Provided by: nvi_1.81.6-13_amd64 bug

NAME

       ex, vi, view - text editors

SYNOPSIS

       ex [-eRrSsv] [-c cmd] [-t tag] [-w size] [file ...]
       vi [-elRrSv] [-c cmd] [-t tag] [-w size] [file ...]
       view [-eRrSv] [-c cmd] [-t tag] [-w size] [file ...]

LICENSE

       The vi program is freely redistributable.  You are welcome to copy, modify and share it with others under
       the conditions listed in the LICENSE file.  If any company (not individual!) finds vi sufficiently useful
       that  you  would  have  purchased  it,  or if any company wishes to redistribute it, contributions to the
       authors would be appreciated.

DESCRIPTION

       Vi is a screen oriented text editor.  Ex is a  line‐oriented  text  editor.   Ex  and  vi  are  different
       interfaces to the same program, and it is possible to switch back and forth during an edit session.  View
       is the equivalent of using the -R (read‐only) option of vi.

       This manual page is the one provided with the nex/nvi versions of the ex/vi text  editors.   Nex/nvi  are
       intended  as  bug‐for‐bug  compatible replacements for the original Fourth Berkeley Software Distribution
       (4BSD) ex and vi programs.  For the rest of this manual page, nex/nvi is used only when it's necessary to
       distinguish it from the historic implementations of ex/vi.

       This  manual page is intended for users already familiar with ex/vi.  Anyone else should almost certainly
       read a good tutorial on the editor before this manual page.  If you're in an unfamiliar environment,  and
       you  absolutely  have  to  get  work  done  immediately,  read the section after the options description,
       entitled “Fast Startup”.  It's probably enough to get you going.

       The following options are available:

       -c     Execute cmd immediately  after  starting  the  edit  session.   Particularly  useful  for  initial
              positioning  in  the  file, however cmd is not limited to positioning commands.  This is the POSIX
              1003.2 interface for the historic “+cmd” syntax.  Nex/nvi supports both the old and new syntax.

       -e     Start editing in ex mode, as if the command name were ex.

       -l     Start editing with the lisp and showmatch options set.

       -R     Start editing in read‐only mode, as if the command name was view, or the readonly option was set.

       -r     Recover the specified files, or, if  no  files  are  specified,  list  the  files  that  could  be
              recovered.   If  no recoverable files by the specified name exist, the file is edited as if the -r
              option had not been specified.

       -S     Run with the secure edit option set, disallowing all access to external programs.

       -s     Enter batch mode; applicable only to ex edit sessions.  Batch  mode  is  useful  when  running  ex
              scripts.   Prompts,  informative  messages  and other user oriented message are turned off, and no
              startup files or environmental variables are read.  This is the POSIX  1003.2  interface  for  the
              historic “-” argument.  Nex/nvi supports both the old and new syntax.

       -t     Start editing at the specified tag.  (See ctags(1)).

       -w     Set the initial window size to the specified number of lines.

       -v     Start editing in vi mode, as if the command name was vi or view.

       Note  that  the  -F  option (which prevented ex/vi from making a full backup of the target file) has been
       removed and is no longer available.

       Command input for ex/vi is read from the standard input.  In the vi interface, it is an error if standard
       input is not a terminal.  In the ex interface, if standard input is not a terminal, ex will read commands
       from it regardless, however, the session will be a batch mode session, exactly as if the  -s  option  had
       been specified.

       Ex/vi exits 0 on success, and greater than 0 if an error occurs.

FAST STARTUP

       This  section  will  tell  you  the minimum amount that you need to do simple editing tasks using vi.  If
       you've never used any screen editor before,  you're  likely  to  have  problems  even  with  this  simple
       introduction.   In that case you should find someone that already knows vi and have them walk you through
       this section.

       Vi is a screen editor.  This means that it takes up almost the entire screen, displaying part of the file
       on each screen line, except for the last line of the screen.  The last line of the screen is used for you
       to give commands to vi, and for vi to give information to you.

