Remove a word in vim

• First install Vim.

• To install the packages, first install ‘vundle’ using following command. Use ‘git-shell’ to run this command in Windows.

  git clone https://github.com/VundleVim/Vundle.vim.git ~/.vim/bundle/Vundle.vim
  
  (in Windows : use 'git-shell' to run below command)
  git clone https://github.com/VundleVim/Vundle.vim.git C:/Users/<Username>/.vim/bundle/Vundle.vim
  

• Copy and paste the .vimrc file in the home directory.

• In Windows, paste in the .vimrc file at C:/Users/<Username>/; and change the line “set rtp+= …” in .vimrc with correct location of “Vundle.vim” i.e. “set rtp+=C:/Users/<Username>/.vim/bundle/Vundle.vim”.

• Use double quote to comment/uncomment the packages in .vimrc file e.g. ” Plugin ‘mattn/emmet-vim’ will not install the package “emmet-vim”. Or add some more packages in .vimrc file as required.

• After selecting the packages, open vim and run the command -> :PluginInstall and it will install the all the plugins.

• Use :help <plugin name> to see the list of operations.

1.1. Starting Vim¶

Commands	Descriptions
:w	save file
:w <filename>	save file as <filename> and keep the current file open
:sav <filename>	save file as <filename> and open <filename>
:q	quit (if already saved)
:q!	quit without saving
:e <filename>	open new/existing <filename> in new buffer
:wq	save and quit
:bn	go to next buffer i.e. file
:b <filename>	go to buffer with <filename>
:bd	close current file without exiting vim
:bd!	close current file without exiting vim and ‘no modification’
:vim *	open all files in the directory (all in same buffer)
:vim file1 file2 file3	open file1, file2 and file3 in vim
:n	go to next file
:n <filename>	go to file name
:prev	go to previous file
ctrl-Z	suspend vim
fg	bring forground vim

1.2. Undo/Redo¶

Commands	Descriptions
u	undo
crtl-r	redo

1.3. Insert¶

Commands	Descriptions
i	insert mode at cursor
I	insert mode at beginning of the line (i.e. first character of line)
s	delete character under the cursor and enter into insert mode
S	delete the line and go to insert mode from the beginning of same line
a	insert mode after the cursor
A	insert mode at the end of line
o	insert mode on below line
O	insert mode at bottom line
C	delete from cursor to end of line and go to insert mode
r	replace current character
R	replace characters until Esc is pressed (i.e. same as insert button in keyboard)

1.4. Copy/Paste/Delete¶

Commands	Descriptions
y	yank (copy)
yiw	copy the word
yw	copy the word after the cursor
yy or Y	copy the line
y$	copy till end of the line from current location of cursor
“+y	copy to clipboard e.g. “+yiw will copy the word in clipboard
<F3>y	same as above (use <F3> for clipboard, remapped in .vimrc)
<F3>p	paste from clipboard (see above line as well)
p	paste after cursor (remapped as ]p in .vimrc )
]p	paste with indentation
P	paste before cursor
ctrl-P	paste from clipboard (remapped in .vimrc)
shift insert	paste from clipboard (remapped in .vimrc)
d<command>	delete<command>
diw	delete word (and stay at normal mode)
ciw	delete word (and go to insert mode)
dw or cw	delete word after the cursor
dd or cc	delete line
D or C	delete till end of line
x	delete character (delete)
X	delete character (backspace)
.	repeat previous operation

1.5. Paste in search or colon commands¶

• Following commands can be used at command mode during search or color commands e.g. :w ctrl r ctrl w etc.

Commands	Descriptions
ctrl r “	paste the last copied data
ctrl r ctrl w	paste the word under cursor
ctrl r %	print the naem of current file
shift insert	paste the data from clipboard

1.6. Search¶

Commands	Descriptions
/	forward then use n/N for next/previous match
?	backward
* (asterisk)	word under cursor forward (exact match)
g*	word under the cursor (partial match)
#	word under cursor backward (exact match)
g#	word under cursor backward (partial match)
/<word1>	search for exact match for “word1”
:set ignorecase	use this option for avoiding case-matches
:set noignorecase	use this option for case-matches

1.7. Replace¶

• Use ‘c’, ‘g’, ‘gc’ and other combination to perform the desired replacement.

Commands	Descriptions
:s /word1/word2	substitute word1 with word2 in current line (only first occurrence)
:s /word1/word2/c	substitute word1 with word2 in current line after confirmation (only first occurrence)
:s /word1/word2/g	substitute word1 with word2 in current line (all occurrence)
:s /word1/word2/gc	substitute word1 with word2 in current line ater confirmation (all occurrence)
:1,4 s /word1/word2	substitute word1 with word2 in lines 1 to 4 (only first occurrence in each line)
:%s /word1/word2/g	replace all occurrences
:%s /word1/word2/gc	replace all occurrence after confirmation
:%s /ctrl-r ctrl-w/word2/gc	replace all occurance of the word under cursor after confirmation (exact match)
:s /<word1>/word2	substitute exactly matched “word1” with word2 in current line

1.8. Indentation¶

Commands	Descriptions
>>	Right indent the current line
5>>	Right indent 5 lines
<<	De-indent line
5==	Re-indent 5 lines
>%	Increase indent of a braced or bracketed block (place cursor on brace first)
=%	Reindent a braced or bracketed block (cursor on brace)
<%	Decrease indent of a braced or bracketed block (cursor on brace)
]p	Paste text, aligning indentation with surroundings
=i{	Re-indent the ‘inner block’, i.e. the contents of the block
=a{	Re-indent ‘a block’, i.e. block and containing braces
>i{	Increase inner block indent
<i{	Decrease inner block indent

Commands	Descriptions
:retab	convert existing tabs to spaces

1.9. Mouse settings¶

Commands	Descriptions
:behave mswin	mouse functionality will work as windows
:behave xterm	mouse functionality will word as x-windows

1.10. Command/Visual Mode¶

Commands	Descriptions
Esc or crtl-[	command mode
v	visual mode
crtl-v	visual block mode

1.11. Cursor movement¶

Note

To run the ‘ctrl-]’ and ‘ctrl-T’ command, we need to create the tags first. In the below command, the ‘tags’ will be created for all the python files in the directory, which will be stored in a file ‘tags’,

(run the following command in shell)
ctags -R *.py

Commands	Descriptions
h	left
j	down
k	up
l	down
w	forward to the beginning of next word
3w	forward 3 words
W	forward to the beginning of next word (only spaces are the end of word)
b	backward to the beginning of next word
B	backward to the beginning of next word (only spaces are the end of word)
e	forward to end of next word
E	forward to end of next word (only spaces are the end of the word)
gg	go to first line of page
G	go to end line of page
10G	go to 10th line
10gg	go to 10th line
0	go to first character of line
$	go to end character of line
^	go to first non-black character of line
M	go to middle of the screen
fa	go to next a in current line
Fa	go to previous a in current line
ta	go to end of next a in current line
Ta	to to end of previous a in current line
ctrl-o	go to previous location e.g. we went to line 10 from line 18, ctrl-o will go to line 18 again
ctrl-i or Tab	go to next location i.e. go to line 10 again from line 18.
gd	go to the local declaration of the word under cursor
gD	go to the global declaration of the word under cursor
g*	search for the word under the cursor
g#	same as g* but in backward direction.
gf	go to the filename under the cursor, use ctrl-o to go back
ctrl-]	go to tag definition (a tag can be a function or variable name etc.); use ctrl-o to go back
ctrl-T	go back to previous loation from where ctrl-] was exectued

1.12. Screen movements¶

Commands	Descriptions
ctrl-d	move half screen down
ctrl-f	page down
ctrl-e	move one line down
ctrl-u	move half screen up
ctrl-b	page up
ctrl-y	move one line up
z<Enter>	move current line to the top of screen (with cursor at the beginning)
zt	move current line to the top with without changing the location of cursor
	move current line to the center of screen (with cursor at the beginning)
zz	move current line to the center of screen (without moving cursor)
z-	move current line to the center of screen (with cursor at the beginning)
zb	move current line to the center of screen (without moving cursor)

1.13. Unix Shell¶

Commands	Descriptions
:shell	go to unix shell
exit	type exit in unix shell to come back in Vim

1.14. Registers¶

Commands	Descriptions
“ayy	copy line in register ‘a’
“ap	paste content of register ‘a’
Capital letters append the new value to previously stored values
“Ayy	copy line and append to previous value in register “a” Then use “a to paste the value in register ‘a’
“=3*2<Enter>p	paste the result i.e. 6 at the current cursor location
:registers	display the values in all the registers
:registers abc	display the values of registers a, b and c

1.15. Multiple Files¶

Commands	Descriptions
:arg grep -l ‘import’ *.py	open all files in current folder which contains word ‘import’

1.16. Mark¶

Commands	Descriptions
ma	mark the line with name ‘a’ (use a-z or 0-9)
	Next go to some other line and excute following command
d’a	delete till line which is marked as ‘a’
:marks	show the list of marks
‘a	go to mark a

1.17. Sorting¶

Commands	Descriptions
!10G (press enter) sort (press enter)	it will sort first ten lines according to name
!G (press enter) sort (press enter)	it will sort all the lines according to names
!!ls	go to terminal, run ls command and print the output on the file (i.e. print list of file in current directory)
!!dates	go to terminal, run date command and print the output on the file

1.18. Printing the code¶

Commands	Descriptions
:hardcopy <filename.pdf>	open the printing-instructions-window
:TOhtml and then save the file	Save in html format, use :colorscheme default for white background

1.19. Mapping¶

• Please read the comments in .vimrc file for more commands and details
• comment/uncomment the command using double quote as per requirement.

Commands	Descriptions
:map	display the key-mappings,

1.19.1. Copy/paste from clip board¶

Use <F3> and then normal copy/paste command from clipboard.

