VIM: usr_25

## USR_25

    *usr_25.txt*	For Vim version 7.4.  Last change: 2007 May 11

    		     VIM USER MANUAL - by Bram Moolenaar

    			     Editing formatted text

    Text hardly ever comes in one sentence per line.  This chapter is about
    breaking sentences to make them fit on a page and other formatting.
    Vim also has useful features for editing single-line paragraphs and tables.

    |25.1|	Breaking lines
    |25.2|	Aligning text
    |25.3|	Indents and tabs
    |25.4|	Dealing with long lines
    |25.5|	Editing tables

         Next chapter: |usr_26|  Repeating
     Previous chapter: |usr_24|  Inserting quickly
    Table of contents: |usr_toc|

    *25.1*	Breaking lines

    Vim has a number of functions that make dealing with text easier.  By default,
    the editor does not perform automatic line breaks.  In other words, you have
    to press <Enter> yourself.  This is useful when you are writing programs where
    you want to decide where the line ends.  It is not so good when you are
    creating documentation and want the text to be at most 70 character wide.
       If you set the 'textwidth' option, Vim automatically inserts line breaks.
    Suppose, for example, that you want a very narrow column of only 30
    characters.  You need to execute the following command:

    	:set textwidth=30

    Now you start typing (ruler added):

    		 1	   2	     3
    	12345678901234567890123456789012345
    	I taught programming for a whi

    If you type "l" next, this makes the line longer than the 30-character limit.
    When Vim sees this, it inserts a line break and you get the following:

    		 1	   2	     3
    	12345678901234567890123456789012345
    	I taught programming for a
    	whil

    Continuing on, you can type in the rest of the paragraph:

    		 1	   2	     3
    	12345678901234567890123456789012345
    	I taught programming for a
    	while. One time, I was stopped
    	by the Fort Worth police,
    	because my homework was too
    	hard. True story.

    You do not have to type newlines; Vim puts them in automatically.

    	Note:
    	The 'wrap' option makes Vim display lines with a line break, but this
    	doesn't insert a line break in the file.

    REFORMATTING

    The Vim editor is not a word processor.  In a word processor, if you delete
    something at the beginning of the paragraph, the line breaks are reworked.  In
    Vim they are not; so if you delete the word "programming" from the first line,
    all you get is a short line:

    		 1	   2	     3
    	12345678901234567890123456789012345
    	I taught for a
    	while. One time, I was stopped
    	by the Fort Worth police,
    	because my homework was too
    	hard. True story.

    This does not look good.  To get the paragraph into shape you use the "gq"
    operator.
       Let's first use this with a Visual selection.  Starting from the first
    line, type:

    	v4jgq

    "v" to start Visual mode, "4j' to move to the end of the paragraph and then
    the "gq" operator.  The result is:

    		 1	   2	     3
    	12345678901234567890123456789012345
    	I taught for a while. One
    	time, I was stopped by the
    	Fort Worth police, because my
    	homework was too hard. True
    	story.

    Note: there is a way to do automatic formatting for specific types of text
    layouts, see |auto-format|.

    Since "gq" is an operator, you can use one of the three ways to select the
    text it works on: With Visual mode, with a movement and with a text object.
       The example above could also be done with "gq4j".  That's less typing, but
    you have to know the line count.  A more useful motion command is "}".  This
    moves to the end of a paragraph.  Thus "gq}" formats from the cursor to the
    end of the current paragraph.
       A very useful text object to use with "gq" is the paragraph.  Try this:

    	gqap

    "ap" stands for "a-paragraph".  This formats the text of one paragraph
    (separated by empty lines).  Also the part before the cursor.
       If you have your paragraphs separated by empty lines, you can format the
    whole file by typing this:

    	gggqG

    "gg" to move to the first line, "gqG" to format until the last line.
       Warning: If your paragraphs are not properly separated, they will be joined
    together.  A common mistake is to have a line with a space or tab.  That's a
    blank line, but not an empty line.

    Vim is able to format more than just plain text.  See |fo-table| for how to
    change this.  See the 'joinspaces' option to change the number of spaces used
    after a full stop.
       It is possible to use an external program for formatting.  This is useful
    if your text can't be properly formatted with Vim's builtin command.  See the
    'formatprg' option.