       The other fact that you need to understand is that vi is a modeful editor, i.e. you are  either  entering
       text  or  you  are  executing commands, and you have to be in the right mode to do one or the other.  You
       will be in command mode when you first start editing a file.  There are commands  that  switch  you  into
       input  mode.  There is only one key that takes you out of input mode, and that is the <escape> key.  (Key
       names are written using less‐than and greater‐than signs, e.g.  <escape> means the “escape” key,  usually
       labeled  “esc”  on  your  terminal's keyboard.)  If you're ever confused as to which mode you're in, keep
       entering the <escape> key until vi beeps at you.  (Generally, vi will beep at  you  if  you  try  and  do
       something that's not allowed.  It will also display error messages.)

       To start editing a file, enter the command “vi file_name<carriage‐return>”.  The command you should enter
       as soon as you start editing is “:set verbose showmode<carriage‐return>”.  This will make the editor give
       you verbose error messages and display the current mode at the bottom of the screen.

       The commands to move around the file are:

       h      Move the cursor left one character.

       j      Move the cursor down one line.

       k      Move the cursor up one line.

       l      Move the cursor right one character.

       <cursor‐arrows>
              The cursor arrow keys should work, too.

       /text<carriage‐return>
              Search for the string “text” in the file, and move the cursor to its first character.

       The commands to enter new text are:

       a      Append new text, after the cursor.

       i      Insert new text, before the cursor.

       o      Open a new line below the line the cursor is on, and start entering text.

       O      Open a new line above the line the cursor is on, and start entering text.

       <escape>
              Once  you've  entered  input mode using the one of the a, i, O or o commands, use <escape> to quit
              entering text and return to command mode.

       The commands to copy text are:

       yy     Copy the line the cursor is on.

       p      Append the copied line after the line the cursor is on.

       The commands to delete text are:

       dd     Delete the line the cursor is on.

       x      Delete the character the cursor is on.

       The commands to write the file are:

       :w<carriage‐return>
              Write the file back to the file with the name that you originally used as an argument  on  the  vi
              command line.

       :w file_name<carriage‐return>
              Write the file back to the file with the name “file_name”.

       The commands to quit editing and exit the editor are:

       :q<carriage‐return>
              Quit editing and leave vi (if you've modified the file, but not saved your changes, vi will refuse
              to quit).

       :q!<carriage‐return>
              Quit, discarding any modifications that you may have made.

       One final caution.  Unusual characters can take up more than one column on the screen, and long lines can
       take up more than a single screen line.  The above commands work on “physical” characters and lines, i.e.
       they affect the entire line no matter how many screen lines it takes  up  and  the  entire  character  no
       matter how many screen columns it takes up.

VI COMMANDS

       The  following  section  describes  the commands available in the command mode of the vi editor.  In each
       entry below, the tag line is a usage synopsis for the command character.

       [count] <control‐A>
              Search forward count times for the current word.

       [count] <control‐B>
              Page backwards count screens.

       [count] <control‐D>
              Scroll forward count lines.

       [count] <control‐E>
              Scroll forward count lines, leaving the current line and column as is, if possible.

       [count] <control‐F>
              Page forward count screens.

       <control‐G>
              Display the file information.

       <control‐H>

       [count] h
              Move the cursor back count characters in the current line.

       [count] <control‐J>

       [count] <control‐N>

       [count] j
              Move the cursor down count lines without changing the current column.

       <control‐L>

       <control‐R>
              Repaint the screen.

       [count] <control‐M>

       [count] +
              Move the cursor down count lines to the first nonblank character of that line.

       [count] <control‐P>

       [count] k
              Move the cursor up count lines, without changing the current column.

       <control‐T>
              Return to the most recent tag context.

       <control‐U>
              Scroll backwards count lines.

       <control‐W>
              Switch to the next lower screen in the window, or, to the first  screen  if  there  are  no  lower
              screens in the window.

       <control‐Y>
              Scroll backwards count lines, leaving the current line and column as is, if possible.

       <control‐Z>
              Suspend the current editor session.

       <escape>
              Execute ex commands or cancel partial commands.

       <control‐]>
              Push a tag reference onto the tag stack.

       <control‐^>
              Switch to the most recently edited file.

       [count] <space>

       [count] l
              Move the cursor forward count characters without changing the current line.

       [count] ! motion shell‐argument(s)
              Replace text with results from a shell command.

       [count] # #|+|-
              Increment or decrement the cursor number.

