vh

Langue: en

Version: 251255 (debian - 07/07/09)

Section: 1 (Commandes utilisateur)

NAME

vh - volks-hypertext browser for the Jargon File

SYNOPSIS

jargon [-cfgimrs] [-b key]
vh [-cfgimrs] [-b key] [document]

DESCRIPTION

This program is a handy hypertext browser, originally written for the Jargon File but convenient for use with text files marked up in the simple format documented below. It allows you to page forward and back through a document, and supports reference chasing so that you can easily follow chains of "See" and "See also" pointers through the text.

Normal usage is simply to type the name of your document to the shell. Thus, `jargon' browses the Jargon File. Interactive help explaining the keyboard commands is available from the screen. If the program sees a mouse, a fairly complete `point-and-shoot' interface is also available. Color will be used if it is available, but may be suppressed with the -m option. If you are using this program under DOS and your CGA develops snow when the video RAM is written directly, use -s.

It is useful to know that there are two modes; one browses the text file, the other the entry index (if you chase a selection in the entry index you are popped to text mode at the corresponding entry).

MOUSE USAGE

The following section applies only to systems with attached and active mice. If you are using a Mac or some other system with a deficient mouse, the single mouse button is treated as a `left' button.

You will notice a scrollbar on the right edge of the screen. One of the characters of the scrollbar is different from the rest. This is called the `thumb' or `scroll box'. As you move through the file, this gives you an approximate indication of where you are in the file. If the thumb is one-third of the way down the screen, you are about one-third of the way through the file. It works in both the text and index files.

If you have a mouse, you can click the left button directly on a reference on the screen and jump to it. You can also scroll or page forward or backward by clicking on the scrollbar. There are up and down arrows above and below the scroll bar for scrolling line by line. Clicking on the scrollbar below the thumb will page forward, and clicking above it will page back. You can also "drag" the thumb by clicking on it and holding, then moving up or down before releasing. This allows you to jump quickly through the file. Holding the mouse down on the arrows or above or below the thumb will cause the scrolling or paging action to repeat until you release the button. This is one of only two places where holding the button has any special effect (the other is described below).

Clicking the right button will cause the program to backtrack the same way as the Esc or Backspace keys.

You may also click the left button on the function key prompts on the bottom line to get the same effect as pressing the function keys themselves. The ^Q (Help) entry is special; if you click it with the mouse, it will come up, but disappear when you let go of the mouse button. This is a feature, not a bug; if you want help to hang out till you tell it to go away, type control-Q.

In the text file only, if you click on the main screen (i.e. not on the scrollbar or the prompt line) outside of a reference in curly braces, the program will page forward one screen.

OTHER OPTIONS

The -i option enables an incremental-lookup feature (but note that this feature may not be available in all ports). In this mode, lookup and string search both behave like an Emacs incremental search. That is, after you type each letter of a key, your viewpoint moves forward to the next key (if any) containing the substring you've already typed. If there is no such key, the browser beeps and drops out of incremental-lookup mode. String search works similarly, behaving almost exactly like an Emacs ^S. As a reminder that you're in these incremental modes, highlights do not light up on the screens you pass through; when you want to leave the mode, press enter and the current page's highlights will light up.

The -b option runs vh in batch mode to retrieve the entry corresponding to a particular given key. The entry, if any, is written to standard output.

The -f (filter) option accepts a list of entry headwords on stdin and sends those entries to stdout.

Finally, the -r option picks an entry at random and sends it to standard output. This may be useful for `fortune cookie' applications.

INDEX GENERATION

Two data files, the default text and index for the Jargon File, should live in /usr/local/lib/vh. To generate an index from a new version, cd to this library directory. Copy or move the textfile to /usr/local/lib/vh/jargon.txt and run the command jargon -g.

For experimental purposes, it is possible to override the default document name with a command-line argument. Thus, assuming a file example.tex is in proper format, you may generate an index for example.txt with vh -g example and browse it with vh example

When you have the `example' database ready for public use, simply link or copy vh to the name `example'. If no arguments are given, this program tries to browse a database with the name it was invoked under.

The -c mode does some format and consistency checks on a text/index pair. Use this if it looks as though your lookups are landing in the wrong places; it will let you know if your index is out of date.

TEXT FILE FORMAT

`Proper format' means:

1. References are surrounded by {} or {{}}.

If the first character of the text file is not a `=', the code also assumes:

2. Reference text may not begin with whitespace, single- or double-quote, nor
   end with a semicolon.

3. Reference targets begin with a `:' at the left margin and are bounded on the right by another `:' (an optional second `:' may follow that).

These rules are useful for filtering out false hits from the index.

FILES

A copy of vh called `foo' would require the following:
/usr/local/lib/vh/foo.txt
Text of your document.
/usr/local/lib/vh/foo.idx
Index of your document.
./foo.cut
Where entries selected by the ^Y (Print) command are appended to.

ENVIRONMENT VARIABLES

VHPATH
Search path for vh documents. Defaults to "/usr/local/lib/vh".

BUGS

If a selection wraps around the right margin, only a mouse click on the part before the line wrap will chase it; clicks on the portion trailing into the next line simply cause a page forward. This glitch was judged more trouble to fix than it's worth.

Use of the ESC key inhibits refresh under some curses(3) versions; thus, you might have to do a ^L to force screen update afterwards. Crocking around this in the obvious way would introduce screen flicker for everybody. Use BS.

Because BSD UNIX's pseudorandom-number generator isn't very good, the fortune-cookie mode under that UNIX isn't either.

Output from a -f list may include alphabetical section headers which are not, strictly speaking, part of the desired text.

AUTHORS

Concept, DOS support, and database code from the MS-DOS `jargon' program by Raymond D. Gardner <FidoNet 1:104/89.2>; new features, docs, and curses(3)-using UNIX code by Eric S. Raymond <esr@snark.thyrsus.com>. See http://www.ccil.org/~esr/home.html for updates and related resources.

SEE ALSO

The New Hacker's Dictionary (Second Edition), by Eric S. Raymond (ed.), MIT Press 1993, ISBN 0-262-68079-3. The Jargon File (version 3.0.0), nicely typeset and bound with additional front matter.

The Jargon File can be obtained by FTP from various archive sites. A copy lives more or less permanently as pub/jargon?????.txt at prep.ai.mit.edu (18.71.0.38), where `?????' is replaced by the current version number. Future updates will be made available there.

Please email your Jargon File entries and corrections to jargon@snark.thyrsus.com.