Vi
vi is a screen-oriented
text editor computer program written by
Bill Joy in 1976 for an early
BSD release.
Encyclopedia
vi is a screen-oriented
text editor computer program written by
Bill Joy in 1976 for an early
BSD release.
About vi
The name vi is an initialism and comes from the shortest unambiguous abbreviation for the command
visual in
ex. The command in question switches the line editor
ex 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 a modal 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 down a line, "k" to move up a line, "x" to delete the character at the current cursor position, 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 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 . Current versions of vi indicate the mode on the status line or graphically. Newer versions of vi also permit use of the PgUp, PgDn, Home, End and Del keys, provided that the terminal type has been correctly set . Graphical implementations of vi 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 MIT until the rise of Emacs after about 1984. As of 2006 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. In 1999, Tim O'Reilly, founder of the eponymous computer book publisher, stated that his company sold more copies of its vi book than its emacs book .
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 Evans Hall at the University of California, Berkeley, on a Lear-Siegler ADM3A terminal. On this machine, the Escape key was where the Tab key is nowadays, thus enabling users to very efficiently switch modes.
- An emacs-lovers' backronym for vi is vicious interface
- David Hitz implemented a Turing machine simulator using vi macros[ftp://ftp.uu.net/pub/text-processing/vi/macros/turing.tar.Z].
- Internet Search Engine Snap.com created a search engine using a vi interface and commands called visearch.com
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 BSD-style free since January 2002.
- nvi is an implementation of the ex/vi text editor originally distributed as part of the Fourth Berkeley Software Distribution. 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 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.
- Vim "Vi IMproved" is an updated and extended modal editor, much like nvi. It is the standard version of vi on most Linux systems.
- Elvis 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.
- vile was initially derived from an early version of Microemacs in an attempt to bring the "modern" benefits of the Emacs multi-window/multi-buffer editing paradigm to users more comfortable with the vi command-set.
- bvi "Binary VI" is an editor for binary files based on the vi text editor.
- viper-mode is a VI emulation mode for Emacs.
- svicc is a small vi clone for the Commodore
- BusyBox includes a tiny vi clone
See also
Further reading
Oualline, Steve Vi IMproved - Vim, New Riders Publishers, 572 pp.
External links
- original document
- Softpanorama page about vi
- The Register is a British [i] technology news website [i] focusing on the computer industry [i] ...
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