*vim_diff.txt*  For Vim version 4.2.  Last modification: 1996 June 16

This is a summary of the differences between VIM and vi. It is not complete.
see also |vim_ref.txt|, look for comments in {}, like "{not in Vi}".

Vim is mostly POSIX 1003.2-1 compliant.  The commands known to be missing
are "Q", ":append", ":change", ":insert", ":open" and ":z".  There are
probably a lot of small differences.


THE MOST INTERESTING ADDITIONS
==============================

Vi compatibility.					|'compatible'|
	Although Vim is 99% Vi compatible, some things in vi can be
	considered to be a bug, or at least need improvement.  Therefore Vim
	behaves a little bit different here and there by default.  When the
	'compatible' option is set, all options are given a vi-compatible
	value,  Vim will behave like the "real" vi as much as possible.  The
	'cpoptions' option can be used to set vi compatibility on/off for a
	few specific items.				|'cpoptions'|

Support for different systems.
	Vim can be used on:
	- All Unix systems (it works on all systems it was tested on).
	- Amiga (500, 1000, 1200, 2000, 3000, 4000, ...).
	- MS-DOS in real-mode (no additional drivers required).
	- In protected mode on Windows 3.1 and MS-DOS (DPMI driver required).
	- Windows 95 and Windows NT, with support for long file names.
	- OS/2 (needs emx.dll)
	- Atari MiNT
	- Macintosh (although there is no binary available, needs some work)

Multi level undo.					|undo|
	'u' goes backward in time, 'ctrl-R' goes forward again.  Set option
	'undolevels' to the number of changes to be remembered (default 1000).
	Set 'undolevels' to 0 for a vi-compatible one level undo. Set it to
	-1 for no undo at all.

	When all changes in a buffer have been undone, the buffer is not
	considered changed anymore.  You can exit it with :q, without <!>.

Multiple windows and buffers.				|vim_win.txt|
	Vim can split the screen into several windows, each editing a
	different buffer or the same buffer at a different location.  Buffers
	can still be loaded (and changed) but not displayed in a window.  This
	is called a hidden buffer.  Many commands and options have been added
	for this facility.

Repeat a series of commands.				|q|
	'q'<c> starts recording typed characters into named register <c>
	(append to the register if register name is upper case).  A subsequent
	'q' stops recording.  The register can then be executed with the
	'@'<c> command.  This is very useful to repeat a complex action.

Flexible insert mode.					|ins_special_special|
	The arrow keys can be used in insert mode to move around in the file.
	This breaks the insert in two parts as far as undo and redo is
	concerned.

	CTRL-O can be used to execute a single command-mode command.  This is
	almost the same as hitting <Esc>, typing the command and hitting 'a'.

Visual mode.						|Visual_mode|
	Visual can be used to first highlight a piece of text and then give a
	command to do something with it.  This is an (easy to use) alternative
	to first giving the operator and then moving to the end of the text
	to be operated upon.  'v' and 'V' are used to start Visual mode.  'v'
	works on characters and 'V' on lines.  Move the cursor to extend the
	Visual part.  It is shown highlighted on the screen.  By typing 'o'
	the other end of the Visual text can be moved.  The Visual text can
	be affected by an operator:
		d	delete
		c	change
		y	yank
		> or <	insert or delete indent
		!	filter through external program
		=	filter through indent
		:	start ":" command for the Visual lines.
		Q	format text to 'textwidth' columns (obsolete)
		gq	format text to 'textwidth' columns
		J	join lines
		~	swap case
		u	make lowercase
		U	make uppercase

Block operators.					|visual_block|
	With Visual a rectangular block of text can be selected.  Start Visual
	with CTRL-V.  The block can be deleted ('d'), yanked ('y') or its case
	can be changed ('~', 'u' and 'U').  A deleted or yanked block can be
	put into the text with the 'p' and 'P' commands.

Online help system.					|:help|
	Help is displayed in a window.  The usual commands can be used to
	move around, search for a string, etc.  Tags can be used to jump
	around in the help files, just like hypertext links.  The ":help"
	command takes an argument to quickly jump to the info on a subject.
	<F1> is the quick access to the help system.  The name of the help
	index file can be set with the 'helpfile' option.

