6. OPTIONS

Options are a primary means of configuring the appearance and behavior of elvis. They are set via the :set command, or the :set, or in an expression. The following tables list the names, type, domain, and description of each option. One table lists all options alphabetically, and the other breaks list down into groups of related options. I recommend the latter, since there are a lot of options.

Most options have two names -- a short name that is easy to type in, and a longer descriptive name. You can type in either name; they work equivalently. Elvis always outputs the longer name when it is listing values.

Each option accepts a specific type of value. The most common types are boolean, number, string, and one-of, but some options have weird types.

Each option serves as an attribute of something. The domain of an option designates what it is an attribute of. For example, the "filename" option is an attribute of buffers; when you switch to a different buffer, it will have a different value for the "filename" option. Other options are attributes of windows, or display modes, etc. Here's a complete list:

.----------.-------------------------------------------------------.
|  DOMAIN  |  DESCRIPTION                                          |
|----------|-------------------------------------------------------|
|   buf    | Attributes of buffers                                 |
|   win    | Attributes of windows                                 |
|   syntax | Attributes of the "syntax" display mode               |
|   x11    | Attributes of the "x11" user interface                |
|   tcap   | Attributes of the "termcap" user interface            |
|   win32  | User interface attributes for the Win32 port          |
|   global | Global options                                        |
|   lp     | Printing options                                      |
|   user   | User variables a - z (Global, useful in ex scripts)   |
^----------^-------------------------------------------------------^
You don't need to know the domain of an option to set it. You can output the values of all options which have the same domain by passing the domain name followed by a question mark to the :set command. The following example outputs all of the attributes of the current buffer: :set buf?

6.1 Options, grouped by function

  • 6.1.1 Options that relate the buffer to a file
  • 6.1.2 Statistics about a buffer
  • 6.1.3 Options that affect movement commands
  • 6.1.4 Options that affect input mode
  • 6.1.5 Ex options
  • 6.1.6 Window statistics
  • 6.1.7 Options affecting the appearance of text
  • 6.1.8 Options for a particular display mode
  • 6.1.9 Messages
  • 6.1.10 Options for a particular user interface
  • 6.1.11 Regular expression options
  • 6.1.12 Tag options
  • 6.1.13 Window update parameters
  • 6.1.14 Cache options
  • 6.1.15 Options that describe the system
  • 6.1.16 External programs
  • 6.1.17 Directory names
  • 6.1.18 Initialization options
  • 6.1.19 Keyboard map options
  • 6.1.20 Printing options
  • 6.1.21 Previous arguments
  • 6.1.22 Unsupported options
  • 6.1.23 User variables
  • 6.1.1 Options that relate the buffer to a file

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | filename, file      | String  | buf    | name of file in buffer      |
    | bufname, buffer     | String  | buf    | name of buffer              |
    | retain, ret         | Boolean | buf    | keep buffer in session file |
    | modified, mod       | Boolean | buf    | buffer differs from file    |
    | edited, samename    | Boolean | buf    | buffer loaded from filename |
    | newfile, new        | Boolean | buf    | filename doesn't exist yet  |
    | readonly, ro        | Boolean | buf    | don't overwrite filename    |
    | defaultreadonly, dro| Boolean | global | assume all files readonly   |
    | autowrite, aw       | Boolean | global | save file before switching  |
    | writeany, wa        | Boolean | global | don't warn of existing file |
    | backup, bk          | Boolean | global | make *.bak file before write|
    | undolevels, undo    | Number  | buf    | number of undoable commands |
    | beautify, bf        | Boolean | global | strip ctrl chars from files |
    ^---------------------^---------^--------^-----------------------------^
    
    The filename option stores the name of the text file whose text was initially loaded into the buffer. If no file name is known (e.g., for an internal buffer or a new, untitled buffer) then this will be an empty string. The :file command can be used to change the filename. Also, the filename is set automatically when you write the buffer out, if it had no filename before.

    The bufname option stores the name of the buffer. Usually this will be the same as the filename, but it can be different. Every buffer has a bufname, even if it doesn't have a filename. The name of a buffer can be changed via the :buffer command.

    The retain option indicates whether the buffer is intended to survive past the end of this elvis process. If this option is true and the tempsession option is false (":set retain notempsession") then elvis will allow you to exit even if this buffer hasn't been saved since its last change. When you restart the session, the buffer will still exist with all its changed text intact. By default, the retain option is false (":set noretain") because that mimics traditional vi behavior.

    The modified option indicates whether the buffer has been modified since the last time it was written out completely.

    The edited option indicates whether the filename option has been modified since the last time it was written out. If this option is false, elvis will be more cautious about writing the file out.

    The newfile option indicates that when the buffer was created it tried to load the file identified by the filename option, but that file did not exist at that time.

    The readonly option indicates that when the buffer was loaded, the original file was marked as being unwritable. Either that, or the defaultreadonly option was set to true (probably via the -R command line flag). This option has two purposes: it gives you a way to detect that you can't write the file out, and it protects you from writing out a file that you meant to just look at without modifying.

    Setting the autowrite option allows elvis to automatically write the current buffer out to a file if it has been modified, before switching to another buffer. By default this option is off, so if you try to switch away from a modified buffer, elvis will just give an error message and refuse to switch until you manually write the file out.

    Elvis tries to save you from accidentally clobbering existing files. Setting the writeany option disables this protection; elvis will allow you to overwrite any file that the operating system will allow, without giving any warnings.

    The backup option isn't used internally by elvis, but the default elvis.bwf file checks this flag to determine whether it should attempt to make a backup of a file it is about to overwrite. By default, this option is false, so backups will not be made.

    For each buffer, the undolevels option indicates the number of "undo" versions elvis will maintain. Each undo level requires at least three blocks of the session file (typically 2K bytes each, 6K total) so you probably don't want to set this higher than 100 or so, and you probably want to keep it much lower. The default is 0, which is a special case that mimics vi's traditional behavior.

    If the beautify option is true, then whenever elvis reads text from a file or external program, it will strip any control characters other than tab, linefeed or formfeed. This is false by default.

    6.1.2 Statistics about a buffer

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | binary, bin         | Boolean | buf    | buffer's data is not text   |
    | bufchars, bufc      | Number  | buf    | number of characters        |
    | buflines, bufl      | Number  | buf    | number of lines             |
    | errlines            | Number  | buf    | buflines when :make was run |
    | internal            | Boolean | buf    | elvis requires this buffer  |
    ^---------------------^---------^--------^-----------------------------^
    
    The binary option indicates whether the buffer contains binary data rather than text. This affects the I/O method used: Text files are subjected to newline conversion, but binary files are not converted in any way. For UNIX this this doesn't matter, but for other operating systems it matters a lot. Usually, the elvis.brf configuration file is used to set this option appropriately before the file's contents are loaded into the buffer.

    The bufchars and buflines options indicate the number of characters and lines in the buffer, respectively. The buflines option works by counting newline characters; it is unaffected by vagaries of the display mode. These options can't be set.

    The errlines option is used to store the number of lines that were in the buffer when the last :make or :cc command was run. Any difference between buflines and errlines is used to adjust the line numbers reported in any error messages, to compensate for lines which have been inserted or deleted since then.

    The internal option indicates that elvis uses the buffer internally. Such buffers can't be deleted.

