UNIX° TEXT PROCESSING

Learning vi

UNIX has a number of editors that can process the contents of readable files, whether those files contain data, source code, or text. There are line editors, such as ed and ex, which display a line of the file on the screen, and there are screen editors, such as vi and emacs, which display a part of the file on your terminal screen.

The most useful standard text editor on your system is vi. Unlike emacs, it is available in nearly identical form on almost every UNIX system, thus providing a kind of text editing lingua franca. The same might be said of ed and ex, but screen editors are generally much easier to use. With a screen editor you can scroll the page, move the cursor, delete lines, insert characters, and more, while seeing the results of your edits as you make them. Screen editors are very popular because they allow you to make changes as you read a file, much as you would edit a printed copy, only faster.

To many beginners, vi looks unintuitive and cumbersome—instead of letting you type normally and use special control keys for word-processing functions, it uses all of the regular keyboard keys for issuing commands. You must be in a special insert mode before you can type. In addition, there seem to be so many commands.

You can’t learn vi by memorizing every single vi command. Begin by learning some basic commands. As you do, be aware of the patterns of usage ...