@comment  Copyright (c) 1994
@comment 	The Regents of the University of California.  All rights reserved.
@comment  Copyright (c) 1994, 1995, 1996
@comment 	Keith Bostic.  All rights reserved.
@comment 
@comment  See the LICENSE file for redistribution information.
@comment 
@comment 	$Id: ex.cmd.texi,v 8.2 2001/08/20 16:05:50 skimo Exp $ (Berkeley) $Date: 2001/08/20 16:05:50 $
@comment 
@chapter Ex Description

The following words have special meanings for
@CO{ex}
commands.
@itemize @bullet
@cindex "<end-of-file>"
@IP{<end-of-file>}

The end-of-file character is used to scroll the screen in the
@CO{ex}
editor.
This character is normally
@LI{<control-D>}.
However, whatever character is set for the current terminal is supported
as well as
@LI{<control-D>}.
@cindex "line"
@IP{line}

A single-line address, given in any of the forms described in the
section entitled
@QB{Ex Addressing} .
The default for
@LI{line}is the current line.
@cindex "range"
@IP{range}

A line, or a pair of line addresses, separated by a comma or semicolon.
(See the section entitled
@QB{Ex Addressing}
for more information.)
The default for range is the current line
@emph{only},
i.e.
@QT{.,.}.
A percent sign
@PQ{%}
stands for the range
@QT{1,$}.
The starting address must be less than, or equal to, the ending address.
@cindex "count"
@IP{count}

A positive integer, specifying the number of lines to be affected by
the command; the default is 1.
Generally, a count past the end-of-file may be specified, e.g. the
command
@QT{p 3000}
in a 10 line file is acceptable, and will print from the current line
through the last line in the file.
@cindex "flags"
@IP{flags}

One or more of the characters
@QQ{#},
@QQ{p},
and
@QQ{l}.
When a command that accepts these flags completes, the addressed line(s)
are written out as if by the corresponding
@CO{#},
@CO{l}
or
@CO{p}
commands.
In addition, any number of
@QT{+}
or
@QT{-}
characters can be specified before, after, or during the flags, in which
case the line written is not necessarily the one affected by the command,
but rather the line addressed by the offset address specified.
The default for
@LI{flags}is none.
@cindex "file"
@IP{file}

A pattern used to derive a pathname; the default is the current file.
File names are subjected to normal
@XR{sh,1}
word expansions.
@end itemize

Anywhere a file name is specified, it is also possible to use
the special string
@QT{/tmp}.
This will be replaced with a temporary file name which can be used
for temporary work, e.g.
@QT{:e /tmp}
creates and edits a new file.

If both a count and a range are specified for commands that use either,
the starting line for the command is the
@emph{last}
line addressed by the range, and
@LI{count}- 1
subsequent lines are affected by the command, e.g. the command
@QT{2,3p4}
prints out lines 3, 4, 5 and 6.

When only a line or range is specified, with no command, the implied
command is either a
@CO{list},
@CO{number}
or
@CO{print}
command.
The command used is the most recent of the three commands to have been
used (including any use as a flag).
If none of these commands have been used before, the
@CO{print}
command is the implied command.
When no range or count is specified and the command line is a blank line,
the current line is incremented by 1 and then the current line is displayed.

Zero or more whitespace characters may precede or follow the addresses,
count, flags, or command name.
Any object following a command name (such as buffer, file, etc.),
that begins with an alphabetic character,
should be separated from the command name by at least one whitespace
character.

Any character, including
@LI{<carriage-return>},
@QT{%}
and
@QT{#}
retain their literal value when preceded by a backslash.
@chapter Ex Commands

The following section describes the commands available in the
@CO{ex}
editor.
In each entry below, the tag line is a usage synopsis for the command.

Each command can be entered as the abbreviation
(those characters in the synopsis command word preceding the
@QQ{[}
character),
the full command (all characters shown for the command word,
omitting the
@QQ{[}
and
@QQ{]}
characters),
or any leading subset of the full command down to the abbreviation.
For example, the args command (shown as
@QT{ar[gs]}
in the synopsis)
can be entered as
@QT{ar},
@QT{arg}
or
@QT{args}.

Each
@CO{ex}
command described below notes the new current line after it
is executed, as well as any options that affect the command.
@cindex DOUBLEQUOTE
@deftypefn Command {} {"}

A comment.
Command lines beginning with the double-quote character
@PQ{"}
are ignored.
This permits comments in editor scripts and startup files.
@end deftypefn
@cindex "<control-D>"
@cindex "<end-of-file>"
@deftypefn Command {} {<control-D>}

@deftypefnx Command {} {<end-of-file>}

Scroll the screen.
Write the next N lines, where N is the value of the
@OP{scroll}
option.
The command is the end-of-file terminal character, which may be
different on different terminals.
Traditionally, it is the
@LI{<control-D>}key.
@sp 1
Historically, the
@CO{eof}
command ignored any preceding count, and the
@LI{<end-of-file>}character was ignored unless it was entered as the first character
of the command.
This implementation treats it as a command
@emph{only}
if entered as the first character of the command line, and otherwise
treats it as any other character.
@table @asis
@item Line:
Set to the last line written.
@item Options:
Affected by the
@OP{scroll}
option.
@end table
@end deftypefn
@cindex "!"
@deftypefn Command {} {!} {argument(s)}

