source: trunk/third/xscreensaver/hacks/webcollage.man @ 20148

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.TH XScreenSaver 1 "17-Jun-99" "X Version 11"
.SH NAME
webcollage - decorate the screen with random images from the web
.SH SYNOPSIS
.B webcollage
[\-display \fIhost:display.screen\fP]
[\-root]
[\-verbose]
[\-timeout \fIsecs\fP]
[\-delay \fIsecs\fP]
[\-background \fIbg\fP]
[\-no-output]
[\-urls-only]
[\-size \fIWxH\fP]
[\-filter \fIcommand\fP]
[\-filter2 \fIcommand\fP]
[\-http\-proxy host[:port]]
[\-dictionary \fIdictionary-file\fP]
[\-driftnet [\fIcmd\fP]]
.SH DESCRIPTION
The \fIwebcollage\fP program pulls random image off of the World Wide Web
and scatters them on the root window.  One satisfied customer described it
as "a nonstop pop culture brainbath."  This program finds its images by
doing random web searches, and extracting images from the returned pages.
It places the images on the root window by using the
.BR giftopnm (1),
.BR djpeg (1),
and
.BR xli (1),
.BR xv (1),
or
.BR xloadimage (1)
tools.

\fIwebcollage\fP is written in
.BR perl (1)
and requires Perl 5.

It will be an order of magnitude faster if you also have
the \fIwebcollage-helper\fP program installed (a GDK/JPEG image
compositor), but \fIwebcollage\fP works without it as well.

\fIwebcollage\fP can be used in conjunction with the
.BR driftnet (1)
program (the Unix equivalent of EtherPEG) to snoop images from traffic
on your local subnet, instead of getting images from search engines.
.SH OPTIONS
.I webcollage
accepts the following options:
.TP 8
.B \-root
Draw on the root window.  This option is manditory, if output is being
produced: drawing to a window other than the root window is not yet
supported.
.TP 8
.B \-verbose \fRor\fP \-v
Print diagnostics to stderr.  Multiple \fI-v\fP switches increase the
amount of output.  \fI-v\fP will print out the URLs of the images,
and where they were placed; \fI-vv\fP will print out any warnings,
and all URLs being loaded; \fI-vvv\fP will print information on
what URLs were rejected; and so on.
.TP 8
.B \-timeout \fIseconds\fP
How long to wait for a URL to complete before giving up on it and
moving on to the next one.
Default 30 seconds.
.TP 8
.B \-delay \fIseconds\fP
How long to sleep between images.  Default 2 seconds.  (Remember that
this program probably spends a lot of time waiting for the network.)
.TP 8
.B \-background \fIcolor-or-ppm\fP
What to use for the background onto which images are pasted.  This may be
a color name, a hexadecimal RGB specification in the form '#rrggbb', or 
the name of a PPM file.
.TP 8
.B \-size \fIWxH\fP
Normally, the output image will be made to be the size of the screen.
This lets you specify the desired size.
.TP 8
.B \-no-output
If this option is specified, then no composite output image will be
generated.  This is only useful when used in conjunction 
with \fB\-verbose\fP.
.TP 8
.B \-urls-only
If this option is specified, then no composite output image will be
generated: instead, a list of image URLs will be printed on stdout.
.TP 8
.B \-filter \fIcommand\fP
Filter all source images through this command.  The command must take
a PPM file on stdin, and write a new PPM file to stdout.  One good 
choice for a filter would be:
.EX
webcollage -root -filter 'vidwhacker -stdin -stdout'
.EE
.TP 8
.B \-filter2 \fIcommand\fP
Filter the \fIcomposite\fP image through this command.  The \fI-filter\fP
option applies to the sub-images; the \fI-filter2\fP applies to the
final, full-screen image.
.TP 8
.B \-http\-proxy \fIhost:port\fP
If you must go through a proxy to connect to the web, you can specify it 
with this option, or with the \fB$http_proxy\fP or \fB$HTTP_PROXY\fP 
environment variables.
.TP 8
.B \-dictionary \fIfile\fP
Webcollage normally looks at the system's default spell-check dictionary
to generate words to feed into the search engines.  You can specify an
alternate dictionary with this option.
.TP 8
.B \-driftnet \fI[ args ]\fP
.BR driftnet (1)
is a program that snoops your local ethernet for packets that look
like they might be image files.  It can be used in conjunction 
with \fIwebcollage\fP to generate a collage of what other people on
your network are looking at, instead of a search-engine collage.
If you have \fIdriftnet\fP installed on your $PATH, just use 
the \fI\-driftnet\fP option.  You can also specify the location
of the program like this:
.EX
-driftnet /path/to/driftnet
.EE
or, you can provide extra arguments like this:
.EX
-driftnet '/path/to/driftnet -extra -args'
.EE
Driftnet version 0.1.5 or later is required.  Note that 
the \fIdriftnet\fP program requires root access, so you'll have
to make \fIdriftnet\fP be setuid-root for this to work.
Please exercise caution.
.SH ENVIRONMENT
.PP
.TP 8
.B DISPLAY
to get the default host and display number.
.TP 8
.B XENVIRONMENT
to get the name of a resource file that overrides the global resources
stored in the RESOURCE_MANAGER property.
.TP 8
.B http_proxy\fR or \fPHTTP_PROXY
to get the default HTTP proxy host and port.
.SH FILES AND URLS
.I /usr/dict/words,
.I /usr/share/lib/dict/words,\fP
or
.I /usr/share/dict/words
to find the random words to feed to search engines.
.PP
.I http://image.altavista.com/,
.I http://images.google.com/,
.I http://news.yahoo.com/
.I http://random.yahoo.com/bin/ryl,
and
.I http://lycospro.lycos.com/,
to find random web pages.
.SH BUGS
When drawing on the root window, it always uses the default colormap.
This is actually a limitation of xv.  But regardless, when using this
program with xscreensaver, it must be given the \fBdefault-n\fP 
visual specification (see the
.BR xscreensaver (1)
manual for more details.)

Animating GIFs are not supported: only the first frame will be used.

Too many of the images that it finds are text, not pictures.  This is 
because most of the web is pictures of text.  Which is pretty sad.
.SH UPGRADES
The latest version of webcollage can be found as a part of
xscreensaver, at 
.B http://www.jwz.org/xscreensaver/,
or on the WebCollage page at 
.B http://www.jwz.org/webcollage/.

DriftNet:
.B http://www.ex-parrot.com/~chris/driftnet/
.SH SEE ALSO
.BR X (1),
.BR xscreensaver (1),
.BR xli (1),
.BR xv (1),
.BR xloadimage (1),
.BR ppmmake (1),
.BR giftopnm (1),
.BR pnmpaste (1),
.BR pnmscale (1),
.BR djpeg (1),
.BR cjpeg (1),
.BR xdpyinfo (1),
.BR perl (1),
.BR vidwhacker (1),
.BR dadadodo (1),
.BR driftnet (1)
.BR EtherPEG ,
.BR EtherPeek
.SH COPYRIGHT
Copyright \(co 1998-2002 by Jamie Zawinski.  Permission to use, copy, modify,
distribute, and sell this software and its documentation for any purpose is
hereby granted without fee, provided that the above copyright notice appear
in all copies and that both that copyright notice and this permission notice
appear in supporting documentation.  No representations are made about the
suitability of this software for any purpose.  It is provided "as is" without
express or implied warranty.
.SH AUTHOR
Jamie Zawinski <jwz@jwz.org>, 24-May-98.