Copy/paste to clip board
<F3> is remapped	nnoremap <F3> “+
<ctrl-P> is remapped	nnoremap <C-P> “+]p (paste with indentation)
<F3>yiw or <F3>yy etc.	copy the word or line etc. in clipboard
<F3>p	paste the data from clipboard

1.19.2. Disable arraow keys¶

Below code can be used in .vimrc file

“Key mappings : disable arrow keys
no <left> <Nop>
no <down> <Nop>
no <up> <Nop>
no <right> <Nop>
ino <down> <Nop>
ino <left> <Nop>
ino <right> <Nop>
ino <up> <Nop>

1.19.3. Code execution¶

“python commands
” Execute : F9 (Below code is used in .vimrc file)
:autocmd FileType python :nmap <F9> :! clear <CR> :! python % <Enter>

“C/C++ commands
“Compile : F9 (Below code is used in .vimrc file)
:autocmd FileType c,cpp :nmap <F9> :! rm -r out <CR> :! clear <CR> :! g++ % -o out <Enter>
“Run : Ctrl+F9 (Below code is used in .vimrc file)
:autocmd FileType c,cpp :nmap <C-F9> :! clear <CR> :! ./out <CR>

1.20. Buffer¶

Commands	Descriptions
:bn	go to next buffer i.e. file
:b <filename>	go to buffer with <filename>
:bd	close current file without exiting vim
:bd!	close current file without exiting vim and ‘no modification’

1.21. Split windows¶

Commands	Descriptions
:split	split window in two part and display current file in both window
:split <filename>	open <filename> in split window
:5 split <filename>	open <filename> in new split window with width of 5 line
:new	split window in two part with second window as blank
crtl-w j	go to below split window
crtl-w k	go to above split window
crtl-ww, crtl-w w	go to next split window
crtl-w +	increase the width of split window by one line
5 crtl-w —	decrease the width of split window by 5 line
crtl-w =	make all split window of equal size
crtl-w _	maximize the current split window

1.22. Auto completion¶

Commands	Descriptions
ctrl-p,ctrl-n	auto complete by looking previous/next words (use ctrl-p or ctrl-n to change the words from list)

1.23. Text files¶

Commands	Descriptions
:set textwidth=50	change the line after 50 character
:1,5 center 50	textwidth = 50 and center the lines 1 to 5
:1,5 right 50	textwidth = 50 and right justify the text on lines 1 to 5
:1,5 left 4	left margin = 4 for lines 1 to 5
Use $ for end of the line as shown below,
:1,$ center 50	textwidth=50 and cneter all the line
or use % sign for the file (results is same as above,
:% center 50
:set wrap	turn the wrap words on
:set nowrap	turn off the wrap words

1.24. Macros¶

Commands	Descriptions
qa	start recording and store in reg ‘a’. Then perform certain operations. press ‘q’ again to stop recording.
@a	execute macro
3@a	repeat macro 3 times

1.25. More commands¶

Commands	Descriptions
ctrl + g	name of current file
ctrl + u	move half screen up
ctrl + d	move half screen down
J	join line below with current line
3J	join below two line with this line (not 3)
z=	spell suggestion
~	change case of letter
:digraphs	to see the list of symbols e.g. copyright etc.

1.26. Block Visual Mode¶

Add same items in the beginning/end/middle of all the lines

Commands	Descriptions
crtl-v	select the block with cursor movement
press I (insert before) or A (insert after) or c (replace)	type the text -> press Esc -> block will be replaces by text

1.27. Zoom Screen¶

Commands	Descriptions
Zoom in	crtl-+
Zoom out	ctrl–

1.28. Save session¶

Commands	Descriptions
:mksession name.vim	save session
:mksession! name.vim	override session
:source name.vim	load session

1.29. Folding¶

Use space (remapped in .vimrc) at the line below the function definition for folding/unfolding the code.

1.30. Plugins¶

First install ‘vundle’ using following command. Use ‘git-shell’ to run this command in Windows.

• git clone https://github.com/VundleVim/Vundle.vim.git ~/.vim/bundle/Vundle.vim
• After that copy and paste the .vimrc file in the home directory (in Windows paste in the director C:/Users/<Username>/)
• Use double quote to comment/uncomment” the packages in .vimrc file e.g. ” Plugin ‘mattn/emmet-vim’ will not install the package “emmet-vim”. Or add some more packages in .vimrc file as required.
• After selecting the packages, open vim and run the command -> :PluginInstall and it will install the all the plugins.
• Use :help <plugin name> to see the list of operations.

1.30.1. NERDTree¶

Commands	Descriptions
NERDTree	turn on the directory structure
NERDTree!	disable the directory structure
m	then use various operations for delete, and create files.
e.g
m-a meher	create a file with name meher
m-a meher/	create a folder with name meher

1.30.2. Surround¶

Commands	Descriptions	Results
ysiw”	add “” to the word	Meher -> “Meher”
ds”	delete surround quotes	“Meher” -> Meher
cs[( or cs])	change surround [] by ()	[2+3]/2 -> (2+3)/2
cst<h1>	change <p> tag to <h1>	<p>Meher Krishna</p> -> <h1>Meher Krishna</h1>

1.30.4. vim-table-mode¶

Follow the below steps to create the ‘rst-table’ in Vim,

• Enable/Disable table mode using ‘:TableModeEnable/TableModeDisable’ or using ‘:TableModeToggle’,
• Type column-names e.g. |Col1 | Col2| and press enter
• Then press | twice to create the table. Do the same to add more lines in the table.
• Also, go above the |Col1 | Col2| and press | twice (required for correct rst-table-format)

1.30.5. vim-extline¶

This is used to underline the text, which is required for making Headings in .rst document.

• Type the symbols (in insert mode) e.g. = and then press ctrl-l ctrl-l to complete it.
• Or press ctrl-l and then press the symbol,
• Or press ctrl-l and then press a number e.g. 1, 2 etc. This is autocomplete the underline base on heading levels.
• Some more commands are listed below,

Commands	Descriptions
ctrl-l ctrl-l	Auto-line update
ctrl-l ctrl-h	Horizontal line update
ctrl-l ctrl-u	Change to underlined title
ctrl-l ctrl-o	Change to overlined title
ctrl-l ctrl-i	Change to underlined and overlined title
ctrl-l = or = ctrl-l	Force Section heading (with = as underline)
ctrl-l 2	Force Section heading (level 2)

1.30.6. ConqureShell¶

Use :ConqueTermSplit to start the terminal in the Vim.

1.30.7. Airline¶

Airline theme plugin for better view e.g. display name of file, line number, column number etc.

Introduction

There are many ways to delete lines in Vim. This popular Linux text editor allows you to remove one, multiple, or specified patterns from a file using a single command.

In this tutorial, learn how to delete lines in Vim with multiple options by range or a pattern.

Options for Deleting Lines in Vim

Delete a Single Line

1. Press Esc to navigate through the file easily.

2. Move the cursor to the line you want to delete.

2. Delete the line by pressing one of the following commands:

dd

D

Delete a Single Word

1. Start by moving into command mode with Esc.

2. Place the cursor at the beginning of the word you want to remove.

3. Press the keys:

dw

Delete Multiple Lines

1. Press Esc.

2. Move the cursor to the first line you want to remove.

3. Use one of the following commands (replacing [#] with the number of lines):

[#]dd

d[#]d

In the example below, we deleted the following 3 lines:

After running the command, the file consists of the remaining lines:

Delete a Range of Lines

1. Use Esc to switch to normal mode in Vim.

2.Use the following command and replace [from] with the number of the line where you want the range to start and [to] where you want it to end:

:[from],[to]d

For instance, if you wanted to remove lines 4, 5, 6, and 7, you would use the command:

:4,7d

Once you press Enter, the specified lines are removed, as in the image below.

Delete All Lines

1. First, press Esc.

2. Then, delete everything within the file by typing:

:%d

3. Once you run this command, the text editor will notify you there are --No lines in buffer--.

Delete From Current Line to the End of File

1. Move the cursor to the first line you want to remove.

2. Ensure you are in command mode by pressing Esc.

3. Delete everything beyond that line with the command:

:.,$d

The following example shows you how it is done. According to the position of the cursor, the text will be removed after running the command.

The image below shows you the end result.

Delete From Current Line to the Beginning of File

1. Move the cursor to the last line you want to delete.

2. Press Esc (if you are not in command mode yet).

3. Delete everything from the current line to the top of the text by typing:

dgg

In this example, we deleted the text in the red box by moving the cursor to the last line we want removed.

After typing the command, the file removed these 6 lines.

Delete Lines According to Pattern

Vim allows you to delete lines that match a specified pattern. There are various ways you can use patterns to remove lines. Below you will find some of the most commonly used commands.

Remove Lines Containing a Specific Word

1. Firstly use Esc to move to normal mode.

2. Then, remove all the lines that contain a specific word by typing:

:g /word/d

Remove Lines that Don’t Contain a Specific Word

1. Navigate to command mode with Esc.

2. Remove the lines that do not contain a specific word with the command:

:g!/word/d

Delete All Blank Lines

1. To delete all blank lines first move to normal mode using the Esc key.

2. Then, type in the following:

:g/^$/d

Conclusion

After reading this article, you now have multiple options for deleting lines and words in Vim. Knowing these commands can help you speed up working with Vim, as you don’t require manually removing unwanted content.

Next, learn how to save and exit a file in Vim.

change.txt    For Vim version 9.0.  Last change: 2023 Feb 27


		  VIM REFERENCE MANUAL    by Bram Moolenaar


This file describes commands that delete or change text.  In this context,
changing text means deleting the text and replacing it with other text using
one command.  You can undo all of these commands.  You can repeat the non-Ex
commands with the "." command.

1. Deleting text		deleting
2. Delete and insert		delete-insert
3. Simple changes		simple-change  		changing
4. Complex changes		complex-change
   4.1 Filter commands		   filter
   4.2 Substitute		   :substitute
   4.3 Search and replace	   search-replace
   4.4 Changing tabs		   change-tabs
5. Copying and moving text	copy-move
6. Formatting text		formatting
7. Sorting text			sorting

For inserting text see insert.txt.

==============================================================================
1. Deleting text					deleting E470

["x]<Del>	or					<Del> x dl
["x]x			Delete [count] characters under and after the cursor
			[into register x] (not linewise).  Does the same as
			"dl".
			The <Del> key does not take a [count].  Instead, it
			deletes the last character of the count.
			See :fixdel if the <Del> key does not do what you
			want.  See 'whichwrap' for deleting a line break
			(join lines).

							X dh
["x]X			Delete [count] characters before the cursor [into
			register x] (not linewise).  Does the same as "dh".
			Also see 'whichwrap'.

							d
["x]d{motion}		Delete text that {motion} moves over [into register
			x].  See below for exceptions.

							dd
["x]dd			Delete [count] lines [into register x] linewise.

							D
["x]D			Delete the characters under the cursor until the end
			of the line and [count]-1 more lines [into register
			x]; synonym for "d$".
			(not linewise)
			When the '#' flag is in 'cpoptions' the count is
			ignored.

{Visual}["x]x	or					v_x v_d v_<Del>
{Visual}["x]d   or
{Visual}["x]<Del>	Delete the highlighted text [into register x] (for
			{Visual} see Visual-mode).

{Visual}["x]CTRL-H   or					v_CTRL-H v_<BS>
{Visual}["x]<BS>	When in Select mode: Delete the highlighted text [into
			register x].

{Visual}["x]X	or					v_X v_D v_b_D
{Visual}["x]D		Delete the highlighted lines [into register x] (for
			{Visual} see Visual-mode).  In Visual block mode,
			"D" deletes the highlighted text plus all text until
			the end of the line.

					:d :de :del :delete :dl :dp
:[range]d[elete] [x]	Delete [range] lines (default: current line) [into
			register x].
			Note these weird abbreviations:
			   :dl		delete and list
			   :dell	idem
			   :delel	idem
			   :deletl	idem
			   :deletel	idem
			   :dp		delete and print
			   :dep		idem
			   :delp	idem
			   :delep	idem
			   :deletp	idem
			   :deletep	idem

:[range]d[elete] [x] {count}
			Delete {count} lines, starting with [range]
			(default: current line cmdline-ranges) [into
			register x].

These commands delete text.  You can repeat them with the . command
(except :d) and undo them.  Use Visual mode to delete blocks of text.  See
registers for an explanation of registers.

An exception for the d{motion} command: If the motion is not linewise, the
start and end of the motion are not in the same line, and there are only
blanks before the start and there are no non-blanks after the end of the
motion, the delete becomes linewise.  This means that the delete also removes
the line of blanks that you might expect to remain. Use the o_v operator to
force the motion to be characterwise.

Trying to delete an empty region of text (e.g., "d0" in the first column)
is an error when 'cpoptions' includes the 'E' flag.