       [count] $
              Move the cursor to the end of a line.

       %      Move to the matching character.

       &      Repeat the previous substitution command on the current line.

       '<character>

       `<character>
              Return to a context marked by the character <character>.

       [count] (
              Back up count sentences.

       [count] )
              Move forward count sentences.

       [count] ,
              Reverse find character count times.

       [count] -
              Move to first nonblank of the previous line, count times.

       [count] .
              Repeat the last vi command that modified text.

       /RE<carriage‐return>

       /RE/ [offset]<carriage‐return>

       ?RE<carriage‐return>

       ?RE? [offset]<carriage‐return>

       N

       n      Search forward or backward for a regular expression.

       0      Move to the first character in the current line.

       :      Execute an ex command.

       [count] ;
              Repeat the last character find count times.

       [count] < motion

       [count] > motion
              Shift lines left or right.

       @ buffer
              Execute a named buffer.

       [count] A
              Enter input mode, appending the text after the end of the line.

       [count] B
              Move backwards count bigwords.

       [buffer] [count] C
              Change text from the current position to the end‐of‐line.

       [buffer] D
              Delete text from the current position to the end‐of‐line.

       [count] E
              Move forward count end‐of‐bigwords.

       [count] F <character>
              Search count times backward through the current line for <character>.

       [count] G
              Move to line count, or the last line of the file if count not specified.

       [count] H
              Move to the screen line count - 1 lines below the top of the screen.

       [count] I
              Enter input mode, inserting the text at the beginning of the line.

       [count] J
              Join lines.

       [count] L
              Move to the screen line count - 1 lines above the bottom of the screen.

        M     Move to the screen line in the middle of the screen.

       [count] O
              Enter input mode, appending text in a new line above the current line.

       [buffer] P
              Insert text from a buffer.

       Q      Exit vi (or visual) mode and switch to ex mode.

       [count] R
              Enter input mode, replacing the characters in the current line.

       [buffer] [count] S
              Substitute count lines.

       [count] T <character>
              Search  backwards,  count  times,  through  the current line for the character after the specified
              <character>.

       U      Restore the current line to its state before the cursor last moved to it.

       [count] W
              Move forward count bigwords.

       [buffer] [count] X
              Delete count characters before the cursor.

       [buffer] [count] Y
              Copy (or “yank”) count lines into the specified buffer.

       ZZ     Write the file and exit vi.

       [count] [[
              Back up count section boundaries.

       [count] ]]
              Move forward count section boundaries.

       ^      Move to first nonblank character on the current line.

       [count] _
              Move down count - 1 lines, to the first nonblank character.

       [count] a
              Enter input mode, appending the text after the cursor.

       [count] b
              Move backwards count words.

       [buffer] [count] c motion
              Change a region of text.

       [buffer] [count] d motion
              Delete a region of text.

       [count] e
              Move forward count end‐of‐words.

       [count] f<character>
              Search forward, count times, through the rest of the current line for <character>.

       [count] i
              Enter input mode, inserting the text before the cursor.

       m <character>
              Save the current context (line and column) as <character>.

       [count] o
              Enter input mode, appending text in a new line under the current line.

       [buffer] p
              Append text from a buffer.

       [count] r <character>
              Replace count characters.

       [buffer] [count] s
              Substitute count characters in the current line starting with the current character.

       [count] t <character>
              Search forward, count times, through  the  current  line  for  the  character  immediately  before
              <character>.

       u      Undo the last change made to the file.

       [count] w
              Move forward count words.

       [buffer] [count] x
              Delete count characters.

       [buffer] [count] y motion
              Copy (or “yank”) a text region specified by the count and motion into a buffer.

       [count1] z [count2] -|.|+|^|<carriage‐return>
              Redraw, optionally repositioning and resizing the screen.

       [count] {
              Move backward count paragraphs.

       [count] |
              Move to a specific column position on the current line.

       [count] }
              Move forward count paragraphs.

       [count] ~
              Reverse the case of the next count character(s), if the tildeop option is unset.

       [count] ~ motion
              Reverse  the  case  of  the  characters in a text region specified by the count and motion, if the
              tildeop option is set.

       <interrupt>
              Interrupt the current operation.

