zgv.1

一个利用SDL语言来实现svgalib函数的示例程序

.RE
.PP
There are many commands for moving the cursor. In summary, most
`special' keys like the cursors do what you'd imagine they do --- also,
a few Emacs-like keys, a few vi-like keys, and the Sinclair
Spectrum-style (!) QAOP keys are supported.
.PP
Using a mouse in the file selector is not covered here. See \fBMouse
Funcs in the File Selector\fR, for details of what you can do with a
mouse. (Experienced users may wish to consult the \fITom & Jerry\fR and
\fIPinky and the Brain\fR cartoons for further enlightenment on this
subject.)
.PP
`\fBCursor Up\fR'
.RS
.RE
`\fB^P\fR'
.RS
.RE
`\fBk\fR'
.RS
.RE
`\fBq\fR'
.RS
Move up. Moving up from a topmost entry moves to the bottom of the
previous column.
.PP
.RE
`\fBCursor Down\fR'
.RS
.RE
`\fB^N\fR'
.RS
.RE
`\fBj\fR'
.RS
.RE
`\fBa\fR'
.RS
Move down. Moving down from a bottommost entry moves to the top of the
next column.
.PP
.RE
`\fBCursor Left\fR'
.RS
.RE
`\fB^B\fR'
.RS
.RE
`\fBh\fR'
.RS
.RE
`\fBo\fR'
.RS
Move left one column.
.PP
.RE
`\fBCursor Right\fR'
.RS
.RE
`\fB^F\fR'
.RS
.RE
`\fBl\fR'
.RS
.RE
`\fBp\fR'
.RS
Move right one column.
.PP
.RE
`\fBPage Up\fR'
.RS
.RE
`\fB^U\fR'
.RS
Move the cursor back (nearly) a page.
.PP
.RE
`\fBPage Down\fR'
.RS
.RE
`\fB^V\fR'
.RS
Move the cursor forward (nearly) a page.
.PP
.RE
`\fBHome\fR'
.RS
.RE
`\fB^A\fR'
.RS
Move the cursor to the start of the list.
.PP
.RE
`\fBEnd\fR'
.RS
.RE
`\fB^E\fR'
.RS
Move the cursor to the end of the list.
.PP
.RE
`\fBg\fR'
.RS
.RE
`\fB'\fR'
.RS
Move the cursor to the first filename starting with the next key
pressed, which would generally be a letter or number. Case is
significant; `\fBa\fR' and `\fBA\fR' are different.
.PP
If no files start with the specified character, it moves to the first
file which starts with a later char (in asciibetical order). If there
are none for which this is the case, it moves to the last file ---
unless there are no files (just directories), in which case it has no
effect.
.PP
.RE
.PP
.SH "VIEWING A FILE"
There are two ways to view files from the file selector. The usual way
is to press `\fBEnter\fR' when you've moved the cursor to the file to
view. However, you can also view tagged files as a `slideshow', which is
described later (see \fBTagging\fR).
.PP
`\fBEnter\fR'
.RS
View a picture file, or if the cursor is on a subdirectory, make that
the current directory. A progress indicator is shown when reading in a
file --- while this is onscreen, you can use `\fBEsc\fR' to abort.
.RE
.PP
.SH "DIALOG BOXES"
If zgv has a serious problem reading a file, it will give an error.
Errors are shown in boxes which appear in the middle of the screen ---
they stay there until you press `\fBEnter\fR' or `\fBEsc\fR' (if using a
mouse, clicking \fIOK\fR has the same effect).
.PP
zgv also uses similar dialog boxes for other things:
.PP
\fB-\fR 
Getting a yes or no answer. `\fBEnter\fR' or `\fBy\fR' picks `yes';
`\fBEsc\fR' or `\fBn\fR' picks no. (Again, you can click on the relevant
button with the mouse to do the same.)
.PP
\fB-\fR 
Reading a directory name. Here you should type the directory name then
`\fBEnter\fR', or press `\fBEsc\fR' to abort. In fact, this line-input
dialog allows a certain amount of editing, and so supports these
additional keys:
.PP
`\fBCursor Left\fR'
.RS
.RE
`\fB^B\fR'
.RS
Move the cursor left. (An underline character shows the cursor
position.)