							J
J			Join [count] lines, with a minimum of two lines.
			Remove the indent and insert up to two spaces (see
			below).  Fails when on the last line of the buffer.
			If [count] is too big it is reduced to the number of
			lines available.

							v_J
{Visual}J		Join the highlighted lines, with a minimum of two
			lines.  Remove the indent and insert up to two spaces
			(see below).

							gJ
gJ			Join [count] lines, with a minimum of two lines.
			Don't insert or remove any spaces.

							v_gJ
{Visual}gJ		Join the highlighted lines, with a minimum of two
			lines.  Don't insert or remove any spaces.

							:j :join
:[range]j[oin][!] [flags]
			Join [range] lines.  Same as "J", except with [!]
			the join does not insert or delete any spaces.
			If a [range] has equal start and end values, this
			command does nothing.  The default behavior is to
			join the current line with the line below it.
			See ex-flags for [flags].

:[range]j[oin][!] {count} [flags]
			Join {count} lines, starting with [range] (default:
			current line cmdline-ranges).  Same as "J", except
			with [!] the join does not insert or delete any
			spaces.
			See ex-flags for [flags].

These commands delete the <EOL> between lines.  This has the effect of joining
multiple lines into one line.  You can repeat these commands (except :j) and
undo them.

These commands, except "gJ", insert one space in place of the <EOL> unless
there is trailing white space or the next line starts with a ')'.  These
commands, except "gJ", delete any leading white space on the next line.  If
the 'joinspaces' option is on, these commands insert two spaces after a '.',
'!' or '?' (but if 'cpoptions' includes the 'j' flag, they insert two spaces
only after a '.').
The 'B' and 'M' flags in 'formatoptions' change the behavior for inserting
spaces before and after a multibyte character fo-table.

The '[ mark is set at the end of the first line that was joined, '] at the end
of the resulting line.


==============================================================================
2. Delete and insert				delete-insert replacing

							R
R			Enter Replace mode: Each character you type replaces
			an existing character, starting with the character
			under the cursor.  Repeat the entered text [count]-1
			times.  See Replace-mode for more details.

							gR
gR			Enter Virtual Replace mode: Each character you type
			replaces existing characters in screen space.  So a
			<Tab> may replace several characters at once.
			Repeat the entered text [count]-1 times.  See
			Virtual-Replace-mode for more details.

							c
["x]c{motion}		Delete {motion} text [into register x] and start
			insert.  When  'cpoptions' includes the 'E' flag and
			there is no text to delete (e.g., with "cTx" when the
			cursor is just after an 'x'), an error occurs and
			insert mode does not start (this is Vi compatible).
			When  'cpoptions' does not include the 'E' flag, the
			"c" command always starts insert mode, even if there
			is no text to delete.

							cc
["x]cc			Delete [count] lines [into register x] and start
			insert linewise.  If 'autoindent' is on, preserve
			the indent of the first line.

							C
["x]C			Delete from the cursor position to the end of the
			line and [count]-1 more lines [into register x], and
			start insert.  Synonym for c$ (not linewise).

							s
["x]s			Delete [count] characters [into register x] and start
			insert (s stands for Substitute).  Synonym for "cl"
			(not linewise).

							S
["x]S			Delete [count] lines [into register x] and start
			insert.  Synonym for "cc" linewise.

{Visual}["x]c	or					v_c v_s
{Visual}["x]s		Delete the highlighted text [into register x] and
			start insert (for {Visual} see Visual-mode).

							v_r
{Visual}r{char}		Replace all selected characters by {char}.

							v_C
{Visual}["x]C		Delete the highlighted lines [into register x] and
			start insert.  In Visual block mode it works
			differently v_b_C.
							v_S
{Visual}["x]S		Delete the highlighted lines [into register x] and
			start insert (for {Visual} see Visual-mode).
							v_R
{Visual}["x]R		Currently just like {Visual}["x]S.  In a next version
			it might work differently.

Notes:
- You can end Insert and Replace mode with <Esc>.
- See the section "Insert and Replace mode" mode-ins-repl for the other
  special characters in these modes.
- The effect of [count] takes place after Vim exits Insert or Replace mode.
- When the 'cpoptions' option contains '$' and the change is within one line,
  Vim continues to show the text to be deleted and puts a '$' at the last
  deleted character.

See registers for an explanation of registers.

Replace mode is just like Insert mode, except that every character you enter
deletes one character.  If you reach the end of a line, Vim appends any
further characters (just like Insert mode).  In Replace mode, the backspace
key restores the original text (if there was any).  (See section "Insert and
Replace mode" mode-ins-repl).

						cw cW
Special case: When the cursor is in a word, "cw" and "cW" do not include the
white space after a word, they only change up to the end of the word.  This is
because Vim interprets "cw" as change-word, and a word does not include the
following white space.
{Vi: "cw" when on a blank followed by other blanks changes only the first
blank; this is probably a bug, because "dw" deletes all the blanks; use the
'w' flag in 'cpoptions' to make it work like Vi anyway}

If you prefer "cw" to include the space after a word, use this mapping: 
	:map cw dwi
Or use "caw" (see aw).

							:c :ch :change
:{range}c[hange][!]	Replace lines of text with some different text.
			Type a line containing only "." to stop replacing.
			Without {range}, this command changes only the current
			line.
			Adding [!] toggles 'autoindent' for the time this
			command is executed.
			This command is not supported in Vim9 script,
			because it is too easily confused with a variable
			name.

==============================================================================
3. Simple changes					simple-change

							r
r{char}			Replace the character under the cursor with {char}.
			If {char} is a <CR> or <NL>, a line break replaces the
			character.  To replace with a real <CR>, use CTRL-V
			<CR>.  CTRL-V <NL> replaces with a <Nul>.

			If {char} is CTRL-E or CTRL-Y the character from the
			line below or above is used, just like with i_CTRL-E
			and i_CTRL-Y.  This also works with a count, thus
			10r<C-E> copies 10 characters from the line below.

			If you give a [count], Vim replaces [count] characters
			with [count] {char}s.  When {char} is a <CR> or <NL>,
			however, Vim inserts only one <CR>: "5r<CR>" replaces
			five characters with a single line break.
			When {char} is a <CR> or <NL>, Vim performs
			autoindenting.  This works just like deleting the
			characters that are replaced and then doing
			"i<CR><Esc>".
			{char} can be entered as a digraph digraph-arg.
			:lmap mappings apply to {char}.  The CTRL-^ command
			in Insert mode can be used to switch this on/off
			i_CTRL-^.  See utf-8-char-arg about using
			composing characters when 'encoding' is Unicode.

							gr
gr{char}		Replace the virtual characters under the cursor with
			{char}.  This replaces in screen space, not file
			space.  See gR and Virtual-Replace-mode for more
			details.  As with r a count may be given.
			{char} can be entered like with r, but characters
			that have a special meaning in Insert mode, such as
			most CTRL-keys, cannot be used.

						digraph-arg
The argument for Normal mode commands like r and t is a single character.
When 'cpo' doesn't contain the 'D' flag, this character can also be entered
like digraphs.  First type CTRL-K and then the two digraph characters.
{not available when compiled without the |+digraphs| feature}

						case
The following commands change the case of letters.  The currently active
locale is used.  See :language.  The LC_CTYPE value matters here.

							~
~			'notildeop' option: Switch case of the character
			under the cursor and move the cursor to the right.
			If a [count] is given, do that many characters.

~{motion}		'tildeop' option: switch case of {motion} text.

							g~
g~{motion}		Switch case of {motion} text.

g~g~							g~g~ g~~
g~~			Switch case of current line.

							v_~
{Visual}~		Switch case of highlighted text (for {Visual} see
			Visual-mode).

							v_U
{Visual}U		Make highlighted text uppercase (for {Visual} see
			Visual-mode).

							gU uppercase
gU{motion}		Make {motion} text uppercase.
			Example: 
				:map! <C-F> <Esc>gUiw`]a
			This works in Insert mode: press CTRL-F to make the
			word before the cursor uppercase.  Handy to type
			words in lowercase and then make them uppercase.


gUgU							gUgU gUU
gUU			Make current line uppercase.

							v_u
{Visual}u		Make highlighted text lowercase (for {Visual} see
			Visual-mode).

							gu lowercase
gu{motion}		Make {motion} text lowercase.

gugu							gugu guu
guu			Make current line lowercase.

							g? rot13
g?{motion}		Rot13 encode {motion} text.

							v_g?
{Visual}g?		Rot13 encode the highlighted text (for {Visual} see
			Visual-mode).

g?g?							g?g? g??
g??			Rot13 encode current line.

To turn one line into title caps, make every first letter of a word
uppercase: 
	:s/v<(.)(w*)/u1L2/g


Adding and subtracting 
							CTRL-A
CTRL-A			Add [count] to the number or alphabetic character at
			or after the cursor.

							v_CTRL-A
{Visual}CTRL-A		Add [count] to the number or alphabetic character in
			the highlighted text.

							v_g_CTRL-A
{Visual}g CTRL-A	Add [count] to the number or alphabetic character in
			the highlighted text. If several lines are
		        highlighted, each one will be incremented by an
			additional [count] (so effectively creating a
			[count] incrementing sequence).
			For Example, if you have this list of numbers:
				1. 
				1. 
				1. 
				1. 
			Move to the second "1." and Visually select three
			lines, pressing g CTRL-A results in:
				1. 
				2. 
				3. 
				4. 

							CTRL-X
CTRL-X			Subtract [count] from the number or alphabetic
			character at or after the cursor.

							v_CTRL-X
{Visual}CTRL-X		Subtract [count] from the number or alphabetic
			character in the highlighted text.

			On MS-Windows, this is mapped to cut Visual text
			dos-standard-mappings.  If you want to disable the
			mapping, use this: 
				silent! vunmap <C-X>

							v_g_CTRL-X
{Visual}g CTRL-X	Subtract [count] from the number or alphabetic
			character in the highlighted text. If several lines
			are highlighted, each value will be decremented by an
			additional [count] (so effectively creating a [count]
			decrementing sequence).

The CTRL-A and CTRL-X commands can work for:
- signed and unsigned decimal numbers
- unsigned binary, octal and hexadecimal numbers
- alphabetic characters

This depends on the 'nrformats' option:
- When 'nrformats' includes "bin", Vim assumes numbers starting with '0b' or
  '0B' are binary.
- When 'nrformats' includes "octal", Vim considers numbers starting with a '0'
  to be octal, unless the number includes a '8' or '9'.  Other numbers are
  decimal and may have a preceding minus sign.
  If the cursor is on a number, the commands apply to that number; otherwise
  Vim uses the number to the right of the cursor.
- When 'nrformats' includes "hex", Vim assumes numbers starting with '0x' or
  '0X' are hexadecimal.  The case of the rightmost letter in the number
  determines the case of the resulting hexadecimal number.  If there is no
  letter in the current number, Vim uses the previously detected case.
- When 'nrformats' includes "alpha", Vim will change the alphabetic character
  under or after the cursor.  This is useful to make lists with an alphabetic
  index.

For decimals a leading negative sign is considered for incrementing/
decrementing, for binary, octal and hex values, it won't be considered.  To
ignore the sign Visually select the number before using CTRL-A or CTRL-X.

