*10*	Multiple-window handling

This chapter gives tips on how to handle multiple windows and multiple
files.

|10_1|	Editing another file
|10_2|	Specifying multiple files
|10_3|	Hiding and unhiding buffers
|10_4|	Multiple window operations
|10_5|	Window size
|10_6|	Vertical splits
|10_7|	Moving windows

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*10_1*	Editing another file

You have finished editing the current file. Now you want to edit another
file >

	:e[dit] otherfile

This will close the current file and open a new file. If you have not saved
the changes of the current file, this open will fail. You can first save
those changes >

	:w[rite]

Or, you can choose to ignore the modifications and force the opening of
other file >

	:e[dit]! otherfile



===========================================================================
*10_2*	Specifying multiple files

You can start editing multiple files by giving a list of files on command
line argument >

	bash> vim first second third

This will open the first file for editing. After you have finished your
editing, you can go to the next file using >

	:n[ext]

If you have made changes in first, which you want to discard >

	:n[ext]!

However, you would mostly want to save the changes and go to the next file >

	:wn[ext]

This is effectively like issuing the :write followed by :next command.


Seeing file list ~

You can have a look at the list of files by typing >

	:ar[gs]


Going back ~

You can go back to previous files by using one of the following >

	:prev[ious]
	:N[ext]

The variants of these commands which save the current file - wprev[ious] and
wN[ext] are also available.


Jumping to the start or end of list ~

You can jump to the beginning or end of the list using >

	:first
	:rewind
	:last

Specifying a count ~

The next and prev commands can also take counts :2next or :5prev


===========================================================================
*10_3*	Hiding and unhiding

You have made some changes to a file. And now, you want to edit another
file, but not write the changes in the current file yet, you can make it
hidden >

	:hid[e] n[ext]

The "next" can be replaced with any edit command. For eg. >

	:hid[e] e[dit] foo.txt


Where did the changes go? ~

The Vim editor uses the term buffer to describe a file being edited.
Actually, a buffer is a copy of the file that you edit.  When you finish
changing the buffer, you write the contents of the buffer to the file.
Buffers not only contain file contents, but also all the marks, settings,
and other stuff that goes with it.

So when you issue the 'hide' command, the buffer which contains the edited
contents is hidden. You can issue the following command to see the buffers
which are existing at any particular instance >

	:buffers

This would produce an output which looks something like

	1 #h + "first"                            line 1
	2 %a   "second"                           line 1
	3      "third"                            line 0

The following is an alternative command to list buffers >

	:ls

The '%' indicates the current file, the '#' indicates the alternate file.
The 'h' indicates that the buffer is hidden while the 'a' denotes the active
buffer. You can switch between the '%' and '#' buffers by using the
following command >

	CTRL-^

You can start editing a particular file by giving its buffer number >

	:b[uffer] 3

But the only way to know the number is by looking in the buffer list.  You
can use the name, or part of it, instead: >

	:b[uffer] t

In this case, vim will start editing file "third" the closest match.

You can move around in the buffer list with these commands: >

	:bn[ext]
	:bp[revious]
	:bN[ext]
	:bf[irst]
	:br[ewind]
	:bl[ast]

===========================================================================
*10_4*	Multiple window operations

The easiest way to open a new window is to use the following command: >

	:split

This command splits the screen into two windows and leaves the cursor in the
top one:

	+----------------------------------+
	|/* file one.c */		   |
	|~				   |
	|~				   |
	|one.c=============================|
	|/* file one.c */		   |
	|~				   |
	|one.c=============================|
	|				   |
	+----------------------------------+

What you see here is two windows on the same file.  The line with "====" is
that status line.  It displays information about the window above it.  (in
practice the status line will be in reverse video.)

The two windows allow you to view two parts of the same file.  For example,
you could make the top window show the variable declarations of a program,
and the bottom one the code that uses these variables. If you give a file
name to the split command, the file is opened in the new window. >

	:split two.c

To open a window on a new, empty file, use this: >

	:new

The CTRL-W w command can be used to jump between the windows.  If you are in
the top window, CTRL-W w jumps to the window below it.  If you are in the
bottom window it will jump to the first window. (CTRL-W CTRL-W does the same
thing, in case you let go of the CTRL key a bit later).


Close the window ~

To close a window, use the command: >

	:close

Actually, any command that quits editing a file works, like ":quit" and
"ZZ".  But ":close" prevents you from accidentally exiting Vim when you
close the last window.