    6.1.3 Options that affect movement commands

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | paragraphs, para    | String  | buf    | nroff paragraph commands    |
    | sections, sect      | String  | buf    | nroff section commands      |
    | sentenceend, se     | String  | global | punct at end of sentence    |
    | sentencequote, sq   | String  | global | punct allowed after se      |
    | sentencegap, sg     | Number  | global | spaces required after sq    |
    | scroll, sc          | Number  | win    | scroll amount for ^D/^U     |
    ^---------------------^---------^--------^-----------------------------^
    
    The paragraphs option stores a list of two-letter nroff paragraph commands. This list is used by the { and } movement commands. Similarly, the sections option stores a list of section commands, affecting the [[ and ]] commands. Their defaults are paragraphs="PPppIPLPQP" and sections="NHSHSSSEse".

    The sentenceend, sentencequote, and sentencegap options all affect the ( and ) sentence motion commands. The sentenceend option is a list of punctuation characters which can appear at the end of a sentence. The sentencegap option is the number spaces that must follow a sentenceend character in order for it to count as the end of a sentence. The sentencequote option is a list of punctuation characters that can appear between the sentenceend character and the spaces. Their defaults are sentenceend="?!.", sentencequote=")\"", and sentencegap=2, which meets the proposed POSIX specifications.

    The scroll option indicates the number of lines that the ^U and ^D commands should scroll the screen by. Its default value is 12.

    6.1.4 Options that affect input mode

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | autoindent, ai      | Boolean | buf    | auto-indent new text        |
    | inputtab, itab      | One-Of  | buf    | input mode's (Tab) key      |
    | autotab, at         | Boolean | buf    | allow autoindent to use '\t'|
    | tabstop, ts         | Number  | buf    | width of tabstop columns    |
    | shiftwidth, sw      | Number  | buf    | width used by < and >       |
    | linelength, ll      | Number  | buf    | width for word-wrap, or 0   |
    | wrapmargin, wm      | (weird) | win    | set linelength from right   |
    | digraph, dig        | Boolean | global | allow X-backspace-Y entry   |
    ^---------------------^---------^--------^-----------------------------^
    
    Setting the autoindent option causes elvis to automatically insert whitespace at the start of each line, to make it line up with the preceding line. This is convenient when you're editing C source code. It is off by default.

    The inputtab option controls the behavior of the Tab key. It can be set to one of the following values:

    The autotab option affects the behavior of the < and > operator commands, and the ^D and ^T input mode keystrokes. If autotab is true then elvis will include tab characters in the indentation whitespace; if it is false then the indentation whitespace will consist entirely of space characters. By default, it is true.

    Note that if you start with a buffer which contains no tabs, and do a ":set inputtab=spaces noautotab" then no amount of editing will result in the buffer containing spaces... unless you get tricky with ^V or something.

    The tabstop option affects the way tab characters are displayed, by specifying how far apart the tab stops should be located. When elvis displays a file with tabs, it displays the tabs as a variable number of spaces. You should probably leave this option at its default value (8) since changing this will make your file look strange in any other context. If you want to use indentation levels of less than 8 characters, you're better off changing shiftwidth.

    The shiftwidth option indicates how far left or right the < and > operator commands (and the ^D and ^T input mode keystrokes) should shift the line of text. This is used for adjusting the indentation of lines.

    When editing a text file in "normal" display mode, the linelength option can be used to cause word-wrap to occur when a line gets to long. The default value of linelength is 0, which disables automatic word-wrap. Setting it to any larger value causes word-wrap to occur when text is inserted into a line, causing that line to become wider than linelength columns. (Note that this has nothing to do with the display formatting of the "html" and "man" display modes.)

    The wrapmargin option is provided for backwards compatibility. It allows you to set the linelength relative to the right edge of the window, instead of the left edge. This option's value is actually derived from the linelength option's value and the window's width, so if you resize a window this option's value will appear to change to correspond to the new width; linelength will not change.

    Digraphs allow you to enter non-ASCII characters as a combination of two ASCII characters. There are two ways to enter digraphs: ^K X Y and X backspace Y. The second form can cause some confusion if you're not expecting it, so the digraph option was created as a way to disable that second form. The first form of digraphs is always available. This option is false by default, to avoid the confusion.

    6.1.5 Ex options

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | prompt              | Boolean | global | issue ":" prompt in ex mode |
    | autoprint, ap       | Boolean | global | print current line in ex    |
    | report              | Number  | global | minimum # lines to report   |
    ^---------------------^---------^--------^-----------------------------^
    
    The prompt option controls whether a ":" prompt is issued before reading each command line in EX mode. It is true by default, and should usually be left that way.

    The autoprint option causes elvis to display the current line of the edit buffer in certain circumstances, while you're in EX mode. It is true by default.

    The report option determines the minimum number of lines that must change in a file, before elvis will bother to display a count of the changed lines. Its default value is 5, so minor changes won't be reported.

    6.1.6 Window statistics

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | windowid, id        | Number  | win    | ID number of current window |
    | columns, cols       | Number  | win    | width of window             |
    | lines, rows         | Number  | win    | height of window            |
    ^---------------------^---------^--------^-----------------------------^
    
    The windowid option stores the ID number of the current window. These window IDs are listed by the :buffer command. Some GUIs may also display the window ID as part of the window's title. This value is set to a unique value automatically when the window is created. You can't change it.

    The columns and lines options indicate the size of the window.

    6.1.7 Options affecting the appearance of text

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | list, li            | Boolean | win    | show markups, newlines, etc.|
    | showmarkups, smu    | Boolean | global | show markup at cursor       |
    | bufdisplay, bufdis  | String  | buf    | default display mode        |
    | display, mode       | String  | win    | name of current display mode|
    | number, nu          | Boolean | win    | display line numbers        |
    | ruler, ru           | Boolean | win    | display cursor's line/column|
    | showmatch, sm       | Boolean | win    | highlight matching parens   |
    | showmode, smd       | Boolean | win    | display the command state   |
    | nonascii, asc       | One-Of  | global | how to display non-ascii    |
    | showstack, sstk     | Boolean | win    | display some debugging info |
    ^---------------------^---------^--------^-----------------------------^
    
    In the "normal" or "c" display modes, the list option causes tab characters to be shown as ^I instead of being expanded to the appropriate amount of whitespace, and it causes the end of each line to be marked with a $ character. In "html" or "man" mode, it causes all of the markups to be displayed.

    In "html" or "man" mode, the showmarkups option cause the markup at the cursor to be displayed, but leaves other markups hidden. It has no effect in other display modes. This option is off by default, so markups won't suddenly become visible as you move the cursor around.

    Each buffer has a bufdisplay option, which indicates that buffer's preferred display mode. Whenever a window starts to show a buffer, it switches its display mode to that buffer's bufdisplay mode. You should set bufdisplay to the name of a supported display mode: normal, syntax, html, man, or hex. The compiled-in default is normal but the standard elvis.arf file tries to choose a more clever default, based on the extension of the buffer's filename.

    The display option indicates which display mode the window is currently in. You can't set this option directly; you must use the :display command instead.

    The number option causes a line number to be prepended to the start of each line. The line numbers are defined as "one plus the number of newlines preceding the start of the line," which is not necessarily how the current display mode defines lines. Consequently, the line numbers may not increment by 1 every time. These line numbers do correspond to the ruler and the visual G command, though. This option is false by default.

    The ruler option causes the current line number and column number to be displayed at the bottom of the screen. This uses the same definition of "line number" as the number option, above. This option is false by default.

    The showmatch option helps you locate matching parentheses. When you're in input mode, and you type a ), ], or } character, elvis will causes the matching (, [, or { character to be highlighted on the screen. This option is false by default.

    The showmode option causes elvis to display a one-word label for its current parse state in the lower right-hand corner of the window. Usually, this will be either "Command" or "Input". This option is false by default, but I suggest you make it true because it really is handy.

