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Previous: 31.1 Why Type More Than You Have To? Chapter 31
Creating Custom Commands in vi
Next: 31.3 What You Lose When You Use map!
 

31.2 Save Time and Typing with the vi map Commands

While you're editing, you may find that you are using a command sequence frequently, or you may occasionally use a very complex command sequence. To save yourself keystrokes, or the time it takes to remember the sequence, assign the sequence to an unused key by using the map and map! commands.

31.2.1 Command Mode Maps

The map command acts a lot like ab (30.31 ) except that you define a macro for command mode instead of text-input mode. (The map! command works during text-input mode. See below.)

map x sequence

Define x as a sequence of editing commands.

unmap x

Disable the x definition.

map

List the characters that are currently mapped.

As with other ex -mode commands, these map commands can be saved in your .exrc file (4.9 ) - or typed in after a colon (: ). If you want a keymap to use only during this editing session, you might find that vi @ -functions (31.4 ) are easier to create and use. The map commands are best for keymaps that you save in your .exrc file and use during many editing sessions.

Before you can start creating your own maps, you need to know the keys not used in command mode that are available for user-defined commands:

Letters:

g K q V v

Control keys:

^A ^K ^O ^T ^W ^X

Symbols:

_ * \ = (Note: the = is used by vi if Lisp mode is set.)

With maps you can create simple or complex command sequences. As a simple example, you could define a command to reverse the order of words. In vi , with the cursor as shown:

you can _the scroll page

the sequence to put the after scroll would be dwwP : delete word, dw ; move to the next word, w ; put the deleted word before that word, P . (You can also use W instead of w .) Saving this sequence:

map v dwwP

enables you to reverse the order of two words at any time in the editing session with the single keystroke v .

You can also map certain multiple-character sequences. Start the map with one of the symbols in the list above. For example, to map the keystrokes *s to put single quotes around a word (' word ' ), and *d to use double quotes (" word " ):

^[
 
map *s Ea'^[Bi'^[
map *d Ea"^[Bi"^[

Now you'll be able to make hundreds of key maps (though your version of vi probably has a limit). Article 31.9 has lots of examples.

You may also be able to associate map sequences with your terminal's function keys if your termcap or terminfo entry (5.2 ) defines those keys. For example, to make function key F1 transpose words:

map #1 dwelp

A final note: map assignments are not really limited to unused keys. You can map keys that are defined as other vi commands, but then the key's original meaning is inaccessible. But this is probably okay if the key is tied to a command that you rarely use. There's more information in article 31.14 about the noremap option.

31.2.2 Text-Input Mode Maps

The map! command works like map , but map! works during text-input mode. You actually set the map! during command mode, in the same way as a plain map : at a colon (: ) prompt, type map! followed by a space and the key(s) that activate the map; then type a space and the text that the text-input mode map stands for. These text-input mode maps are a lot like abbreviations (30.31 ) ; the difference is that map! lets you switch from text-input mode to command mode, execute commands, then go back to text-input mode. To go to command mode during a map! , you'll need to put an ESC key in the value of the map by typing CTRL-v and then ESC (31.6 ) . After your map! does whatever in command mode, it can re-enter text-input mode with the usual commands a , i , and so on.

Let's say you normally never type the caret (^ ) key during input mode. When you're typing along, as you realize that what you're typing is important, you want to press the caret key. Then, vi should open a line above and insert the phrase "THIS IS IMPORTANT:". Finally, vi should return you to text-input mode at the end of the line where you pressed the caret key. To do that, go to command mode and enter the following map! command. The first ^ comes from pressing the caret key. Then you'll see two places with ^[ ; that's made by pressing CTRL-v followed by the ESC key. Finish the map by pressing RETURN:

:map! ^ ^[OTHIS IS IMPORTANT:^[jA

What does that do? It executes the same vi commands you'd use to add those three words yourself, manually. During text-input mode, typing a caret (^ ) will:

  1. Do ESC to go to command mode,

  2. Use O to open a new line above (in text-input mode),

  3. Enter the text THIS IS IMPORTANT:

  4. Do another ESC to go back to command mode,

  5. Do j to go down a line (to the line where you started), and

  6. Do A to put you at the end of the line, in text-input mode.

The trick is to use map! only to redefine keys you'll never use for anything else during text-input mode. To temporarily disable a text-input mode map, press CTRL-v before the key. For example, to put a real caret into your file, type [CTRL-v] [^ ] To disable an input-mode map for the rest of your vi session, type :unmap! followed by the character(s) that activate the map.

A more common example is mapping your keyboard's arrow or function keys to do something during text-input mode. These keys send a special series of characters. Normally, without a map! defined for these keys, the characters they send will be put into your editor buffer - just as if you'd typed the characters they make, yourself, one by one. For instance, my left arrow key sends the characters ESC , then [ (left bracket), then D . Without an text-input mode map! defined for that three-character sequence, vi will be hopelessly confused [1] if I press that arrow key. Many UNIX developers have added text-input mode maps for arrow keys. You can see them when you list all your text-input mode maps by typing :map! by itself, with nothing after:

[1] Actually, the ESC will switch vi back to command mode. The first [ will make vi think you're about to type the section-motion command [[ , so the following D will make vi beep. Ugly, eh?

up      ^[[A    ^[ka
down    ^[[B    ^[ja
left    ^[[D    ^[hi
right   ^[[C    ^[la
^       ^       ^[OTHIS IS IMPORTANT:^[jA

Article 31.3 lists some problems with map! .

- JP , DG , LL


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