@deftypefnx Command {}  {[range]!} {argument(s)}
Execute a shell command, or filter lines through a shell command.
In the first synopsis, the remainder of the line after the
@QT{!}
character is passed to the program named by the
@OP{shell}
option, as a single argument.
@sp 1
Within the rest of the line,
@QT{%}
and
@QT{#}
are expanded into the current and alternate pathnames, respectively.
The character
@QT{!}
is expanded with the command text of the previous
@CO{!}
command.
(Therefore, the command
@CO{!!}
repeats the previous
@CO{!}
command.)
The special meanings of
@QT{%},
@QT{#},
and
@QT{!}
can be overridden by escaping them with a backslash.
If no
@CO{!}
or
@CO{:!}
command has yet been executed, it is an error to use an unescaped
@QT{!}
character.
The
@CO{!}
command does
@emph{not}
do shell expansion on the strings provided as arguments.
If any of the above expansions change the command the user entered,
the command is redisplayed at the bottom of the screen.
@sp 1
@CO{Ex}
then executes the program named by the
@OP{shell}
option, with a
@strong{-c}
flag followed by the arguments (which are bundled into a single argument).
@sp 1
The
@CO{!}
command is permitted in an empty file.
@sp 1
If the file has been modified since it was last completely written,
the
@CO{!}
command will warn you.
@sp 1
A single
@QT{!}
character is displayed when the command completes.
@sp 1
In the second form of the
@CO{!}
command, the remainder of the line after the
@QT{!}
is passed to the program named by the
@OP{shell}
option, as described above.
The specified lines are passed to the program as standard input,
and the standard and standard error output of the program replace
the original lines.
@table @asis
@item Line:
Unchanged if no range was specified, otherwise set to the first
line of the range.
@item Options:
Affected by the
@OP{shell}
and
@OP{warn}
options.
@end table
@end deftypefn
@cindex "#"
@deftypefn Command {[range]} {#} {[count] [flags]}

@cindex "number"
@deftypefnx Command  {[range]} {nu[mber]} {[count] [flags]}
Display the selected lines, each preceded with its line number.
@sp 1
The line number format is
@QQ{%6d},
followed by two spaces.
@table @asis
@item Line:
Set to the last line displayed.
@item Options:
Affected by the
@OP{list}
option.
@end table
@end deftypefn
@cindex "@@"
@deftypefn Command {@@} {buffer}

@cindex "*"
@deftypefnx Command {}  {*} {buffer}
Execute a buffer.
Each line in the named buffer is executed as an
@CO{ex}
command.
If no buffer is specified, or if the specified buffer is
@QT{@@}
or
@QT{*},
the last buffer executed is used.
@end deftypefn
@cindex <
@deftypefn Command {[range]} {<[< ...]} {[count] [flags]}

Shift lines left or right.
The specified lines are shifted to the left (for the
@CO{<}
command) or right (for the
@CO{>}
command), by the number of columns specified by the
@OP{shiftwidth}
option.
Only leading whitespace characters are deleted when shifting left;
once the first column of the line contains a nonblank character,
the
@CO{shift}
command will succeed, but the line will not be modified.
@sp 1
If the command character
@CO{<}
or
@CO{>}
is repeated more than once, the command is repeated once for each
additional command character.
@table @asis
@item Line:
If the current line is set to one of the lines that are affected
by the command, it is unchanged.
Otherwise, it is set to the first nonblank character of the lowest
numbered line shifted.
@item Options:
Affected by the
@OP{shiftwidth}
option.
@end table
@end deftypefn
@cindex =
@deftypefn Command {[line]} {=} {[flags]}

Display the line number of
@LI{line}(which defaults to the last line in the file).
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex >
@deftypefn Command {[range]} {>[> ...]} {[count] [flags]}

Shift right.
The specified lines are shifted to the right by the number of columns
specified by the
@OP{shiftwidth}
option, by inserting tab and space characters.
Empty lines are not changed.
@sp 1
If the command character
@QT{>}
is repeated more than once, the command is repeated once for each
additional command character.
@table @asis
@item Line:
Set to the last line modified by the command.
@item Options:
Affected by the
@OP{shiftwidth}
option.
@end table
@end deftypefn
@cindex abbrev
@deftypefn Command {} {ab[brev]} {lhs rhs}

Add an abbreviation to the current abbreviation list.
When inserting text in
@CO{vi},
each time a non-word character is entered after a word character,
a set of characters ending at the word character are checked for
a match with
@LI{lhs}.
If a match is found, they are replaced with
@LI{rhs}.
The set of characters that are checked for a match are defined as follows,
for inexplicable historical reasons.
If only one or two characters were entered before the non-word character
that triggered the check,
and after the beginning of the insertion,
or the beginning of the line or the file,
or the last
@LI{<blank>}character that was entered,
then the one or the both characters are checked for a match.
Otherwise, the set includes both characters,
as well as the characters that precede them that are the same word
class (i.e. word or non-word) as the
@strong{second}
to last character entered before the non-word character that triggered
the check,
back to the first
@LI{<blank>}character,
the beginning of the insertion,
or the beginning of the line or the file.
@sp 1
For example, the abbreviations:
@sp 1
@multitable {:abbreviate} {/*#i} {/********************}
@item :abbreviate @tab abc @tab ABC
@item :abbreviate @tab #i @tab #include
@item :abbreviate @tab /*#i @tab /*#include
@end multitable
will all work, while the abbreviations:
@sp 1
@multitable {:abbreviate} {/*#i} {/********************}
@item :abbreviate @tab a#i @tab A#include
@item :abbreviate @tab /* @tab /********************
@end multitable
will not work, and are not permitted by
@CO{nvi}.
@sp 1
To keep the abbreviation expansion from happening,
the character immediately following the
@LI{lhs}characters should be quoted with a
@LI{<literal-next>}character.
@sp 1
The replacement
@LI{rhs}is itself subject to both further abbreviation expansion and further
map expansion.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex append
@deftypefn Command {[line]} {a[ppend][!]}

