1.6. Introducing the vim editor

Vim is a highly configurable text editor built to make creating and changing any kind of text very efficient. It is included as vi with most *nix systems and with Apple OS X. Among its features are:

If you plan to program in C++, you should have at least a minimal familiarity with vi. vi is a very old, but very capable text editor with many features specifically designed for writing software. Technically, vi came first, and vim is a separate program (Vi IMproved), but often typing either ‘vi’ or ‘vim’ invokes the same program, and the distinction is unimportant until you begin exploring some of the features vim has added. This text uses the two terms interchangeably.

Vi has thousands of features. No one knows them all, that is not the point. Vi is a very efficient editor that has intuitive commands. Because vi was created by programmers, for programmers, most vi commands ‘reward’ you, if you know how to touch type. The idea is to spend less time messing with menu commands and to spend more time writing code.

Benefits of learning Vim

Once the basics of the vi editor have been mastered, you’ll find the skills learned to master vi translate to other tasks you’ll perform as a programmer as well.

  1. It is well integrated into Unix and Linux. Many Linux tools use the same key bindings as vim to perform similar actions, so while learning vim, you are also learning these commands without even knowing it.

  2. The command shell history can be edited using vi commands.

  3. Files can be edited directly over a network connection.

  4. Vim can edit zip files directly with no need to extract their contents first.

  5. Vim can easily compile programs and has rules for building many kinds of programs

Vim help

Vim is delivered with an extensive set of searchable, hyperlinked documentation. Access vim help using :help (or just :h. By default a help window open with basic vim navigation and how to jump to hyperlinked topics within the documentation.

1.6.1. Modes

One of the first things to get used to with vi is that it is a modal editor. Anyone who has used a computer to edit the contents of a text file has most likely used a “mode-less” editor; for example, programs like Microsoft Word, Notepad or Notepad++. In a “mode-less” editor there is actually one mode: the text input mode. For composing an essay this is more than likely all that is needed.

The vi editor has more modes than just “insert text”. Modes allow vi to do two basic things:

  • accept a command, such as deleting a line

  • accept text, written by you

Some commands tell vim to enter a new mode which affects what your next keystrokes will do. In vi, type :help vim-modes to get help on modes and how to use them.

In the vi editor, each of these tasks is achieved by putting the editor into a particular mode of operation (normally just called a mode). When you wish to give vi a command, you enter command mode, and when you want to enter text, you enter insert mode.

It is important to set the correct mode before you begin writing, but this is simple to do. When you first start vi, it is automatically in normal mode.

Name

Description

help page

normal

For navigation and manipulation of text. This is the mode that vim will usually start in, which you can usually get back to with ESC.

:help Normal-mode

insert

For inserting new text. The main difference from vi is that many important “normal” commands are also available in insert mode - provided you have a keyboard with enough meta keys (such as Ctrl, Alt, Windows-key, etc.).

:help Insert-mode

visual

For navigation and manipulation of text selections, this mode allows you to perform most normal commands, and a few extra commands, on selected text.

:help Visual-mode

select

Similar to visual, but with a more MS Windows-like behavior.

:help Select-mode

command-line

For entering editor commands - like the help commands in the 3rd column.

:help Command-line-mode

Ex-mode

Similar to the command-line mode but optimized for batch processing.

:help Ex-mode

There are many sources of vim tutorials and resources for learning about vim. The best place to start is at your terminal, if you have one. At the command prompt, type vimtutor:

host@user: vimtutor

Will launch a short tutorial designed to get you started with the basics.

The site http://www.openvim.com hosts a web-based vim tutor that is easy to use.

Linux.com also has a decent introduction to vim.

1.6.2. Motions

A motion is simply a command that moves the cursor. There’s plenty of them, with h, j, k, and l being the most easily understood: move left, move up, move right, move down; all by only a single character.

1.6.2.1. Word motions

w To the beginning of the next word.

e To the end of the current word.

W To the beginning of the next WORD.

E To the end of the current WORD.

b Go backward a word.

B Go backward a WORD.

1.6.2.2. Other motions

gg Go to the first line.

G Go to the very last line.

0 Go to the very first character of the line.

^ Go to the very first non-whitespace character of the line.

$ Go to the very last character of the line.

1.6.3. Selections

Selections are slightly different than motions in that they don’t move the cursor but they do alter the way in which commands work. They will apply a command or operation to something like a word, or a sentence, or a block of text inside paired parenthesis, etc. A single selection can do a lot to make life in Vim easy.

aw A word

aW A WORD

iw An inner word

iW An inner WORD

1.6.4. Command & motion examples

  • Re-indent everything gg=G

  • Re-indent a block of code, including braces =aB or =a{

    • If the cursor is on a brace, =% is the same as =aB

  • Re-indent ‘inner block’, excluding braces =iB or =i{

  • Delete to the next word: daw

  • Delete to the next x character (replace ‘x’ with your character): dtx

  • Change a sentence: cas

  • Change 3 letters: 3cl

  • Delete everything inside parenthesis: di)

  • Visually select a paragraph: vap

1.6.5. Creating ‘Hello World’ using vim

It is best to review this section after completing the vimtutor. The vimtutor does a good job of explaining the basics of vim, but doesn’t provide information specific to compiling and running programs.

  1. Before jumping into the editor, first let’s plan to save our project in a directory of its own:

    host@user: mkdir work
host@user: cd work

    I chose to work in the directory, work, but you could have named it hello, project1, or anything else. Just pick something that works for you, preferably related to the task at hand. Recommendation: avoid spaces in directory names.

  2. At the command prompt, open a new cpp source file:

    host@user: vi hello.cpp

    You’ll now be in vi, which initially, will show a blank canvas. Use the commands you learned in vimtutor to enter insert mode and begin typing your program:

    #include <iostream>

int main() {
  std::cout << "Hello, World!\n";
}

  3. When done typing, press ESC to leave insert mode.

  4. Save your work by typing :w.

  5. Still within vim, run the make command: type :make hello. You should see something similar to:

    c++ hello.cpp   -o hello

Press ENTER or type command to continue

  6. If you type :make hello a second time (when hello already exists and you haven’t yet modified hello.cpp), then you should see:

    make: `hello' is up to date.

  7. At this point, you can run your program, also without leaving vi, by typing :!./hello. The :! command (bang command) executes shell commands from vim. If you typed the above source code, you should see:

    Hello, World!

Press ENTER or type command to continue
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