.PP
.RE
`\fBCursor Right\fR'
.RS
.RE
`\fB^F\fR'
.RS
Move the cursor right.
.PP
.RE
`\fBHome\fR'
.RS
.RE
`\fB^A\fR'
.RS
Move the cursor to the start of the line.
.PP
.RE
`\fBEnd\fR'
.RS
.RE
`\fB^E\fR'
.RS
Move the cursor to the end of the line.
.PP
.RE
`\fBInsert\fR'
.RS
.RE
`\fB^I\fR'
.RS
Toggle insert/overwrite mode. (Insert mode is the default.) In insert
mode, characters you type are inserted at the cursor position. In
overwrite mode, they replace the existing chars.
.PP
.RE
`\fBBackspace\fR'
.RS
.RE
`\fB^H\fR'
.RS
Delete char to the left of the cursor. (This assumes `\fBBackspace\fR'
really generates a `\fBDEL\fR', which is the usual setup on Linux. Note
that `\fBBackspace\fR' is (usually) the key above the main `\fBEnter\fR'
key; it is often labelled simply as an arrow.)
.PP
.RE
`\fBDelete\fR'
.RS
.RE
`\fB^D\fR'
.RS
Delete the char the cursor is on.
.RE
.RE
.PP
.SH "TAGGING"
The file selector is not restricted to working on one file at a time.
You can `tag' as many (or as few) files as you wish, and certain
commands described in this section will act on them.
.PP
Initially, all files are untagged, and the filenames appear in black.
Tagged files appear in red. (See \fBConfiguring zgv\fR, if you'd prefer zgv
to use different colours.)
.PP
.SS "Tag and Untag Commands"
There are several ways to tag or untag files. The ones which work on
individual files also move the cursor forward one place afterwards, to
make tagging or untagging multiple files easier.
.PP
As elsewhere in zgv, the case of the keys is significant --- the `\fBt\fR'
(unshifted `\fBt\fR') command has quite a different effect to that of
`\fBT\fR' (shifted `\fBt\fR').
.PP
There is also a command available in the viewer to tag the
currently-viewed file. See \fBChanging Picture\fR, for details.
.PP
`\fBt\fR'
.RS
Tag file.
.PP
.RE
`\fBn\fR'
.RS
Untag file. Note that this is `\fBn\fR' (for `no tag', er, or something
like that); `\fBu\fR' would be more logical, but that is used for updating
thumbnails.
.PP
.RE
`\fBT\fR'
.RS
Tag all files.
.PP
.RE
`\fBN\fR'
.RS
Untag all files. This is on `\fBN\fR' rather than `\fBU\fR' for consistency.
.PP
.RE
`\fBSpace\fR'
.RS
Toggle the tag status of the file --- if it's tagged, untag it; if it's
untagged, tag it.
.RE
.PP
To see how many files are tagged, use `\fBAlt-f\fR' (see \fBOther File Sel
Commands\fR).
.PP
.SS "Slideshows"
A `slideshow' lets you view all the tagged files in the current
directory one after the other, or in a randomised order if `shuffling'
is enabled (see \fBFile Selector Toggles\fR):
.PP
`\fBTab\fR'
.RS
View the tagged files as a slideshow. (`\fBTab\fR' is usually the key
above `\fBCaps Lock\fR', which is often labelled with two arrows.)
.RE
.PP
Each file is shown for a certain amount of time, normally 4 seconds.
(See \fBOptions\fR, if you find this too short or long.) After the
time runs out, the next file is shown. You can cut this delay short by
hand using one of the viewer's change-picture commands such as
`\fBSpace\fR' (see \fBChanging Picture\fR), or abort the slideshow
prematurely by pressing `\fBEsc\fR'. You can also pause a slideshow so
that you remain on the current file until you unpause it (see \fBPausing
Slideshows\fR).
.PP
Normally, once each file has been shown the slideshow ends, and you are
returned to the file selector. But if looping is enabled, the slideshow
repeats until you press `\fBEsc\fR' (see \fBFile Selector Toggles\fR).