VI TEXT INPUT COMMANDS

       The following section describes the commands available in the text input mode of the vi editor.

       <nul>  Replay the previous input.

       <control‐D>
              Erase to the previous shiftwidth column boundary.

       ^<control‐D>
              Erase all of the autoindent characters, and reset the autoindent level.

       0<control‐D>
              Erase all of the autoindent characters.

       <control‐T>
              Insert sufficient <tab> and <space> characters to move  forward  to  the  next  shiftwidth  column
              boundary.

       <erase>

       <control‐H>
              Erase the last character.

       <literal next>
              Quote the next character.

       <escape>
              Resolve all text input into the file, and return to command mode.

       <line erase>
              Erase the current line.

       <control‐W>

       <word erase>
              Erase the last word.  The definition of word is dependent on the altwerase and ttywerase options.

       <control‐X>[0-9A-Fa-f]+
              Insert a character with the specified hexadecimal value into the text.

       <interrupt>
              Interrupt text input mode, returning to command mode.

EX COMMANDS

       The  following  section  describes the commands available in the ex editor.  In each entry below, the tag
       line is a usage synopsis for the command.

       <end‐of‐file>
              Scroll the screen.

       ! argument(s)

       [range]! argument(s)
              Execute a shell command, or filter lines through a shell command.

       "      A comment.

       [range] nu[mber] [count] [flags]

       [range] # [count] [flags]
              Display the selected lines, each preceded with its line number.

       @ buffer

       * buffer
              Execute a buffer.

       [line] a[ppend][!]
              The input text is appended after the specified line.

       [range] c[hange][!] [count]
              The input text replaces the specified range.

       cs[cope] add | find | help | kill | reset
              Execute a Cscope command.

       [range] d[elete] [buffer] [count] [flags]
              Delete the lines from the file.

       di[splay] b[uffers] | c[onnections] | s[creens] | t[ags]
              Display buffers, Cscope connections, screens or tags.

       [Ee][dit][!] [+cmd] [file]

       [Ee]x[!] [+cmd] [file]
              Edit a different file.

       exu[sage] [command]
              Display usage for an ex command.

       f[ile] [file]
              Display and optionally change the file name.

       [Ff]g [name]
              Vi mode only.  Foreground the specified screen.

       [range] g[lobal] /pattern/ [commands]

       [range] v /pattern/ [commands]
              Apply commands to lines matching (or not matching) a pattern.

       he[lp] Display a help message.

       [line] i[nsert][!]
              The input text is inserted before the specified line.

       [range] j[oin][!] [count] [flags]
              Join lines of text together.

       [range] l[ist] [count] [flags]
              Display the lines unambiguously.

       map[!] [lhs rhs]
              Define or display maps (for vi only).

       [line] ma[rk] <character>

       [line] k <character>
              Mark the line with the mark <character>.

       [range] m[ove] line
              Move the specified lines after the target line.

       mk[exrc][!] file
              Write the abbreviations, editor options and maps to the specified file.

       [Nn][ext][!] [file ...]
              Edit the next file from the argument list.

       [line] o[pen] /pattern/ [flags]
              Enter open mode.

       pre[serve]
              Save the file in a form that can later be recovered using the ex -r option.

       [Pp]rev[ious][!]
              Edit the previous file from the argument list.

       [range] p[rint] [count] [flags]
              Display the specified lines.

       [line] pu[t] [buffer]
              Append buffer contents to the current line.

       q[uit][!]
              End the editing session.

       [line] r[ead][!] [file]
              Read a file.

       rec[over] file
              Recover file if it was previously saved.

       res[ize] [+|-]size
              Vi mode only.  Grow or shrink the current screen.

       rew[ind][!]
              Rewind the argument list.

       se[t] [option[=[value]] ...] [nooption ...] [option? ...] [all]
              Display or set editor options.

       sh[ell]
              Run a shell program.

       so[urce] file
              Read and execute ex commands from a file.

       [range] s[ubstitute] [/pattern/replace/] [options] [count] [flags]

       [range] & [options] [count] [flags]

       [range] ~ [options] [count] [flags]
              Make substitutions.

       su[spend][!]

       st[op][!]

       <suspend>
              Suspend the edit session.