Command-line editing and history.			|cmdline_editing|
	You can insert or delete at any place in the command-line using the
	cursor keys.  The right/left cursor keys can be used to move
	forward/backward one character.  The shifted right/left cursor keys
	can be used to move forward/backward one word.  CTRL-B/CTRL-E can be
	used to go to the begin/end of the command-line.

							|cmdline_history|
	The command-lines are remembered.  The up/down cursor keys can be used
	to recall previous command-lines.  The 'history' option can be set to
	the number of lines that will be remembered.  There is a separate
	history for commands and for search patterns.

Command-line completion.				|cmdline_completion|
	While entering a command-line (on the bottom line of the screen)
	<Tab> can be typed to complete
	   what		example
	- command	:e<Tab>
	- tag		:ta scr<Tab>
	- option	:set sc<Tab>
	- option value  :set hf=<Tab>
	- filename	:e ve<Tab>
	- etc.

	If there are multiple matches, CTRL-N (next) and CTRL-P (previous)
	will walk through the matches.  <Tab> works like CTRL-N, but wraps
	around to the first match.

	The 'wildchar' option can be set to the character for command-line
	completion, <Tab> is the default.  CTRL-D can be typed after an
	(incomplete) wildcard; all matches will be listed.  CTRL-A will insert
	all matches.  CTRL-L will insert the longest common part of the
	matches.

Horizontal scrolling.					|'wrap'|
	If the 'wrap' option is off, long lines will not wrap and only part
	of them will be shown.  When the cursor is moved to a part that is not
	shown, the screen will scroll horizontally.  The minimum number of
	columns to scroll can be set with the 'sidescroll' option.  The "zh"
	and "zl" commands can be used to scroll sideways.

Text formatting.					|formatting|
	The 'textwidth' option can be used to automatically limit the line
	length.  This supplements the 'wrapmargin' option of Vi, which was not
	very useful.  The "gq" operator can be used to format a piece of text
	(for example, "gqp" formats the current paragraph).  Commands for text
	alignment: ":center", ":left" and ":right".

Edit-compile-edit speedup.				|quickfix|
	The ":make" command can be used to run the compilation and jump to
	the first error.  Alternatively Vim can be started with the "-e"
	option from the compiler.  A file with compiler error messages is
	interpreted.  Vim starts editing at the first error.

	Each line in the error file is scanned for the name of a file, line
	number and error message.  The 'errorformat' option can be set to a
	list of scanf-like strings to handle output from many compilers.

	The ":cn" command can be used to jump to the next error.
	":cl" lists all the error messages.  Other commands are available
	(almost the same as with Manx's Z editor on the Amiga).
	The 'errorfile' option has the name of the file with error messages.
	The 'makeprg' option contains the name of the program to be executed
	with the ":make" command.
	The 'shellpipe' option contains the string to be used to put the
	output of the compiler into the errorfile.

Improved indenting for C programs			|'cindent'|
	When the 'cindent' option is on the indent of each line is
	automatically adjusted.  C syntax is mostly recognized.  The indent
	for various styles can be set with 'cinoptions'.  The keys to trigger
	indenting can be set with 'cinkeys'.

	Comments can be automatically formatted.  The 'comment' option can be
	set to the characters that start and end a comment.  This works best
	for C code, but also works for e-mail (">" at start of the line) and
	other types of text.  The "=" operator can be used to re-indent
	lines.

Searching for words in include files			|include_search|
	The "[i" command can be used to search for a match of the word under
	the cursor in the current and included files.  The 'include' option
	can be set the a pattern that describes a command to include a file
	(the default is for C programs).
	The "[I" command lists all matches, the "[ CTRL-I" command jumps to
	a match.
	The "[d", "[D" and "[ CTRL-D" commands do the same, but only for
	lines where the pattern given with the 'define' option matches.

