'
`--auto-animate'
Automatically animate multiple-image GIF files (see Multiple-image
GIF Animation). This limits your viewing options greatly, but can be
handy for slideshows and the like.
`--auto-mode-fit'
Automatically switch modes to suit image size.
`--auto-mode-fit-diff diff'
When choosing an auto-mode-fit mode, add diff to each mode's
width and height. For example, with a value of 20 any picture up to
820x620 will be displayed in an 800x600 mode if possible. If
diff is negative, for example -20, the effect is reversed; any
picture above 780x580 will be displayed in a mode with a resolution
higher than 800x600 if possible.
`-p'
`--avoid-single-progress'
Don't show progress indicator when loading a single file from the
command-line.
`--black-background'
Try to use a black (or nearest-to-black) background when in 8-bit modes.
This can be quite nice for consistency's sake when viewing (say) a
mixture of GIFs and JPEGs, but the extra pass over the loaded image
slows things down slightly.
`-b'
`--block-cursor'
Use a blocky outline cursor in the selector, which is rather unsubtle
but more obvious.
`--brightness adjust_val'
Specify how much to add to colour values to change brightness (default
0). Values less than zero decrease brightness, values greater than zero
increase it. Brightness is applied after contrast by default.
`--centre'
`--center'
(Normally enabled, use e.g. `--centre=off' to disable.) By default
zgv centres pictures smaller than the screen, in whichever dimensions
they are smaller. This setting gives you a way to disable this, so that
pictures always start in the top-left.
`--clear-screen-on-exit'
Clear the screen on exit. (Normally, zgv leaves the original screen
contents intact.)
`--col-black r g b'
Set colour used for `black' (text) in selector; RGB values should be in
the range 0-63 for this and the other colour settings below, and the
three numbers should be quoted, e.g. `--col-black "10 20 30"'.
`--col-dark r g b'
Set colour used for lowlights in selector.
`--col-light r g b'
Set colour used for highlights in selector.
`--col-medium r g b'
Set colour used for background in selector.
`--col-tagged r g b'
Set colour used for tagged files in selector.
`--contrast multiplier'
Specify how much to multiply colour values by to change contrast
(default 1.0). zgv multiplies each colour's difference from grey by this
number; values less than one decrease contrast, values greater than one
increase it. Negative values are also allowed, and act in a similar way,
but with the picture's colours inverted. Contrast is applied before
brightness by default.
`--delete-single-prompt'
(Normally enabled, use `--delete-single-prompt=off' to disable.) If
disabled, don't prompt for confirmation when deleting a single file.
`--delete-tagged-prompt'
(Normally enabled, use `--delete-tagged-prompt=off' to disable.)
If disabled, don't prompt for confirmation when deleting all tagged
files.
`--dither-16col-fast'
(Normally enabled, use `--dither-16col-fast=off' to disable.) By
default, zgv uses a (reasonably fast) ordered dither when displaying a
dithered colour image in 640x480x4 mode. But if you disable this
setting, it uses error-diffused dithering (which looks better but is
rather noticeably slower).
`--fake-cols'
(Normally enabled, use `--fake-cols=off' to disable.) If disabled,
don't fake extra greyscales and colour depth in 8-bit modes.
See Increased Greyscales, for details.
`--force-fs-16col'
Force the use of the 640x480 16-colour mode for the selector.
`-j'
`--force-viewer-8bit'
Force all images to be loaded as 8-bit. Normally zgv will load 24-bit
images (e.g. colour JPEGs) as 24-bit if you have any modes capable of
displaying the image in 15, 16, 24, or 32-bit colour.
`--fs-16col-colour-thumbnails'
`--fs-16col-color-thumbnails'
Use low-quality colour thumbnail pictures when the file selector is
using 640x480 16-colour mode. Normally zgv uses higher-quality
monochrome thumbnails in this situation.
`--fs-ignore-old-pos'
Don't recall previous cursor position in a directory when returning to
it later. (This mechanism only applies when changing directory
`normally'; jumping directly to another dir with `G' never does such
a save/restore (see Changing Directory).)
`--fs-magic'
Use `magic number'-type identification to determine which files should
be listed in the file selector. This is more accurate, but very much
slower. See File Type Identification, for a discussion of the
tradeoffs involved.
`--fs-perfect-cols'
Don't change thumbnail colours when using the file selector to make the
rest of the selector look right. See Thumbnail Issues.
`--fs-slow-thumbnail-update'
`walk' through the directory when updating thumbnails, moving the cursor
over every single picture whether it needs updating or not. Normally,
zgv completely skips any pictures which don't need updating, which makes
it considerably faster on large directories and/or slow machines.
`--fs-small-text'
Reduce the size of the filename text in the selector. You may find this
useful if you think the text is too big, or if you'd like to see more of
the filename without having to press `:'.
`--fs-start-mode modespec'
Specify the video mode zgv should start off using for the file
selector. (The default is 640x480x8 if possible, otherwise 640x480x4.)
The `modespec' should be the width, height, and depth in quotes, e.g.
`"640 480 8"'. See Video Modes, for details of precisely what
this means. The specified depth is actually ignored in this case, as
you can only choose 8-bit modes for the selector.
`-t'
`--fs-thick-text'
Thicken the text (filenames etc.) in the file selector (and elsewhere).
(Note that if line-text has been enabled, then
fs-thick-text only has an effect if block-cursor is on as
well.)
`-G val'
`--gamma val'
Set the gamma adjustment used (see Gamma Adjustment). This also sets
the `initial value' used when resetting the gamma adjustment. The
default is 1.0, i.e. no adjustment.
`--gnulitically-correct'
GNU has POSIXLY_CORRECT for compatibility with silly POSIX
misfeatures, and zgv has...
`-h'
`--help'
Display a list of options and a terse description of what the options
do.
`-i'
`--ignore-errors'
When loading a single file from the command-line, ignore (some) errors.
Only meaningful for PNG currently.
`--jpeg-index-style style'
Specify how to read JPEGs when creating thumbnails. Style `1' is
the quickest, but sometimes generates rather fuzzy/blocky thumbnails;
`2' is fairly cautious (and the default), but still quite fast;
`3' is an extremely cautious and slow method.
`-J type'
`--jpeg-speed type'
Set JPEG speed/quality tradeoff. Type `1' is slow but accurate;
`2' is faster but not as accurate (and the default); `3' is
the fastest but the least accurate.
`--line-text'
Draw text by drawing lines rather than using bitmap fonts. This looks
worse but is faster.
`-M'
`--mouse'
Enable mouse support in zgv. /dev/mouse must be (usually a
symlink to) the mouse device. The actual configuration of the mouse
should be done via svgalib's config file libvga.config; see the
man page for that for details.
`--mouse-scale scale'
Set the ratio of `mouse pixels' to onscreen pixels. The larger the
number, the slower the mouse moves, and vice versa. (However, the number
must be greater than zero.) If the mouse pointer moves at the wrong
speed for your tastes, play about with this setting and you should be
able to fix it.
`--pcd-res resnum'
Selects the resolution used for Photo-CD files; 1=192x128, 2=384x256,
3=768x512 (default), 4=1536x1024, 5=3072x2048. (This setting only has an
effect if Photo-CD support was enabled at compile-time.)
`-g'
`--pgm-truecol'
This one needs some background to fully explain --- greyscale files are
normally displayed in 8-bit modes, which due to VGA's limited palette
means that only 64 greyscales can be shown (zgv normally fakes extra
ones, though; see Increased Greyscales). But for people who work
with greyscale files and have 24/32-bit video modes available this can
be frustrating, as 24/32-bit modes display 256 greyscales. For this
reason, using the `--pgm-truecol' option enables a special-case
hack to read (only) PGM files as if they were 24-bit. Using a 24/32-bit
mode then gives you 256 greyscales. (Be careful to avoid 15/16-bit modes
as these will only give 32! See Drawbacks of 15/16-bit Modes.)
`-r seconds'
`--reload-delay seconds'
If seconds is >0, then any picture displayed is re-read and
redisplayed (without clearing the screen first) every seconds
seconds. If it is `-1', then the picture is re-read as often as
possible. If it's `0' (zero), the picture is only read once --- the
default. Unless this option has suddenly inspired you to write an
interesting little shell script, you're unlikely ever to have a use for
it. :-)
`--reverse-bc-order'
Normally, any brightness modification is applied after applying any
contrast. Enabling this reverses the order.
`--revert-orient'
(Normally enabled, use `--revert-orient=off' to disable.) If
disabled, orientation (flip/mirror/rotate) state is retained between
pictures.
`--revert-scale'
(Normally enabled, use `--revert-scale=off' to disable.) If
disabled, scaling is retained between pictures.
`--scrollbar'
(Normally enabled, use `--scrollbar=off' to disable.) If disabled,
don't show a scrollbar below the selector.
`-s'
`--show-dimensions'
Cause zgv to output the x and y offsets, and width and height of the
section of the image being displayed when you exit zgv. Can be useful
for things like `pnmcut `zgv -s input.ppm` input.ppm > output.ppm'.
`-T'
`--show-tagged'
Print names of tagged files on exit. This can be useful in constructions
something like `mv `zgv -T` /tmp', which moves to /tmp only
the files you select.
`--show-xvpics-dir'
Show any .xvpics directories so that the thumbnails can be viewed
even if the files they referred to no longer exist. (However, it's
usually easier to simply start zgv in the .xvpics dir.)
`-S delay'
`--slideshow-delay delay'
Set time to wait in seconds before loading the next picture in a
slideshow. The default is 4.
`-l'
`--slideshow-loop'
Loop in slideshows `forever' (or rather, until you exit).
`-R'
`--slideshow-randomise'
`--slideshow-randomize'
Randomise picture order in slideshows. Due to the shuffling approach
taken, there will be no repeats or omissions.
`--viewer-16col-colour'
`--viewer-16col-color'
Give a dithered colour image in 640x480x4 mode when in the viewer
(see The Viewer 640x480x4 Mode), rather than greyscale.
`-m modespec'
`--viewer-start-mode modespec'
Specify the video mode zgv should start off using for the viewer. The
default is generally 640x480x8, but it's actually a bit more complicated
than that (see Default Video Mode). The `modespec' should be the
width, height, and depth in quotes, e.g. `"640 480 8"'. See Video
Modes, for details of precisely what this means.
`--visual'
(Normally enabled, use `--visual=off' to disable.) If disabled, no
thumbnails are shown.
`-k'
`--vkludge'
enables vkludge, which smoothes slightly when `zooming' a big picture
down to screen size, and also when in 320x400 and 360x480 modes.
`--version'
Show version number.
`-w'
`--write-ppm'
Write the file as a PPM to stdout rather than viewing it. (This only
works if you run zgv on a single file, specified on the command-line.)
You're usually better off using a dedicated image-converting program,
though.
`--xzgv-keys'
Makes zgv acts a bit more like xzgv, at least in terms of the keypresses
it supports (see xzgv Compatibility).
`-z'
`--zoom'
Enable zoom mode, which resizes the picture to fit the screen.
See Zoom Mode.
`--zoom-reduce-only'
When in zoom mode, only reduce pictures to fit; i.e. make big
pictures viewable all-at-once while leaving small picures intact.
If zgv is started with `zgv file', zgv auto-loads the file
(bypassing the file selector), and exits when you exit from viewing the
picture. (By the way, this also makes it possible to view single files
without the usual extensions such as .gif, etc. See File Type
Identification.)
If started with `zgv file file2 ...' --- i.e. with more than
one filename --- zgv works in a similar way, except the multiple files
are shown as a slideshow, one after the other. You may want to specify
`-l' so that zgv will loop around these pictures until `Esc' is
pressed, and the `-R' option to shuffle (randomise) the picture
order may also be of interest.
If started with `zgv start-dir', zgv starts up with the usual
file selector, but with the current directory being the one specified.
Settings which are either on or off (boolean) are, as you might expect,
enabled by using e.g. `-z' or `--zoom'. However, there's an
alternative long-option form for setting these, resembling how they're
set in config files --- the syntax is `--option=state', where
state is `on'/`y'/`yes'/`1' to enable the
option, or `off'/`n'/`no'/`0' to disable it. The
most useful thing about this is that it allows you to disable options
which were previously enabled, by using e.g. `--zoom=off'.
(Readers used to the way GNU-style long options work should note that,
since this `on'/`off'/etc. arg is optional, you can't use the
`--option arg' form in this case; it must be `--option=arg'
for it to work.)