       [Tt]a[g][!] tagstring
              Edit the file containing the specified tag.

       tagn[ext][!]
              Edit the file containing the next context for the current tag.

       tagp[op][!] [file | number]
              Pop to the specified tag in the tags stack.

       tagp[rev][!]
              Edit the file containing the previous context for the current tag.

       unm[ap][!] lhs
              Unmap a mapped string.

       ve[rsion]
              Display the version of the ex/vi editor.

       [line] vi[sual] [type] [count] [flags]
              Ex mode only.  Enter vi.

       [Vi]i[sual][!] [+cmd] [file]
              Vi mode only.  Edit a new file.

       viu[sage] [command]
              Display usage for a vi command.

       [range] w[rite][!] [>>] [file]

       [range] w[rite] [!] [file]

       [range] wn[!] [>>] [file]

       [range] wq[!] [>>] [file]
              Write the file.

       [range] x[it][!] [file]
              Write the file if it has been modified.

       [range] ya[nk] [buffer] [count]
              Copy the specified lines to a buffer.

       [line] z [type] [count] [flags]
              Adjust the window.

SET OPTIONS

       There are a large number of options that may be set (or unset) to change  the  editor's  behavior.   This
       section describes the options, their abbreviations and their default values.

       In  each  entry  below,  the  first  part of the tag line is the full name of the option, followed by any
       equivalent abbreviations.  The part in square brackets is the default value of the option.  Most  of  the
       options are boolean, i.e. they are either on or off, and do not have an associated value.

       Options  apply  to both ex and vi modes, unless otherwise specified. Multiple options can be given in one
       set or unset, separated by spaces or tabs.  Spaces and tabs can be included in string options  (eg.  tags
       or filec) by preceding each with a backslash.  There's no way to get backslash itself into an option.

       altwerase [off]
              Vi only.  Select an alternate word erase algorithm.

       autoindent, ai [off]
              Automatically indent new lines.

       autoprint, ap [off]
              Ex only.  Display the current line automatically.

       autowrite, aw [off]
              Write modified files automatically when changing files.

       backup [""]
              Backup files before they are overwritten.

       beautify, bf [off]
              Discard control characters.

       cdpath [environment variable CDPATH, or current directory]
              The directory paths used as path prefixes for the cd command.

       cedit [no default]
              Set the character to edit the colon command‐line history.

       columns, co [80]
              Set the number of columns in the screen.

       comment [off]
              Vi only.  Skip leading comments in shell, C and C++ language files.

       directory, dir [environment variable TMPDIR, or /tmp]
              The directory where temporary files are created.

       edcompatible, ed [off]
              Remember  the  values  of  the  “c”  and  “g”  suffices  to  the  substitute  commands, instead of
              initializing them as unset for each new command.

       errorbells, eb [off]
              Ex only.  Announce error messages with a bell.

       exrc, ex [off]
              Read the startup files in the local directory.

       extended [off]
              Regular expressions are extended (i.e.  egrep(1)-style) expressions.

       filec [no default]
              Set the character to perform file path completion on the colon command line.

       flash [on]
              Flash the screen instead of beeping the keyboard on error.

       hardtabs, ht [8]
              Set the spacing between hardware tab settings.

       iclower [off]
              Makes all Regular Expressions case‐insensitive, as long as an upper‐case letter does not appear in
              the search string.

       ignorecase, ic [off]
              Ignore case differences in regular expressions.

       keytime [6]
              The 10th's of a second ex/vi waits for a subsequent key to complete a key mapping.

       leftright [off]
              Vi only.  Do left‐right scrolling.

       lines, li [24]
              Vi only.  Set the number of lines in the screen.

       lisp [off]
              Vi  only.   Modify  various search commands and options to work with Lisp.  This option is not yet
              implemented.

       list [off]
              Display lines in an unambiguous fashion.

       lock [on]
              Attempt to get an exclusive lock on any file being edited, read or written.

       magic [on]
              Treat certain characters specially in regular expressions.

       matchtime [7]
              Vi only.  The 10th's of a second ex/vi pauses on the matching character when the showmatch  option
              is set.

       mesg [on]
              Permit messages from other users.