Word completion in Insert mode				|ins_completion|
	In insert mode "CTRL-N" and "CTRL-P" can be used to find match with
	the word before the cursor.  This is useful to complete long words.
	"CTRL-X CTRL-I" can be used to complete the word before the cursor
	from the current and included files.
	"CTRL-X CTRL-K" can be used to complete the word before the cursor
	from a dictionary file, given with the 'dictionary' option

Automatic commands					|autocommand|
	Commands can be automatically executed when reading a file, writing a
	file, jumping to another buffer, etc., depending on the file name.
	This is useful to set options and mappings for C programs,
	documentation, plain text, e-mail, etc.  This also makes it possible
	to edit compressed files.

Viminfo							|viminfo_file|
	The command-line history, marks and registers can be stored in a file
	that is read on startup.  This can be used to repeat a search command
	or command-line command after exiting and restarting Vim.  It is also
	possible to jump right back to where the last edit stopped with "'0".
	The 'viminfo' option can be set to select which items to store in the
	.viminfo file.  This is off by default.

Mouse support						|mouse_using|
	The mouse is supported in the GUI version, in an xterm for Unix, for
	MS-DOS, and Win32.  It can be used to position the cursor, select the
	visual area, paste a register, etc.

Graphical User Interface (GUI)				|gui|
	Included support for GUI: menu's, mouse, scrollbars, etc.  You can
	define your own menus.  Better support for CTRL/SHIFT/ALT keys in
	combination with special keys and mouse.  Currently only with Motif
	and Athena interface.


IMPROVEMENTS FROM VERSION 3.0 TO VERSION 4.0
============================================

Besides the big changes mentioned here there are an awful lot of small
improvements.  For a more complete list see |new_features|.

New on-line help system					|new_help|
	Help is now displayed in a window.
	Tags can be used to jump around in all the documentation (like
	hypertext links).

Command-line editing improved				|new_commandline|
	Separate history for search commands.
	Improved command-line completion.

Improved indenting for C programs			|new_cindent|
	Added 'cindent' option for configurable C indent mode.
	The "=" operator can be used to indent lines.
	Formatting of comments (also for other languages and e-mail).

Searching for words in include files			|new_include|
	Added commands to search for a word in the current file and in
	included files.
	List the first match, list all matches or jump to a match.

Word completion in Insert mode				|new_complete|
	Added commands to complete the word before the cursor in Insert mode.
	Matches can be found in the current file, included files and/or a
	dictionary.

Automatic commands					|new_autocmd|
	Execute commands for a specific file type.
	Can be used to set options to a different value for C code, plain
	text e-mail, etc.

Text objects						|new_textobj|
	After an operator and in visual mode text object commands can be used
	to quickly select a word, line or paragraph.

Options							|new_options|
	Added '&' after an option: reset to default value.
	Added '!' after a boolean option: invert value.
	A whole bunch of new options.
	Command-line completion can be used to get the old value.

Support for editing one-line paragraphs			|new_para|
	When a line is longer than the window width, it can be broken at a
	space or other convenient position.
	Commands have been added to move the cursor a screen line up/down.

Usage of key names					|new_keys|
	Special keys now all have a name like <Up>, <End>, etc.
	This name is used for mappings, in listings, and many other things.
	Added a number of new special keys.

Viminfo							|new_viminfo|
	The command-line history, marks and registers can be stored in a file
	that is read on startup.

Compilation improvements				|compilation|
	Autoconf is used to adjust to different Unix flavors, editing the
	Makefile is rarely required.

Tag support improved					|new_tags|
	Static tags and Emacs tag files are now supported.
	Tag completion works better.

Improved (error) messages				|new_msg|
	A lot of error messages include the reason for the error.
	The text shown when 'showcmd' is set includes partially typed
	mappings.

Swap file						|new_swapfile|
	Included checking of the actual file name in a swap file, avoids
	giving bogus "swap file exists" messages.
	Give more information about the swap file with the "swap file exists"
	message and when recovering.
	Included catching of deadly signals for Unix.  Swap files for
	unmodified buffers are deleted, other swap files are preserved before
	exiting.
	Improved recovery when there are multiple swap files.

Mouse support						|new_mouse|
	The mouse is supported in the GUI version, in an xterm for Unix, for
	MS-DOS, and Win32.  It can be used to position the cursor, select the
	visual area, paste a register, etc.

Graphical User Interface (GUI)				|new_gui|
	Included support for GUI: menu's, mouse, scrollbars, etc.  Currently
	only with Motif and Athena interface.

Support for Windows 95/NT				|new_win32|
	There is now a version of Vim for Windows NT and Windows 95.  It
	supports long file names, uses all available memory and many more
	enhancements.
	There is also a protected mode version, compiled with DJGPP, that
	runs under Windows 3.1 and MS-DOS.  It supports long file names where
	available.

Miscellaneous new features				|new_misc|
	Implemented incremental search.
	A whole bunch of commands that start with "g": Goto declaration, show
	ascii value of character under the cursor, go back to end of word,
	reselect last Visual area, etc..
	Added the ":retab" command.  Can be used to change the size of a
	<Tab>, replace spaces with a <Tab> or a <Tab> with spaces.
	Implemented "Vim -r" to list any swap files that can be found.
	The "Q" operator no longer affects empty lines.
	Added '-' register for deletes of less than one line, see |registers|.
	Quickfix: Support for several error formats at the same time.
	Added separate mapping for normal mode and visual mode.
	Allow for digraphs to be entered in reverse.
	Added commands to search for #if/#endif and start/end of comment.
	Added ":abclear" and ":mapclear": remove all abbreviations/mappings.
	Added check for last modification time of original file before
	overwriting it.

vi compatibility improvements				|vi_compat|
	A few more things have been made vi-compatible.
	The 'cpoptions' option has a few flags to switch specific
	vi-compatibility items on/off.


OLDER VIM FEATURES
==================

These features were already present in Vim version 3.0.


Vim arguments:

When Vim is started with "-v" (View) then readonly mode is used (includes
"-n").

When Vim is started with "-b" (Binary) then some options are set to be able
to edit binary or executable files.

When Vim is started with "-s scriptfile", the characters read from
"scriptfile" are treated as if you typed them.  If end of file is reached
before the editor exits, further characters are read from the console.

The "-w" option can be used to record all typed characters in a script file.
This file can then be used to redo the editing, possibly on another file or
after changing some commands in the script file.

The "-n" option disables the writing of a ".swp" file (see below).

The "-c command" option does the same as the "+command" option.

The "-T terminal" option sets the terminal type.

The "-e" option starts Vim in quickfix mode.

The "-o" option opens a window for each argument.  "-o4" opens four windows.


In command mode:

Missing command: "Q" (go to Ex mode) (but see |pseudo-Q|).
Missing Ex commands: append, change, insert, open and z.

The command characters are shown in the last line of the screen.  They are
removed when the command is finished.  If you do not want this (on a slow
terminal) reset the 'showcmd' option.

If the 'ruler' option is set, the current cursor position is shown in the
last line of the screen.

'u' and CTRL-R accept a count for the number of undos/redos.

'U' still works after having moved off the last changed line and after 'u'.

Nulls in the file are replaced with <NL> internally.  This allows editing of
binary files (more or less).

Characters with the 8th bit set are displayed.  The characters between '~' and
0xa0 are displayed as "~?", "~@", "~A", etc., unless the "graphic' option is
set.

'=' is an operator to filter lines through an external command (vi: lisp
stuff).  The name of the command can be set with the 'equalprg' option.  The
default is "indent".

'][' goes to the next ending of a C function ('}' in column 1).
'[]' goes to the previous ending of a C function ('}' in column 1).

']f', '[f' and 'gf' start editing the file whose name is under the cursor.
CTRL-W f splits the window and starts editing the file whose name is under
the cursor.

'*' searches forward for the identifier under the cursor, '#' backward.
'K' runs the program defined by the "keywordprg" option, with the identifier
under the cursor as argument.

'%' can be preceded with a count.  The cursor jumps to the line that
percentage down in the file.  The normal '%' function to jump to the matching
brace skips braces inside quotes.