The following variants of the :write and :quit commands can also be used to
perform similar operations on all windows >

	:wall	(Write all)
	:qall	(Quit all)
	:wqall	(Write-Quit all)
	:qall!	(Quit all discarding changes)

Closing all other windows ~

If you have opened a whole bunch of windows, but now want to concentrate on
one of them, this command will be useful: >

	:only

This closes all windows, except for the current one.  If any of the other
windows has changes, you will get an error message and that window won't be
closed.


===========================================================================
*10_5*	Window size

The :split command can take a number argument.  If specified, this will be
the height of the new window.  For example, the following opens a new window
three lines high and starts editing the file alpha.c: >

	:3split alpha.c

For existing windows you can change the size in several ways.  When you have
a working mouse, it is easy: Move the mouse pointer to the status line that
separates two windows, and drag it up or down.

To increase the size of a window: >

	CTRL-W +

To decrease it: >

	CTRL-W -

Both of these commands take a count and increase or decrease the window size
by that many lines.  Thus "4 CTRL-W +" make the window four lines higher.

To set the window height to a specified number of lines: >

	{height}CTRL-W _

That's: a number {height}, CTRL-W and then an underscore (the - key with
Shift on English-US keyboards).

To make a window as high as it can be, use the CTRL-W _ command without a
count.


Using the mouse ~

In Vim you can do many things very quickly from the keyboard.
Unfortunately, the window resizing commands require quite a bit of typing.
In this case, using the mouse is faster.  Position the mouse pointer on a
status line.  Now press the left mouse button and drag.  The status line
will move, thus making the window on one side higher and the other smaller.


===========================================================================
*10_6*	Vertical splits

The ":split" command creates the new window above the current one.  To make
the window appear at the left side, use: >

	:vsplit

or: >
	:vsplit two.c

The result looks something like this:

	+--------------------------------------+
	|/* file two.c */   |/* file one.c */  |
	|~		    |~		       |
	|~		    |~		       |
	|~		    |~		       |
	|two.c===============one.c=============|
	|				       |
	+--------------------------------------+

Actually, the | lines in the middle will be in reverse video.  This is
called the vertical separator.  It separates the two windows left and right
of it.

There is also the "vnew" command, to open a vertically split window on a
new, empty file.  Another way to do this: >

	:vertical new

The ":vertical" command can be inserted before another command that splits a
window.  This will cause that command to split the window vertically instead
of horizontally.  (if the command doesn't split a window, it works
unmodified).


Moving between windows ~

Since you can split windows horizontally and vertically as much as you like,
you can create any layout of windows.  Then you can use these commands to
move between them:

	CTRL-W h	move to the window on the left
	CTRL-W j	move to the window below
	CTRL-W k	move to the window above
	CTRL-W l	move to the window on the right

	CTRL-W t	move to the TOP window
	CTRL-W b	move to the BOTTOM window

You will notice the same letters as used for moving the cursor.  And the
cursor keys can also be used, if you like.


===========================================================================
*10_7*	Moving windows

You have split a few windows, but now they are in the wrong place.  Then you
need a command to move the window somewhere else.  For example, you have
three windows like this:

	+----------------------------------+
	|/* file two.c */		   |
	|~				   |
	|~				   |
	|two.c=============================|
	|/* file three.c */		   |
	|~				   |
	|~				   |
	|three.c===========================|
	|/* file one.c */		   |
	|~				   |
	|one.c=============================|
	|				   |
	+----------------------------------+

Clearly the last one should be at the top.  Go to that window (using CTRL-W
w) and the type this command: >

	CTRL-W K

This uses the uppercase letter K.  What happens is that the window is moved
to the very top.  You will notice that K is again used for moving upwards.

When you have vertical splits, CTRL-W K will move the current window to the
top and make it occupy the full with of the Vim window.  If this is your
layout:

	+-------------------------------------------+
	|/* two.c */  |/* three.c */  |/* one.c */  |
	|~	      |~	      |~	    |
	|~	      |~	      |~	    |
	|~	      |~	      |~	    |
	|~	      |~	      |~	    |
	|~	      |~	      |~	    |
	|two.c=========three.c=========one.c========|
	|					    |
	+-------------------------------------------+

Then using CTRL-W K in the middle window (three.c) will result in:

	+-------------------------------------------+
	|/* three.c */				    |
	|~					    |
	|~					    |
	|three.c====================================|
	|/* two.c */	       |/* one.c */	    |
	|~		       |~		    |
	|two.c==================one.c===============|
	|					    |
	+-------------------------------------------+

The other three similar commands (you can probably guess these now):

	CTRL-W H	move window to the far left
	CTRL-W J	move window to the bottom
	CTRL-W L	move window to the far right


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vim:ft=help:tw=76:ts=8:nomodifiable