For numbers with leading zeros (including all octal and hexadecimal numbers),
Vim preserves the number of characters in the number when possible.  CTRL-A on
"0077" results in "0100", CTRL-X on "0x100" results in "0x0ff".
There is one exception: When a number that starts with a zero is found not to
be octal (it contains a '8' or '9'), but 'nrformats' does include "octal",
leading zeros are removed to avoid that the result may be recognized as an
octal number.

Note that when 'nrformats' includes "octal", decimal numbers with leading
zeros cause mistakes, because they can be confused with octal numbers.

Note similarly, when 'nrformats' includes "bin", binary numbers with a leading
'0x' or '0X' can be interpreted as hexadecimal rather than binary since '0b'
are valid hexadecimal digits.

The CTRL-A command is very useful in a macro.  Example: Use the following
steps to make a numbered list.

1. Create the first list entry, make sure it starts with a number.
2. qa	     - start recording into register 'a'
3. Y	     - yank the entry
4. p	     - put a copy of the entry below the first one
5. CTRL-A    - increment the number
6. q	     - stop recording
7. <count>@a - repeat the yank, put and increment <count> times


SHIFTING LINES LEFT OR RIGHT				shift-left-right

							<
<{motion}		Shift {motion} lines one 'shiftwidth' leftwards.

			If the 'vartabstop' feature is enabled, and the
			'shiftwidth' option is set to zero, the amount of
			indent is calculated at the first non-blank character
			in the line.
							<<
<<			Shift [count] lines one 'shiftwidth' leftwards.

							v_<
{Visual}[count]<	Shift the highlighted lines [count] 'shiftwidth'
			leftwards (for {Visual} see Visual-mode).

							>
 >{motion}		Shift {motion} lines one 'shiftwidth' rightwards.

			If the 'vartabstop' feature is enabled, and the
			'shiftwidth' option is set to zero, the amount of
			indent is calculated at the first non-blank character
			in the line.
							>>
 >>			Shift [count] lines one 'shiftwidth' rightwards.

							v_>
{Visual}[count]>	Shift the highlighted lines [count] 'shiftwidth'
			rightwards (for {Visual} see Visual-mode).

							:<
:[range]<		Shift [range] lines one 'shiftwidth' left.  Repeat '<'
			for shifting multiple 'shiftwidth's.

:[range]< {count}	Shift {count} lines one 'shiftwidth' left, starting
			with [range] (default current line cmdline-ranges).
			Repeat '<' for shifting multiple 'shiftwidth's.

:[range]le[ft] [indent]	left align lines in [range].  Sets the indent in the
			lines to [indent] (default 0).

							:>
:[range]> [flags]	Shift {count} [range] lines one 'shiftwidth' right.
			Repeat '>' for shifting multiple 'shiftwidth's.
			See ex-flags for [flags].

:[range]> {count} [flags]
			Shift {count} lines one 'shiftwidth' right, starting
			with [range] (default current line cmdline-ranges).
			Repeat '>' for shifting multiple 'shiftwidth's.
			See ex-flags for [flags].

The ">" and "<" commands are handy for changing the indentation within
programs.  Use the 'shiftwidth' option to set the size of the white space
which these commands insert or delete.  Normally the 'shiftwidth' option is 8,
but you can set it to, say, 3 to make smaller indents.  The shift leftwards
stops when there is no indent.  The shift right does not affect empty lines.

If the 'shiftround' option is on, the indent is rounded to a multiple of
'shiftwidth'.

If the 'smartindent' option is on, or 'cindent' is on and 'cinkeys' contains
'#' with a zero value, shift right does not affect lines starting with '#'
(these are supposed to be C preprocessor lines that must stay in column 1).
This can be changed with the 'cino' option, see cino-#.

When the 'expandtab' option is off (this is the default) Vim uses <Tab>s as
much as possible to make the indent.  You can use ">><<" to replace an indent
made out of spaces with the same indent made out of <Tab>s (and a few spaces
if necessary).  If the 'expandtab' option is on, Vim uses only spaces.  Then
you can use ">><<" to replace <Tab>s in the indent by spaces (or use
:retab!).

To move a line several 'shiftwidth's, use Visual mode or the : commands.
For example: 
	Vjj4>		move three lines 4 indents to the right
	:<<<		move current line 3 indents to the left
	:>> 5		move 5 lines 2 indents to the right
	:5>>		move line 5 2 indents to the right

==============================================================================
4. Complex changes					complex-change

4.1 Filter commands					filter

A filter is a program that accepts text at standard input, changes it in some
way, and sends it to standard output.  You can use the commands below to send
some text through a filter, so that it is replaced by the filter output.
Examples of filters are "sort", which sorts lines alphabetically, and
"indent", which formats C program files (you need a version of indent that
works like a filter; not all versions do).  The 'shell' option specifies the
shell Vim uses to execute the filter command (See also the 'shelltype'
option).  You can repeat filter commands with ".".  Vim does not recognize a
comment (starting with '"') after the :! command.

							!
!{motion}{filter}	Filter {motion} text lines through the external
			program {filter}.

							!!
!!{filter}		Filter [count] lines through the external program
			{filter}.

							v_!
{Visual}!{filter}	Filter the highlighted lines through the external
			program {filter} (for {Visual} see Visual-mode).

:{range}![!]{filter} [!][arg]				:range!
			Filter {range} lines through the external program
			{filter}.  Vim replaces the optional bangs with the
			latest given command and appends the optional [arg].
			Vim saves the output of the filter command in a
			temporary file and then reads the file into the buffer
			tempfile.  Vim uses the 'shellredir' option to
			redirect the filter output to the temporary file.
			However, if the 'shelltemp' option is off then pipes
			are used when possible (on Unix).
			When the 'R' flag is included in 'cpoptions' marks in
			the filtered lines are deleted, unless the
			:keepmarks command is used.  Example: 
				:keepmarks '<,'>!sort
			When the number of lines after filtering is less than
			before, marks in the missing lines are deleted anyway.

							=
={motion}		Filter {motion} lines through the external program
			given with the 'equalprg' option.  When the 'equalprg'
			option is empty (this is the default), use the
			internal formatting function C-indenting and
			'lisp'.  But when 'indentexpr' is not empty, it will
			be used instead indent-expression.  When Vim was
			compiled without internal formatting then the "indent"
			program is used as a last resort.

							==
==			Filter [count] lines like with ={motion}.

							v_=
{Visual}=		Filter the highlighted lines like with ={motion}.


						tempfile setuid
Vim uses temporary files for filtering, generating diffs and also for
tempname().  For Unix, the file will be in a private directory (only
accessible by the current user) to avoid security problems (e.g., a symlink
attack or other people reading your file).  When Vim exits the directory and
all files in it are deleted.  When Vim has the setuid bit set this may cause
problems, the temp file is owned by the setuid user but the filter command
probably runs as the original user.
Directory for temporary files is created in the first of these directories
that works:
	Unix:    $TMPDIR, /tmp, current-dir, $HOME.
	Windows: $TMP, $TEMP, c:TMP, c:TEMP
For MS-Windows the GetTempFileName() system function is used.
For other systems the tmpnam() library function is used.



4.2 Substitute						:substitute
							:s :su
:[range]s[ubstitute]/{pattern}/{string}/[flags] [count]
			For each line in [range] replace a match of {pattern}
			with {string}.
			For the {pattern} see pattern.
			{string} can be a literal string, or something
			special; see sub-replace-special.
			When [range] and [count] are omitted, replace in the
			current line only.  When [count] is given, replace in
			[count] lines, starting with the last line in [range].
			When [range] is omitted start in the current line.
							E939
			[count] must be a positive number.  Also see
			cmdline-ranges.

			See :s_flags for [flags].
			The delimiter doesn't need to be /, see
			pattern-delimiter.

:[range]s[ubstitute] [flags] [count]
:[range]&[&][flags] [count]					:&
			Repeat last :substitute with same search pattern and
			substitute string, but without the same flags.  You
			may add [flags], see :s_flags.
			Note that after :substitute the '&' flag can't be
			used, it's recognized as a pattern separator.
			The space between :substitute and the 'c', 'g',
			'i', 'I' and 'r' flags isn't required, but in scripts
			it's a good idea to keep it to avoid confusion.
			Also see the two and three letter commands to repeat
			:substitute below :substitute-repeat.

:[range]~[&][flags] [count]					:~
			Repeat last substitute with same substitute string
			but with last used search pattern.  This is like
			:&r.  See :s_flags for [flags].

								&
&			Synonym for :s (repeat last substitute).  Note
			that the flags are not remembered, thus it might
			actually work differently.  You can use :&& to keep
			the flags.

								g&
g&			Synonym for :%s//~/& (repeat last substitute with
			last search pattern on all lines with the same flags).
			For example, when you first do a substitution with
			:s/pattern/repl/flags and then /search for
			something else, g& will do :%s/search/repl/flags.
			Mnemonic: global substitute.

						:snomagic :sno
:[range]sno[magic] ...	Same as :substitute, but always use 'nomagic'.

						:smagic :sm
:[range]sm[agic] ...	Same as :substitute, but always use 'magic'.

							:s_flags
The flags that you can use for the substitute commands:

							:&&
[&]	Must be the first one: Keep the flags from the previous substitute
	command.  Examples: 
		:&&
		:s/this/that/&
	Note that :s and :& don't keep the flags.

[c]	Confirm each substitution.  Vim highlights the matching string (with
	hl-IncSearch).  You can type:  				:s_c
	    'y'	    to substitute this match
	    'l'	    to substitute this match and then quit ("last")
	    'n'	    to skip this match
	    <Esc>   to quit substituting
	    'a'	    to substitute this and all remaining matches
	    'q'	    to quit substituting
	    CTRL-E  to scroll the screen up
	    CTRL-Y  to scroll the screen down
	If the 'edcompatible' option is on, Vim remembers the [c] flag and
	toggles it each time you use it, but resets it when you give a new
	search pattern.

							:s_e
[e]     When the search pattern fails, do not issue an error message and, in
	particular, continue in maps as if no error occurred.  This is most
	useful to prevent the "No match" error from breaking a mapping.  Vim
	does not suppress the following error messages, however:
		Regular expressions can't be delimited by letters
		 should be followed by /, ? or &
		No previous substitute regular expression
		Trailing characters
		Interrupted

							:s_g
[g]	Replace all occurrences in the line.  Without this argument,
	replacement occurs only for the first occurrence in each line.  If
	the 'edcompatible' option is on, Vim remembers this flag and toggles
	it each time you use it, but resets it when you give a new search
	pattern.  If the 'gdefault' option is on, this flag is on by default
	and the [g] argument switches it off.

							:s_i
[i]	Ignore case for the pattern.  The 'ignorecase' and 'smartcase' options
	are not used.

							:s_I
[I]	Don't ignore case for the pattern.  The 'ignorecase' and 'smartcase'
	options are not used.

							:s_n
[n]	Report the number of matches, do not actually substitute.  The [c]
	flag is ignored.  The matches are reported as if 'report' is zero.
	Useful to count-items.
	If = sub-replace-expression is used, the expression will be
	evaluated in the sandbox at every match.