    The nonascii option tells elvis how to display characters 0x80 through 0xff. It can have one of the following values:

    	.-------.------------------------------------------------.
    	| VALUE | MEANING                                        |
    	|-------|------------------------------------------------|
    	| all   | All characters 0x80-0xff are visible           |
    	| most  | Chars 0xa0-0xff are visible, but not 0x80-0x9f |
    	| none  | Chars 0x80-0xff are not visible                |
    	| strip | Convert 0xa0-0xfe to ASCII; others not visible |
    	^-------^------------------------------------------------^
    
    Any characters which aren't visible will be displayed as '.' characters. Note that this only affects the way the characters are displayed; they are actually stored with their true 8-bit value. The default value of nonascii is "most", because that is the correct value for the Latin-1 symbol set.

    The showstack option causes some debugging output to appear on the bottom row of the window. It is false by default, and you should leave it that way.

    6.1.8 Options for a particular display mode

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | commentfont, cfont  | One-Of  | syntax | font used for comments      |
    | stringfont, sfont   | One-Of  | syntax | font used for strings       |
    | keywordfont, kfont  | One-Of  | syntax | font used for reserved words|
    | functionfont, ffont | One-Of  | syntax | font used for function names|
    | variablefont, vfont | One-Of  | syntax | font used for variables     |
    | prepfont, pfont     | One-Of  | syntax | font used for preprocessor  |
    | otherfont, ofont    | One-Of  | syntax | font used for other symbols |
    ^---------------------^---------^--------^-----------------------------^
    
    In the syntax display mode, the commentfont, stringfont, keywordfont, functionfont, variablefont, prepfont and otherfont options specify which font is to be used for different parts of the source code. Each option can be set to normal, bold, emphasized, italics, underlined, or other. The prepfont is used for preprocessor directives. The keywordfont is used for reserved words such as "int" and "return". The functionfont is used for any other word which is followed by an opening parenthesis character. The otherfont is used for any other word which matches some language-dependent criteria; for C, the word must either contain no lowercase letters or end with a "_t" (probably a constant or a user-defined type). The variablefont is used for all other words. Punctuation is always in the normal font; you can't control that.

    You can set these variables during initialization, in the .exrc or elvis.rc file. After that, your window must actually be in the "syntax" mode for these to be accessible.

    As a separate step, some user interfaces allow you to specify a color to be used for each font, via the :color command.

    6.1.9 Messages

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | terse, te           | Boolean | global | don't translate messages    |
    | verbose             | Boolean | global | give more status messages   |
    | errorbells, eb      | Boolean | global | ring bell for error message |
    | warningbells, wb    | Boolean | global | ring bell for warning msg   |
    | flash, vbell        | Boolean | global | substitute flash for bell   |
    ^---------------------^---------^--------^-----------------------------^
    
    The terse option indicates whether elvis should attempt to translate messages via the elvis.msg file. If terse is true, then no such translation takes place; the built-in messages are used. If terse is false, then elvis will search through the file (actually the "Elvis messages" buffer) for a line which looks like "terse:verbose" and if found it'll use the verbose version instead. By default, terse is false.

    The verbose option has nothing to do with the terse option. Instead, it indicates whether elvis was started with the -V flag, indicating that the user wants more status messages to be generated. This is handy when elvis isn't initializing itself the way you expected it to.

    The errorbells and warningbells options cause the terminal's bell to ring when an error message or warning message is generated, respectively. By default the errorbells option is true, and the warningbells option is false.

    Setting the flash option causes elvis to use a visible alternative to the bell, if one exists. This is nice in a crowded terminal room. By default this option is false.

    6.1.10 Options for a particular user interface

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | term, termtype      | String  | tcap   | terminal's termcap entry    |
    | ttyrows, ttylines   | Number  | tcap   | height of screen            |
    | ttycolumns, ttycols | Number  | tcap   | width of screen             |
    | ttyunderline, ttyu  | Boolean | tcap   | okay to mix color & underln |
    | codepage, cp        | Number  | win32  | console character set       |
    |---------------------|---------|--------|-----------------------------|
    | normalfont, xfn     | String  | x11    | name of normal font         |
    | boldfont, xfb       | String  | x11    | name of bold font           |
    | italicfont, xfi     | String  | x11    | name of italic font         |
    | scrollbarwidth, xsw | Number  | x11    | size of scrollbar, in pixels|
    | scrollbartime, xst  | Number  | x11    | delay for scrollbar repeat  |
    | dblclicktime, xdct  | Number  | x11    | double-click speed, 1/10 Sec|
    | xrows, xlines       | Number  | x11    | height of new windows       |
    | xcolumns, xcols     | Number  | x11    | width of new windows        |
    | firstx, xpos        | Number  | x11    | horiz. position of first win|
    | firsty, ypos        | Number  | x11    | vert. position of first win |
    | stagger             | Number  | x11    | offset for next new window  |
    | icon                | Boolean | x11    | use the built-in icon?      |
    | stopshell, ssh      | String  | x11    | interactive shell command   |
    | autoiconify, aic    | Boolean | x11    | iconify old window          |
    | altkey, metakey     | One of  | x11    | effect of the Alt key       |
    | warpto, wt          | One of  | x11    | ^W^W forces pointer movement|
    | warpback, wb        | Boolean | x11    | upon exit, point to xterm   |
    ^---------------------^---------^--------^-----------------------------^
    
    The term, ttyrows, ttycolumns, and ttyunderline options are only present if you're using the termcap user interface. They indicate the name of the termcap entry being used (normally taken from the TERM environment variable), the size of the screen, and whether it is safe to try underlining text when colors have been assigned to fonts. The ttyunderline option is true by default, but it should be made false on the Linux console, because the console driver has a bug which prevents underlined text from being shown in color.

    The codepage option only exists in the Win32 version (for WindowsNT and Windows95). It indicates which code page (character map) the console is using. Its value is persistent; if you change it in elvis, the console will remain changed even after you exit elvis. Changing the code page as no effect on the digraph table, or elvis' idea of which non-ASCII characters should be treated as letters; it only reconfigures the console driver. Typical values are 437 for the standard IBM PC character set, and 850 for extra European characters.

    The other options all apply to the x11 interface. The normalfont, boldfont, and italicfont options control the X fonts used for displaying text. They can only be changed before the first window is created; typically, the elvis.ini or ".exrc" file will set this. If you do choose to set it in one of these files, be sure to have your initialization script check which interface is being used because if elvis is using the termcap interface then these x11 options won't exist. These options all default to an empty string; this is a special case which causes elvis to use the "fixed" font for normal text, and to derive the bold and italic fonts from the normal font.

    The scrollbarwidth option controls the size of the x11 scrollbar. The default value is 16 pixels, and the allowed range is 5 to 40 pixels.

    The scrollbar buttons automatically repeat if you hold a mouse button down scrollbartime tenths of a second. The default is 4 tenths of a second.

    The dblclicktime option allows you to adjust the speed of mouse double-clicks to match your own clicking habits. The default is 3 tenths of a second.

    The xrows and xcolumns options control the initial size of windows. They default to 34 and 80, respectively, and can also be set via the -geometry command-line flag. After a window has been created, you can use your window manager to resize the window.

    The firstx and firsty options, if set, control the position of the first window that elvis creates. If they are unset, then elvis doesn't specify a position for the window. The -geometry command-line flag can be used to set these options. After the first window has been created, if the stagger option is set to a non-zero value then any new windows are created that many pixels down and to the right of the current window.

