vi - Setting Environment Options

The following table contains brief descriptions of all set command options. In the first column, options are listed in alphabetical order; if the option can be abbreviated, that abbreviation is shown in parentheses on the line below. The second column shows the default setting that vi uses unless you issue an explicit set command (either manually or in the .exrc file). The last column describes what the option does when enabled.
Option	Default	Description
autoindent (ai)	noai	In insert mode, indents each line to the same level as the line above or below. Use with shiftwidth option.
autoprint (ap)	ap	Displays changes after each editor command. (For global replacement, displays last replacement.)
autowrite (aw)	noaw	Automatically writes (saves) file if changed before opening another file with :n or before giving UNIX command with :! .
beautify (bf)	nobf	Ignores all control characters during input (except tab, newline, or formfeed).
directory (dir)	/tmp	Names directory in which ex stores buffer files. (Directory must be writable.)
edcompatible	noedcompatible	Uses ed-like features on substitute commands.
errorbells (eb)	errorbells	Sounds bell when an error occurs.
exrc (ex)	noexrc	Allows the execution of .exrc files that reside outside the user's home directory. (System V only.)
hardtabs (ht)	=8	Defines boundaries for terminal hardware tabs.
ignorecase (ic)	noic	Disregards case during a search.
lisp	nolisp	Inserts indents in appropriate lisp format. (), {}, [[, and ]] are modified to have meaning for lisp.
list	nolist	Prints tabs as ^I ; marks ends of lines with $ . (Use list to tell if end character is a tab or a space.)
magic	magic	Wildcard characters . (dot), * (asterisk), and [ ] (brackets) have special meaning in patterns.
mesg	mesg	Permits system messages to display on terminals while editing in vi .
number (nu)	nonu	Displays line numbers on left of screen during editing session.
open	open	Allows entry to open or visual mode from ex .
optimize (opt)	noopt	Abolishes carriage returns at the end of lines when printing multiple lines, speeds output on dumb terminals when printing lines with leading white space (blanks or tabs).
paragraphs (para)	=IPLPPPQPLIpplpipbp	Defines paragraph delimiters for movement by { or }. The pairs of characters in the value are the names of nroff/troff macros that begin paragraphs.
prompt	prompt	Displays the ex prompt (:) when vi's Q command is given.
readonly (ro)	noro	Any writes (saves) of a file will fail unless you use ! after the write (works with w, ZZ or autowrite).
redraw (re)	noredraw	Terminal redraws screen whenever edits are made (in other words, insert mode pushes over existing characters, and deleted lines immediately close up). Default depends on line speed and terminal type. noredraw is useful at slow speeds on a dumb terminal; deleted lines show up as @, and inserted text appears to overwrite existing text until you press ESC.
remap	remap	Allows nested map sequences.
report	=5	Displays a message on the prompt line whenever you make an edit that affects at least a certain number of lines. For example, 6dd reports the message "6 lines deleted".
scroll	=[1/2 window ]	Amount of screen to scroll.
sections (sect)	=SHNHH HU	Defines section delimiters for [[ ]] movement. The pairs of characters in the value are the names of nroff/troff macros that begin sections.
shell (sh)	=/bin/sh	Pathname of shell used for shell escape (:!) and shell command (:sh). Default value is derived from shell environment, which varies on different systems.
shiftwidth (sw)	=8	Defines number of spaces in backward (^D) tabs when using the autoindent option.
showmatch (sm)	nosm	In vi, when ) or } is entered, cursor moves briefly to matching ( or {. (If match is not on the screen, rings the error message bell.) Very useful for programming.
showmode	noshowmode	In insert6 mode, displays a message on the prompt line indicating the type of insert you are making. For example, "Open Mode", or "Append Mode". (System V only.)
slowopen (slow)		Holds off display during insert. Default depends on line speed and terminal type.
tabstop (ts)	=8	Defines number of spaces that a TAB indents during editing session. (Printer still uses system tab of 8.)
taglength (tl)	=0	Defines number of characters that are significant for tags. Default (zero) means that all characters are significant.
tags	=tags /usr/lib/tags a	Defines pathname of files containing tags (see the UNIX ctags command). (By default, systems searches /usr/lib/tags and the file tags in the current directory.)
term		Sets terminal type.
terse	noterse	Displays shorter error messages.
timeout (to)	timeout	Keyboard maps "time out" after 1 second. ***
ttytype		Sets terminal type.
warn	warn	Displays the warning message, "No write since last change.".
window (w)		Shows a certain number of lines fo the file on the screen. Default depends on the line speed and terminal type.
wrapscan (ws)	ws	Searches wrap around either end of file.
wrapmargin (wm)	=0	Defines right margin. If greater than zero, automatically inserts carriage returns to break lines.
writeany (wa)	nowa	Allows saving to any file.