[p]	Print the line containing the last substitute.  :s_p

[#]	Like [p] and prepend the line number.  :s_#

[l]	Like [p] but print the text like :list.  :s_l

							:s_r
[r]	Only useful in combination with :& or :s without arguments.  :&r
	works the same way as :~:  When the search pattern is empty, use the
	previously used search pattern instead of the search pattern from the
	last substitute or :global.  If the last command that did a search
	was a substitute or :global, there is no effect.  If the last
	command was a search command such as "/", use the pattern from that
	command.
	For :s with an argument this already happens: 
		:s/blue/red/
		/green
		:s//red/   or  :~   or  :&r
	The last commands will replace "green" with "red". 
		:s/blue/red/
		/green
		:&
	The last command will replace "blue" with "red".

Note that there is no flag to change the "magicness" of the pattern.  A
different command is used instead, or you can use /v and friends.  The
reason is that the flags can only be found by skipping the pattern, and in
order to skip the pattern the "magicness" must be known.  Catch 22!

If the {pattern} for the substitute command is empty, the command uses the
pattern from the last substitute or :global command.  If there is none, but
there is a previous search pattern, that one is used.  With the [r] flag, the
command uses the pattern from the last substitute, :global, or search
command.

If the {string} is omitted the substitute is done as if it's empty.  Thus the
matched pattern is deleted.  The separator after {pattern} can also be left
out then.  Example: 
	:%s/TESTING
This deletes "TESTING" from all lines, but only one per line.
								E1270
For compatibility with Vi these two exceptions are allowed in legacy script:
"/{string}/" and "?{string}?" do the same as "//{string}/r".
"&{string}&" does the same as "//{string}/".
				pattern-delimiter E146 E1241 E1242
Instead of the '/' which surrounds the pattern and replacement string, you can
use another single-byte character.  This is useful if you want to include a
'/' in the search pattern or replacement string.  Example: 
	:s+/+//+

You can use most characters, but not an alphanumeric character, '', '"' or
'|'.  In Vim9 script you should not use '#' because it may be recognized as
the start of a comment.

For the definition of a pattern, see pattern.  In Visual block mode, use
/%V in the pattern to have the substitute work in the block only.
Otherwise it works on whole lines anyway.

					sub-replace-special :s=
When the {string} starts with "=" it is evaluated as an expression, see
sub-replace-expression.  You can use that for complex replacement or special
characters.

The substitution is limited in recursion to 4 levels. E1290

Otherwise these characters in {string} have a special meaning:
								:s%
When {string} is equal to "%" and '/' is included with the 'cpoptions' option,
then the {string} of the previous substitute command is used, see cpo-/

magic	nomagic	  action    
  &	  &	  replaced with the whole matched pattern	     s/&
 &	   &	  replaced with &
      	  replaced with the whole matched pattern	    s/
      1	  replaced with the matched pattern in the first
		  pair of ()					     s/1
      2	  replaced with the matched pattern in the second
		  pair of ()					     s/2
      ..	  ..						     s/3
      9	  replaced with the matched pattern in the ninth
		  pair of ()					     s/9
  ~	  ~	  replaced with the {string} of the previous
		  substitute					     s~
 ~	   ~	  replaced with ~				     s/~
      u	  next character made uppercase			     s/u
      U	  following characters made uppercase, until E      s/U
      l	  next character made lowercase			     s/l
      L	  following characters made lowercase, until E      s/L
      e	  end of u, U, l and L (NOTE: not <Esc>!)	     s/e
      E	  end of u, U, l and L			     s/E
      <CR>	  split line in two at this point
		  (Type the <CR> as CTRL-V <Enter>)		     s<CR>
      r	  idem						     s/r
      <CR>	  insert a carriage-return (CTRL-M)
		  (Type the <CR> as CTRL-V <Enter>)		     s/<CR>
      n	  insert a <NL> (<NUL> in the file)
		  (does NOT break the line)			     s/n
      b	  insert a <BS>					     s/b
      t	  insert a <Tab>				     s/t
      \	  insert a single backslash			     s/\
      x	  where x is any character not mentioned above:
		  Reserved for future expansion

The special meaning is also used inside the third argument {sub} of
the substitute() function with the following exceptions:
  - A % inserts a percent literally without regard to 'cpoptions'.
  - magic is always set without regard to 'magic'.
  - A ~ inserts a tilde literally.
  - <CR> and r inserts a carriage-return (CTRL-M).
  - <CR> does not have a special meaning. It's just one of x.

Examples: 
  :s/a|b/xxxxxx/g		 modifies "a b"	     to "xxxaxxx xxxbxxx"
  :s/([abc])([efg])/21/g	 modifies "af fa bg" to "fa fa gb"
  :s/abcde/abc^Mde/		 modifies "abcde"    to "abc", "de" (two lines)
  :s/$/^M/			 modifies "abcde"    to "abcde^M"
  :s/w+/u/g		 modifies "bla bla"  to "Bla Bla"
  :s/w+/Lu/g		 modifies "BLA bla"  to "Bla Bla"

Note: "Lu" can be used to capitalize the first letter of a word.  This is
not compatible with Vi and older versions of Vim, where the "u" would cancel
out the "L". Same for "Ul".

Note: In previous versions CTRL-V was handled in a special way.  Since this is
not Vi compatible, this was removed.  Use a backslash instead.

command		text	result 
:s/aa/a^Ma/	aa	a<line-break>a
:s/aa/a^Ma/	aa	a^Ma
:s/aa/a\^Ma/	aa	a<line-break>a

(you need to type CTRL-V <CR> to get a ^M here)

The numbering of "1", "2" etc. is done based on which "(" comes first in
the pattern (going left to right).  When a parentheses group matches several
times, the last one will be used for "1", "2", etc.  Example: 
  :s/((a[a-d] )*)/2/      modifies "aa ab x" to "ab x"
The "2" is for "(a[a-d] )".  At first it matches "aa ", secondly "ab ".

When using parentheses in combination with '|', like in ([ab])|([cd]),
either the first or second pattern in parentheses did not match, so either
1 or 2 is empty.  Example: 
  :s/([ab])|([cd])/1x/g   modifies "a b c d"  to "ax bx x x"


		:sc :sce :scg :sci :scI :scl :scp :sg :sgc
		:sge :sgi :sgI :sgl :sgn :sgp :sgr :sI :si
		:sic :sIc :sie :sIe :sIg :sIl :sin :sIn :sIp
		:sip :sIr :sir :sr :src :srg :sri :srI :srl
		:srn :srp :substitute-repeat
2-letter and 3-letter :substitute commands 

These commands repeat the previous :substitute command with the given flags.
The first letter is always "s", followed by one or two of the possible flag
characters.  For example :sce works like :s///ce.  The table lists the
possible combinations, not all flags are possible, because the command is
short for another command.

     List of :substitute commands
     |      c    e    g    i    I    n    p    l    r
     | c  :sc  :sce :scg :sci :scI :scn :scp :scl
     | e
     | g  :sgc :sge :sg  :sgi :sgI :sgn :sgp :sgl :sgr
     | i  :sic :sie      :si  :siI :sin :sip      :sir
     | I  :sIc :sIe :sIg :sIi :sI  :sIn :sIp :sIl :sIr
     | n
     | p
     | l
     | r  :src      :srg :sri :srI :srn :srp :srl :sr

Exceptions:
     :scr  is  :scriptnames
     :se   is  :set
     :sig  is  :sign
     :sil  is  :silent
     :sn   is  :snext
     :sp   is  :split
     :sl   is  :sleep
     :sre  is  :srewind


Substitute with an expression			sub-replace-expression
						sub-replace-= s/=
When the substitute string starts with "=" the remainder is interpreted as an
expression.

The special meaning for characters as mentioned at sub-replace-special does
not apply except for "<CR>".  A <NL> character is used as a line break, you
can get one with a double-quote string: "n".  Prepend a backslash to get a
real <NL> character (which will be a NUL in the file).

The "=" notation can also be used inside the third argument {sub} of
substitute() function.  In this case, the special meaning for characters as
mentioned at sub-replace-special does not apply at all. Especially, <CR> and
<NL> are interpreted not as a line break but as a carriage-return and a
new-line respectively.

When the result is a List then the items are joined with separating line
breaks.  Thus each item becomes a line, except that they can contain line
breaks themselves.

The submatch() function can be used to obtain matched text.  The whole
matched text can be accessed with "submatch(0)".  The text matched with the
first pair of () with "submatch(1)".  Likewise for further sub-matches in ().

Be careful: The separation character must not appear in the expression!
Consider using a character like "@" or ":".  There is no problem if the result
of the expression contains the separation character.

Examples: 
	:s@n@="r" .. expand("$HOME") .. "r"@
This replaces an end-of-line with a new line containing the value of $HOME. 

	s/E/="<Char-0x20ac>"/g
This replaces each 'E' character with a euro sign.  Read more in <Char->.


4.3 Search and replace					search-replace

							:pro :promptfind
:promptf[ind] [string]
			Put up a Search dialog.  When [string] is given, it is
			used as the initial search string.
			{only for Win32, Motif and GTK GUI}

						:promptr :promptrepl
:promptr[epl] [string]
			Put up a Search/Replace dialog.  When [string] is
			given, it is used as the initial search string.
			{only for Win32, Motif and GTK GUI}


4.4 Changing tabs					change-tabs
							:ret :retab :retab!
:[range]ret[ab][!] [new_tabstop]
			Replace all sequences of white-space containing a
			<Tab> with new strings of white-space using the new
			tabstop value given.  If you do not specify a new
			tabstop size or it is zero, Vim uses the current value
			of 'tabstop'.
			The current value of 'tabstop' is always used to
			compute the width of existing tabs.
			With !, Vim also replaces strings of only normal
			spaces with tabs where appropriate.
			With 'expandtab' on, Vim replaces all tabs with the
			appropriate number of spaces.
			This command sets 'tabstop' to the new value given,
			and if performed on the whole file, which is default,
			should not make any visible change.
			Careful: This command modifies any <Tab> characters
			inside of strings in a C program.  Use "t" to avoid
			this (that's a good habit anyway).
			:retab! may also change a sequence of spaces by
			<Tab> characters, which can mess up a printf().
			If the +vartabs feature is enabled then a list of
			tab widths separated by commas may be used in place of
			a single tabstop.  Each value in the list represents
			the width of one tabstop, except the final value which
			applies to all following tabstops.

							retab-example
Example for using autocommands and ":retab" to edit a file which is stored
with tabstops at 8 but edited with tabstops set at 4.  Warning: white space
inside of strings can change!  Also see 'softtabstop' option. 

  :auto BufReadPost	*.xx	retab! 4
  :auto BufWritePre	*.xx	retab! 8
  :auto BufWritePost	*.xx	retab! 4
  :auto BufNewFile	*.xx	set ts=4

==============================================================================
5. Copying and moving text				copy-move

							quote
"{register}		Use {register} for next delete, yank or put.  Use
			an uppercase character to append with delete and yank.
			Registers ".", "%", "#" and ":" only work with put.

							:reg :registers
:reg[isters]		Display the type and contents of all numbered and
			named registers.  If a register is written to for
			:redir it will not be listed.
			Type can be one of:
			"c"	for characterwise text
			"l"	for linewise text
			"b"	for blockwise-visual text


:reg[isters] {arg}	Display the contents of the numbered and named
			registers that are mentioned in {arg}.  For example: 
				:reg 1a
			to display registers '1' and 'a'.  Spaces are allowed
			in {arg}.