    The icon option can only be set in an initialization file such as elvis.ini or ".exrc"; once the first window has been created it is too late to change it. This option controls whether the window will be given the default, built-in icon. It is true by default, so windows will get the icon. This is usually a good thing. Some window managers don't allow you to override built-in icons, though, so if you want your window manager to use a different icon for elvis then you'll need to have a "set noicon" in your elvis.ini file.

    The stopshell option stores a command which runs an interactive shell. It is used for the :stop ex commands, and the ^Z visual command. Normally, this is set to "xterm &" so you get a shell in a window. The "&" at the end of the command allows elvis to continue responding to user input while the shell is running.

    When the ^W^W visual command switches keyboard control to an X11 window which as been iconified, elvis automatically deiconifies it. When it does this, if the autoiconify option is set then elvis will iconify the previous window, so the number of iconified elvis windows remains constant. By default, this option is false. Regardless of whether autoiconify is set, you can always use your window manager to iconify or deiconify windows manually.

    The altkey option controls the effect of the Alt or Meta keys. It can be set to either control-O, setbit, or ignore. The ignore value is self explanatory. If the option is set to control-O then the x11 interface will simulate a ^O keystroke before each actual keystroke. This is handy because if you're in input mode you can just hold down Alt/Meta to perform a series of visual commands. If the option is set to setbit then the x11 interface will set the most significant bit of each ASCII character while the Alt/Meta key is held down. Some other programs use this trick as a means of entering non-ASCII characters. (Elvis has a better way though; check out the :digraph command.) The default is setbit.

    The warpto option can cause elvis to force the mouse pointer to move whenever you use keyboard commands such as ^W^W to switch from one elvis window to another. There are two reasons you may wish to do this: either your window manager requires the pointer to be in a window for that window to receive keystrokes, or you want to have your X server automatically pan the screen to bring the next window into view.

    You can set the warpto option to any one of the following values: don't, scrollbar, origin, or corners. The default is don't which prevents any automatic pointer movement. The scrollbar value causes the pointer to move to the scrollbar, and origin moves it to the upper-left corner. The corners value causes the pointer to move first to the corner furthest from the window's text cursor, and then to the nearest corner; this will cause the X server to pan (if necessary) to bring the entire window into view.

    The warpback option, if set, causes the X terminal's graphic cursor to be moved back to the window which held keyboard focus at the time when elvis was started. Usually this will be the xterm where you typed in the "elvis files..." command line. Just as the firstx, firsty, and stagger options are intended to allow mouseless positioning of elvis windows, the warpback option is intended to serve as a mouseless way to switch keyboard focus back to the original xterm, so that mouse haters will find elvis' x11 interface as convenient to use as the termcap interface. By default, warpback is false.

    6.1.11 Regular expression options

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | ignorecase, ic      | Boolean | global | regexp uppercase=lowercase  |
    | magic, ma           | Boolean | global | use normal regexp syntax    |
    | autoselect, as      | Boolean | global | visibly mark searched text  |
    | wrapscan, ws        | Boolean | global | searching wraps at EOF<->BOF|
    | edcompatible, ed    | Boolean | global | remember regsub flags       |
    ^---------------------^---------^--------^-----------------------------^
    
    Setting the ignorecase option to true will cause elvis to treat uppercase and lowercase letters as being equal. When ignorecase is false (the default), they are treated as different.

    The magic option selects one of two different syntaxes for regular expressions. When magic is true, it uses the normal syntax in which * and . are special characters. When magic is false, it uses a simplified syntax.

    The autoselect option, when true, causes a successful visual search command such as /regexp to visibly mark the matching text just like the v command does. This is intended to compensate for elvis 2.0's lack of a "c" option in the :s/old/new/ command. By default, autoselect is false.

    The wrapscan option determines what happens when a search command bumps into the top or bottom of a buffer. If wrapscan is true, then the search will wrap around to the other end of the buffer, so if there's a match anywhere in the buffer, the search will find it. If wrapscan is false, then searches fail when they hit the end of the buffer. By default, wrapscan is true.

    The edcompatible option causes elvis to remember any flags that are passed into the :s/old/new/flags command, and use them as the default for the next such command. Explicitly naming a flag will toggle that flag's value. This is not the way the old ed editor worked, but this option's name and behavior are traditional in vi. This option is false by default.

    6.1.12 Tag options

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | taglength, tl       | Number  | global | significant length of tags  |
    | tags, tagpath       | String  | global | list of possible tag files  |
    | tagstack, tsk       | Boolean | global | remember origin of tag srch |
    ^---------------------^---------^--------^-----------------------------^
    
    These options control how elvis performs tag lookup, as for the :tag ex command or the previoustag option.

    The taglength option defines how many characters are significant in a tag name. By default this option is set to 0, which is a special value indicating that all characters are significant. If you have a lot of long names, you might want to set this to some other value so that you could type in abbreviated names.

    The tags option stores a list of filenames or directory names where tags are stored. (For directory names, it looks for a file named "tags" in that directory.) When performing tag lookup, elvis will begin by looking for it in the first directory/file mentioned in the list; if it doesn't find it there, then it moves on to the next one, and so on. By default, it just looks in a file named "tags" in the current directory.

    If the tagstack option is true, then before switching to the file and location of a looked-up tag, elvis will store the original file and position on a stack. Later, you can use the :pop or visual ^T commands to return to your original position. If tagstack is false, then the tag stack is unaffected by tag look-up. It is true by default.

    6.1.13 Window update parameters

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | exrefresh, er       | Boolean | global | redraw scrn after each line |
    | nearscroll, ns      | Number  | global | scroll vs. jump¢er param|
    | sidescroll, ss      | Number  | win    | sideways scrolling amount   |
    | optimize, opt       | Boolean | global | run faster                  |
    | pollfrequency, pf   | Number  | global | rate of testing for ^C      |
    | maptrace, mt        | One of  | global | debugger: off, run, or step |
    | maplog, mlog        | One of  | global | logging: off, reset, append |
    ^---------------------^---------^--------^-----------------------------^
    
    The exrefresh option affects the frequency of window updates when in EX mode. It is normally false, which causes the window to be refreshed at the end of each EX command. If you set exrefresh to true, then elvis will update the window's image every time an output line is generated; this makes the command run much slower, but gives you more feedback.

    The nearscroll option controls elvis' behavior when the cursor is moved off the top or bottom of the window. If the new cursor position is within nearscroll lines of the window, then the window is scrolled to bring the new line into view. If the new cursor position is outside that range, then elvis uses a "jump and center" approach, in which the window's image is drawn from scratch with the new cursor line shown in the center of the window. Its default value is 5.

    The sidescroll option is normally 0, which causes elvis to display long lines by wrapping them onto multiple rows of the window. This is the traditional vi behavior. Setting sidescroll to a larger value will switch to sidescrolling mode, where each row of the window displays part a single line, and you can scroll the window sideways by moving the cursor off the left or right edge. When you do this, the window will scroll in increments of sidescroll characters.

    The optimize option affects the efficiency of screen updates. It is normally true, which tells elvis to update the screen image only when it must wait for user input. If you make it false, then elvis will update the screen after every command; among other things, this allows you to see intermediate effects of macros. You'll need to do a ":set nooptimize" before running any animation macros.

    When elvis is performing some time-consuming operations, such as a global substitution, it will periodically check to see if the user is trying to cancel the operation. For some user interfaces, this inspection takes a significant amount of time so elvis allows the pollfrequency option to reduce the frequency of these checks. The default is 20. Larger values of pollfrequency will make global substitutions run faster; smaller values make elvis respond to ^C sooner.