    *25.2*	Aligning text

    To center a range of lines, use the following command:

    	:{range}center [width]

    {range} is the usual command-line range.  [width] is an optional line width to
    use for centering.  If [width] is not specified, it defaults to the value of
    'textwidth'.  (If 'textwidth' is 0, the default is 80.)
       For example:

    	:1,5center 40

    results in the following:

           I taught for a while. One
           time, I was stopped by the
         Fort Worth police, because my
          homework was too hard. True
    		 story.

    RIGHT ALIGNMENT

    Similarly, the ":right" command right-justifies the text:

    	:1,5right 37

    gives this result:

    	    I taught for a while. One
    	   time, I was stopped by the
    	Fort Worth police, because my
    	  homework was too hard. True
    			       story.

    LEFT ALIGNMENT

    Finally there is this command:

    	:{range}left [margin]

    Unlike ":center" and ":right", however, the argument to ":left" is not the
    length of the line.  Instead it is the left margin.  If it is omitted, the
    text will be put against the left side of the screen (using a zero margin
    would do the same).  If it is 5, the text will be indented 5 spaces.  For
    example, use these commands:

    	:1left 5
    	:2,5left

    This results in the following:

    	     I taught for a while. One
    	time, I was stopped by the
    	Fort Worth police, because my
    	homework was too hard. True
    	story.

    JUSTIFYING TEXT

    Vim has no built-in way of justifying text.  However, there is a neat macro
    package that does the job.  To use this package, execute the following
    command:

    	:runtime macros/justify.vim

    This Vim script file defines a new visual command "_j".  To justify a block of
    text, highlight the text in Visual mode and then execute "_j".
       Look in the file for more explanations.  To go there, do "gf" on this name:
    $VIMRUNTIME/macros/justify.vim.

    An alternative is to filter the text through an external program.  Example:

    	:%!fmt

    *25.3*	Indents and tabs

    Indents can be used to make text stand out from the rest.  The example texts
    in this manual, for example, are indented by eight spaces or a tab.  You would
    normally enter this by typing a tab at the start of each line.  Take this
    text:
    	the first line
    	the second line

    This is entered by typing a tab, some text, <Enter>, tab and more text.
       The 'autoindent' option inserts indents automatically:

    	:set autoindent

    When a new line is started it gets the same indent as the previous line.  In
    the above example, the tab after the <Enter> is not needed anymore.

    INCREASING INDENT

    To increase the amount of indent in a line, use the ">" operator.  Often this
    is used as ">>", which adds indent to the current line.
       The amount of indent added is specified with the 'shiftwidth' option.  The
    default value is 8.  To make ">>" insert four spaces worth of indent, for
    example, type this:

    	:set shiftwidth=4

    When used on the second line of the example text, this is what you get:

    	the first line
    	    the second line

    "4>>" will increase the indent of four lines.

    TABSTOP

    If you want to make indents a multiple of 4, you set 'shiftwidth' to 4.  But
    when pressing a <Tab> you still get 8 spaces worth of indent.  To change this,
    set the 'softtabstop' option:

    	:set softtabstop=4

    This will make the <Tab> key insert 4 spaces worth of indent.  If there are
    already four spaces, a <Tab> character is used (saving seven characters in the
    file).  (If you always want spaces and no tab characters, set the 'expandtab'
    option.)

    	Note:
    	You could set the 'tabstop' option to 4.  However, if you edit the
    	file another time, with 'tabstop' set to the default value of 8, it
    	will look wrong.  In other programs and when printing the indent will
    	also be wrong.  Therefore it is recommended to keep 'tabstop' at eight
    	all the time.  That's the standard value everywhere.

    CHANGING TABS

    You edit a file which was written with a tabstop of 3.  In Vim it looks ugly,
    because it uses the normal tabstop value of 8.  You can fix this by setting
    'tabstop' to 3.  But you have to do this every time you edit this file.
       Vim can change the use of tabstops in your file.  First, set 'tabstop' to
    make the indents look good, then use the ":retab" command:

    	:set tabstop=3
    	:retab 8

    The ":retab" command will change 'tabstop' to 8, while changing the text such
    that it looks the same.  It changes spans of white space into tabs and spaces
    for this.  You can now write the file.  Next time you edit it the indents will
    be right without setting an option.
       Warning: When using ":retab" on a program, it may change white space inside
    a string constant.  Therefore it's a good habit to use "\t" instead of a
    real tab.

