCH
The screen is resized.
See the
.Nm vi Ns / Ns Nm ex
reference manual section
.Sx Sizing the Screen
for more information.
.\" .Pp
.\" .It Dv SIGCONT
.\" .It Dv SIGTSTP
.\" .Nm vi Ns / Ns Nm ex
.\" ignores these signals.
.El
.Sh FILES
.Bl -tag -width "/var/tmp/vi.recover"
.It Pa /bin/sh
The default user shell.
.It Pa /etc/vi.exrc
System-wide
.Nm vi
startup file.
It is read for
.Nm ex
commands first in the startup sequence.
Must be owned by root or the user,
and writable only by the owner.
.It Pa /tmp
Temporary file directory.
.It Pa /var/tmp/vi.recover
The default recovery file directory.
.It Pa $HOME/.nexrc
First choice for user's home directory startup file, read for
.Nm ex
commands right after
.Pa /etc/vi.exrc
unless either
.Ev NEXINIT
or
.Ev EXINIT
are set.
Must be owned by root or the user,
and writable only by the owner.
.It Pa $HOME/.exrc
Second choice for user's home directory startup file, read for
.Nm ex
commands under the same conditions as
.Pa $HOME/.nexrc .
.It Pa .nexrc
First choice for local directory startup file, read for
.Nm ex
commands at the end of the startup sequence if the
.Cm exrc
option was turned on earlier.
Must be owned by the user
and writable only by the owner.
.It Pa .exrc
Second choice for local directory startup file, read for
.Nm ex
commands under the same conditions as
.Pa .nexrc .
.El
.Sh EXIT STATUS
The
.Nm ex
and
.Nm vi
utilities exit 0 on success,
and \*(Gt0 if an error occurs.
.Sh SEE ALSO
.Xr ctags 1 ,
.Xr re_format 7
.Sh STANDARDS
.Nm nex Ns / Ns Nm nvi
is close to
.St -p1003.1-2008 .
That document differs from historical
.Nm ex Ns / Ns Nm vi
practice in several places; there are changes to be made on both sides.
.Sh HISTORY
The
.Nm ex
editor first appeared in
.Bx 1 .
The
.Nm nex Ns / Ns Nm nvi
replacements for the
.Nm ex Ns / Ns Nm vi
editor first appeared in
.Bx 4.4 .
.Sh AUTHORS
.An Bill Joy
wrote the original version of
.Nm ex
in 1977.