							:di :dis :display
:di[splay] [arg]	Same as :registers.

							y yank
["x]y{motion}		Yank {motion} text [into register x].  When no
			characters are to be yanked (e.g., "y0" in column 1),
			this is an error when 'cpoptions' includes the 'E'
			flag.

							yy
["x]yy			Yank [count] lines [into register x] linewise.

							Y
["x]Y			yank [count] lines [into register x] (synonym for
			yy, linewise).  If you like "Y" to work from the
			cursor to the end of line (which is more logical,
			but not Vi-compatible) use ":map Y y$".

							zy
["x]zy{motion}		Yank {motion} text [into register x].  Only differs
			from y when selecting a block of text, see v_zy.

							v_y
{Visual}["x]y		Yank the highlighted text [into register x] (for
			{Visual} see Visual-mode).

							v_Y
{Visual}["x]Y		Yank the highlighted lines [into register x] (for
			{Visual} see Visual-mode).

							v_zy
{Visual}["x]zy		Yank the highlighted text [into register x].  Trailing
			whitespace at the end of each line of a selected block
			won't be yanked.  Especially useful in combination
			with zp.  (for {Visual} see Visual-mode)

							:y :yank E850
:[range]y[ank] [x]	Yank [range] lines [into register x]. Yanking to the
			"* or "+ registers is possible only when the
			+clipboard feature is included.

:[range]y[ank] [x] {count}
			Yank {count} lines, starting with last line number
			in [range] (default: current line cmdline-ranges),
			[into register x].

						p put E353 E1240
["x]p			Put the text [from register x] after the cursor
			[count] times.

							P
["x]P			Put the text [from register x] before the cursor
			[count] times.

							<MiddleMouse>
["x]<MiddleMouse>	Put the text from a register before the cursor [count]
			times.  Uses the "* register, unless another is
			specified.
			Leaves the cursor at the end of the new text.
			Using the mouse only works when 'mouse' contains 'n'
			or 'a'.
			If you have a scrollwheel and often accidentally paste
			text, you can use these mappings to disable the
			pasting with the middle mouse button: 
				:map <MiddleMouse> <Nop>
				:imap <MiddleMouse> <Nop>
			You might want to disable the multi-click versions
			too, see double-click.

							gp
["x]gp			Just like "p", but leave the cursor just after the new
			text.

							gP
["x]gP			Just like "P", but leave the cursor just after the new
			text.

							:pu :put
:[line]pu[t] [x]	Put the text [from register x] after [line] (default
			current line).  This always works linewise, thus
			this command can be used to put a yanked block as new
			lines.
			If no register is specified, it depends on the 'cb'
			option: If 'cb' contains "unnamedplus", paste from the
			+ register quoteplus.  Otherwise, if 'cb' contains
			"unnamed", paste from the * register quotestar.
			Otherwise, paste from the unnamed register
			quote_quote.
			The register can also be '=' followed by an optional
			expression.  The expression continues until the end of
			the command.  You need to escape the '|' and '"'
			characters to prevent them from terminating the
			command.  Example: 
				:put ='path' .. ",/test"
			If there is no expression after '=', Vim uses the
			previous expression.  You can see it with ":dis =".

:[line]pu[t]! [x]	Put the text [from register x] before [line] (default
			current line).

["x]]p		    or					]p ]<MiddleMouse>
["x]]<MiddleMouse>	Like "p", but adjust the indent to the current line.
			Using the mouse only works when 'mouse' contains 'n'
			or 'a'.

["x][P		    or					[P
["x]]P		    or					]P
["x][p		    or					[p [<MiddleMouse>
["x][<MiddleMouse>	Like "P", but adjust the indent to the current line.
			Using the mouse only works when 'mouse' contains 'n'
			or 'a'.

["x]zp		    or					zp zP
["x]zP			Like "p" and "P", except without adding trailing spaces
			when pasting a block.  Thus the inserted text will not
			always be a rectangle.  Especially useful in
			combination with v_zy.

You can use these commands to copy text from one place to another.  Do this
by first getting the text into a register with a yank, delete or change
command, then inserting the register contents with a put command.  You can
also use these commands to move text from one file to another, because Vim
preserves all registers when changing buffers (the CTRL-^ command is a quick
way to toggle between two files).

				linewise-register characterwise-register
You can repeat the put commands with "." (except for :put) and undo them.  If
the command that was used to get the text into the register was linewise,
Vim inserts the text below ("p") or above ("P") the line where the cursor is.
Otherwise Vim inserts the text after ("p") or before ("P") the cursor.  With
the ":put" command, Vim always inserts the text in the next line.  You can
exchange two characters with the command sequence "xp".  You can exchange two
lines with the command sequence "ddp".  You can exchange two words with the
command sequence "deep" (start with the cursor in the blank space before the
first word).  You can use the "']" or "`]" command after the put command to
move the cursor to the end of the inserted text, or use "'[" or "`[" to move
the cursor to the start.

						put-Visual-mode v_p v_P
When using a put command like p or P in Visual mode, Vim will try to
replace the selected text with the contents of the register.  Whether this
works well depends on the type of selection and the type of the text in the
register.  With blockwise selection it also depends on the size of the block
and whether the corners are on an existing character.  (Implementation detail:
it actually works by first putting the register after the selection and then
deleting the selection.)
With p the previously selected text is put in the unnamed register (and
possibly the selection and/or clipboard).  This is useful if you want to put
that text somewhere else.  But you cannot repeat the same change.
With P the unnamed register is not changed (and neither the selection or
clipboard), you can repeat the same change. But the deleted text cannot be
used.  If you do need it you can use p with another register.  E.g., yank
the text to copy, Visually select the text to replace and use "0p .  You can
repeat this as many times as you like, and the unnamed register will be
changed each time.
							blockwise-put
When a register contains text from one line (characterwise), using a
blockwise Visual selection, putting that register will paste that text
repeatedly in each of the selected lines, thus replacing the blockwise
selected region by multiple copies of the register text.  For example:
	- yank the word "TEXT" into a register with yw
	- select a visual block, marked with "v" in this text:
	    aaavvaaa
	    bbbvvbbb
	    cccvvccc
	- press p, results in:
	    aaaTEXTaaa
	    bbbTEXTbbb
	    cccTEXTccc

							blockwise-register
If you use a blockwise Visual mode command to get the text into the register,
the block of text will be inserted before ("P") or after ("p") the cursor
column in the current and next lines.  Vim makes the whole block of text start
in the same column.  Thus the inserted text looks the same as when it was
yanked or deleted.  Vim may replace some <Tab> characters with spaces to make
this happen.  However, if the width of the block is not a multiple of a <Tab>
width and the text after the inserted block contains <Tab>s, that text may be
misaligned.

Use zP/zp to paste a blockwise yanked register without appending trailing
spaces.

Note that after a characterwise yank command, Vim leaves the cursor on the
first yanked character that is closest to the start of the buffer.  This means
that "yl" doesn't move the cursor, but "yh" moves the cursor one character
left.
Rationale:	In Vi the "y" command followed by a backwards motion would
		sometimes not move the cursor to the first yanked character,
		because redisplaying was skipped.  In Vim it always moves to
		the first character, as specified by Posix.
With a linewise yank command the cursor is put in the first line, but the
column is unmodified, thus it may not be on the first yanked character.

There are ten types of registers:		registers {register} E354
1. The unnamed register ""
2. 10 numbered registers "0 to "9
3. The small delete register "-
4. 26 named registers "a to "z or "A to "Z
5. Three read-only registers ":, "., "%
6. Alternate buffer register "#
7. The expression register "=
8. The selection and drop registers "*, "+ and "~ 
9. The black hole register "_
10. Last search pattern register "/

1. Unnamed register ""				quote_quote quotequote
Vim fills this register with text deleted with the "d", "c", "s", "x" commands
or copied with the yank "y" command, regardless of whether or not a specific
register was used (e.g.  "xdd).  This is like the unnamed register is pointing
to the last used register.  Thus when appending using an uppercase register
name, the unnamed register contains the same text as the named register.
An exception is the '_' register: "_dd does not store the deleted text in any
register.
Vim uses the contents of the unnamed register for any put command (p or P)
which does not specify a register.  Additionally you can access it with the
name '"'.  This means you have to type two double quotes.  Writing to the ""
register writes to register "0.
{Vi: register contents are lost when changing files, no '"'}

2. Numbered registers "0 to "9		quote_number quote0 quote1
					quote2 quote3 quote4 quote9
Vim fills these registers with text from yank and delete commands.
   Numbered register 0 contains the text from the most recent yank command,
unless the command specified another register with ["x].
   Numbered register 1 contains the text deleted by the most recent delete or
change command, unless the command specified another register or the text is
less than one line (the small delete register is used then).  An exception is
made for the delete operator with these movement commands: %, (, ), `,
/, ?, n, N, { and }.  Register "1 is always used then (this is Vi
compatible).  The "- register is used as well if the delete is within a line.
Note that these characters may be mapped.  E.g. % is mapped by the matchit
plugin.
   With each successive deletion or change, Vim shifts the previous contents
of register 1 into register 2, 2 into 3, and so forth, losing the previous
contents of register 9.
{Vi: numbered register contents are lost when changing files; register 0 does
not exist}

3. Small delete register "-				quote_- quote-
This register contains text from commands that delete less than one line,
except when the command specifies a register with ["x].

4. Named registers "a to "z or "A to "Z			quote_alpha quotea
Vim fills these registers only when you say so.  Specify them as lowercase
letters to replace their previous contents or as uppercase letters to append
to their previous contents.  When the '>' flag is present in 'cpoptions' then
a line break is inserted before the appended text.

5. Read-only registers ":, ". and "%
These are '%', ':' and '.'.  You can use them only with the "p", "P",
and ":put" commands and with CTRL-R.
						quote_. quote. E29
	".	Contains the last inserted text (the same as what is inserted
		with the insert mode commands CTRL-A and CTRL-@).  Note: this
		doesn't work with CTRL-R on the command-line.  It works a bit
		differently, like inserting the text instead of putting it
		('textwidth' and other options affect what is inserted).
							quote_% quote%
	"%	Contains the name of the current file.
						quote_: quote: E30
	":	Contains the most recent executed command-line.  Example: Use
		"@:" to repeat the previous command-line command.
		The command-line is only stored in this register when at least
		one character of it was typed.  Thus it remains unchanged if
		the command was completely from a mapping.
		{not available when compiled without the +cmdline_hist
		feature}
							quote_# quote#
6. Alternate file register "#
Contains the name of the alternate file for the current window.  It will
change how the CTRL-^ command works.
This register is writable, mainly to allow for restoring it after a plugin has
changed it.  It accepts buffer number: 
    let altbuf = bufnr(@#)
    ...
    let @# = altbuf
It will give error E86 if you pass buffer number and this buffer does not
exist.
It can also accept a match with an existing buffer name: 
    let @# = 'buffer_name'
Error E93 if there is more than one buffer matching the given name or E94
if none of buffers matches the given name.

7. Expression register "=			quote_= quote= @=
This is not really a register that stores text, but is a way to use an
expression in commands which use a register.  The expression register is
read-write.

When typing the '=' after " or CTRL-R the cursor moves to the command-line,
where you can enter any expression (see expression).  All normal
command-line editing commands are available, including a special history for
expressions.  When you end the command-line by typing <CR>, Vim computes the
result of the expression.  If you end it with <Esc>, Vim abandons the
expression.  If you do not enter an expression, Vim uses the previous
expression (like with the "/" command).