The input text is appended to the specified line.
If line 0 is specified, the text is inserted at the beginning of the file.
Set to the last line input.
If no lines are input, then set to
@LI{line},
or to the first line of the file if a
@LI{line}of 0 was specified.
Following the command name with a
@QT{!}
character causes the
@OP{autoindent}
option to be toggled for the duration of the command.
@table @asis
@item Line:
Unchanged.
@item Options:
Affected by the
@OP{autoindent}
and
@OP{number}
options.
@end table
@end deftypefn
@cindex args
@deftypefn Command {} {ar[gs]}

Display the argument list.
The current argument is displayed inside of
@QT{[}
and
@QT{]}
characters.
The argument list is the list of operands specified on startup,
which can be replaced using the
@CO{next}
command.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex bg
@deftypefn Command {} {bg}

@CO{Vi}
mode only.
Background the current screen.
The screen is unchanged,
but is no longer accessible and disappears from the display.
Use the
@CO{fg}
command to bring the screen back to the display foreground.
@table @asis
@item Line:
Set to the current line when the screen was last edited.
@item Options:
None.
@end table
@end deftypefn
@cindex change
@deftypefn Command {[range]} {c[hange][!]} {[count]}

Replace the lines with input text.
Following the command name with a
@QT{!}
character causes the
@OP{autoindent}
option to be toggled for the duration of the command.
@table @asis
@item Line:
Set to the last line input, or, if no lines were input,
set to the line before the target line, or to the first
line of the file if there are no lines preceding the target line.
@item Options:
Affected by the
@OP{autoindent}
and
@OP{number}
options.
@end table
@cindex cd
@end deftypefn
@cindex chdir
@deftypefn Command {} {chd[ir][!]} {[directory]}

@deftypefnx Command {}  {cd[!]} {[directory]}
Change the current working directory.
The
@LI{directory}argument is subjected to
@XR{sh,1}
word expansions.
When invoked with no directory argument and the
@LI{HOME}environment variable is set, the directory named by the
@LI{HOME}environment variable becomes the new current directory.
Otherwise, the new current directory becomes the directory returned
by the
@XR{getpwent,3}
routine.
@sp 1
The
@CO{chdir}
command will fail if the file has been modified since the last complete
write of the file.
You can override this check by appending a
@QT{!}
character to the command.
@table @asis
@item Line:
Unchanged.
@item Options:
Affected by the
@OP{cdpath}
option.
@end table
@cindex copy
@end deftypefn
@cindex t
@deftypefn Command {[range]} {co[py]} {line [flags]}

@deftypefnx Command  {[range]} {t} {line [flags]}
Copy the specified lines (range) after the destination line.
Line 0 may be specified to insert the lines at the beginning of
the file.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex cscope
@deftypefn Command {} {cs[cope]} {command [args]}

Execute a
@CO{cscope}
command.
For more information, see the section of the reference manual entitled
@QB{Tags, Tag Stacks, and Cscope} .
@end deftypefn
@cindex delete
@deftypefn Command {[range]} {d[elete]} {[buffer] [count] [flags]}

Delete the lines from the file.
The deleted text is saved in the specified buffer, or, if no buffer
is specified, in the unnamed buffer.
If the command name is followed by a letter that could be interpreted
as either a buffer name or a flag value (because neither a
@LI{count}or
@LI{flags}values were given),
@CO{ex}
treats the letter as a
@LI{flags}value if the letter immediately follows the command name,
without any whitespace separation.
If the letter is preceded by whitespace characters,
it treats it as a buffer name.
@table @asis
@item Line:
Set to the line following the deleted lines,
or to the last line if the deleted lines were at the end.
@item Options:
None.
@end table
@end deftypefn
@cindex display
@deftypefn Command {} {di[splay]} {b[uffers] | c[onnections] | s[creens] | t[ags]}

Display buffers,
@CO{cscope}
connections, screens or tags.
The
@CO{display}
command takes one of three additional arguments, which are as follows:
@table @asis
@item b[uffers]
Display all buffers (including named, unnamed, and numeric)
that contain text.
@item c[onnections]
Display the source directories for all attached
@CO{cscope}
databases.
@item s[creens]
Display the file names of all background screens.
@item t[ags]
Display the tags stack.
@end table
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex edit
@deftypefn Command {} {e[dit][!]} {[+cmd] [file]}
@deftypefnx Command {}  {ex[!]} {[+cmd] [file]}
@deftypefnx Command {} {vs[plit][!]} {[+cmd] [file]}
Edit a different file.
If the current buffer has been modified since the last complete write,
the command will fail.
You can override this by appending a
@QT{!}
character to the command name.
@sp 1
If the
@QT{+cmd}
option is specified, that
@CO{ex}
command will be executed in the new file.
Any
@CO{ex}
command may be used, although the most common use of this feature is
to specify a line number or search pattern to set the initial location
in the new file.
@sp 1
Capitalizing the first letter of the command, i.e.,
@CO{Edit}
or
@CO{Ex},
while in
@CO{vi}
mode, will edit the file in a new screen.
In this case, any modifications to the current file are ignored.
@cindex vertical split
@cindex splitting, vertically
@CO{vsplit} is similar, but the screen will be split vertically
to produce the new screen, rather than horizontally.