       modelines, modeline [off]
              Read  the  first  and  last  few  lines  of  each file for ex commands.  This option will never be
              implemented.

       noprint [""]
              Characters that are never handled as printable characters.

       number, nu [off]
              Precede each line displayed with its current line number.

       octal [off]
              Display unknown characters as octal numbers, instead of the default hexadecimal.

       open [on]
              Ex only.  If this option is not set, the open and visual commands are disallowed.

       optimize, opt [on]
              Vi only.  Optimize text throughput to dumb terminals.  This option is not yet implemented.

       paragraphs, para [IPLPPPQPP LIpplpipbp]
              Vi only.  Define additional paragraph boundaries for the { and } commands.

       path []
              Define additional directories to search for files being edited.

       print [""]
              Characters that are always handled as printable characters.

       prompt [on]
              Ex only.  Display a command prompt.

       readonly, ro [off]
              Mark the file and session as read‐only.

       recdir [/var/tmp/vi.recover]
              The directory where recovery files are stored.

       redraw, re [off]
              Vi only.  Simulate an intelligent terminal on a dumb one.  This option is not yet implemented.

       remap [on]
              Remap keys until resolved.

       report [5]
              Set the number of lines about which the editor reports changes or yanks.

       ruler [off]
              Vi only.  Display a row/column ruler on the colon command line.

       scroll, scr [window / 2]
              Set the number of lines scrolled.

       searchincr [off]
              Makes the / and ?  commands incremental.

       sections, sect [NHSHH HUnhsh]
              Vi only.  Define additional section boundaries for the [[ and ]] commands.

       secure [off]
              Turns off all access to external programs.

       shell, sh [environment variable SHELL, or /bin/sh]
              Select the shell used by the editor.

       shellmeta [~{[*?$`'"\]
              Set the meta characters checked to determine if file name expansion is necessary.

       shiftwidth, sw [8]
              Set the autoindent and shift command indentation width.

       showmatch, sm [off]
              Vi only.  Note matching “{” and “(” for “}” and “)” characters.

       showmode, smd [off]
              Vi only.  Display the current editor mode and a “modified” flag.

       sidescroll [16]
              Vi only.  Set the amount a left‐right scroll will shift.

       slowopen, slow [off]
              Delay display updating during text input.  This option is not yet implemented.

       sourceany [off]
              Read startup files not owned by the current user.  This option will never be implemented.

       tabstop, ts [8]
              This option sets tab widths for the editor display.

       taglength, tl [0]
              Set the number of significant characters in tag names.

       tags, tag [tags /var/db/libc.tags /sys/kern/tags]
              Set the list of tags files.

       term, ttytype, tty [environment variable TERM]
              Set the terminal type.

       terse [off]
              This option has historically made editor  messages  less  verbose.   It  has  no  effect  in  this
              implementation.

       tildeop [off]
              Modify the ~ command to take an associated motion.

       timeout, to [on]
              Time out on keys which may be mapped.

       ttywerase [off]
              Vi only.  Select an alternate erase algorithm.

       verbose [off]
              Vi only.  Display an error message for every error.

       w300 [no default]
              Vi only.  Set the window size if the baud rate is less than 1200 baud.

       w1200 [no default]
              Vi only.  Set the window size if the baud rate is equal to 1200 baud.

       w9600 [no default]
              Vi only.  Set the window size if the baud rate is greater than 1200 baud.

       warn [on]
              Ex  only.   This  option  causes  a warning message to the terminal if the file has been modified,
              since it was last written, before a !  command.

       window, w, wi [environment variable LINES]
              Set the window size for the screen.

       windowname [off]
              Change the icon/window name to the current file name even if it can't be restored on editor exit.

       wraplen, wl [0]
              Vi only.  Break lines automatically, the specified number of columns from  the  left‐hand  margin.
              If both the wraplen and wrapmargin edit options are set, the wrapmargin value is used.

       wrapmargin, wm [0]
              Vi  only.   Break lines automatically, the specified number of columns from the right‐hand margin.
              If both the wraplen and wrapmargin edit options are set, the wrapmargin value is used.

       wrapscan, ws [on]
              Set searches to wrap around the end or beginning of the file.

       writeany, wa [off]
              Turn off file‐overwriting checks.