The expression must evaluate to a String.  A Number is always automatically
converted to a String.  For the "p" and ":put" command, if the result is a
Float it's converted into a String.  If the result is a List each element is
turned into a String and used as a line.  A Dictionary or FuncRef results in
an error message (use string() to convert).

If the "= register is used for the "p" command, the String is split up at <NL>
characters.  If the String ends in a <NL>, it is regarded as a linewise
register.

8. Selection and drop registers "*, "+ and "~ 
Use these registers for storing and retrieving the selected text for the GUI.
See quotestar and quoteplus.  When the clipboard is not available or not
working, the unnamed register is used instead.  For Unix systems the clipboard
is only available when the +xterm_clipboard feature is present.

Note that there is only a distinction between "* and "+ for X11 systems.  For
an explanation of the difference, see x11-selection.  Under MS-Windows, use
of "* and "+ is actually synonymous and refers to the gui-clipboard.

						quote_~ quote~ <Drop>
The read-only "~ register stores the dropped text from the last drag'n'drop
operation.  When something has been dropped onto Vim, the "~ register is
filled in and the <Drop> pseudo key is sent for notification.  You can remap
this key if you want; the default action (for all modes) is to insert the
contents of the "~ register at the cursor position.
{only available when compiled with the +dnd feature, currently only with the
GTK GUI}

Note: The "~ register is only used when dropping plain text onto Vim.
Drag'n'drop of URI lists is handled internally.

9. Black hole register "_				quote_
When writing to this register, nothing happens.  This can be used to delete
text without affecting the normal registers.  When reading from this register,
nothing is returned.

10. Last search pattern register	"/		quote_/ quote/
Contains the most recent search-pattern.  This is used for "n" and 'hlsearch'.
It is writable with :let, you can change it to have 'hlsearch' highlight
other matches without actually searching.  You can't yank or delete into this
register.  The search direction is available in v:searchforward.
Note that the value is restored when returning from a function
function-search-undo.

							@/
You can write to a register with a :let command :let-@.  Example: 
	:let @/ = "the"

If you use a put command without specifying a register, Vim uses the register
that was last filled (this is also the contents of the unnamed register).  If
you are confused, use the :dis command to find out what Vim will put (this
command displays all named and numbered registers; the unnamed register is
labelled '"').

The next three commands always work on whole lines.

:[range]co[py] {address}				:co :copy
			Copy the lines given by [range] to below the line
			given by {address}.

							:t
:t			Synonym for copy.
			This command is not supported in Vim9 script,
			because it is too easily confused with a variable
			name.

:[range]m[ove] {address}			:m :mo :move E134
			Move the lines given by [range] to below the line
			given by {address}.

==============================================================================
6. Formatting text					formatting

:[range]ce[nter] [width]				:ce :center
			Center lines in [range] between [width] columns
			(default 'textwidth' or 80 when 'textwidth' is 0).

:[range]ri[ght] [width]					:ri :right
			Right-align lines in [range] at [width] columns
			(default 'textwidth' or 80 when 'textwidth' is 0).

							:le :left
:[range]le[ft] [indent]
			Left-align lines in [range].  Sets the indent in the
			lines to [indent] (default 0).

							gq
gq{motion}		Format the lines that {motion} moves over.
			Formatting is done with one of three methods:
			1. If 'formatexpr' is not empty the expression is
			   evaluated.  This can differ for each buffer.
			2. If 'formatprg' is not empty an external program
			   is used.
			3. Otherwise formatting is done internally.

			In the third case the 'textwidth' option controls the
			length of each formatted line (see below).
			If the 'textwidth' option is 0, the formatted line
			length is the screen width (with a maximum width of
			79).
			The 'formatoptions' option controls the type of
			formatting fo-table.
			The cursor is left on the first non-blank of the last
			formatted line.
			NOTE: The "Q" command formerly performed this
			function.  If you still want to use "Q" for
			formatting, use this mapping: 
				:nnoremap Q gq

gqgq							gqgq gqq
gqq			Format the current line.  With a count format that
			many lines.

							v_gq
{Visual}gq		Format the highlighted text.  (for {Visual} see
			Visual-mode).

							gw
gw{motion}		Format the lines that {motion} moves over.  Similar to
			gq but puts the cursor back at the same position in
			the text.  However, 'formatprg' and 'formatexpr' are
			not used.

gwgw							gwgw gww
gww			Format the current line as with "gw".

							v_gw
{Visual}gw		Format the highlighted text as with "gw".  (for
			{Visual} see Visual-mode).

Example: To format the current paragraph use:			gqap  
	gqap

The "gq" command leaves the cursor in the line where the motion command takes
the cursor.  This allows you to repeat formatting repeated with ".".  This
works well with "gqj" (format current and next line) and "gq}" (format until
end of paragraph).  Note: When 'formatprg' is set, "gq" leaves the cursor on
the first formatted line (as with using a filter command).

If you want to format the current paragraph and continue where you were, use: 
	gwap
If you always want to keep paragraphs formatted you may want to add the 'a'
flag to 'formatoptions'.  See auto-format.

If the 'autoindent' option is on, Vim uses the indent of the first line for
the following lines.

Formatting does not change empty lines (but it does change lines with only
white space!).

The 'joinspaces' option is used when lines are joined together.

You can set the 'formatexpr' option to an expression or the 'formatprg' option
to the name of an external program for Vim to use for text formatting.  The
'textwidth' and other options have no effect on formatting by an external
program.

                                                        format-formatexpr
The 'formatexpr' option can be set to a Vim script function that performs
reformatting of the buffer.  This should usually happen in an ftplugin,
since formatting is highly dependent on the type of file.  It makes
sense to use an autoload script, so the corresponding script is only loaded
when actually needed and the script should be called <filetype>format.vim.

For example, the XML filetype plugin distributed with Vim in the $VIMRUNTIME
directory, sets the 'formatexpr' option to: 

   setlocal formatexpr=xmlformat#Format()

That means, you will find the corresponding script, defining the
xmlformat#Format() function, in the directory:
$VIMRUNTIME/autoload/xmlformat.vim

Here is an example script that removes trailing whitespace from the selected
text.  Put it in your autoload directory, e.g. ~/.vim/autoload/format.vim: 

  func! format#Format()
    " only reformat on explicit gq command
    if mode() != 'n'
      " fall back to Vim's internal reformatting
      return 1
    endif
    let lines = getline(v:lnum, v:lnum + v:count - 1)
    call map(lines, {key, val -> substitute(val, 's+$', '', 'g')})
    call setline('.', lines)

    " do not run internal formatter!
    return 0
  endfunc

You can then enable the formatting by executing: 
  setlocal formatexpr=format#Format()

Note: this function explicitly returns non-zero when called from insert mode
(which basically means, text is inserted beyond the 'textwidth' limit).  This
causes Vim to fall back to reformat the text by using the internal formatter.

However, if the gq command is used to reformat the text, the function
will receive the selected lines, trim trailing whitespace from those lines and
put them back in place.  If you are going to split single lines into multiple
lines, be careful not to overwrite anything.

If you want to allow reformatting of text from insert or replace mode, one has
to be very careful, because the function might be called recursively.  For
debugging it helps to set the 'debug' option.

							right-justify
There is no command in Vim to right justify text.  You can do it with
an external command, like "par" (e.g.: "!}par" to format until the end of the
paragraph) or set 'formatprg' to "par".

							
An overview of comment formatting is in section 30.6 of the user manual.

Vim can automatically insert and format comments in a special way.  Vim
recognizes a comment by a specific string at the start of the line (ignoring
white space).  Three types of comments can be used:

- A comment string that repeats at the start of each line.  An example is the
  type of comment used in shell scripts, starting with "#".
- A comment string that occurs only in the first line, not in the following
  lines.  An example is this list with dashes.
- Three-piece comments that have a start string, an end string, and optional
  lines in between.  The strings for the start, middle and end are different.
  An example is the C style comment:
	/*
	 * this is a C comment
	 */

The 'comments' option is a comma-separated list of parts.  Each part defines a
type of comment string.  A part consists of:
	{flags}:{string}

{string} is the literal text that must appear.

{flags}:
  n	Nested comment.  Nesting with mixed parts is allowed.  If 'comments'
	is "n:),n:>" a line starting with "> ) >" is a comment.

  b	Blank (<Space>, <Tab> or <EOL>) required after {string}.

  f	Only the first line has the comment string.  Do not repeat comment on
	the next line, but preserve indentation (e.g., a bullet-list).

  s	Start of three-piece comment

  m	Middle of a three-piece comment

  e	End of a three-piece comment

  l	Left align. Used together with 's' or 'e', the leftmost character of
	start or end will line up with the leftmost character from the middle.
	This is the default and can be omitted. See below for more details.

  r	Right align. Same as above but rightmost instead of leftmost. See
	below for more details.

  O	Don't consider this comment for the "O" command.

  x	Allows three-piece comments to be ended by just typing the last
	character of the end-comment string as the first action on a new
	line when the middle-comment string has been inserted automatically.
	See below for more details.

  {digits}
	When together with 's' or 'e': add {digit} amount of offset to an
	automatically inserted middle or end comment leader. The offset begins
	from a left alignment. See below for more details.

  -{digits}
	Like {digits} but reduce the indent.  This only works when there is
	some indent for the start or end part that can be removed.

When a string has none of the 'f', 's', 'm' or 'e' flags, Vim assumes the
comment string repeats at the start of each line.  The flags field may be
empty.

Any blank space in the text before and after the {string} is part of the
{string}, so do not include leading or trailing blanks unless the blanks are a
required part of the comment string.

When one comment leader is part of another, specify the part after the whole.
For example, to include both "-" and "->", use 
	:set comments=f:->,f:-

A three-piece comment must always be given as start,middle,end, with no other
parts in between.  An example of a three-piece comment is 
	sr:/*,mb:*,ex:*/
for C-comments.  To avoid recognizing "*ptr" as a comment, the middle string
includes the 'b' flag.  For three-piece comments, Vim checks the text after
the start and middle strings for the end string.  If Vim finds the end string,
the comment does not continue on the next line.  Three-piece comments must
have a middle string because otherwise Vim can't recognize the middle lines.

Notice the use of the "x" flag in the above three-piece comment definition.
When you hit Return in a C-comment, Vim will insert the middle comment leader
for the new line: " * ".  To close this comment you just have to type "/"
before typing anything else on the new line.  This will replace the
middle-comment leader with the end-comment leader and apply any specified
alignment, leaving just " */".  There is no need to hit Backspace first.

When there is a match with a middle part, but there also is a matching end
part which is longer, the end part is used.  This makes a C style comment work
without requiring the middle part to end with a space.

Here is an example of alignment flags at work to make a comment stand out
(kind of looks like a 1 too). Consider comment string: 
	:set comments=sr:/***,m:**,ex-2:******/

                                   /*** 
                                     **<--right aligned from "r" flag 
                                     ** 
offset 2 spaces for the "-2" flag--->** 
                                   ******/ 
In this case, the first comment was typed, then return was pressed 4 times,
then "/" was pressed to end the comment.

