7.  Set Commands

Vi has a number of internal variables and switches which can be set to achieve special affects. These options come in three forms, those that are switches, which toggle from off to on and back, those that require a numeric value, and those that require an alphanumeric string value. The toggle options are set by a command of the form:

:set option<nl>

:set nooption<nl>

:set option=value<nl>

:set option?<nl>

:set<nl>

:set all<nl>

      Most of the options have a long form and an abbreviation. Both are listed in the following table as well as the normal default value.

      To arrange to have values other than the default used every time you enter vi, place the appropriate set command in EXINIT in your environment, e.g.

EXINIT='set ai aw terse sh=/bin/csh'
export EXINIT

setenv EXINIT 'set ai aw terse sh=/bin/csh'

autoindent ai

Default: noai Type: toggle
When in autoindent mode, vi helps you indent code by starting each line in the same column as the preceding line. Tabbing to the right with <tab> or <^T> will move this boundary to the right, and it can be moved to the left with <^D>.

autoprint ap

Default: ap Type: toggle
Causes the current line to be printed after each ex text modifying command. This is not of much interest in the normal vi visual mode.

autowrite aw

Default: noaw type: toggle
Autowrite causes an automatic write to be done if there are unsaved changes before certain commands which change files or otherwise interact with the outside world. These commands are :!, :tag, :next, :rewind, ^^, and ^].

beautify bf

Default: nobf Type: toggle
Causes all control characters except <tab>, <nl>, and <ff> to be discarded.

directory dir

Default: dir=/tmp Type: string
This is the directory in which vi puts its temporary file.

errorbells eb

Default: noeb Type: toggle
Error messages are preceded by a <bell>.

hardtabs ht

Default: hardtabs=8 Type: numeric
This option contains the value of hardware tabs in your terminal, or of software tabs expanded by the Unix system.

ignorecase ic

Default: noic Type: toggle
All upper case characters are mapped to lower case in regular expression matching.

lisp

Default: nolisp Type: toggle
Autoindent for lisp code. The commands ( ) [[ and ]] are modified appropriately to affect s-expressions and functions.

list

Default: nolist Type: toggle
All printed lines have the <tab> and <nl> characters displayed visually.

magic

Default: magic Type: toggle
Enable the metacharacters for matching. These include . * < > [string] [^string] and [<chr>-<chr>].

number nu

Default: nonu Type: toggle
Each line is displayed with its line number.

open

Default: open Type: toggle
When set, prevents entering open or visual modes from ex or edit. Not of interest from vi.

optimize opt

Default: opt Type: toggle
Basically of use only when using the ex capabilities. This option prevents automatic <cr>s from taking place, and speeds up output of indented lines, at the expense of losing typeahead on some versions of UNIX.

paragraphs para

Default: para=IPLPPPQPP bp Type: string
Each pair of characters in the string indicate nroff macros which are to be treated as the beginning of a paragraph for the { and } commands. The default string is for the -ms and -mm macros. To indicate one letter nroff macros, such as .P or .H, quote a space in for the second character position. For example:

                :set paragraphs=P\ bp<nl>

would cause vi to consider .P and .bp as paragraph delimiters.

prompt

Default: prompt Type: toggle
In ex command mode the prompt character : will be printed when ex is waiting for a command. This is not of interest from vi.

redraw

Default: noredraw Type: toggle
On dumb terminals, force the screen to always be up to date, by sending great amounts of output. Useful only at high speeds.

report

Default: report=5 Type: numeric
This sets the threshold for the number of lines modified. When more than this number of lines are modified, removed, or yanked, vi will report the number of lines changed at the bottom of the screen.

scroll

Default: scroll={1/2 window} Type: numeric
This is the number of lines that the screen scrolls up or down when using the <^U> and <^D> commands.

sections

Default: sections=SHNHH HU Type: string
Each two character pair of this string specify nroff macro names which are to be treated as the beginning of a section by the ]] and [[ commands. The default string is for the -ms and -mm macros. To enter one letter nroff macros, use a quoted space as the second character. See paragraphs for a fuller explanation.

shell sh

Default: sh=from environment SHELL or /bin/sh Type: string
This is the name of the sh to be used for "escaped" commands.

shiftwidth sw

Default: sw=8 Type: numeric
This is the number of spaces that a <^T> or <^D> will move over for indenting, and the amount < and > shift by.

showmatch sm

Default: nosm Type: toggle
When a ) or } is typed, show the matching ( or { by moving the cursor to it for one second if it is on the current screen.

slowopen slow

Default: terminal dependent Type: toggle
On terminals that are slow and unintelligent, this option prevents the updating of the screen some of the time to improve speed.

tabstop ts

Default: ts=8 Type: numeric
<tab>s are expanded to boundaries that are multiples of this value.

taglength tl

Default: tl=0 Type: numeric
If nonzero, tag names are only significant to this many characters.

term

Default: (from environment TERM, else dumb) Type: string
This is the terminal and controls the visual displays. It cannot be changed when in "visual" mode, you have to Q to command mode, type a set term command, and do ``vi.'' to get back into visual. Or exit vi, fix $TERM, and reenter. The definitions that drive a particular terminal type are found in the file /etc/termcap.

terse

Default: terse Type: toggle
When set, the error diagnostics are short.

warn

Default: warn Type: toggle
The user is warned if she/he tries to escape to the shell without writing out the current changes.

window

Default: window={8 at 600 baud or less, 16 at 1200 baud, and screen size - 1 at 2400 baud or more} Type: numeric
This is the number of lines in the window whenever vi must redraw an entire screen. It is useful to make this size smaller if you are on a slow line.

w300, w1200, w9600

These set window, but only within the corresponding speed ranges. They are useful in an EXINIT to fine tune window sizes. For example,

set w300=4 w1200=12

causes a 4 lines window at speed up to 600 baud, a 12 line window at 1200 baud, and a full screen (the default) at over 1200 baud.

wrapscan ws

Default: ws Type: toggle
Searches will wrap around the end of the file when is option is set. When it is off, the search will terminate when it reaches the end or the beginning of the file.

wrapmargin wm

Default: wm=0 Type: numeric
Vi will automatically insert a <nl> when it finds a natural break point (usually a <sp> between words) that occurs within "wm" spaces of the right margin. Therefore with "wm=0" the option is off. Setting it to 10 would mean that any time you are within 10 spaces of the right margin vi would be looking for a <sp> or <tab> which it could replace with a <nl>. This is convenient for people who forget to look at the screen while they type. (In version 3, wrapmargin behaves more like nroff, in that the boundary specified by the distance from the right edge of the screen is taken as the rightmost edge of the area where a break is allowed, instead of the leftmost edge.)

writeany wa

Default: nowa Type: toggle
Vi normally makes a number of checks before it writes out a file. This prevents the user from inadvertently destroying a file. When the "writeany" option is enabled, vi no longer makes these checks.