@table @asis
@item Line:
If you have previously edited the file, the current line will be set
to your last position in the file.
If that position does not exist, or you have not previously edited the
file, the current line will be set to the first line of the file if
you are in
@CO{vi}
mode, and the last line of the file if you are in
@CO{ex}.
@item Options:
None.
@end table
@end deftypefn
@cindex exusage
@deftypefn Command {} {exu[sage]} {[command]}

Display usage for an
@CO{ex}
command.
If
@LI{command}is specified, a usage statement for that command is displayed.
Otherwise, usage statements for all
@CO{ex}
commands are displayed.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex file
@deftypefn Command {} {f[ile]} {[file]}

Display and optionally change the file name.
If a file name is specified, the current pathname is changed to the
specified name.
The current pathname, the number of lines, and the current position
in the file are displayed.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex fg
@deftypefn Command {} {fg} {[name]}

@CO{Vi}
mode only.
Foreground the specified screen.
If the argument name doesn't exactly match the name of a file displayed
by a background screen,
it is compared against the last component of each of the file names.
If no background screen is specified,
the first background screen is foregrounded.
@sp 1
By default,
foregrounding causes the current screen to be swapped with the backgrounded
screen.
Capitalizing the first letter of the command, i.e.
@CO{Fg},
will foreground the backgrounded screen in a new screen instead of
swapping it with the current screen.
@table @asis
@item Line:
Set to the current line when the screen was last edited.
@item Options:
None.
@end table
@end deftypefn
@cindex global
@deftypefn Command {[range]} {g[lobal]} {/pattern/ [commands]}

@cindex v
@deftypefnx Command  {[range]} {v} {/pattern/ [commands]}
Apply commands to lines matching (or not matching) a pattern.
The lines within the given range that match
@PQ{g[lobal]},
or do not match
@PQ{v}
the given pattern are selected.
Then, the specified
@CO{ex}
command(s) are executed with the current line
@PQ{.}
set to each selected line.
If no range is specified, the entire file is searched for matching,
or not matching, lines.
@sp 1
Multiple commands can be specified, one per line, by escaping each
@LI{<newline>}character with a backslash, or by separating commands with a
@QT{|}
character.
If no commands are specified, the command defaults to the
@CO{print}
command.
@sp 1
For the
@CO{append},
@CO{change}
and
@CO{insert}
commands, the input text must be part of the global command line.
In this case, the terminating period can be omitted if it ends the commands.
@sp 1
The
@CO{visual}
command may also be specified as one of the
@CO{ex}
commands.
In this mode, input is taken from the terminal.
Entering a
@CO{Q}
command in
@CO{vi}
mode causes the next line matching the pattern to be selected and
@CO{vi}
to be reentered, until the list is exhausted.
@sp 1
The
@CO{global},
@CO{v}
and
@CO{undo}
commands cannot be used as part of these commands.
@sp 1
The editor options
@OP{autoindent},
@OP{autoprint}
and
@OP{report}
are turned off for the duration of the
@CO{global}
and
@CO{v}
commands.
@table @asis
@item Line:
The last line modified.
@item Options:
Affected by the
@OP{ignorecase}
and
@OP{magic}
options.
Turns off the
@OP{autoindent},
@OP{autoprint}
and
@OP{report}
options.
@end table
@end deftypefn
@cindex help
@deftypefn Command {} {he[lp]}

Display a help message.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex insert
@deftypefn Command {[line]} {i[nsert][!]}

The input text is inserted before the specified line.
Following the command name with a
@QT{!}
character causes the
@OP{autoindent}
option setting to be toggled for the duration of this command.
@table @asis
@item Line:
Set to the last line input; if no lines were input,
set to the line before the target line, or to the first line
of the file if there are no lines preceding the target line.
Affected by the
@OP{autoindent}
and
@OP{number}
options.
@end table
@end deftypefn
@cindex join
@deftypefn Command {[range]} {j[oin][!]} {[count] [flags]}

Join lines of text together.
@sp 1
A
@LI{count}specified to the
@CO{join}
command specifies that the last line of the
@LI{range}plus
@LI{count}subsequent lines will be joined.
(Note, this differs by one from the general rule where only
@LI{count}- 1
subsequent lines are affected.)
@sp 1
If the current line ends with a whitespace character, all whitespace
is stripped from the next line.
Otherwise, if the next line starts with a open parenthesis
@PQ{(},
do nothing.
Otherwise, if the current line ends with a question mark
@PQ{?},
period
@PQ{.}
or exclamation point
@PQ{!},
insert two spaces.
Otherwise, insert a single space.
@sp 1
Appending a
@QT{!}
character to the command name causes a simpler join with no
white-space processing.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex list
@deftypefn Command {[range]} {l[ist]} {[count] [flags]}

Display the lines unambiguously.
Tabs are displayed as
@QT{^I},
and the end of the line is marked with a
@QT{$}
character.
@table @asis
@item Line:
Set to the last line displayed.
@item Options:
Affected by the
@OP{number}
option.
@end table
@end deftypefn
@cindex map
@deftypefn Command {} {map[!]} {[lhs rhs]}

