Vi

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

Related Topics:
'''ex''' - Line editor

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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 {{IPA|}} (in IPA), but generally not as a word, as {{IPA|}}, and never like the Roman numeral VI (i.e., "six").

Related Topics:
Initialism - IPA - Roman numeral

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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 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.

Related Topics:
Modal - Escape key - Cursor

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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.

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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.

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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 2002 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.

Related Topics:
De facto - Unix - Hacker - MIT - Emacs - 1984 - 2002 - Single UNIX Specification

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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.

Related Topics:
1991 - USENET

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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.

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

Related Topics:
Emacs - Editor war

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