zgv.texi

zgv-5.6,一个Linux系统下的图片浏览器(VGA/SVGA)

@vindex delete-single-prompt
@item --delete-single-prompt
(Normally enabled, use @code{--delete-single-prompt=off} to disable.) If
disabled, don't prompt for confirmation when deleting a single file.

@vindex delete-tagged-prompt
@item --delete-tagged-prompt
(Normally enabled, use @code{--delete-tagged-prompt=off} to disable.)
If disabled, don't prompt for confirmation when deleting all tagged
files.

@vindex dither-16col-fast
@item --dither-16col-fast
(Normally enabled, use @code{--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).

@vindex fake-cols
@item --fake-cols
(Normally enabled, use @code{--fake-cols=off} to disable.) If disabled,
don't fake extra greyscales and colour depth in 8-bit modes.
@xref{Increased Greyscales}, for details.

@vindex force-fs-16col
@item --force-fs-16col
Force the use of the 640x480 16-colour mode for the selector.

@item -j
@vindex force-viewer-8bit
@itemx --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.

@vindex fs-16col-colour-thumbnails
@vindex fs-16col-color-thumbnails
@item --fs-16col-colour-thumbnails
@itemx --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.

@vindex fs-ignore-old-pos
@item --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 @kbd{G} never does such
a save/restore (@pxref{Changing Directory}).)

@vindex fs-magic
@item --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. @xref{File Type Identification}, for a discussion of the
tradeoffs involved.

@vindex fs-perfect-cols
@item --fs-perfect-cols
Don't change thumbnail colours when using the file selector to make the
rest of the selector look right. @xref{Thumbnail Issues}.

@vindex fs-slow-thumbnail-update
@item --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.

@vindex fs-small-text
@item --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 @code{:}.

@vindex fs-start-mode
@item --fs-start-mode @var{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.
@code{"640 480 8"}. @xref{Video Modes}, for details of precisely what
this means.

@item -t
@vindex fs-thick-text
@itemx --fs-thick-text
Thicken the text (filenames etc.) in the file selector (and elsewhere).
(Note that if @samp{line-text} has been enabled, then
@samp{fs-thick-text} only has an effect if @samp{block-cursor} is on as
well.)

@item -G @var{val}
@vindex gamma
@itemx --gamma @var{val}
Set the gamma adjustment used (@pxref{Gamma Adjustment}). This also sets
the `initial value' used when resetting the gamma adjustment. The
default is 1.0, i.e. no adjustment.

@vindex gnulitically-correct
@item --gnulitically-correct
GNU has @samp{POSIXLY_CORRECT} for compatibility with silly POSIX
misfeatures, and zgv has@dots{}

@item -h
@c not config var
@itemx --help
Display a list of options and a terse description of what the options
do.

@item -i
@vindex ignore-errors
@itemx --ignore-errors
When loading a single file from the command-line, ignore (some) errors.
Only meaningful for PNG currently.

@vindex jpeg-index-style
@item --jpeg-index-style @var{style}
Specify how to read JPEGs when creating thumbnails. Style @code{1} is
the quickest, but sometimes generates rather fuzzy/blocky thumbnails;
@code{2} is fairly cautious (and the default), but still quite fast;
@code{3} is an extremely cautious and slow method.

@item -J @var{type}
@vindex jpeg-speed
@itemx --jpeg-speed @var{type}
Set JPEG speed/quality tradeoff. Type @code{1} is slow but accurate;
@code{2} is faster but not as accurate (and the default); @code{3} is
the fastest but the least accurate.

@vindex line-text
@item --line-text
Draw text by drawing lines rather than using bitmap fonts. This looks
worse but is faster.

@item -M
@vindex mouse
@itemx --mouse
Enable mouse support in zgv. @file{/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 @file{libvga.config}; see the
man page for that for details.

@vindex mouse-scale
@item --mouse-scale @var{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.

@vindex pcd-res
@item --pcd-res @var{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.)

@item -g
@vindex pgm-truecol
@itemx --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; @pxref{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 @code{--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! @xref{Drawbacks of 15/16-bit Modes}.)

@vindex reverse-bc-order
@item --reverse-bc-order
Normally, any brightness modification is applied after applying any
contrast. Enabling this reverses the order.

@vindex revert-orient
@item --revert-orient
(Normally enabled, use @code{--revert-orient=off} to disable.) If
disabled, orientation (flip/mirror/rotate) state is retained between
pictures.

@vindex revert-scale
@item --revert-scale
(Normally enabled, use @code{--revert-scale=off} to disable.) If
disabled, scaling is retained between pictures.

@vindex scrollbar
@item --scrollbar
(Normally enabled, use @code{--scrollbar=off} to disable.) If disabled,
don't show a scrollbar below the selector.

@vindex show-xvpics-dir
@item --show-xvpics-dir
Show any @file{.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 @file{.xvpics} dir.)

@item -T
@c not config var
@itemx --show-tagged
Print names of tagged files on exit. This can be useful in constructions
something like @code{mv `zgv -T` /tmp}, which moves to @file{/tmp} only
the files you select.

@item -S @var{delay}
@vindex slideshow-delay
@itemx --slideshow-delay @var{delay}
Set time to wait in seconds before loading the next picture in a
slideshow. The default is 4.