Define or display maps (for
@CO{vi}
only).
@sp 1
If
@QT{lhs}
and
@QT{rhs}
are not specified, the current set of command mode maps are displayed.
If a
@QT{!}
character is appended to to the command,
the text input mode maps are displayed.
@sp 1
Otherwise, when the
@QT{lhs}
character sequence is entered in
@CO{vi},
the action is as if the corresponding
@QT{rhs}
had been entered.
If a
@QT{!}
character is appended to the command name,
the mapping is effective during text input mode,
otherwise, it is effective during command mode.
This allows
@QT{lhs}
to have two different macro definitions at the same time: one for command
mode and one for input mode.
@sp 1
Whitespace characters require escaping with a
@LI{<literal-next>}character to be entered in the
@LI{lhs}string in visual mode.
@sp 1
Normally, keys in the
@LI{rhs}string are remapped (see the
@OP{remap}
option),
and it is possible to create infinite loops.
However, keys which map to themselves are not further remapped,
regardless of the setting of the
@OP{remap}
option.
For example, the command
@QT{:map n nz.}
maps the
@QT{n}
key to the
@CO{n}
and
@CO{z}
commands.
@sp 1
To exit an infinitely looping map, use the terminal
@LI{<interrupt>}character.
@table @asis
@item Line:
Unchanged.
@item Options:
Affected by the
@OP{remap}
option.
@end table
@cindex mark
@end deftypefn
@cindex k
@deftypefn Command {[line]} {ma[rk]} {<character>}

@deftypefnx Command  {[line]} {k} {<character>}
Mark the line with the mark
@LI{<character>}.
The expressions
@QT{'<character>}
and
@QT{`<character>}
can then be used as an address in any command that uses one.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex move
@deftypefn Command {[range]} {m[ove]} {line}

Move the specified lines after the target line.
A target line of 0 places the lines at the beginning of the file.
@table @asis
@item Line:
Set to the first of the moved lines.
@item Options:
None.
@end table
@end deftypefn
@cindex mkexrc
@deftypefn Command {} {mk[exrc][!]} {file}

Write the abbreviations, editor options and maps to the specified
file.
Information is written in a form which can later be read back in
using the
@CO{ex}
@CO{source}
command.
If
@LI{file}already exists, the
@CO{mkexrc}
command will fail.
This check can be overridden by appending a
@QT{!}
character to the command.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex next
@deftypefn Command {} {n[ext][!]} {[file ...]}

Edit the next file from the argument list.
The
@CO{next}
command will fail if the file has been modified since the last complete
write.
This check can be overridden by appending the
@QT{!}
character to the command name.
The argument list can optionally be replaced by specifying a new one
as arguments to this command.
In this case, editing starts with the first file on the new list.
@sp 1
Capitalizing the first letter of the command, i.e.
@CO{Next},
while in
@CO{vi}
mode, will set the argument list and edit the file in a new screen.
In this case, any modifications to the current file are ignored.
@table @asis
@item Line:
Set as described for the
@CO{edit}
command.
@item Options:
Affected by the options
@OP{autowrite}
and
@OP{writeany}.
@end table
@end deftypefn
@cindex open
@deftypefn Command {[line]} {o[pen]} {/pattern/ [flags]}

Enter open mode.
Open mode is the same as being in
@CO{vi},
but with a one-line window.
All the standard
@CO{vi}
commands are available.
If a match is found for the optional RE argument,
the cursor is set to the start of the matching pattern.
@sp 1
@emph{This command is not yet implemented.}
@table @asis
@item Line:
Unchanged, unless the optional RE is specified, in which case it is
set to the line where the matching pattern is found.
@item Options:
Affected by the
@OP{open}
option.
@end table
@end deftypefn
@cindex preserve
@deftypefn Command {} {pre[serve]}

Save the file in a form that can later be recovered using the
@CO{ex}
@strong{-r}
option.
When the file is preserved, an email message is sent to the user.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex previous
@deftypefn Command {} {prev[ious][!]}

Edit the previous file from the argument list.
The
@CO{previous}
command will fail if the file has been modified since the last complete
write.
This check can be overridden by appending the
@QT{!}
character to the command name.
@sp 1
Capitalizing the first letter of the command, i.e.
@CO{Previous},
while in
@CO{vi}
mode, will edit the file in a new screen.
In this case, any modifications to the current file are ignored.
@table @asis
@item Line:
Set as described for the
@CO{edit}
command.
@item Options:
Affected by the options
@OP{autowrite}
and
@OP{writeany}.
None.
@end table
@end deftypefn
@cindex print
@deftypefn Command {[range]} {p[rint]} {[count] [flags]}

Display the specified lines.
@table @asis
@item Line:
Set to the last line displayed.
@item Options:
Affected by the
@OP{list}
and
@OP{number}
option.
@end table
@end deftypefn
@cindex put
@deftypefn Command {[line]} {pu[t]} {[buffer]}

Append buffer contents to the current line.
If a buffer is specified, its contents are appended to the line,
otherwise, the contents of the unnamed buffer are used.
@table @asis
@item Line:
Set to the line after the current line.
@item Options:
None.
@end table
@end deftypefn
@cindex quit
@deftypefn Command {} {q[uit][!]}

End the editing session.
If the file has been modified since the last complete write, the
@CO{quit}
command will fail.
This check may be overridden by appending a
@QT{!}
character to the command.
@sp 1
If there are more files to edit, the
@CO{quit}
command will fail.
Appending a
@QT{!}
character to the command name or entering two
@CO{quit}
commands (i.e.
@CO{wq},
@CO{quit},
@CO{xit}
or
@CO{ZZ})
in a row) will override this check and the editor will exit.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex read
@deftypefn Command {[line]} {r[ead][!]} {[file]}