    The maptrace option controls elvis' built-in macro debugger. It can be off, run or step. The default is off, which causes macros to run normally. If you change it to run then elvis will display the contents of the mapping queue at the bottom of the screen while running any macro. The step value also displays the mapping queue, but then waits for a keystroke before proceeding. If the keystroke is ^C then the macro is terminated. If the keystroke is r then maptrace is set to run. Any other keystroke causes elvis to pause again after processing the macro's next character. See section 14.1 How to debug macros for more suggestions for debugging macros.

    The maplog option can be used to log the information displayed by the maptrace option. It is off by default. Setting it to append causes the map trace information to be appended to an internal edit buffer named "Elvis map log". Setting it to reset causes that buffer to be clobbered before the next map trace; when that happens, maplog will be automatically switched to append. You can view the logged data via the command...

    :(Elvis map log)split

    6.1.14 Cache options

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | blkcache, cache     | Number  | global | number of blocks in cache   |
    | blksize, bsz        | Number  | global | size of cache block         |
    | blkfill, bfill      | Number  | global | initial chars per text block|
    | blkhash, hash       | Number  | global | size of cache hash table    |
    | blkgrow, bgr        | Number  | global | allocation table parameter  |
    | sync                | Boolean | global | force changes to disk       |
    ^---------------------^---------^--------^-----------------------------^
    
    You probably don't need to know about the "blk" options. The blkcache option indicates how many blocks from the session file elvis should keep in its own internal cache, blksize indicates the size of each block, blkfill indicates how many characters should be stuffed into each block initially (leaving room for more text that the user may insert later), and blkhash and blkgrow affect a couple of internal tables.

    If the sync option is true, then elvis will flush all dirty blocks from its cache at the end of each edit command. Doing this will just about guarantee that you can recover your changes after a crash, but it can slow down the computer tremendously. The sync option is false by default, and on multi-user systems it should be left that way. On a single-user system, you might consider setting the sync option.

    6.1.15 Options that describe the system

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | bitsperchar, bits   | Number  | global | character size (always 8)   |
    | gui                 | String  | global | name of user interface      |
    | os                  | String  | global | name of operating system    |
    | session, ses        | String  | global | name of session file        |
    | tempsession, temp   | Boolean | global | delete session file on exit |
    | newsession, newses  | Boolean | global | session file is new         |
    | recovering, rflag   | Boolean | global | recovering after a crash    |
    | exitcode, exit      | Number  | global | exit code of elvis process  |
    ^---------------------^---------^--------^-----------------------------^
    
    The bitsperchar option indicates the size of characters that elvis uses internally. Currently this is always 8, but I expect to support 16-bit characters eventually.

    The gui option indicates which user interface is being used. This can be handy in your initialization files. For example, you might prefer white characters on a blue background when using the "termcap" interface, and black characters on a white background when using the "x11" interface.

    The os option allows elvis' initialization files to act differently on different operating systems. Its value indicates the name of the local operating system.

    The session option stores the name of the current session file. There is rarely any need to check this, but I had to store it someplace and it might as well be accessible, I figured.

    The tempsession, newsession, and recovering options describe different aspects of the session file. If tempsession is true, then elvis will delete the session file when it exits. If newsession is true, then elvis has just created the file so there may be extra initialization that needs to take place in elvis.ini or someplace. If recovering is true, then the session file may be damaged, so it may be a good idea to skip some initialization steps, or automatically write out all user buffers.

    The exitcode is the value that elvis will return to its parent process when the elvis process exits. Initially this is 0, which is the conventional indication of a normal, successful exit. You can explicitly set it to other values to indicate special situations. Also, if elvis outputs an error message and exitcode has not been explicitly set, then elvis changes exitcode to 1, so the parent process can know that elvis had an error.

    6.1.16 External programs

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | ccprg, cc           | String  | buf    | shell command for :cc       |
    | makeprg, make       | String  | buf    | shell command for :make     |
    | equalprg, eq        | String  | buf    | shell command for = operator|
    | keywordprg, kw      | String  | buf    | shell command for K command |
    | shell, sh           | String  | global | name of shell program       |
    | warn                | Boolean | global | warn if file not saved      |
    | anyerror, ae        | Boolean | global | allow :errlist if readonly  |
    ^---------------------^---------^--------^-----------------------------^
    
    The ccprg and makeprg are the programs used by the :cc and :make commands. Before the program strings are executed, they are subjected to the same sort of expression evaluation as the :eval command, with $1 representing any extra arguments from the ex command line, and $2 representing the name of the current file. Their defaults are cc="cc ($1?$1:$2)" and make="make $1".

    The equalprg option stores the name of a program to be executed for the visual = operator command. Its default value is "fmt", which is a simple text formatting program.

    The keywordprg option stores the name of the program used by the visual K command. This string is evaluated with $1 being replaced with the word under the cursor at that time. The default value is "ref $1"; the ref program looks up a tag and displays it.

    The shell option stores the name of the system's command-line interpreter. It is used when executing all of the above programs, as well as commands entered for the EX :! and visual ! commands. Its default value is system-dependent; typically it will be "/bin/sh" for UNIX, and "C:\COMMAND.COM" for MS-DOS.

    When any external program is executed, if the current buffer has been changed but not written out to the file, then elvis will normally give a warning message. Setting the warn option to false disables this message.

    When searching for error messages after a :cc or :make command, elvis will normally ignore errors about files that you don't have write access to. Usually this is convenient, because it prevents elvis from reading header files that you've misused. However, setting anyerror to true will make it read any file that generates a complaint, even if you can't write to it.

    6.1.17 Directory names

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | home, home          | String  | global | home directory              |
    | elvispath, epath    | String  | global | list of possible config dirs|
    | sessionpath, spath  | String  | global | list of possible session dir|
    | directory, dir      | String  | global | where to store temp files   |
    ^---------------------^---------^--------^-----------------------------^
    
    The home option is the name of your home directory. The value of this option is used for replacing the ~ character at the start of a full pathname. If an environment variable named HOME exists, then home is initialized from its value. Otherwise, its default value is set as follows:
    For UNIX:
    The default is "/".
    For Win32:
    The default is derived from environment variables named HOMEDRIVE and HOMEPATH, which will normally always be defined. Their default value is usually "C:/users/default". If either of those environment variables is undefined, then elvis will attempt to find the pathname of the program, and use its directory. As a last resort, elvis will use "C:\" as the default home directory.
    For MS-DOS:
    The default home directory is the one containing ELVIS.EXE.

    The elvispath option stores a list of directory names where elvis might find its configuration files. Usually it is set to a value such as "~/.elvislib:/usr/local/lib/elvis" so that elvis will search first in a subdirectory of the user's home directory, and then in the directory where the standard versions of those files were installed. A path like this allows users to override elvis' behavior if they want. The default value depends the operating system, as follows:

    For UNIX:
    The default contains ~/.elvislib and the directory that you specified as the data directory when you ran the configure script. (E.g, "configure --datadir=/usr/lib/elvis") The default data directory is /usr/local/lib/elvis, so usually elvispath will default to "~/.elvislib:/usr/local/lib/elvis".
    For Win32 or MS-DOS:
    The default contains ~\elvislib, the directory where elvis.exe resides, and a subdirectory under that named "lib".

    The sessionpath option gives elvis a list of possible directories where session files might be placed. When elvis uses the first writable directory in that list, and ignores all of the others. The default value depends on the operating system, and can be overridden by the SESSIONPATH environment variable. You can't change the sessionpath option after elvis has started, because the session file has already been created by then.

    The directory option gives the name of the directory where elvis will store its temporary files. The default value is system-dependent. Note that this is not where the session file is stored; the session option gives the name of the session file.

    6.1.18 Initialization options

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | exrc, ex            | Boolean | global | interpret ./.exrc file      |
    | modelines, modeline | Boolean | global | interpret modelines         |
    | safer, trapunsafe   | Boolean | global | be paranoid                 |
    | initialstate, is    | One-Of  | global | command mode of new windows |
    ^---------------------^---------^--------^-----------------------------^
    
    The exrc option has no built-in meaning to elvis, however the default elvis.ini file uses this option to determine whether it should look for a ".exrc" file in the current directory.

    The modelines option controls whether elvis will look for modelines in each buffer after it has been loaded from a file. If modelines is true, then elvis will search through the first five and last five lines of the buffer for something that looks like "ex:commands:" or "vi:commands:" and if found, it executes the commands as an ex command line. This is typically used for changing tabstops and the like. The modelines option is false by default.

    The safer option closes some security holes. It is intended to make modelines and a .exrc file in the current directory safe to use, but I'm not making any promises. When the "safer" option is true, certain commands are disabled, wildcard expansion in filenames is disabled, and certain options are locked (including the safer option itself). Typically you will use the ex command :safer to execute an untrusted file, and :source to execute a trusted one, rather than futz with the value of the safer option directly.

    The initialstate option determines what command mode new windows will start in. It can be one of input, replace, vi, or ex. The default is vi, the visual command mode.

    6.1.19 Keyboard map options

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | remap               | Boolean | global | allow key maps to use maps  |
    | keytime, kt         | Number  | global | timeout for function keys   |
    | usertime, ut        | Number  | global | timeout for multi-key maps  |
    ^---------------------^---------^--------^-----------------------------^
    
    Elvis allows keystrokes to be mapped via the :map command. Once a map has been defined, these options control how and when those maps are recognized.

    The remap option controls how many times elvis will attempt to reapply key maps. If the remap option is true (the default), then elvis will repeatedly attempt to reapply maps as long as there are any that match. This means that maps can be written to use other maps, allowing some very complex behavior. If remap is false, then it will attempt to apply maps only once, so the result of any map is not altered any further. By default, remap is true.

    The keytime and usertime options come into play when characters are received which partially match one or more maps. For example, suppose the arrow keys are mapped to h, j, k, and l, those arrow keys send escape sequences when pressed, and elvis has just received an escape character. How can it tell whether the user hit the Esc key or an arrow key?

    In this situation, elvis must perform a read-keystrokes-with-timeout operation to determine which map applies, if any. If all of the partially matching maps are for special keys such as function keys, then elvis will use the keytime value. If at least one of them is for a user map, then elvis will use the usertime value. Either way, the values indicate the time, in tenths of a second, that elvis should allow for the rest of the map characters to arrive. If they don't arrive, then none of the partially matching maps is used.

    Typically, the usertime value will be much longer than the keytime value, because the user must hit a series of keys for a user map. For example, many people like to create maps consisting of a semicolon and one or two following letters. (If you're a touch typist, then your right-hand pinky normally rests on the semicolon key, so this is convenient.) By distinguishing between key maps and user maps, elvis can give quick response to the Esc while still allowing users to key in their own keymaps at a leisurely pace. Their default values are keytime=3 and usertime=15.

    6.1.20 Printing options

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | lptype, lpt         | String  | lp     | printer type                |
    | lpconvert, lpcvt    | Boolean | lp     | convert Latin-1 to PC-8     |
    | lpcrlf, lpc         | Boolean | lp     | printer needs CR-LF newline |
    | lpout, lpo          | String  | lp     | printer file or filter      |
    | lpcolumns, lpcols   | Number  | lp     | width of printer page       |
    | lpwrap, lpw         | Boolean | lp     | simulate line-wrap          |
    | lplines, lprows     | Number  | lp     | length of printer page      |
    | lpformfeed, lpff    | Boolean | lp     | send form-feed after last pg|
    | lppaper, lpp        | String  | lp     | paper size (letter, a4, ...)|
    ^---------------------^---------^--------^-----------------------------^
    
    The lptype option lets elvis know what type of printer you're using, so it can use the correct escape codes (or whatever) to switch fonts. It should be set to one of the following values:
    	.-------.----------------------------------------------.
    	| VALUE | PRINTER DESCRIPTION                          |
    	|-------|----------------------------------------------|
    	| ps    | PostScript, one logical page per sheet       |
    	| ps2   | PostScript, two logical pages per sheet      |
    	| epson | Most dot-matrix printers, no graphic chars   |
    	| pana  | Panasonic dot-matrix printers                |
    	| ibm   | Dot-matrix printers with IBM graphic chars   |
    	| hp    | HP printers, and most non-PostScript lasers  |
    	| cr    | Line printers, overtypes via carriage-return |
    	| bs    | Overtypes via backspace, like nroff          |
    	| dumb  | Plain ASCII, no font control                 |
    	^-------^----------------------------------------------^
    
    The lpconvert option, when set, causes some printer types to convert non-ASCII Latin-1 characters to PC-8 characters. Most computers use Latin-1 internally for storing text, but many printers use PC-8; hence the need for conversion. This option has no effect on ASCII characters because they never need conversion. This option is ignored if your computer doesn't appear to be using Latin-1 (or, more precisely, if there is no digraph which maps AE to 0xc6, the Latin-1 code for the Æ ligature.) This option is false by default.
    NOTE: Not all printer types obey the lpconvert option. Postscript printers don't do conversion because they use Latin-1 themselves. The "cr", "bs", and "dumb" printer types ignore it simply because they are typically used for writing to files, not actual printers, and as long as the text remains in the computer no conversion is necessary. Only the "epson", "pana", "ibm", and "hp" printers will obey the lpconvert option.

    The lpcrlf option forces elvis to convert each newline character to a CR/LF pair. Some printers, on some systems, require this. Most don't, so this option is false by default. If you attempt to print something and only the first line is visible, or the text is badly jumbled, then try ":set lpcrlf" and maybe that'll fix it.

    The lpout option should be either the name of a file or device (such as LPT: or /dev/lp0) to which the printer output should be sent, or ! character followed by a shell command (such as !lpr) which reads printer text from stdin and submits it to the printer spooler. The default is system dependent.

    NOTE: Microsoft's print spooler command, PRINT, is unable to read printer data from stdin; it can only print from a file whose name is given in its argument list. To get around this limitation, the Win32 port of elvis has been extended slightly. Elvis will store the text in a temporary file, and any occurrence "$1" in a filter command will be replaced by the name of that temporary file. So under Win32, the default value of lpout is "!print $1".

    The MS-DOS port of elvis has the same extension, but it doesn't help. The MS-DOS version of PRINT doesn't make its own copy of the input file, and elvis deletes the file immediately after PRINT returns; so PRINT looses its input after printing about half a page. Under MS-DOS, you should print to the "PRN" device.

    The lpcolumns option tells elvis how wide the printer page is. The default is 80 columns. If you have a wide-carriage printer, you may wish to set lpcolumns=132. If you have a postscript printer and set lpcolumns to a value greater than 80, elvis will compress the characters to make the longer lines fit.

    The lpwrap option tells elvis how to handle lines that are wider than lpcolumns. If this options is true (the default) then long lines will wrap onto multiple printed lines. If lpwrap is false, then it will clip long lines.

    The lplines option tells elvis how long the usable portion of each page is; i.e., how many lines it should print on each page. The default is 60. Some display modes ("html" and "man") print headers at the top of each page; those lines are included in the lplines count. Setting lplines=0 causes elvis to assume that pages are infinitely long, which sounds about right for fan-fold printer paper. If you have a PostScript printer and set lplines to a value greater than 60, then the page will be compressed vertically to make it fit.

    The lpformfeed option controls whether elvis will send a form-feed control character after the last page of any print job. This should generally be false if you're printing through a print spooler program, because print spoolers usually add the final formfeed themselves. Under MS-DOS, elvis is normally configured to send the text directly to the printer device, prn, and you may wish to set the lpformfeed option there.

    The lppaper option is only significant for PostScript printers. The value of lppaper is inserted into the PostScript output before the contents of the elvis.ps file. elvis.ps contains code which scales the output to fit on the paper. The default version supports letter, legal, executive, a4 and a3 paper sizes. Adding new paper sizes to that file is fairly easy. You should be careful when setting lppaper because elvis won't prevent you from setting it to an unsupported value. The default value is letter.

    6.1.21 Previous arguments

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | previousfile        | String  | global | name of alternate file      |
    | previousfileline    | Number  | global | line# from previousfile     |
    | previouscommand     | String  | global | previous shell command line |
    | previoustag, ptag   | String  | global | previous search tag         |
    ^---------------------^---------^--------^-----------------------------^
    
    These options all store the previous value of some type of input, so that the same value can be used again later. You can set these options, but there really isn't much point to it, usually.

    The previousfile option stores the name of an alternate file. Usually this is the name of the last file you mentioned, other than that of the current file. When you switch from one file to another, the name of the previous file is stored here, along with the line number (in previousfileline), so you can easily bounce between this file and the previous one. Whenever you type in a filename as an argument to an ex command, any instances of the # character are replaced by the value of previousfile.

    The previouscommand option stores the last shell command you typed in. When you enter the next shell command line, any instances of the ! character will be replaced by the value of previouscommand.

    The previoustag option stores the name of the last tag you looked up. This value is also stored on the tagstack in the hope that it may help you remember where you were when you performed all of your recent tag lookups.

    6.1.22 Unsupported options

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | window, wi          | Number  | global | lines to show (ignored)     |
    | novice              | Boolean | global | beginner mode               |
    | mesg                | Boolean | global | disable SysAdmin messages   |
    ^---------------------^---------^--------^-----------------------------^
    
    The window, novice and mesg options exist in elvis, but they don't do anything. Perhaps some day...

    6.1.23 User variables

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | a                   | String  | user   | user variable               |
    | b                   | String  | user   | user variable               |
    | c                   | String  | user   | user variable               |
    | d                   | String  | user   | user variable               |
    | e                   | String  | user   | user variable               |
    | f                   | String  | user   | user variable               |
    | g                   | String  | user   | user variable               |
    | h                   | String  | user   | user variable               |
    | i                   | String  | user   | user variable               |
    | j                   | String  | user   | user variable               |
    | k                   | String  | user   | user variable               |
    | l                   | String  | user   | user variable               |
    | m                   | String  | user   | user variable               |
    | n                   | String  | user   | user variable               |
    | o                   | String  | user   | user variable               |
    | p                   | String  | user   | user variable               |
    | q                   | String  | user   | user variable               |
    | r                   | String  | user   | user variable               |
    | s                   | String  | user   | user variable               |
    | t                   | String  | user   | user variable               |
    | u                   | String  | user   | user variable               |
    | v                   | String  | user   | user variable               |
    | w                   | String  | user   | user variable               |
    | x                   | String  | user   | user variable               |
    | y                   | String  | user   | user variable               |
    | z                   | String  | user   | user variable               |
    ^---------------------^---------^--------^-----------------------------^
    
    These one-letter options have no preset purpose. They are useful for holding temporary values which you expect to use in an expression later. These are all string values, but because the expression evaluator doesn't distinguish between a number and a string which happens to look like number, you can also use these as numbers. For example, the command... :let i=i+1 ...does exactly what you would expect.

