08Splitting windows

Display two different files above each other. Or view two locations in the file at the same time. See the difference between two files by putting them side by side. All this is possible with split windows.

    Table of contents

  1. Split a window
  2. Split a window on another file
  3. Window size
  4. Vertical splits
  5. Moving windows
  6. Commands for all windows
  7. Viewing differences with vimdiff
  8. Various
  9. Tab pages

08.1Split a window

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 the 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.

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.

#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.

08.2Split a window on another file

The following command opens a second window and starts editing the given file:

:split two.c

If you were editing one.c, then the result looks like this:

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

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

:new

You can repeat the :split and :new commands to create as many windows as you like.

08.3Window 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.

#Options

The winheight option can be set to a minimal desired height of a window and winminheight to a hard minimum height.

Likewise, there is winwidth for the minimal desired width and winminwidth for the hard minimum width.

The equalalways option, when set, makes Vim equalize the windows sizes when a window is closed or opened.

08.4Vertical 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 almost any layout of windows. Then you can use these commands to move between them:

CTRL‑W hmove to the window on the left
CTRL‑W jmove to the window below
CTRL‑W kmove to the window above
CTRL‑W lmove to the window on the right
CTRL‑W tmove to the TOP window
CTRL‑W bmove 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.

More commands to move to other windows: Q_wi.

08.5Moving 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 width 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 Hmove window to the far left
CTRL‑W Jmove window to the bottom
CTRL‑W Lmove window to the far right

08.6Commands for all windows

When you have several windows open and you want to quit Vim, you can close each window separately. A quicker way is using this command:

:qall

This stands for "quit all". If any of the windows contain changes, Vim will not exit. The cursor will automatically be positioned in a window with changes. You can then either use :write to save the changes, or :quit! to throw them away.

If you know there are windows with changes, and you want to save all these changes, use this command:

:wall

This stands for "write all". But actually, it only writes files with changes. Vim knows it doesn't make sense to write files that were not changed.

And then there is the combination of :qall and :wall: the "write and quit all" command:

:wqall

This writes all modified files and quits Vim.

Finally, there is a command that quits Vim and throws away all changes:

:qall!

Be careful, there is no way to undo this command!

#Opening a window for all arguments

To make Vim open a window for each file, start it with the -o argument:

vim -o one.txt two.txt three.txt

This results in:

+-------------------------------+
|file one.txt			|
|~				|
|one.txt========================|
|file two.txt			|
|~				|
|two.txt========================|
|file three.txt			|
|~				|
|three.txt======================|
|				|
+-------------------------------+

The -O argument is used to get vertically split windows.

When Vim is already running, the :all command opens a window for each file in the argument list. :vertical all does it with vertical splits.

08.7Viewing differences with vimdiff

There is a special way to start Vim, which shows the differences between two files. Let's take a file main.c and insert a few characters in one line. Write this file with the backup option set, so that the backup file main.c~ will contain the previous version of the file.

Type this command in a shell (not in Vim):

vimdiff main.c~ main.c

Vim will start, with two windows side by side. You will only see the line in which you added characters, and a few lines above and below it.

 VV		      VV
+-----------------------------------------+
|+ +--123 lines: /* a|+ +--123 lines: /* a|  <- fold
|  text		     |	text		  |
|  text		     |	text		  |
|  text		     |	text		  |
|  text		     |	changed text	  |  <- changed line
|  text		     |	text		  |
|  text		     |	------------------|  <- deleted line
|  text		     |	text		  |
|  text		     |	text		  |
|  text		     |	text		  |
|+ +--432 lines: text|+ +--432 lines: text|  <- fold
|  ~		     |	~		  |
|  ~		     |	~		  |
|main.c~==============main.c==============|
|					  |
+-----------------------------------------+

(This picture doesn't show the highlighting, use the vimdiff command for a better look.)

The lines that were not modified have been collapsed into one line. This is called a closed fold. They are indicated in the picture with "<- fold". Thus the single fold line at the top stands for 123 text lines. These lines are equal in both files.

The line marked with "<- changed line" is highlighted, and the inserted text is displayed with another color. This clearly shows what the difference is between the two files.

The line that was deleted is displayed with --- in the main.c window. See the "<- deleted line" marker in the picture. These characters are not really there. They just fill up main.c, so that it displays the same number of lines as the other window.

#The fold column

Each window has a column on the left with a slightly different background. In the picture above these are indicated with VV. You notice there is a plus character there, in front of each closed fold. Move the mouse pointer to that plus and click the left button. The fold will open, and you can see the text that it contains.

The fold column contains a minus sign for an open fold. If you click on this -, the fold will close.

Obviously, this only works when you have a working mouse. You can also use zo to open a fold and zc to close it.

#Diffing in vim

Another way to start in diff mode can be done from inside Vim. Edit the main.c file, then make a split and show the differences:

:edit main.c
:vertical diffsplit main.c~

The :vertical command is used to make the window split vertically. If you omit this, you will get a horizontal split.

If you have a patch or diff file, you can use the third way to start diff mode. First edit the file to which the patch applies. Then tell Vim the name of the patch file:

:edit main.c
:vertical diffpatch main.c.diff

WARNING: The patch file must contain only one patch, for the file you are editing. Otherwise you will get a lot of error messages, and some files might be patched unexpectedly.

The patching will only be done to the copy of the file in Vim. The file on your harddisk will remain unmodified (until you decide to write the file).

#Scroll binding

When the files have more changes, you can scroll in the usual way. Vim will try to keep both the windows start at the same position, so you can easily see the differences side by side.

When you don't want this for a moment, use this command:

:set noscrollbind

#Jumping to changes

When you have disabled folding in some way, it may be difficult to find the changes. Use this command to jump forward to the next change:

]c

To go the other way use:

[c

Prepended a count to jump further away.

#Removing changes

You can move text from one window to the other. This either removes differences or adds new ones. Vim doesn't keep the highlighting updated in all situations. To update it use this command:

:diffupdate

To remove a difference, you can move the text in a highlighted block from one window to another. Take the main.c and main.c~ example above. Move the cursor to the left window, on the line that was deleted in the other window. Now type this command:

dp

The change will be removed by putting the text of the current window in the other window. dp stands for "diff put".

You can also do it the other way around. Move the cursor to the right window, to the line where changed was inserted. Now type this command:

do

The change will now be removed by getting the text from the other window. Since there are no changes left now, Vim puts all text in a closed fold. do stands for "diff obtain". dg would have been better, but that already has a different meaning (dgg deletes from the cursor until the first line).

For details about diff mode, see vimdiff.

08.8Various

The laststatus option can be used to specify when the last window has a statusline:

0never
1only when there are split windows (the default)
2always

Many commands that edit another file have a variant that splits the window. For Command-line commands this is done by prepending an s. For example: :tag jumps to a tag, :stag splits the window and jumps to a tag.

For Normal mode commands a CTRL‑W is prepended. CTRL‑^ jumps to the alternate file, CTRL‑W CTRL‑^ splits the window and edits the alternate file.

The splitbelow option can be set to make a new window appear below the current window. The splitright option can be set to make a vertically split window appear right of the current window.

When splitting a window you can prepend a modifier command to tell where the window is to appear:

:leftabove {cmd}left or above the current window
:aboveleft {cmd}idem
:rightbelow {cmd}right or below the current window
:belowright {cmd}idem
:topleft {cmd}at the top or left of the Vim window
:botright {cmd}at the bottom or right of the Vim window

08.9Tab pages

You will have noticed that windows never overlap. That means you quickly run out of screen space. The solution for this is called Tab pages.

Assume you are editing thisfile. To create a new tab page use this command:

:tabedit thatfile

This will edit the file thatfile in a window that occupies the whole Vim window. And you will notice a bar at the top with the two file names:

+----------------------------------+
| thisfile | /thatfile/ __________X|    (thatfile is bold)
|/* thatfile */			   |
|that				   |
|that				   |
|~				   |
|~				   |
|~				   |
|				   |
+----------------------------------+

You now have two tab pages. The first one has a window for thisfile and the second one a window for thatfile. It's like two pages that are on top of each other, with a tab sticking out of each page showing the file name.

Now use the mouse to click on thisfile in the top line. The result is

+----------------------------------+
| /thisfile/ | thatfile __________X|    (thisfile is bold)
|/* thisfile */			   |
|this				   |
|this				   |
|~				   |
|~				   |
|~				   |
|				   |
+----------------------------------+

Thus you can switch between tab pages by clicking on the label in the top line. If you don't have a mouse or don't want to use it, you can use the gt command. Mnemonic: Goto Tab.

Now let's create another tab page with the command:

:tab split

This makes a new tab page with one window that is editing the same buffer as the window we were in:

+-------------------------------------+
| thisfile | /thisfile/ | thatfile __X|   (thisfile is bold)
|/* thisfile */			      |
|this				      |
|this				      |
|~				      |
|~				      |
|~				      |
|				      |
+-------------------------------------+

You can put :tab before any Ex command that opens a window. The window will be opened in a new tab page. Another example:

:tab help gt

Will show the help text for gt in a new tab page.

A few more things you can do with tab pages:

For more information about tab pages see tab‑page.