Read a file.
A copy of the specified file is appended to the line.
If
@LI{line}is 0, the copy is inserted at the beginning of the file.
If no file is specified, the current file is read; if there is no
current file, then
@LI{file}becomes the current file.
If there is no current file and no
@LI{file}is specified, then the
@CO{read}
command will fail.
@sp 1
If
@LI{file}is preceded by a
@QT{!}
character,
@LI{file}is treated as if it were a shell command, and passed to the program
named by the
@OP{shell}
edit option.
The standard and standard error outputs of that command are read into
the file after the specified line.
The special meaning of the
@QT{!}
character can be overridden by escaping it with a backslash
@PQ{\e}
character.
@table @asis
@item Line:
When executed from
@CO{ex},
the current line is set to the last line read.
When executed from
@CO{vi},
the current line is set to the first line read.
@item Options:
None.
@end table
@end deftypefn
@cindex recover
@deftypefn Command {} {rec[over]} {file}

Recover
@LI{file}if it was previously saved.
If no saved file by that name exists, the
@CO{recover}
command behaves equivalently to the
@CO{edit}
command.
@table @asis
@item Line:
Set as described for the
@CO{edit}
command.
@item Options:
None.
@end table
@end deftypefn
@cindex resize
@deftypefn Command {} {res[ize]} {[+|-]size}

@CO{Vi}
mode only.
Grow or shrink the current screen.
If
@LI{size}is a positive, signed number, the current screen is grown by that many lines.
If
@LI{size}is a negative, signed number, the current screen is shrunk by that many lines.
If
@LI{size}is not signed, the current screen is set to the specified
@LI{size}.
Applicable only to split screens.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex rewind
@deftypefn Command {} {rew[ind][!]}

Rewind the argument list.
If the current file has been modified since the last complete write,
the
@CO{rewind}
command will fail.
This check may be overridden by appending the
@QT{!}
character to the command.
@sp 1
Otherwise, the current file is set to the first file in the argument
list.
@table @asis
@item Line:
Set as described for the
@CO{edit}
command.
@item Options:
Affected by the
@OP{autowrite}
and
@OP{writeany}
options.
@end table
@end deftypefn
@cindex set
@deftypefn Command {} {se[t]} {[option[=[value]] ...] [nooption ...] [option? ...] [all]}

Display or set editor options.
When no arguments are specified, the editor option
@OP{term},
and any editor options whose values have been changed from the
default settings are displayed.
If the argument
@LI{all}is specified, the values of all of editor options are displayed.
@sp 1
Specifying an option name followed by the character
@QT{?}
causes the current value of that option to be displayed.
The
@QT{?}
can be separated from the option name by whitespace characters.
The
@QT{?}
is necessary only for Boolean valued options.
Boolean options can be given values by the form
@QT{set option}
to turn them on, or
@QT{set nooption}
to turn them off.
String and numeric options can be assigned by the form
@QT{set option=value}.
Any whitespace characters in strings can be included literally by preceding
each with a backslash.
More than one option can be set or listed by a single set command,
by specifying multiple arguments, each separated from the next by
whitespace characters.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex shell
@deftypefn Command {} {sh[ell]}

Run the shell program.
The program named by the
@OP{shell}
option is run with a
@strong{-i}
(for interactive) flag.
Editing is resumed when that program exits.
@table @asis
@item Line:
Unchanged.
@item Options:
Affected by the
@OP{shell}
option.
@end table
@end deftypefn
@cindex source
@deftypefn Command {} {so[urce]} {file}

Read and execute
@CO{ex}
commands from a file.
@CO{Source}
commands may be nested.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex substitute
@deftypefn Command {[range]} {s[ubstitute]} {[/pattern/replace/] [options] [count] [flags]}

@cindex &
@deftypefnx Command  {[range]} {&} {[options] [count] [flags]}
@cindex ~
@deftypefnx Command  {[range]} {~} {[options] [count] [flags]}
Make substitutions.
Replace the first instance of
@LI{pattern}with the string
@LI{replace}on the specified line(s).
If the
@QT{/pattern/repl/}
argument is not specified, the
@QT{/pattern/repl/}
from the previous
@CO{substitute}
command is used.
Any character other than an alphabetic, numeric, <blank> or backslash
character may be used as the delimiter.
@sp 1
If
@LI{options}includes the letter
@QT{c}
(confirm), you will be prompted for confirmation before each replacement
is done.
An affirmative response (in English, a
@QT{y}
character) causes the replacement to be made.
A quit response (in English, a
@QT{q}
character) causes the
@CO{substitute}
command to be terminated.
Any other response causes the replacement not to be made, and the
@CO{substitute}
command continues.
If
@LI{options}includes the letter
@QT{g}
(global), all nonoverlapping instances of
@LI{pattern}in the line are replaced.
@sp 1
The
@CO{&}
version of the command is the same as not specifying a pattern
or replacement string to the
@CO{substitute}
command, and the
@QT{&}
is replaced by the pattern and replacement information from the
previous substitute command.
@sp 1
The
@CO{~}
version of the command is the same as
@CO{&}
and
@CO{s},
except that the search pattern used is the last RE used in
@emph{any}
command, not necessarily the one used in the last
@CO{substitute}
command.
@sp 1
For example, in the sequence
@example
s/red/blue/
/green
~
@end example
the
@QT{~}
is equivalent to
@QT{s/green/blue/}.
@sp 1
The
@CO{substitute}
command may be interrupted, using the terminal interrupt character.
All substitutions completed before the interrupt are retained.
@table @asis
@item Line:
Set to the last line upon which a substitution was made.
@item Options:
Affected by the
@OP{ignorecase}
and
@OP{magic}
option.
@end table
@end deftypefn
@cindex suspend
@deftypefn Command {} {su[spend][!]}

@cindex stop
@deftypefnx Command {}  {st[op][!]}
@deftypefnx Comamnd {}  <control-Z>
Suspend the edit session.
Appending a
@QT{!}
character to these commands turns off the
@OP{autowrite}
option for the command.
@table @asis
@item Line:
Unchanged.
@item Options:
Affected by the
@OP{autowrite}
and
@OP{writeany}
options.
@end table
@end deftypefn
@cindex tag
@deftypefn Command {} {ta[g][!]} {tagstring}

Edit the file containing the specified tag.
If the tag is in a different file, then the new file is edited.
If the current file has been modified since the last complete write,
the
@CO{tag}
command will fail.
This check can be overridden by appending the
@QT{!}
character to the command name.
@sp 1
The
@CO{tag}
command searches for
@LI{tagstring}in the tags file(s) specified by the
@OP{tags}
option.
(See
@XR{ctags,1}
for more information on tags files.)
@sp 1
Capitalizing the first letter of the command, i.e.
@CO{Tag},
while in
@CO{vi}
mode, will edit the file in a new screen.
In this case, any modifications to the current file are ignored.
@table @asis
@item Line:
Set to the line indicated by the tag.
@item Options:
Affected by the
@OP{autowrite},
@OP{taglength},
@OP{tags}
and
@OP{writeany}
options.
@end table
@end deftypefn
@cindex tagnext
@deftypefn Command {} {tagn[ext][!]}

Edit the file containing the next context for the current tag.
If the context is in a different file, then the new file is edited.
If the current file has been modified since the last complete write,
the
@CO{tagnext}
command will fail.
This check can be overridden by appending the
@QT{!}
character to the command name.
@sp 1
Capitalizing the first letter of the command, i.e.
@CO{Tagnext},
while in 
@CO{vi}
mode, will edit the file in a new screen.
In this case, any modifications to the current file are ignored.
@table @asis 
@item Line:
Set to the line indicated by the tag.
@item Options:
Affected by the 
@OP{autowrite}
and
@OP{writeany}
options.
@end table
@end deftypefn
@cindex tagpop
@deftypefn Command {} {tagp[op][!]} {[file | number]}

Pop to the specified tag in the tags stack.
If neither
@LI{file}or
@LI{number}is specified, the
@CO{tagpop}
command pops to the most recent entry on the tags stack.
If
@LI{file}or
@LI{number}is specified, the
@CO{tagpop}
command pops to the most recent entry in the tags stack for that file,
or numbered entry in the tags stack, respectively.
(See the
@CO{display}
command for information on displaying the tags stack.)
@sp 1
If the file has been modified since the last complete write, the
@CO{tagpop}
command will fail.
This check may be overridden by appending a
@QT{!}
character to the command name.
@table @asis
@item Line:
Set to the line indicated by the tag.
@item Options:
Affected by the
@OP{autowrite}
and
@OP{writeany}
options.
@end table
@end deftypefn
@cindex tagprev
@deftypefn Command {} {tagp[rev][!]}

Edit the file containing the previous context for the current tag.
If the context is in a different file, then the new file is edited.
If the current file has been modified since the last complete write,
the
@CO{tagprev}
command will fail.
This check can be overridden by appending the
@QT{!}
character to the command name.
@sp 1
Capitalizing the first letter of the command, i.e.
@CO{Tagprev},
while in 
@CO{vi}
mode, will edit the file in a new screen.
In this case, any modifications to the current file are ignored.
@table @asis 
@item Line:
Set to the line indicated by the tag.
@item Options:
Affected by the 
@OP{autowrite}
and
@OP{writeany}
options.
@end table
@end deftypefn
@cindex tagtop
@deftypefn Command {} {tagt[op][!]}

Pop to the least recent tag on the tags stack, clearing the tags stack.
@sp 1
If the file has been modified since the last complete write, the
@CO{tagtop}
command will fail.
This check may be overridden by appending a
@QT{!}
character to the command name.
@table @asis
@item Line:
Set to the line indicated by the tag.
@item Options:
Affected by the
@OP{autowrite}
and
@OP{writeany}
options.
@end table
@end deftypefn
@cindex unabbrev
@deftypefn Command {} {una[bbrev]} {lhs}

Delete an abbreviation.
Delete
@LI{lhs}from the current list of abbreviations.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex undo
@deftypefn Command {} {u[ndo]}

Undo the last change made to the file.
Changes made by
@CO{global},
@CO{v},
@CO{visual}
and map sequences are considered a single command.
If repeated, the
@CO{u}
command alternates between these two states, and is its own inverse.
@table @asis
@item Line:
Set to the last line modified by the command.
@item Options:
None.
@end table
@end deftypefn
@cindex unmap
@deftypefn Command {} {unm[ap][!]} {lhs}

Unmap a mapped string.
Delete the command mode map definition for
@LI{lhs}.
If a
@QT{!}
character is appended to the command name, delete the text input mode
map definition instead.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex version
@deftypefn Command {} {ve[rsion]}

Display the version of the
@CO{ex/vi}
editor.
@end deftypefn
@cindex visual
@deftypefn Command {[line]} {vi[sual]} {[type] [count] [flags]}