ENVIRONMENT VARIABLES

       COLUMNS
              The number of columns on the screen.  This value overrides any system or terminal specific values.
              If  the  COLUMNS  environmental  variable  is  not  set  when ex/vi runs, or the columns option is
              explicitly reset by the user, ex/vi enters the value into the environment.

       EXINIT A list of ex startup commands, read if the variable NEXINIT is not set.

       HOME   The user's home directory, used as the initial directory path for the startup  “$HOME/.nexrc”  and
              “$HOME/.exrc” files.  This value is also used as the default directory for the vi cd command.

       LINES  The  number  of  rows on the screen.  This value overrides any system or terminal specific values.
              If the LINES environmental variable is not set when ex/vi runs, or the lines option is  explicitly
              reset by the user, ex/vi enters the value into the environment.

       NEXINIT
              A list of ex startup commands.

       SHELL  The user's shell of choice (see also the shell option).

       TERM   The  user's terminal type.  The default is the type “unknown”.  If the TERM environmental variable
              is not set when ex/vi runs, or the term option is explicitly reset by the user, ex/vi  enters  the
              value into the environment.

       TMPDIR The location used to stored temporary files (see also the directory edit option).

ASYNCHRONOUS EVENTS

       SIGALRM
              Vi/ex  uses  this signal for periodic backups of file modifications and to display “busy” messages
              when operations are likely to take a long time.

       SIGHUP

       SIGTERM
              If the current buffer has changed since it was last written in its entirety, the  editor  attempts
              to  save  the  modified file so it can be later recovered.  See the vi/ex Reference manual section
              entitled “Recovery” for more information.

       SIGINT When an interrupt occurs, the current operation is halted, and the editor returns to  the  command
              level.   If  interrupted during text input, the text already input is resolved into the file as if
              the text input had been normally terminated.

       SIGWINCH
              The screen is resized.  See the vi/ex Reference manual section entitled “Sizing  the  Screen”  for
              more information.

       SIGCONT

       SIGQUIT

       SIGTSTP
              Vi/ex ignores these signals.

FILES

       /bin/sh
              The default user shell.

       /etc/vi.exrc
              System‐wide vi startup file.

       /tmp   Temporary file directory.

       /var/tmp/vi.recover
              The default recovery file directory.

       $HOME/.nexrc
              1st choice for user's home directory startup file.

       $HOME/.exrc
              2nd choice for user's home directory startup file.

       .nexrc 1st choice for local directory startup file.

       .exrc  2nd choice for local directory startup file.

SEE ALSO

       ctags(1), more(1), curses(3), dbopen(3)

       The “Vi Quick Reference” card.

       “An  Introduction  to Display Editing with Vi”, found in the “UNIX User's Manual Supplementary Documents”
       section of both the 4.3BSD and 4.4BSD manual sets.  This document is the closest thing  available  to  an
       introduction to the vi screen editor.

       “Ex Reference Manual (Version 3.7)”, found in the “UNIX User's Manual Supplementary Documents” section of
       both the 4.3BSD and 4.4BSD manual sets.  This document is the final  reference  for  the  ex  editor,  as
       distributed in most historic 4BSD and System V systems.

       “Edit:  A  tutorial”,  found  in  the  “UNIX User's Manual Supplementary Documents” section of the 4.3BSD
       manual set.  This document is an introduction to a simple version of the ex screen editor.

       “Ex/Vi Reference Manual”, found in the “UNIX User's Manual Supplementary Documents” section of the 4.4BSD
       manual  set.  This document is the final reference for the nex/nvi text editors, as distributed in 4.4BSD
       and 4.4BSD‐Lite.

       Roff source for all of these documents is distributed with nex/nvi in the nvi/USD.doc  directory  of  the
       nex/nvi source code.

       The  files  “autowrite”, “input”, “quoting” and “structures” found in the nvi/docs/internals directory of
       the nex/nvi source code.

HISTORY

       The nex/nvi replacements for the ex/vi editor first appeared in 4.4BSD.

STANDARDS

       Nex/nvi is close to IEEE Std1003.2 (“POSIX”).  That document differs from historical  ex/vi  practice  in
       several places; there are changes to be made on both sides.