.PP
.SS "Copying/Moving/Deleting Files"
You can copy or move tagged files to a directory you specify, or
delete all tagged files. If no files are tagged, zgv
copies/moves/deletes the file the cursor is currently on --- unless
the cursor is on a subdirectory, in which case it gives an error.
.PP
Note that the commands given here are uppercase --- lowercase `\fBc\fR',
`\fBm\fR', and `\fBd\fR' do not do the same thing.
.PP
`\fBC\fR'
.RS
Copy tagged files (or the current file) to a given directory. zgv asks
for the destination directory using a dialog (see \fBDialog Boxes\fR) and
copies the files there. If it comes to copy a file but there is an
existing file in the dir with the same name, the file is not copied and
nor are any of the remaining files.
.PP
.RE
`\fBM\fR'
.RS
Move tagged files (or the current file) similarly.
.PP
.RE
`\fBD\fR'
.RS
Delete tagged files (or the current file) similarly. In this case,
there's obviously no need to specify any directory :-) but you're
prompted before deletion starts (unless this is disabled,
see \fBConfiguring zgv\fR). It also deletes thumbnails, for those files
which have them.
.RE
.PP
.SH "RENAMING A FILE"
As well as copying/moving files, you can rename them:
.PP
`\fBR\fR'
.RS
.RE
`\fBAlt-r\fR'
.RS
Rename the current file or directory --- zgv will refuse to overwrite
any existing files/directories. The new name must remain in the
current directory. (See \fBCopying/Moving/Deleting Files\fR, for how to
move a file to a different directory (albeit keeping the same name).)
.RE
.PP
It's better to use `\fBR\fR' than `\fBAlt-r\fR'; the latter never made much
sense, and is likely to be removed before long.
.PP
.SH "CHANGING DIRECTORY"
The easiest way to change the current directory in zgv is usually to
select a directory entry in the file list and press `\fBEnter\fR'.
(Selecting `\fB(..)\fR' moves to the parent directory of the current
one.)
.PP
There is an alternative though:
.PP
(Note that this command is shift-`\fBg\fR', not `\fBg\fR'.)
.PP
`\fBG\fR'
.RS
Go to a specified directory. zgv asks for the destination directory
using a dialog box which you should type the dir's name into
(see \fBDialog Boxes\fR), and moves to that directory if it exists.
.PP
If the directory turns out to be unreadable --- i.e. you do not have
permission to read it --- zgv resorts to going to your home directory.
(This is actually a general mechanism in zgv, but this command is the
most likely trigger of it.) If that in turn is unreadable, zgv gives up
in disgust and exits. :-)
.RE
.PP
.SH "CHANGING THE SORTING ORDER"
Normally, the files are listed in asciibetical order by name. However,
you can instead have the file list sorted by size, last-modified
date/time, or by `extension' (the file type).
.PP
(Only the order of files can be altered; directories are always listed
first, and always in name order.)
.PP
`\fBAlt-n\fR'
.RS
Sort by name. This is the default.
.PP
.RE
`\fBAlt-s\fR'
.RS
Sort by size. The biggest files are listed last.
.PP
.RE
`\fBAlt-d\fR'
.RS
.RE
`\fBAlt-t\fR'
.RS
Sort by last-modified date/time. The newest files are listed last.
.PP
.RE
`\fBAlt-e\fR'
.RS
Sort by extension.
.RE
.PP
.SH "FILE SELECTOR TOGGLES"
Various aspects of the file selector's behaviour can be configured while
zgv is running, by using these toggle commands (which enable the feature
if it was previously disabled, and vice versa).
.PP
These settings can also be altered using command-line options
(see \fBOptions\fR) and/or config file settings (see \fBConfiguring
zgv\fR).
.PP
`\fBv\fR'
.RS
Toggle display of thumbnails (default is on). The without-thumbnails
display can sometimes be useful for navigating around large directories
(many filenames are shown onscreen at once), and it is of course faster.
.PP
.RE
`\fBs\fR'
.RS
Toggle scrollbar on/off (default is on). The scrollbar shows which part
and which proportion of the list is currently being shown onscreen, and
when mouse support is enabled can be used to move around the list.
.PP
.RE
`\fBS\fR'