    *25.4*	Dealing with long lines

    Sometimes you will be editing a file that is wider than the number of columns
    in the window.  When that occurs, Vim wraps the lines so that everything fits
    on the screen.
       If you switch the 'wrap' option off, each line in the file shows up as one
    line on the screen.  Then the ends of the long lines disappear off the screen
    to the right.
       When you move the cursor to a character that can't be seen, Vim will scroll
    the text to show it.  This is like moving a viewport over the text in the
    horizontal direction.
       By default, Vim does not display a horizontal scrollbar in the GUI.  If you
    want to enable one, use the following command:

    	:set guioptions+=b

    One horizontal scrollbar will appear at the bottom of the Vim window.

    If you don't have a scrollbar or don't want to use it, use these commands to
    scroll the text.  The cursor will stay in the same place, but it's moved back
    into the visible text if necessary.

    	zh		scroll right
    	4zh		scroll four characters right
    	zH		scroll half a window width right
    	ze		scroll right to put the cursor at the end
    	zl		scroll left
    	4zl		scroll four characters left
    	zL		scroll half a window width left
    	zs		scroll left to put the cursor at the start

    Let's attempt to show this with one line of text.  The cursor is on the "w" of
    "which".  The "current window" above the line indicates the text that is
    currently visible.  The "window"s below the text indicate the text that is
    visible after the command left of it.

    			      |<-- current window -->|
    		some long text, part of which is visible in the window
    	ze	  |<--	   window     -->|
    	zH	   |<--     window     -->|
    	4zh		  |<--	   window     -->|
    	zh		     |<--     window	 -->|
    	zl		       |<--	window	   -->|
    	4zl			  |<--	   window     -->|
    	zL				|<--	 window     -->|
    	zs			       |<--	window	   -->|

    MOVING WITH WRAP OFF

    When 'wrap' is off and the text has scrolled horizontally, you can use the
    following commands to move the cursor to a character you can see.  Thus text
    left and right of the window is ignored.  These never cause the text to
    scroll:

    	g0		to first visible character in this line
    	g^		to first non-blank visible character in this line
    	gm		to middle of this line
    	g$		to last visible character in this line

    		|<--	 window    -->|
    	some long    text, part of which is visible
    		 g0  g^    gm	     g$

    BREAKING AT WORDS				*edit-no-break*

    When preparing text for use by another program, you might have to make
    paragraphs without a line break.  A disadvantage of using 'nowrap' is that you
    can't see the whole sentence you are working on.  When 'wrap' is on, words are
    broken halfway, which makes them hard to read.
       A good solution for editing this kind of paragraph is setting the
    'linebreak' option.  Vim then breaks lines at an appropriate place when
    displaying the line.  The text in the file remains unchanged.
       Without 'linebreak' text might look like this:

    	+---------------------------------+
    	|letter generation program for a b|
    	|ank.  They wanted to send out a s|
    	|pecial, personalized letter to th|
    	|eir richest 1000 customers.  Unfo|
    	|rtunately for the programmer, he |
    	+---------------------------------+
    After:

    	:set linebreak

    it looks like this:

    	+---------------------------------+
    	|letter generation program for a  |
    	|bank.  They wanted to send out a |
    	|special, personalized letter to  |
    	|their richest 1000 customers.    |
    	|Unfortunately for the programmer,|
    	+---------------------------------+

    Related options:
    'breakat' specifies the characters where a break can be inserted.
    'showbreak' specifies a string to show at the start of broken line.
    Set 'textwidth' to zero to avoid a paragraph to be split.

    MOVING BY VISIBLE LINES

    The "j" and "k" commands move to the next and previous lines.  When used on
    a long line, this means moving a lot of screen lines at once.
       To move only one screen line, use the "gj" and "gk" commands.  When a line
    doesn't wrap they do the same as "j" and "k".  When the line does wrap, they
    move to a character displayed one line below or above.
       You might like to use these mappings, which bind these movement commands to
    the cursor keys:

    	:map <Up> gk
    	:map <Down> gj

    TURNING A PARAGRAPH INTO ONE LINE

    If you want to import text into a program like MS-Word, each paragraph should
    be a single line.  If your paragraphs are currently separated with empty
    lines, this is how you turn each paragraph into a single line:

    	:g/./,/^$/join

    That looks complicated.  Let's break it up in pieces:

    	:g/./		A ":global" command that finds all lines that contain
    			at least one character.
    	     ,/^$/	A range, starting from the current line (the non-empty
    			line) until an empty line.
    		  join	The ":join" command joins the range of lines together
    			into one line.

    Starting with this text, containing eight lines broken at column 30:

    	+----------------------------------+
    	|A letter generation program	   |
    	|for a bank.  They wanted to	   |
    	|send out a special,		   |
    	|personalized letter.		   |
    	|				   |
    	|To their richest 1000		   |
    	|customers.  Unfortunately for	   |
    	|the programmer,		   |
    	+----------------------------------+

    You end up with two lines:

    	+----------------------------------+
    	|A letter generation program for a |
    	|bank.	They wanted to send out a s|
    	|pecial, personalized letter.	   |
    	|To their richest 1000 customers.  |
    	|Unfortunately for the programmer, |
    	+----------------------------------+

    Note that this doesn't work when the separating line is blank but not empty;
    when it contains spaces and/or tabs.  This command does work with blank lines:

    	:g/\S/,/^\s*$/join

    This still requires a blank or empty line at the end of the file for the last
    paragraph to be joined.

    *25.5*	Editing tables

    Suppose you are editing a table with four columns:

    	nice table	  test 1	test 2	    test 3
    	input A		  0.534
    	input B		  0.913

    You need to enter numbers in the third column.  You could move to the second
    line, use "A", enter a lot of spaces and type the text.
       For this kind of editing there is a special option:

    	set virtualedit=all

    Now you can move the cursor to positions where there isn't any text.  This is
    called "virtual space".  Editing a table is a lot easier this way.
       Move the cursor by searching for the header of the last column:

    	/test 3

    Now press "j" and you are right where you can enter the value for "input A".
    Typing "0.693" results in:

    	nice table	  test 1     test 2	 test 3
    	input A		  0.534			 0.693
    	input B		  0.913

    Vim has automatically filled the gap in front of the new text for you.  Now,
    to enter the next field in this column use "Bj".  "B" moves back to the start
    of a white space separated word.  Then "j" moves to the place where the next
    field can be entered.

    	Note:
    	You can move the cursor anywhere in the display, also beyond the end
    	of a line.  But Vim will not insert spaces there, until you insert a
    	character in that position.

    COPYING A COLUMN

    You want to add a column, which should be a copy of the third column and
    placed before the "test 1" column.  Do this in seven steps:
    1.  Move the cursor to the left upper corner of this column, e.g., with
        "/test 3".
    2.  Press CTRL-V to start blockwise Visual mode.
    3.  Move the cursor down two lines with "2j".  You are now in "virtual space":
        the "input B" line of the "test 3" column.
    4.  Move the cursor right, to include the whole column in the selection, plus
        the space that you want between the columns.  "9l" should do it.
    5.  Yank the selected rectangle with "y".
    6.  Move the cursor to "test 1", where the new column must be placed.
    7.  Press "P".

    The result should be:

    	nice table	  test 3    test 1     test 2	   test 3
    	input A		  0.693     0.534		   0.693
    	input B			    0.913

    Notice that the whole "test 1" column was shifted right, also the line where
    the "test 3" column didn't have text.

    Go back to non-virtual cursor movements with:

    	:set virtualedit=

    VIRTUAL REPLACE MODE

    The disadvantage of using 'virtualedit' is that it "feels" different.  You
    can't recognize tabs or spaces beyond the end of line when moving the cursor
    around.  Another method can be used: Virtual Replace mode.
       Suppose you have a line in a table that contains both tabs and other
    characters.  Use "rx" on the first tab:

    	inp	0.693   0.534	0.693

    	       |
    	   rx  |
    	       V

    	inpx0.693   0.534	0.693

    The layout is messed up.  To avoid that, use the "gr" command:

    	inp	0.693   0.534	0.693

    	       |
    	  grx  |
    	       V

    	inpx	0.693   0.534	0.693

    What happens is that the "gr" command makes sure the new character takes the
    right amount of screen space.  Extra spaces or tabs are inserted to fill the
    gap.  Thus what actually happens is that a tab is replaced by "x" and then
    blanks added to make the text after it keep its place.  In this case a
    tab is inserted.
       When you need to replace more than one character, you use the "R" command
    to go to Replace mode (see |04.9|).  This messes up the layout and replaces
    the wrong characters:

    	inp	0	0.534	0.693

    		|
    	 R0.786 |
    		V

    	inp	0.78634	0.693

    The "gR" command uses Virtual Replace mode.  This preserves the layout:

    	inp	0	0.534	0.693

    		|
    	gR0.786 |
    		V

    	inp	0.786	0.534	0.693

    Next chapter: |usr_26|  Repeating

    Copyright: see |manual-copyright|  vim:tw=78:ts=8:ft=help:norl:

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