With the CTRL-] command, the cursor may be in the middle of the identifier.

The used tags are remembered.  Commands that can be used with the tag stack
are CTRL-T, ':pop' and ':tag'.  ':tags' lists the tag stack.

The 'tags' option can be set to a list of tag file names.  Thus multiple
tag files can be used.  For file names that start with '.', the '.' is
replaced with the path of the current file.  This makes it possible to use a
tags file in the same directory as the file being edited.

Previously used file names are remembered in the alternate file name list.
CTRL-^ accepts a count, which is an index in this list.

Search patterns have more features.  The <NL> character is seen as part of the
search pattern and the substitute string of ":s".  Vi sees it as the end of
the command.

Searches can put the cursor on the end of a match and may include a character
offset.

Count added to '~', ':next', ':Next', 'n' and 'N'.

The command ":next!" with 'autowrite' set does not write the file.  In vi the
file was written, but this is considered to be a bug, because one does not
expect it and the file is not written with ':rewind!'.

"5r<CR>" replaces five characters with five line breaks.  Vi replaces five
characters with a single line break.

In Vi when entering a <CR> in replace mode deletes a character only when 'ai'
is set (but does not show it until you hit <Esc>).  Vim always deletes a
character (and shows it immediately).

Added :wnext command.  Same as ":write" followed by ":next".

The ":w!" command always writes, also when the file is write protected.

If option "tildeop" has been set, '~' is an operator (must be followed by a
movement command).

With the 'J' (join) command you can reset the 'joinspaces' (js) option to
have only one space after a period (Vi inserts two spaces).

'cw' can be used to change white space formed by several characters (Vi is
confusing: 'cw' only changes one space, while 'dw' deletes all white space).

'o' and 'O' accept a count for repeating the insert (Vi clears a part of
display).

':dis' command shows the contents of the yank registers.

Previously used file names are remembered in the alternate file name list.
":files" command shows the list of alternate filenames.
'#'<N> is replaced with the <N>th alternate filename in the list.
"#<" is replaced with the current filename without extension.

Flags after command not supported (no plans to include it).

On non-UNIX systems ":cd" command shows current directory instead of going to
the home directory.  ":pwd" prints the current directory on all systems.

':source!' command reads Vi commands from a file.

':mkexrc' command writes current modified options and mappings to a ".exrc"
file.  ':mkvimrc' writes to a ".vimrc" file.

No check for "tail recursion" with mappings.  This allows things like
":map! foo ^]foo".

When a mapping starts with number, vi loses the count typed before it (e.g.
when using the mapping ":map g 4G" the command "7g" goes to line 4).  This is
considered a vi bug.  Vim concatenates the counts (in the example it becomes
"74G"), as most people would expect.

The :put! command inserts the contents of a register above the current line.

The 'p' and 'P' commands of vi cannot be repeated with '.' when the putted
text is less than a line.  In Vim they can always be repeated.

The named register '.' can be used with commands p, P and :put.  The contents
of the register is the last inserted text.

":noremap" command can be used to enter a mapping that will not be remapped.
This is useful to exchange the meaning of two keys.  ":cmap", ":cunmap" and
":cnoremap" can be used for mapping in command-line editing only.  ":imap",
":iunmap" and ":inoremap" can be used for mapping in insert mode only.
Similar commands exist for abbreviations: ":noreabbrev", ":iabbrev"
":cabbrev", ":iunabbrev", ":cunabbrev", ":inoreabbrev", ":cnoreabbrev".

In vi the command ":map foo bar" would remove a previous mapping
":map bug foo".  This is considered a bug, so it is not included in Vim.
":unmap! foo" does remove ":map! bug foo", because unmapping would be very
difficult otherwise (this is vi compatible).

":@r" command executes register r (is in some versions of vi).

The ':' register contains the last command-line.
The '%' register contians the current file name.

CTRL-O/CTRL-I can be used to jump to older/newer positions.  These are the
same positions as used with the '' command, but may be in another file.  The
':jumps' command lists the older positions.

If the 'shiftround' option is set, an indent is rounded to a multiple of
'shiftwidth' with '>' and '<' commands.

The 'scrolljump' option can be set to the minimum number of lines to scroll
when the cursor gets off the screen.  Use this when scrolling is slow.

The 'scrolloff' option can be set to the minimum number of lines to keep
above and below the cursor.  This gives some context to where you are
editing.  When set to a large number the cursor line is always in the middle
of the window.

Uppercase marks can be used to jump between files.  The ':marks' command lists
all currently set marks.  The commands "']" and "`]" jump to the end of the
previous operator or end of the text inserted with the put command.  "'[" and
"`[" do jump to the start.

The 'shelltype' option can be set to reflect the type of shell used.

The 'highlight' option can be set for the higlight mode to be used for
several commands.

The CTRL-A (add) and CTRL-X (subtract) commands are new.  The count to the
command (default 1) is added to/subtracted from the number at or after the
cursor.  That number may be decimal, octal (starts with a '0') or hexadecimal
(starts with '0x').  Very useful in macros.

With the :set command the prefix "inv" can be used to invert toggle options.

In both Vi and Vim you can create a line break with the ":substitute" command
by using a CTRL-M.  For Vi this means you cannot insert a real CTRL-M in the
text.  With Vim you can put a real CTRL-M in the text by preceding it with a
CTRL-V.


In insert mode:

If the 'revins' option is set, insert happens backwards.  This is for typing
Hebrew.  When inserting normal characters the cursor will not be shifted and
the text moves rightwards.  Backspace, CTRL-W and CTRL-U will also work in
the opposite direction.  CTRL-B toggles the 'revins' option.  In replace mode
'revins' has no effect.

The backspace key can be used just like CTRL-D to remove auto-indents.

You can backspace, ctrl-U and CTRL-W over line breaks if the 'backspace' (bs)
option is set to non-zero.  You can backspace over the start of insert if the
'backspace' option is set to 2.

When the 'paste' option is set, a few option are reset and mapping in insert
mode and abbreviation are disabled.  This allows for pasting text in windowing
systems without unexpected results.  When the 'paste' option is reset, the old
option values are restored.

CTRL-T/CTRL-D always insert/delete an indent in the current line, no matter
what column the cursor is in.

CTRL-@ (insert previously inserted text) works always (Vi: only when typed as
first character).

CTRL-A works like CTRL-@ but does not leave insert mode.

CTRL-R <0-9a-z> can be used to insert the contents of a register.

When the 'smartindent' (si) option is set, C programs will be better
auto-indented.

CTRL-Y and CTRL-E can be used to copy a character from above/below the
current cursor position.

After CTRL-V you can enter a three digit decimal number.  This byte value is
inserted in the text as a single character.  Useful for international
characters that are not on your keyboard.

When the 'expandtab' (et) option is set, a <Tab> is expanded to the
appropriate number of spaces.

The window always reflects the contents of the buffer (Vi does not do this
when changing text and in some other cases).

If Vim is compiled with DIGRAPHS defined, digraphs are supported.  A set of
normal Amiga digraphs is included.  They are shown with the :digraph" command.
More can be added with ":digraph {char1}{char2} {number}".  A digraph is
entered with "CTRL-K {char1} {char2}" or "{char1} BS {char2}" (only when
'digraph' option is set).

When repeating an insert, e.g. "10atest <Esc>" vi would only handle wrapmargin
for the first insert.  Vim does it for all.

A count to the 'i' or 'a' command is used for all the text.  Vi uses the count
only for one line.  "3iabc<NL>def<Esc>" would insert "abcabcacc<NL>def" in Vi
but "abc<NL>defabc<NL>defabc<NL>def" in Vim.


In Command-line mode:

<Esc> terminates the command-line without executing it. In vi the command
line would be executed, which is not what most people expect (hitting <Esc>
should always get you back to command mode).  To avoid problems with some
obscure macros, an <Esc> in a macro will execute the command.  If you want a
typed <Esc> to execute the command like vi does you can fix this with
	":cmap ^V<Esc> ^V<CR>"

general:

Missing options: autoprint (ap), beautify (bf), hardtabs (ht), lisp, mesg,
open, optimize (op), prompt, redraw, slowopen (slow), window, w300, w1200 and
w9600.  These options can be set but are otherwise ignored.

When the 'compatible' option is set, all options are set for maximum
vi-compatibility

The 'ttimeout' option is like 'timeout', but only works for cursor and
function keys, not for ordinary mapped characters.  The 'timoutlen' option
gives the number of milliseconds that is waited for.  If the 'esckeys' option
is not set, cursor and function keys that start with <Esc> are not recognized
in insert mode.

There is an option for each terminal string.  Can be used when termcap is not
supported or to change individual strings.

When the 'textmode' option is set (default for MS-DOS, OS/2, and Win32)
<CR><NL> is used as line separator.  When reset (default for Unix and Amiga)
<NL> is used.  When the 'textauto' option is set, Vim tries to detect the
type of line separator used by reading up to the first <NL>.  The 'textmode'
option is set accordingly.

On systems that have no job control (older Unix systems and non-Unix systems)
the CTRL-Z, ":stop" or ":suspend" command starts a new shell.

If Vim is started on the Amiga without an interactive window for output, a
window is opened (and :sh still works).  You can give a device to use for
editing with the '-d' argument, e.g. "-d con:20/20/600/150".

On startup the VIMINIT or EXINIT environment variables, the file s:.vimrc or
s:.exrc and .vimrc or .exrc are read for initialization commands.  When
reading .vimrc and .exrc some commands are not allowed because of security
reasons (shell commands and writing to a file, :map commands are echoed).
This can be overrided with the 'secure' option.

Line length can be at least up to the maximum value of an int (for the Amiga
32767 characters, for most 32-bit systems much larger).  Editing such lines
is not always possible.  File length up to 2147483646 lines.  If a line is
larger than the screen, the last line is filled with <@>s and only the part
of the line before that is shown (unless 'wrap' option is reset).

The 'columns' option is used to set or get the width of the display.

The name of the current file name is shown in the title bar of the window.

Wildcards in file names are expanded.

Option settings are read from the first and last few lines of the file.
Option 'modelines' determines how many lines are tried (default is 5).  Note
that this is different from the Vi versions that can execute any Ex command
in a modeline (a major security problem).

If the 'insertmode' option is set (e.g. in .exrc), Vim starts in insert mode.

All text is kept in memory.  Available memory limits the file size (and other
things such as undo).  This may be a problem with MS-DOS, is hardly a problem
on the Amiga and almost never with Unix and Win32.

If the 'backup' or 'writebackup' option is set: Before a file is overwritten,
a backup file (.bak) is made.  If the "backup" option is set it is left
behind.

If the 'binary' option is set and the file does not have an end-of-line for
the last line, the end-of-line is not appended when writing.

Vim creates a file ending in ".swp" to store parts of the file that have been
changed or that do not fit in memory.  This file can be used to recover from
an aborted editing session with "vim -r file".  Using the swap file can be
switched off by setting the 'updatecount' option to 0 or starting Vim with
the "-n" option.  Use the 'directory' option for placing the .swp file
somewhere else.

The 'shortname' (sn) option, when set, tells Vim that ".bak" and ".swp"
filenames are to be MS-DOS-like: 8 characters plus 3 for extention.  This
should be used on messydos or crossdos filesystems on the Amiga.  If this
option is off, Vim tries to guess if MS-DOS filename restrictions are
effective.

Error messages are shown at least one second (Vi overwrites error messages).

If Vim asks to "Hit RETURN to continue", you can hit any key.  Characters
other than <CR>, <NL> and <Space> are interpreted as the (start of) a
command.  (Vi only accepts a command starting with ':').

The contents of the numbered and unnamed registers is remembered when
changing files.

The "No lines in buffer" message is a normal message instead of an error
message, since that may cause a mapping to be aborted.

The AUX: device of the Amiga is supported.

 vim:tw=77:js:
