XDVI(1)

NAME
xdvi - DVI Previewer for the X Window System

SYNOPSIS
xdvi [+[page]] [-s shrink] [-S density] [-p pixels] [-l] [-paper papertype] [-mgs[n] size] [-hushspecials] [-hushchars] [-hush] [-altfont font] [-margins dimen] [-sidemargin dimen] [-topmargin dimen] [-offsets dimen] [-xoffset dimen] [-yoffset dimen] [-keep] [-rv] [-fg color] [-bg color] [-hl color] [-bd color] [-cr color] [-bw width] [-geometry geometry] [-icongeometry geometry] [-iconic] [-display display] [-copy] [-thorough] [-nogrey] [-gamma gamma] [-version] dvi_file

DESCRIPTION
Xdvi is a program which runs under the X window system. It is used to preview DVI files, such as are produced by TeX.

This program has the capability of showing the file shrunken by various (integer) factors, and also has a ``magnifying glass'' which allows one to see a small part of the unshrunk image momentarily.

Before displaying any page or part thereof, it checks to see if the dvi file has changed since the last time it was displayed. If this is the case, then xdvi will reinitialize itself for the new dvi file. For this reason, exposing parts of the xdvi window while TeX is running should be avoided. This feature allows you to preview many versions of the same file while running xdvi only once.

OPTIONS
In addition to specifying the .dvi file (with or without the .dvi), xdvi supports the following command line options. If the option begins with a `+' instead of a `-', the option is restored to its default value. By default, these options can be set via the resource names given in parentheses in the description of each option.

+page
    Specifies the first page to show. If + is given without a number, the last page is assumed; the first page is the default.

-s shrink
    (.shrinkFactor) Defines the initial shrink factor. The default value is 3.

-S density
    (.densityPercent) Determines the density used when shrinking bitmaps for fonts. A higher value produces a lighter font. The default value is 40.

-density density
    Same as -S.

-p pixels
    (.pixelsPerInch) Defines the size of the fonts to use, in pixels per inch. The default value is 300.

-altfont font
    (.altFont) Declares a default font to use when the font in the dvi file cannot be found. This is useful, for example, with PostScript <tm> fonts.

-l  (.listFonts) Causes the names of the fonts used to be listed.

-hushspecials
    (.hushSpecials) Causes xdvi to suppress warnings about \special strings which it cannot process.

-hushchars
    (.hushLostChars) Causes xdvi to suppress warnings about references to characters which are not defined in the font.

-hush
    (.Hush) Causes xdvi to suppress all suppressable warnings.

-rv (.reverseVideo) Causes the page to be displayed with white characters on a black background, instead of vice versa.

-bw width
    (.borderWidth) Specifies the width of the border of the window.

-borderwidth width
    Same as -bw.

-fg color
    (.foreground) Determines the color of the text (foreground).

-foreground color
    Same as -fg.

-bg color
    (.background) Determines the color of the background.

-background color
    Same as -bg.

-hl color
    (.highlight) Determines the color of the page border. The default is the foreground color.

-bd color
    (.borderColor) Determines the color of the window border.

-bordercolor color
    Same as -bd.

-cr color
    (.cursorColor) Determines the color of the cursor. The default is the color of the page border.

-thorough
    (.thorough) Xdvi will usually try to ensure that overstrike characters (e.g. \notin) are printed correctly. On monochrome displays, this is always possible with one logical operation, either and or or. On color displays, however, this may take two operations, one to set the appropriate bits and one to clear other bits. If this is the case, then by default xdvi will instead use the copy operation, which does not handle overstriking correctly. The ``thorough'' option chooses the slower but more correct choice. See also -copy, below.

-copy
    (.copy) Always use the copy operation when writing characters to the display. This option may be necessary for correct operation on a color display, but overstrike characters will be incorrect. If greyscale anti-aliasing is in use, the copy operation will disable the use of colorplanes and make overstrikes come out incorrectly.

-keep
    (.keepPosition) Sets a flag to indicate that xdvi should not move to the home position when moving to a new page. See also the `k' keystroke.

-version
    Print information on the version of xdvi.

-margins dimen
    (.Margin) Specifies the size of both the top margin and side margin. This should be a decimal number optionally followed by "cm", e.g., 1.5 or 3cm, giving a measurement in inches or centimeters. It determines the ``home'' position of the page within the window as follows. If the entire page fits in the window, then the margin settings are ignored. If, even after removing the margins from the left, right, top, and bottom, the page still cannot fit in the window, then the page is put in the window such that the top and left margins are hidden, and presumably the upper left-hand corner of the text on the page will be in the upper left-hand corner of the window. Otherwise, the text is centered in the window. See also `M' under the KEYSTROKES section.

-sidemargin dimen
    (.sideMargin) Specifies the side margin (see above).

-topmargin dimen
    (.topMargin) Specifies the top and bottom margins (see above).

-offsets dimen
    (.Offset) Specifies the size of both the horizontal and vertical offsets of the output on the page. This should be a decimal number optionally followed by "cm", e.g., 1.5 or 3cm, giving a measurement in inches or centimeters. By decree of the Stanford TeX Project, the default TeX page origin is always 1 inch over and down from the top-left page corner, even when non-American paper sizes are used. Therefore, the default offsets are 1.0 inch.

-xoffset dimen
    (.xOffset) Specifies the size of the horizontal offset of the output on the page (see above).

-yoffset dimen
    (.yOffset) Specifies the size of the vertical offset of the output on the page (see above).

-paper papertype
    (.paper) Specifies the size of the printed page. This may be of the form wxh (or wxhcm), where w is the width in inches (or cm) and h is the height in inches (or cm), respectively. There are also synonyms which may be used: us (8.5x11), usr (11x8.5), legal (8.5x14), foolscap (13.5x17), as well as the ISO sizes a1-a7, b1-b7, c1-c7, a1r-a7r (a1-a7 rotated), etc. The default size is 8.5 x 11 inches.

-nogrey
    (.grey) Turns off the use of greyscale anti-aliasing when printing shrunken bitmaps. (In this case, the logic of the corresponding resource is the reverse: -nogrey corresponds to grey:off; +nogrey to grey:on.) See also the `G' keystroke.

-gamma gamma
    (.gamma) Controls the interpolation of colors in the greyscale anti-aliasing color palette. Default value is 1.0. For 0 < gamma < 1, the fonts will be lighter (more like the background), and for gamma > 1, the fonts will be darker (more like the foreground). Negative values behave the same way, but use a slightly different algorithm.

-mgs[n] size
    (.magnifierSize[n]) Specifies the size of the window to be used for the ``magnifying glass'' for Button n. See the MOUSE ACTIONS section. Defaults are 200, 350, 600, 900, and 1200.

-mgs size
    Same as -mgs1.

-geometry geometry
    (*geometry) Specifies the initial geometry of the window.

-icongeometry geometry
    (.iconGeometry) Specifies the initial position for the icon.

-iconic
    (.iconic) Causes the XDVI window to start in the iconic state. The default is to start with the window open.

-display host:display
    Specifies the host and screen to be used for displaying the dvi file. This is normally obtained from the environment variable ``DISPLAY.''

KEYSTROKES
Xdvi recognizes the following keystrokes when typed in its window. Each may optionally be preceded by a (positive or negative) number, whose interpretation will depend on the particular keystroke. Also, the "Home", "Prior", "Next", and arrow cursor keys are synonyms for `^', `b', `f', `l', `r', `u', and `d' keys, respectively.

q   Quits the program. Control-C and control-D will do this, too.

n   Moves to the next page (or to the nth next page if a number is given). Synonyms are `f', Space, Return, and Line Feed.

p   Moves to the previous page (or back n pages). Synonyms are `b', control-H, and Delete.

g   Moves to the page with the given number. Initially, the first page is assumed to be page number 1, but this can be changed with the `P' keystroke, below. If no page number is given, then it goes to the last page.

P   ``This is page number n.'' This can be used to make the `g' keystroke refer to actual page numbers instead of absolute page numbers.

Control-L
    Redisplays the current page.

^   Move to the ``home'' position of the page. This is normally the upper left-hand corner of the page, depending on the margins as described in the -margins option, above.

u   Moves up two thirds of a window-full.

d   Moves down two thirds of a window-full.

l   Moves left two thirds of a window-full.

r   Moves right two thirds of a window-full.

c   Moves the page so that the point currently beneath the cursor is moved to the middle of the window. It also (gasp!) warps the cursor to the same place.

M   Sets the margins so that the point currently under the cursor is the upper left-hand corner of the text in the page. Note that this command itself does not move the image at all. For details on how the margins are used, see the -margins option.

s   Changes the shrink factor to the given number. If no number is given, the smallest factor that makes the entire page fit in the window will be used. (Margins are ignored in this computation.)

S   Sets the density factor to be used when shrinking bitmaps. This should be a number between 0 and 100; higher numbers produce lighter characters.

R   Forces the dvi file to be reread. This allows you to preview many versions of the same file while running xdvi only once.

k   Normally when xdvi switches pages, it moves to the home position as well. The `k' keystroke toggles a `keep-position' flag which, when set, will keep the same position when moving between pages. Also `0k' and `1k' clear and set this flag, respectively. See also the -keep option.

G   This key toggles the use of greyscale anti-aliasing for displaying shrunken bitmaps. In addition, the key sequences `0G' and `1G' clear and set this flag, respectively. See also the -nogrey option.

MOUSE ACTIONS
If the shrink factor is set to any number other than one, then clicking any mouse button will pop up a ``magnifying glass'' which shows the unshrunk image in the vicinity of the mouse click. This subwindow disappears when the mouse button is released. Different mouse buttons produce different sized windows, as indicated by the -mgs option. Moving the cursor while holding the button down will move the magnifying glass.

Also, the scrollbars (if present) behave in the standard way: pushing Button 2 in a scrollbar moves the top or left edge of the scrollbar to that point and optionally drags it; pushing Button 1 moves the image up or right by an amount equal to the distance from the button press to the upper left-hand corner of the window; pushing Button 3 moves the image down or left by the same amount.

ENVIRONMENT
Uses the environment variable ``DISPLAY'' to specify which bit map display terminal to use.

The environment variable ``XDVIFONTS'' determines the path(s) searched for fonts in the following manner. The string consists of one or more strings separated by colons. In each such string, the substring ``%f'' is changed to the font name; ``%d'' is changed to the magnification; and ``%p'' is changed to the font family (``gf'', ``pk'', or ``pxl''). If no ``%f'' appears in the string, then the string ``/%f.%d%p'' is added on the end. For example, if the string is ``/usr/TeX/lib/tex/fonts'' and the font is cmr10 at 300dpi, then it searches for /usr/TeX/lib/tex/fonts/cmr10.300gf, /usr/TeX/lib/tex/fonts/cmr10.300pk, and /usr/TeX/lib/tex/fonts/cmr10.1500pxl, in that order. An extra colon anywhere in the ``XDVIFONTS'' variable causes the system default paths to be tried at that point. If the font is not found in the desired size, then xdvi will invoke Metafont to create the font in the correct size. Failing that, it will try to find the nearest size. If the font cannot be found at all, then xdvi will try to vary the point size of the font (within a certain range), and if this fails, then it will use the font specified as the alternate font (cf. -altfont).

For compatibility with TeX, you may also use ``TEXFONTS'' in place of ``XDVIFONTS'', although in that case the variable should not include any ``%'' specifiers. The reason for recognizing TEXFONTS is that certain versions of TeX also support the convention regarding an extra colon in the font path; therefore, users who create their own fonts can put both their .tfm and raster files in the same directory and do ``setenv TEXFONTS :MFdir'' or ``setenv TEXFONTS MFdir:'' in order to get both TeX and xdvi to search their directory in addition to the system standard directories. The XDVIFONTS variable overrides the TEXFONTS variable, so that on those sites where TEXFONTS must be set explicitly, and therefore this feature is not useful, the XDVIFONTS may be set to an empty string (i.e., ``setenv XDVIFONTS'') to cause xdvi to ignore TEXFONTS.

xdvi also recognizes the PKFONTS variable, which is checked after XDVIFONTS but before TEXFONTS.

You can also enable recursive searching in the font path by using the ``*'' and ``**'' specifiers. At this point in the path, xdvi will recursively search subdirectories of the given directory in order to find font files. A single asterisk limits the search to one level; a double asterisk will search through an arbitrary number of levels. Also, the variable TEXFONTS_SUBDIR can be used to give a colon-separated list of directories to recursively search. This is equivalent to including the specifiers with a ``*'' after each; the usual conventions regarding extra colons applies here, too, relative to a default subdirectory path. Asterisks may not be preceded by a ``%'' specifier in any path component.

The ``XDVISIZES'' variable must be set to indicate which sizes of fonts are available. It should consist of a list of numbers separated by colons. If the list begins with a colon, the system default sizes are used, as well. Sizes are expressed in dots per inch; decimals may be used for ``pxl'' files: for example, a 300 dots per inch file magnified by half a step comes out to 1643 dots per five inches, which should be encoded as 328.6. The current default set of sizes is 300 : 328.6 : 360 : 432 : 518.4 : 622 : 746.4. xdvi will also try the actual size of the font before trying any of the given sizes.

Virtual fonts are also supported, although xdvi does not have any built-in fonts to which they can refer. The search path for .vf files can be specified with the ``XDVIVFS'' environment variable in a similar manner to that for the ``XDVIFONTS'' variable. xdvi will also check the VFFONTS variable if the XDVIFONTS variable is not set. Virtual fonts are searched for immediately after looking for the font as a normal font in the exact size specified.

FILES

/usr/TeX/lib/tex/fonts   Font pixel files.

/usr/TeX/lib/tex/fonts   Virtual font files.

SEE ALSO
X(1).

AUTHORS
Eric Cooper, CMU, did a version for direct output to a QVSS. Modified for X by Bob Scheifler, MIT Laboratory for Computer Science. Modified for X11 by Mark Eichin, MIT SIPB. Additional enhancements by many others.