Vi

vi is a screen-oriented text editor computer program written by Bill Joy in 1976 for an early Berkeley Software Distribution release.

= About vi =

The name vi comes from the shortest unambiguous abbreviation for the command visual in ex (editor). The command in question switches the line editor ex (editor) to visual mode.

Typically, as a matter of convenience, the same program will start up in vi or ex mode, depending on the name with which it is started. vi is an initialism; pronounced letter by letter as (in International Phonetic Alphabet for English), but generally not as a word, as , and never like the Roman numeral VI (i.e., six ).

vi is a Mode (computer interface) editor and assigns different meanings to buttons or keystrokes depending on the active editing mode. In insert mode , text typed is inserted into the document. Pressing the escape key while in insert mode will switch the editor to command mode , where letters correspond to cursor movements or editing functions (for example, j to move the cursor (computers) down a line, k to move up a line, x to delete the character under the cursor (where the position under the cursor may be to the right of an I-beam, over an underscore, or under a block character depending on the terminal), and i to return to insert mode). Keys pressed while in command mode are not inserted into the text, which is a common cause for confusion among new users.

In command mode, multiple editing operations can be performed in a row with simple keystrokes, without having to hold down the , , or other special modifier keys. More complicated editing operations are strung together from simple primitives (for example, dw to delete a word, or c2fa to change text from the cursor until finding the second a ). For experienced users, this can lead to faster work. It also means that the user s hands never need to leave the keyboard.

Early versions of vi did not give any indication as to which mode they were in, and it is typical of users to simply press the Escape key to ensure that the editor is in command mode (it will beep if already in command mode). Current versions of vi indicate the mode on the status line or graphically. Graphical implementations of vi (for example, gvim) also fully support the use of a mouse and menus to access editing commands.

vi became the de facto standard Unix editor and a nearly undisputed Hacker favorite outside of Massachusetts Institute of Technology until the rise of Emacs after about 1984. As of 2005 either vi or one of its clones can still be found on nearly all installations of Unix. The Single UNIX Specification specifies vi, so any system conforming to the Single UNIX Specification will have vi.

vi is still widely used by users of Unix variants. About half the respondents in a 1991 Usenet poll preferred vi. It starts up faster than the bulkier versions of Emacs and uses less memory. Consequently, even some Emacs fans will resort to it as a mail editor and for small editing jobs.

When a rescue floppy is being built for restores following a hard drive crash, vi is often the editor chosen because it is compact enough to fit on a floppy, and because almost anyone performing rescue operations will be able to use it.

vi and Emacs are classically the two sides in the editor wars.

= vi trivia =

vi was written in [http://csua.berkeley.edu/~tobin/wiki/moin.cgi/Evans_20Hall Evans Hall] at the University of California, Berkeley.

George Ouzounian, better known as Maddox, creator of The Best Page in the Universe (thebestpageintheuniverse.net) stated he writes all the code in his website in vi, as anything else is for failures.

=vi derivatives and clones=

*vi is a port of the classic BSD vi 3.7 to modern Unix systems. It uses Ed as a codebase, which is Berkeley Software Distribution-style free since January 2002. [http://ex-vi.sourceforge.net/] *Nvi is an implementation of the ex/vi text editor originally distributed as part of the Fourth Berkeley Software Distribution(4BSD). This is the version of vi that is shipped with all BSD-based open source distributions. It has many improvements over the classical vi, including command history and editing, filename completions, multiple edit buffers, multi-windowing (including multiple windows on the same edit buffer) and many more. Other than the improvements, it is more or less the same as the classical vi in terms of look and feel. It is small and fast and blends quite naturally with the unix environment. *elvis (text editor) is a free vi clone for Unix and other operating systems. *Vigor the popular Unix editor vi with the addition of the Vigor Assistant, a deliberately irritating animated character modelled on Microsoft Office s Clippy.[http://vigor.sourceforge.net/] *VILE *Vim (text editor) "Vi IMproved" is an updated and extended modal editor, considered by many to be roughly equivalent in editing power to Emacs. *bvi "Binary VI" is an editor for binary files based on the vi text editor.[http://bvi.sourceforge.net/] *svicc is a small VI Clone for the Commodore (64) [http://www.floodgap.com/retrotech/cbm/svicc/]

=See also=

*List of text editors *Comparison of text editors *Editor war (Emacs vs. vi)

=Further reading=

Oualline, Steve (2001) Vi IMproved - Vim , New Riders Publishers, 572 pp.

=External links=

*[http://www.thomer.com/vi/vi.html vi lovers home page] *[http://www.softpanorama.org/Editors/vim.shtml Western Orthodox Editors Page] Softpanorama page about vi that considers vi and its derivatives (vim) to be a special class of editors, an orthodox editors. *[http://www.saki.com.au/mirror/vi/ The vi Editor and its clones and programs with a vi like interface] *[http://www.webmaster.crevier.org/vi/ vi Editor Resources] *[http://vilearn.org/ The interactive vi tutorial] *[http://www.hut.fi/~thyle/vi_opas.html Quick vi tutorial] *[http://www.ibiblio.org/web-gentoo/images/vicheat-final.png The Semi-Official IBM developerWorks Vi-Cheat-Sheet]