@CO{Ex}
mode only.
Enter
@CO{vi}.
The
@LI{type}is optional, and can be
@QT{-},
@QT{+}
or
@QT{^},
as in the
@CO{ex}
@CO{z}
command, to specify the position of the specified line in the screen
window.
(The default is to place the line at the top of the screen window.)
A
@LI{count}specifies the number of lines that will initially be displayed.
(The default is the value of the
@OP{window}
editor option.)
@table @asis
@item Line:
Unchanged unless
@LI{line}is specified, in which case it is set to that line.
@item Options:
None.
@end table
@end deftypefn
@cindex visual
@deftypefn Command {} {vi[sual][!]} {[+cmd] [file]}

@CO{Vi}
mode only.
Edit a new file.
Identical to the
@QT{edit[!] [+cmd] [file]}
command.
@sp 1
Capitalizing the first letter of the command, i.e.
@CO{Visual},
will edit the file in a new screen.
In this case, any modifications to the current file are ignored.
@end deftypefn
@cindex viusage
@deftypefn Command {} {viu[sage]} {[command]}

Display usage for a
@CO{vi}
command.
If
@LI{command}is specified, a usage statement for that command is displayed.
Otherwise, usage statements for all
@CO{vi}
commands are displayed.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex write
@deftypefn Command {[range]} {w[rite][!]} {[>>] [file]}

@deftypefnx Command  {[range]} {w[rite]} {[!] [file]}
@cindex wn
@deftypefnx Command  {[range]} {wn[!]} {[>>] [file]}
@cindex wq
@deftypefnx Command  {[range]} {wq[!]} {[>>] [file]}
Write the file.
The specified lines (the entire file, if no range is given) is written
to
@LI{file}.
If
@LI{file}is not specified, the current pathname is used.
If
@LI{file}is specified, and it exists, or if the current pathname was set using the
@CO{file}
command, and the file already exists, these commands will fail.
Appending a
@QT{!}
character to the command name will override this check and the write
will be attempted, regardless.
@sp 1
Specifying the optional
@QT{>>}
string will cause the write to be appended to the file, in which case
no tests are made for the file already existing.
@sp 1
If the file is preceded by a
@QT{!}
character, the program named by the shell edit option is
invoked with file as its second argument, and the specified
lines are passed as standard input to that command.
The
@QT{!}
in this usage must be separated from command name by at least one
whitespace character.
The special meaning of the
@QT{!}
may be overridden by escaping it with a backslash
@PQ{\e}
character.
@sp 1
The
@CO{wq}
version of the write command will exit the editor after writing the file,
if there are no further files to edit.
Appending a
@QT{!}
character to the command name or entering two
@QQ{quit}
commands (i.e.
@CO{wq},
@CO{quit},
@CO{xit}
or
@CO{ZZ})
in a row) will override this check and the editor will exit,
ignoring any files that have not yet been edited.
@sp 1
The
@CO{wn}
version of the write command will move to the next file after writing
the file, unless the write fails.
@table @asis
@item Line:
Unchanged.
@item Options:
Affected by the
@OP{readonly}
and
@OP{writeany}
options.
@end table
@end deftypefn
@cindex xit
@deftypefn Command {[range]} {x[it][!]} {[file]}

Write the file if it has been modified.
The specified lines are written to
@LI{file},
if the file has been modified since the last complete write to any
file.
If no
@LI{range}is specified, the entire file is written.
@sp 1
The
@CO{xit}
command will exit the editor after writing the file,
if there are no further files to edit.
Appending a
@QT{!}
character to the command name or entering two
@QQ{quit}
commands (i.e.
@CO{wq},
@CO{quit},
@CO{xit}
or
@CO{ZZ})
in a row) will override this check and the editor will exit,
ignoring any files that have not yet been edited.
@table @asis
@item Line:
Unchanged.
@item Options:
Affected by the
@OP{readonly}
and
@OP{writeany}
options.
@end table
@end deftypefn
@cindex yank
@deftypefn Command {[range]} {ya[nk]} {[buffer] [count]}

Copy the specified lines to a buffer.
If no buffer is specified, the unnamed buffer is used.
@table @asis
@item Line:
Unchanged.
@item Options:
None.
@end table
@end deftypefn
@cindex z
@deftypefn Command {[line]} {z} {[type] [count] [flags]}

Adjust the window.
If no
@LI{type}is specified, then
@LI{count}lines following the specified line are displayed.
The default
@LI{count}is the value of the
@OP{window}
option.
The
@LI{type}argument changes the position at which
@LI{line}is displayed on the screen by changing the number of lines
displayed before and after
@LI{line}.
The following
@LI{type}characters may be used:
@table @asis
@item -
Place the line at the bottom of the screen.
@item +
Place the line at the top of the screen.
@item .
Place the line in the middle of the screen.
@item ^
Write out count lines starting
@LI{count * 2}lines before
@LI{line};
the net effect of this is that a
@QT{z^}
command following a
@CO{z}
command writes the previous page.
@item =
Center
@LI{line}on the screen with a line of hyphens displayed immediately before and
after it.
The number of preceding and following lines of text displayed are
reduced to account for those lines.
@end table
@table @asis
@item Line:
Set to the last line displayed, with the exception of the
@QT{=}
@LI{type},
where the current line is set to the line specified by the command.
@item Options:
Affected by the
@OP{scroll}
option.
@end table
@end deftypefn