@item -l
@vindex slideshow-loop
@itemx --slideshow-loop
Loop in slideshows `forever' (or rather, until you exit).

@item -R
@vindex slideshow-randomise
@vindex slideshow-randomize
@itemx --slideshow-randomise
@itemx --slideshow-randomize
Randomise picture order in slideshows. Due to the shuffling approach
taken, there will be no repeats or omissions.

@vindex viewer-16col-colour
@vindex viewer-16col-color
@item --viewer-16col-colour
@itemx --viewer-16col-color
Give a dithered colour image in 640x480x4 mode when in the viewer
(@pxref{The Viewer 640x480x4 Mode}), rather than greyscale.

@item -m @var{modespec}
@vindex viewer-start-mode
@itemx --viewer-start-mode @var{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 (@pxref{Default Video Mode}). The `modespec' should be the
width, height, and depth in quotes, e.g. @code{"640 480 8"}. @xref{Video
Modes}, for details of precisely what this means.

@vindex visual
@item --visual
(Normally enabled, use @code{--visual=off} to disable.) If disabled, no
thumbnails are shown.

@item -k
@vindex vkludge
@itemx --vkludge
enables vkludge, which smoothes slightly when `zooming' a big picture
down to screen size, and also when in 320x400 and 360x480 modes.

@c not config var
@item --version
Show version number.

@vindex xzgv-keys
@item --xzgv-keys
Makes zgv acts a bit more like xzgv, at least in terms of the keypresses
it supports (@pxref{xzgv Compatibility}).

@item -z
@vindex zoom
@itemx --zoom
Enable zoom mode, which resizes the picture to fit the screen.
@xref{Zoom Mode}.

@vindex zoom-reduce-only
@item --zoom-reduce-only
When in zoom mode, only @emph{reduce} pictures to fit; i.e. make big
pictures viewable all-at-once while leaving small picures intact.
@end table

If zgv is started with @code{zgv @var{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 @file{.gif}, etc. @xref{File Type
Identification}.)

If started with @code{zgv @var{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
@code{-l} so that zgv will loop around these pictures until @kbd{Esc} is
pressed, and the @code{-R} option to shuffle (randomise) the picture
order may also be of interest.

If started with @code{zgv @var{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. @code{-z} or @code{--zoom}. However, there's an
alternative long-option form for setting these, resembling how they're
set in config files --- the syntax is @code{--option=@var{state}}, where
@var{state} is @code{on}/@code{y}/@code{yes}/@code{1} to enable the
option, or @code{off}/@code{n}/@code{no}/@code{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. @code{--zoom=off}.

(Readers used to the way GNU-style long options work should note that,
since this @code{on}/@code{off}/etc. arg is optional, you can't use the
@code{--option arg} form in this case; it must be @code{--option=arg}
for it to work.)


@node  Online help, The File Selector, Invoking zgv, Top
@comment  node-name,  next,  previous,  up
@chapter Online help

@cindex online help
@cindex help, online

Online help (of a sort) is available in both the file selector and
viewer:

@table @kbd
@kindex ?
@item ?
Gives online help. This lists some of the most commonly-used keypresses
in the current context.
@end table

In the viewer, you can also get a list of which key combinations select
which video modes. @xref{Selecting a Video Mode}.


@node  The File Selector, The Viewer, Online help, Top
@comment  node-name,  next,  previous,  up
@chapter The File Selector

@c XXX could do with synonyms for `selector' here...
@cindex file selector
@cindex the file selector
@cindex selector

Usually, on starting up zgv, you will enter the file selector, which
lets you pick files to view (among other things). This lists the
subdirectories and picture files in the current directory, along with
small `thumbnail' versions of the pictures if they exist.

@menu
* Exiting zgv::                 Why would you want to? :-)
* Thumbnails::                  How to create thumbnails, and how they
                                  work.
* Screen Layout::               The file selector lists dirs/files.
* Moving Around The List::      How to move the cursor.
* Viewing a File::              How to view a single file.
* Dialog Boxes::                How zgv reports errors and asks you things.
* Tagging::                     You can tag (mark) multiple files, then
                                  view/copy/move/delete them.
* Renaming a File::             Renaming a single file or directory.
* Changing Directory::          As well as the normal dir-by-dir way,
                                  you can jump directly to a directory.
* Changing the Sorting Order::  Files can be sorted by name,
                                  `extension', size, and date/time.
* File Selector Toggles::       Some options can be changed while zgv is
                                  running.
* Other File Sel Commands::     Miscellaneous operations.
* Showing More Files::          You can use different video modes for the
                                  file selector, showing more files at
                                  once.
* 16-colour File Selector::     If 640x480 256-colour mode is absent
                                  thumbnails don't look as good, but you
                                  can choose between monochrome and
                                  colour approximations.
@end menu


@node  Exiting zgv, Thumbnails, The File Selector, The File Selector
@comment  node-name,  next,  previous,  up
@section Exiting zgv

@cindex exiting zgv
@cindex quitting zgv
@cindex leaving zgv

Exiting zgv can be achieved two ways:

@table @kbd
@kindex Esc (Selector)