    6.2 Alphabetical list of options

    .---------------------.---------.--------.-----------------------------.
    | OPTION NAMES        | TYPE    | DOMAIN | DESCRIPTION                 |
    |---------------------|---------|--------|-----------------------------|
    | a                   | String  | user   | user variable               |
    | altkey, metakey     | One of  | x11    | effect of the Alt key       |
    | anyerror, ae        | Boolean | global | allow :errlist if readonly  |
    | autoiconify, aic    | Boolean | x11    | iconify old window          |
    | autoindent, ai      | Boolean | buf    | auto-indent new text        |
    | autoprint, ap       | Boolean | global | print current line in ex    |
    | autoselect, as      | Boolean | global | visibly mark searched text  |
    | autotab, at         | Boolean | buf    | allow autoindent to use '\t'|
    | autowrite, aw       | Boolean | global | save file before switching  |
    | b                   | String  | user   | user variable               |
    | backup, bk          | Boolean | global | make *.bak file before write|
    | beautify, bf        | Boolean | global | strip ctrl chars from files |
    | binary, bin         | Boolean | buf    | buffer's data is not text   |
    | bitsperchar, bits   | Number  | global | character size (always 8)   |
    | blkcache, cache     | Number  | global | number of blocks in cache   |
    | blkfill, bfill      | Number  | global | initial chars per text block|
    | blkgrow, bgr        | Number  | global | allocation table parameter  |
    | blkhash, hash       | Number  | global | size of cache hash table    |
    | blksize, bsz        | Number  | global | size of cache block         |
    | boldfont, xfb       | String  | x11    | name of bold font           |
    | bufchars, bufc      | Number  | buf    | number of characters        |
    | bufdisplay, bufdis  | String  | buf    | default display mode        |
    | buflines, bufl      | Number  | buf    | number of lines             |
    | bufname, buffer     | String  | buf    | name of buffer              |
    | c                   | String  | user   | user variable               |
    | ccprg, cc           | String  | buf    | shell command for :cc       |
    | codepage, cp        | Number  | win32  | console character set       |
    | columns, cols       | Number  | win    | width of window             |
    | commentfont, cfont  | One-Of  | syntax | font used for comments      |
    | d                   | String  | user   | user variable               |
    | dblclicktime, xdct  | Number  | x11    | double-click milliseconds   |
    | defaultreadonly, dro| Boolean | global | assume all files readonly   |
    | digraph, dig        | Boolean | global | allow X-backspace-Y entry   |
    | directory, dir      | String  | global | where to store temp files   |
    | display, mode       | String  | win    | name of current display mode|
    | e                   | String  | user   | user variable               |
    | edcompatible, ed    | Boolean | global | remember regsub flags       |
    | edited, samename    | Boolean | buf    | buffer loaded from filename |
    | elvispath, epath    | String  | global | list of possible config dirs|
    | equalprg, eq        | String  | buf    | shell command for = operator|
    | errlines            | Number  | buf    | buflines when :make was run |
    | errorbells, eb      | Boolean | global | ring bell for error message |
    | exitcode, exit      | Number  | global | exit code of elvis process  |
    | exrc, ex            | Boolean | global | interpret ./.exrc file      |
    | exrefresh, er       | Boolean | global | redraw scrn after each line |
    | f                   | String  | user   | user variable               |
    | filename, file      | String  | buf    | name of file in buffer      |
    | firstx, xpos        | Number  | x11    | horiz. position of first win|
    | firsty, ypos        | Number  | x11    | vert. position of first win |
    | flash, vbell        | Boolean | global | substitute flash for bell   |
    | functionfont, ffont | One-Of  | syntax | font used for function names|
    | g                   | String  | user   | user variable               |
    | gui                 | String  | global | name of user interface      |
    | h                   | String  | user   | user variable               |
    | home, home          | String  | global | home directory              |
    | i                   | String  | user   | user variable               |
    | icon                | Boolean | x11    | use the built-in icon?      |
    | ignorecase, ic      | Boolean | global | regexp uppercase=lowercase  |
    | initialstate, is    | One-Of  | global | command mode of new windows |
    | inputtab, itab      | One-Of  | buf    | input mode's (Tab) key      |
    | internal            | Boolean | buf    | elvis requires this buffer  |
    | italicfont, xfi     | String  | x11    | name of italic font         |
    | j                   | String  | user   | user variable               |
    | k                   | String  | user   | user variable               |
    | keytime, kt         | Number  | global | timeout for function keys   |
    | keywordfont, kfont  | One-Of  | syntax | font used for reserved words|
    | keywordprg, kw      | String  | buf    | shell command for K command |
    | l                   | String  | user   | user variable               |
    | linelength, ll      | Number  | buf    | width for word-wrap, or 0   |
    | lines, rows         | Number  | win    | height of window            |
    | list, li            | Boolean | win    | show markups, newlines, etc.|
    | lpcolumns, lpcols   | Number  | lp     | width of printer page       |
    | lpcrlf, lpc         | Boolean | lp     | printer needs CR-LF newline |
    | lpformfeed, lpff    | Boolean | lp     | send form-feed after last pg|
    | lplines, lprows     | Number  | lp     | length of printer page      |
    | lppaper, lpp        | String  | lp     | paper size (letter, a4, ...)|
    | lpout, lpo          | String  | lp     | printer file or filter      |
    | lptype, lpt         | String  | lp     | printer type                |
    | lpwrap, lpw         | Boolean | lp     | simulate line-wrap          |
    | m                   | String  | user   | user variable               |
    | magic, ma           | Boolean | global | use normal regexp syntax    |
    | makeprg, make       | String  | buf    | shell command for :make     |
    | maplog, mlog        | One of  | global | logging: off, reset, append |
    | maptrace, mt        | One of  | global | debugger: off, run, or step |
    | mesg                | Boolean | global | disable SysAdmin messages   |
    | modelines, modeline | Boolean | global | interpret modelines         |
    | modified, mod       | Boolean | buf    | buffer differs from file    |
    | n                   | String  | user   | user variable               |
    | nearscroll, ns      | Number  | global | scroll vs. jump¢er param|
    | newfile, new        | Boolean | buf    | filename doesn't exist yet  |
    | newsession, newses  | Boolean | global | session file is new         |
    | nonascii, asc       | One-Of  | global | how to display non-ascii    |
    | normalfont, xfn     | String  | x11    | name of normal font         |
    | novice              | Boolean | global | beginner mode               |
    | number, nu          | Boolean | win    | display line numbers        |
    | o                   | String  | user   | user variable               |
    | optimize, opt       | Boolean | global | run faster                  |
    | os                  | String  | global | name of operating system    |
    | otherfont, ofont    | One-Of  | syntax | font used for other symbols |
    | p                   | String  | user   | user variable               |
    | paragraphs, para    | String  | buf    | nroff paragraph commands    |
    | pollfrequency, pf   | Number  | global | rate of testing for ^C      |
    | prepfont, pfont     | One-Of  | syntax | font used for preprocessor  |
    | previouscommand     | String  | global | previous shell command line |
    | previousfile        | String  | global | name of alternate file      |
    | previousfileline    | Number  | global | line# from previousfile     |
    | previoustag, ptag   | String  | global | previous search tag         |
    | prompt              | Boolean | global | issue ":" prompt in ex mode |
    | q                   | String  | user   | user variable               |
    | r                   | String  | user   | user variable               |
    | readonly, ro        | Boolean | buf    | don't overwrite filename    |
    | recovering, rflag   | Boolean | global | recovering after a crash    |
    | remap               | Boolean | global | allow key maps to use maps  |
    | report              | Number  | global | minimum # lines to report   |
    | retain, ret         | Boolean | buf    | keep buffer in session file |
    | ruler, ru           | Boolean | win    | display cursor's line/column|
    | s                   | String  | user   | user variable               |
    | safer, trapunsafe   | Boolean | global | be paranoid                 |
    | scroll, sc          | Number  | win    | scroll amount for ^D/^U     |
    | scrollbartime, xst  | Number  | x11    | delay for scrollbar repeat  |
    | scrollbarwidth, xsw | Number  | x11    | size of scrollbar, in pixels|
    | sections, sect      | String  | buf    | nroff section commands      |
    | sentenceend, se     | String  | global | punct at end of sentence    |
    | sentencegap, sg     | Number  | global | spaces required after sq    |
    | sentencequote, sq   | String  | global | punct allowed after se      |
    | session, ses        | String  | global | name of session file        |
    | sessionpath, spath  | String  | global | list of possible session dir|
    | shell, sh           | String  | global | name of shell program       |
    | shiftwidth, sw      | Number  | buf    | width used by < and >       |
    | showmatch, sm       | Boolean | win    | highlight matching parens   |
    | showmarkups, smu    | Boolean | global | show markup at cursor       |
    | showmode, smd       | Boolean | win    | display the command state   |
    | showstack, sstk     | Boolean | win    | display some debugging info |
    | sidescroll, ss      | Number  | win    | sideways scrolling amount   |
    | stagger             | Number  | x11    | offset for next new window  |
    | stringfont, sfont   | One-Of  | syntax | font used for strings       |
    | sync                | Boolean | global | force changes to disk       |
    | t                   | String  | user   | user variable               |
    | tabstop, ts         | Number  | buf    | width of tabstop columns    |
    | taglength, tl       | Number  | global | significant length of tags  |
    | tags, tagpath       | String  | global | list of possible tag files  |
    | tagstack, tsk       | Boolean | global | remember origin of tag srch |
    | tempsession, temp   | Boolean | global | delete session file on exit |
    | term, termtype      | String  | tcap   | terminal's termcap entry    |
    | terse, te           | Boolean | global | don't translate messages    |
    | ttycolumns, ttycols | Number  | tcap   | width of screen             |
    | ttyrows, ttylines   | Number  | tcap   | height of screen            |
    | ttyunderline, ttyu  | Boolean | tcap   | okay to mix color & underln |
    | u                   | String  | user   | user variable               |
    | undolevels, undo    | Number  | buf    | number of undoable commands |
    | usertime, ut        | Number  | global | timeout for multi-key maps  |
    | v                   | String  | user   | user variable               |
    | variablefont, vfont | One-Of  | syntax | font used for variables     |
    | verbose             | Boolean | global | give more status messages   |
    | w                   | String  | user   | user variable               |
    | warn                | Boolean | global | warn if file not saved      |
    | warningbells, wb    | Boolean | global | ring bell for warning msg   |
    | warpback, wb        | Boolean | x11    | upon exit, point to xterm   |
    | warpto, wt          | One of  | x11    | ^W^W forces pointer movement|
    | window, wi          | Number  | global | lines to show (ignored)     |
    | windowid, id        | Number  | win    | ID number of current window |
    | wrapmargin, wm      | (weird) | win    | set linelength from right   |
    | wrapscan, ws        | Boolean | global | searching wraps at EOF<->BOF|
    | writeany, wa        | Boolean | global | don't warn of existing file |
    | x                   | String  | user   | user variable               |
    | xcolumns, xcols     | Number  | x11    | width of new windows        |
    | xrows, xlines       | Number  | x11    | height of new windows       |
    | y                   | String  | user   | user variable               |
    | z                   | String  | user   | user variable               |
    ^---------------------^---------^--------^-----------------------------^