Here are some finer points of three part comments. There are three times when
alignment and offset flags are taken into consideration: opening a new line
after a start-comment, opening a new line before an end-comment, and
automatically ending a three-piece comment.  The end alignment flag has a
backwards perspective; the result is that the same alignment flag used with
"s" and "e" will result in the same indent for the starting and ending pieces.
Only one alignment per comment part is meant to be used, but an offset number
will override the "r" and "l" flag.

Enabling 'cindent' will override the alignment flags in many cases.
Reindenting using a different method like gq or = will not consult
alignment flags either. The same behaviour can be defined in those other
formatting options. One consideration is that 'cindent' has additional options
for context based indenting of comments but cannot replicate many three piece
indent alignments.  However, 'indentexpr' has the ability to work better with
three piece comments.

Other examples: 
   "b:*"	Includes lines starting with "*", but not if the "*" is
		followed by a non-blank.  This avoids a pointer dereference
		like "*str" to be recognized as a comment.
   "n:>"	Includes a line starting with ">", ">>", ">>>", etc.
   "fb:-"	Format a list that starts with "- ".

By default, "b:#" is included.  This means that a line that starts with
"#include" is not recognized as a comment line.  But a line that starts with
"# define" is recognized.  This is a compromise.

							fo-table
You can use the 'formatoptions' option  to influence how Vim formats text.
'formatoptions' is a string that can contain any of the letters below.  The
default setting is "tcq".  You can separate the option letters with commas for
readability.

letter	 meaning when present in 'formatoptions'    
							fo-t
t	Auto-wrap text using 'textwidth'
							fo-c
c	Auto-wrap comments using 'textwidth', inserting the current comment
	leader automatically.
							fo-r
r	Automatically insert the current comment leader after hitting
	<Enter> in Insert mode.
							fo-o
o	Automatically insert the current comment leader after hitting 'o' or
	'O' in Normal mode.  In case comment is unwanted in a specific place
	use CTRL-U to quickly delete it. i_CTRL-U
							fo-/
/	When 'o' is included: do not insert the comment leader for a //
	comment after a statement, only when // is at the start of the line.
							fo-q
q	Allow formatting of comments with "gq".
	Note that formatting will not change blank lines or lines containing
	only the comment leader.  A new paragraph starts after such a line,
	or when the comment leader changes.
							fo-w
w	Trailing white space indicates a paragraph continues in the next line.
	A line that ends in a non-white character ends a paragraph.
							fo-a
a	Automatic formatting of paragraphs.  Every time text is inserted or
	deleted the paragraph will be reformatted.  See auto-format.
	When the 'c' flag is present this only happens for recognized
	comments.
							fo-n
n	When formatting text, recognize numbered lists.  This actually uses
	the 'formatlistpat' option, thus any kind of list can be used.  The
	indent of the text after the number is used for the next line.  The
	default is to find a number, optionally followed by '.', ':', ')',
	']' or '}'.  Note that 'autoindent' must be set too.  Doesn't work
	well together with "2".
	Example: 
		1. the first item
		   wraps
		2. the second item
							fo-2
2	When formatting text, use the indent of the second line of a paragraph
	for the rest of the paragraph, instead of the indent of the first
	line.  This supports paragraphs in which the first line has a
	different indent than the rest.  Note that 'autoindent' must be set
	too.  Example: 
			first line of a paragraph
		second line of the same paragraph
		third line.
	This also works inside comments, ignoring the comment leader.
							fo-v
v	Vi-compatible auto-wrapping in insert mode: Only break a line at a
	blank that you have entered during the current insert command.  (Note:
	this is not 100% Vi compatible.  Vi has some "unexpected features" or
	bugs in this area.  It uses the screen column instead of the line
	column.)
							fo-b
b	Like 'v', but only auto-wrap if you enter a blank at or before
	the wrap margin.  If the line was longer than 'textwidth' when you
	started the insert, or you do not enter a blank in the insert before
	reaching 'textwidth', Vim does not perform auto-wrapping.
							fo-l
l	Long lines are not broken in insert mode: When a line was longer than
	'textwidth' when the insert command started, Vim does not
	automatically format it.
							fo-m
m	Also break at a multibyte character above 255.  This is useful for
	Asian text where every character is a word on its own.
							fo-M
M	When joining lines, don't insert a space before or after a multibyte
	character.  Overrules the 'B' flag.
							fo-B
B	When joining lines, don't insert a space between two multibyte
	characters.  Overruled by the 'M' flag.
							fo-1
1	Don't break a line after a one-letter word.  It's broken before it
	instead (if possible).
							fo-]
]	Respect 'textwidth' rigorously. With this flag set, no line can be
	longer than 'textwidth', unless line-break-prohibition rules make this
	impossible.  Mainly for CJK scripts and works only if 'encoding' is
	"utf-8".
							fo-j
j	Where it makes sense, remove a comment leader when joining lines.  For
	example, joining:
		int i;   // the index 
		         // in the list 
	Becomes:
		int i;   // the index in the list 
							fo-p
p	Don't break lines at single spaces that follow periods.  This is
	intended to complement 'joinspaces' and cpo-J, for prose with
	sentences separated by two spaces.  For example, with 'textwidth' set
	to 28: 
		Surely you're joking, Mr. Feynman!
	Becomes: 
		Surely you're joking,
		Mr. Feynman!
	Instead of: 
		Surely you're joking, Mr.
		Feynman!


With 't' and 'c' you can specify when Vim performs auto-wrapping:
value	action	
""	no automatic formatting (you can use "gq" for manual formatting)
"t"	automatic formatting of text, but not comments
"c"	automatic formatting for comments, but not text (good for C code)
"tc"	automatic formatting for text and comments

Note that when 'textwidth' is 0, Vim does no automatic formatting anyway (but
does insert comment leaders according to the 'comments' option).  An exception
is when the 'a' flag is present. auto-format

Note that when 'paste' is on, Vim does no formatting at all.

Note that 'textwidth' can be non-zero even if Vim never performs auto-wrapping;
'textwidth' is still useful for formatting with "gq".

If the 'comments' option includes "/*", "*" and/or "*/", then Vim has some
built in stuff to treat these types of comments a bit more cleverly.
Opening a new line before or after "/*" or "*/" (with 'r' or 'o' present in
'formatoptions') gives the correct start of the line automatically.  The same
happens with formatting and auto-wrapping.  Opening a line after a line
starting with "/*" or "*" and containing "*/", will cause no comment leader to
be inserted, and the indent of the new line is taken from the line containing
the start of the comment.
E.g.:
    /* 
     * Your typical comment. 
     */ 
    The indent on this line is the same as the start of the above
    comment.

All of this should be really cool, especially in conjunction with the new
:autocmd command to prepare different settings for different types of file.

Some examples:
  for C code (only format comments): 
	:set fo=croq
 for Mail/news	(format all, don't start comment with "o" command): 
	:set fo=tcrq


Automatic formatting				auto-format autoformat

When the 'a' flag is present in 'formatoptions' text is formatted
automatically when inserting text or deleting text.  This works nicely for
editing text paragraphs.  A few hints on how to use this:

- You need to properly define paragraphs.  The simplest is paragraphs that are
  separated by a blank line.  When there is no separating blank line, consider
  using the 'w' flag and adding a space at the end of each line in the
  paragraphs except the last one.

- You can set the 'formatoptions' based on the type of file filetype or
  specifically for one file with a modeline.

- Set 'formatoptions' to "aw2tq" to make text with indents like this:

	    bla bla foobar bla 
	bla foobar bla foobar bla
	    bla bla foobar bla 
	bla foobar bla bla foobar

- Add the 'c' flag to only auto-format comments.  Useful in source code.

- Set 'textwidth' to the desired width.  If it is zero then 79 is used, or the
  width of the screen if this is smaller.

And a few warnings:

- When part of the text is not properly separated in paragraphs, making
  changes in this text will cause it to be formatted anyway.  Consider doing 

	:set fo-=a

- When using the 'w' flag (trailing space means paragraph continues) and
  deleting the last line of a paragraph with dd, the paragraph will be
  joined with the next one.

- Changed text is saved for undo.  Formatting is also a change.  Thus each
  format action saves text for undo.  This may consume quite a lot of memory.

- Formatting a long paragraph and/or with complicated indenting may be slow.

==============================================================================
7. Sorting text						sorting

Vim has a sorting function and a sorting command.  The sorting function can be
found here: sort(), uniq().

							:sor :sort
:[range]sor[t][!] [b][f][i][l][n][o][r][u][x] [/{pattern}/]
			Sort lines in [range].  When no range is given all
			lines are sorted.

			With [!] the order is reversed.

			With [i] case is ignored.

			With [l] sort uses the current collation locale.
			Implementation details: strcoll() is used to compare
			strings. See :language to check or set the collation
			locale. Example: 
				:language collate en_US.UTF-8
				:%sort l
			v:collate can also used to check the current locale.
			Sorting using the locale typically ignores case.
			This does not work properly on Mac.

			Options [n][f][x][o][b] are mutually exclusive.

			With [n] sorting is done on the first decimal number
			in the line (after or inside a {pattern} match).
			One leading '-' is included in the number.

			With [f] sorting is done on the Float in the line.
			The value of Float is determined similar to passing
			the text (after or inside a {pattern} match) to
			str2float() function. This option is available only
			if Vim was compiled with Floating point support.

			With [x] sorting is done on the first hexadecimal
			number in the line (after or inside a {pattern}
			match).  A leading "0x" or "0X" is ignored.
			One leading '-' is included in the number.

			With [o] sorting is done on the first octal number in
			the line (after or inside a {pattern} match).

			With [b] sorting is done on the first binary number in
			the line (after or inside a {pattern} match).

			With [u] (u stands for unique) only keep the first of
			a sequence of identical lines (ignoring case when [i]
			is used).  Without this flag, a sequence of identical
			lines will be kept in their original order.
			Note that leading and trailing white space may cause
			lines to be different.

			When /{pattern}/ is specified and there is no [r] flag
			the text matched with {pattern} is skipped, so that
			you sort on what comes after the match.
			'ignorecase' applies to the pattern, but 'smartcase'
			is not used.
			Instead of the slash any non-letter can be used.
			For example, to sort on the second comma-separated
			field: 
				:sort /[^,]*,/
			To sort on the text at virtual column 10 (thus
			ignoring the difference between tabs and spaces): 
				:sort /.*%10v/
			To sort on the first number in the line, no matter
			what is in front of it: 
				:sort /.{-}zed/
			(Explanation: ".{-}" matches any text, "ze" sets the
			end of the match and d matches a digit.)
			With [r] sorting is done on the matching {pattern}
			instead of skipping past it as described above.
			For example, to sort on only the first three letters
			of each line: 
				:sort /aaa/ r

			If a {pattern} is used, any lines which don't have a
			match for {pattern} are kept in their current order,
			but separate from the lines which do match {pattern}.
			If you sorted in reverse, they will be in reverse
			order after the sorted lines, otherwise they will be
			in their original order, right before the sorted
			lines.

			If {pattern} is empty (e.g. // is specified), the
			last search pattern is used.  This allows trying out
			a pattern first.

Note that using :sort with :global doesn't sort the matching lines, it's
quite useless.

:sort does not use the current locale unless the l flag is used.
Vim does do a "stable" sort.

The sorting can be interrupted, but if you interrupt it too late in the
process you may end up with duplicated lines.  This also depends on the system
library function used.

 vim:tw=78:ts=8:noet:ft=help:norl: