X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?p=xscreensaver;a=blobdiff_plain;f=hacks%2Fwebcollage;h=cd3fa4319bbf911a96d56e7323ed3320f84eb98c;hp=49768c978262200eeb7bbc1883029a47814c4db6;hb=c494fd2e6b3b25582375d62e40f4f5cc984ca424;hpb=df7adbee81405e2849728a24b498ad2117784b1f

diff --git a/hacks/webcollage b/hacks/webcollage
index 49768c97..cd3fa431 100755
--- a/hacks/webcollage
+++ b/hacks/webcollage
@@ -1,6 +1,6 @@
-#!/usr/local/bin/perl5 -w
+#!/usr/bin/perl -w
 #
-# webcollage, Copyright (c) 1999 by Jamie Zawinski <jwz@jwz.org>
+# webcollage, Copyright (c) 1999-2005 by Jamie Zawinski <jwz@jwz.org>
 # This program decorates the screen with random images from the web.
 # One satisfied customer described it as "a nonstop pop culture brainbath."
 #
@@ -9,105 +9,300 @@
 # 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 
+# software for any purpose.  It is provided "as is" without express or
 # implied warranty.
 
+
 # To run this as a display mode with xscreensaver, add this to `programs':
 #
-#   default-n:  webcollage -root					\n\
-#   default-n:	webcollage -root -filter 'vidwhacker -stdin -stdout'    \n\
-#
-# To run this as a CGI program on a web site, do this (these instructions
-# work with Apache 1.3 or newer):
-#
-#   1:  Place this program in your document directory, named "webcollage".
-#       The name shouldn't end in .cgi or .html, since this CGI behaves like
-#       a directory.
-#   2:  Make it world-readable and world-executable.
-#   3:  Create a ".htaccess" file in the same directory containing these lines:
-#         <Files ~ "^webcollage$">
-#         SetHandler cgi-script
-#         </Files>
-#   4:  Create these files in the same directory, world-writable, zero-length:
-#        collage.ppm
-#        collage.tmp
-#        collage.jpg
-#        collage.pending
-#        collage.map
-#
-# Now the CGI is ready to go.
-
-my $copyright = "WebCollage, Copyright (c) 1999" .
-    " Jamie Zawinski <jwz\@jwz.org>\n" .
-    "            http://www.jwz.org/xscreensaver/\n";
+#     webcollage -root
+#     webcollage -root -filter 'vidwhacker -stdin -stdout'
+#
+#
+# You can see this in action at http://www.jwz.org/webcollage/ --
+# it auto-reloads about once a minute.  To make a page similar to
+# that on your own system, do this:
+#
+#     webcollage -size '800x600' -imagemap $HOME/www/webcollage/index
+#
+#
+# If you have the "driftnet" program installed, webcollage can display a
+# collage of images sniffed off your local ethernet, instead of pulled out
+# of search engines: in that way, your screensaver can display the images
+# that your co-workers are downloading!
+#
+# Driftnet is available here: http://www.ex-parrot.com/~chris/driftnet/
+# Use it like so:
+#
+#     webcollage -root -driftnet
+#
+# Driftnet is the Unix implementation of the MacOS "EtherPEG" program.
+
+
+require 5;
+use strict;
+
+# We can't "use diagnostics" here, because that library malfunctions if
+# you signal and catch alarms: it says "Uncaught exception from user code"
+# and exits, even though I damned well AM catching it!
+#use diagnostics;
 
-my $argv0 = $0;
-my $progname = $argv0; $progname =~ s@.*/@@g;
-my $version = q{ $Revision: 1.7 $ }; $version =~ s/^[^0-9]+([0-9.]+).*$/$1/;
 
 use Socket;
 require Time::Local;
 require POSIX;
 use Fcntl ':flock'; # import LOCK_* constants
+use POSIX qw(strftime);
+
+use bytes;  # Larry can take Unicode and shove it up his ass sideways.
+            # Perl 5.8.0 causes us to start getting incomprehensible
+            # errors about UTF-8 all over the place without this.
+
+
+my $progname = $0; $progname =~ s@.*/@@g;
+my $version = q{ $Revision: 1.133 $ }; $version =~ s/^[^0-9]+([0-9.]+).*$/$1/;
+my $copyright = "WebCollage $version, Copyright (c) 1999-2005" .
+    " Jamie Zawinski <jwz\@jwz.org>\n" .
+    "            http://www.jwz.org/webcollage/\n";
+
+
+
+my @search_methods = (  56, "altavista",    \&pick_from_alta_vista_random_link,
+                        11, "livejournal",  \&pick_from_livejournal_images,
+                         5, "yahoorand",    \&pick_from_yahoo_random_link,
+                        10, "googlephotos", \&pick_from_google_image_photos,
+                         5, "googleimgs",   \&pick_from_google_images,
+                         3, "googlenums",   \&pick_from_google_image_numbers,
+                         2, "flickr_recent", \&pick_from_flickr_recent,
+                         8, "flickr_random", \&pick_from_flickr_random,
+
+                     # In Apr 2002, Google asked me to stop searching them.
+                     # I asked them to add a "random link" url.  They said
+                     # "that would be easy, we'll think about it" and then
+                     # never wrote back.  Booo Google!  Booooo!  So, screw
+                     # those turkeys, I've turned Google searching back on.
+                     # I'm sure they can take it.  (Jan 2005.)
+
+                     # Jan 2005: Yahoo fucked up their search form so that
+                     # it's no longer possible to do "or" searches on news
+                     # images, so we rarely get any hits there any more.
+                     # 
+                     #  0, "yahoonews",   \&pick_from_yahoo_news_text,
+
+                     # Dec 2004: the ircimages guy's server can't take the
+                     # heat, so he started banning the webcollage user agent.
+                     # I tried to convince him to add a lighter-weight page to
+                     # support webcollage better, but he doesn't care.
+                     #
+                     #  0, "ircimages", \&pick_from_ircimages,
+
+                     # Dec 2002: Alta Vista has a new "random link" URL now.
+                     # They added it specifically to better support webcollage!
+                     # That was super cool of them.  This is how we used to do
+                     # it, before:
+                     #
+                     #  0, "avimages", \&pick_from_alta_vista_images,
+                     #  0, "avtext",   \&pick_from_alta_vista_text,
+
+                     # This broke in 2004.  Eh, Lycos sucks anyway.
+                     #
+                     #   0, "lycos",      \&pick_from_lycos_text,
+
+                     # This broke in 2003, I think.  I suspect Hotbot is
+                     # actually the same search engine data as Lycos.
+                     #
+                     #  0, "hotbot",     \&pick_from_hotbot_text,
+                      );
+
+# programs we can use to write to the root window (tried in ascending order.)
+#
+my @root_displayers = (
+  "xscreensaver-getimage -root -file",
+  "chbg       -once -xscreensaver -max_size 100",
+  "xv         -root -quit -viewonly +noresetroot -quick24 -rmode 5" .
+  "           -rfg black -rbg black",
+  "xli        -quiet -onroot -center -border black",
+  "xloadimage -quiet -onroot -center -border black",
 
+# this lame program wasn't built with vroot.h:
+# "xsri       -scale -keep-aspect -center-horizontal -center-vertical",
+);
 
-#  CGI Parameters
 
-my $data_dir     = "";		  # if you want the following files to go in
-                                  # some directory below ".", name it here.
+# Some sites need cookies to work properly.   These are they.
+#
+my %cookies = (
+  "www.altavista.com"  =>  "AV_ALL=1",   # request uncensored searches
+  "web.altavista.com"  =>  "AV_ALL=1",
 
-my $image_ppm    = "${data_dir}collage.ppm"; # names of the various data files.
-my $image_tmp    = "${data_dir}collage.tmp";
-my $image_jpg    = "${data_dir}collage.jpg";
-my $pending_file = "${data_dir}collage.pending";
-my $map_file     = "${data_dir}collage.map";
+                                         # log in as "cipherpunk"
+  "www.nytimes.com"    =>  'NYT-S=18cHMIlJOn2Y1bu5xvEG3Ufuk6E1oJ.' .
+                           'FMxWaQV0igaB5Yi/Q/guDnLeoL.pe7i1oakSb' .
+                           '/VqfdUdb2Uo27Vzt1jmPn3cpYRlTw9',
 
-my $url_generation_time  = 60;	  # total time to spend getting URLs.
-my $image_retrieval_time = 60;    # maximum time to spend loading all images.
-my $max_map_entries = 100;	  # how many lines to save in $map_file.
-my $pastes_per_load = 3;          # how many images to try and paste each time.
+  "ircimages.com"      =>  'disclaimer=1',
+);
 
-my $max_age = 5 * 60;             # minutes before it is considered stale.
-my $scale = 1.0;                  # client-side image expansion.
 
-my $img_width = 800;		  # size of the image being generated.
-my $img_height = 600;
+# If this is set, it's a helper program to use for pasting images together:
+# this is a lot faster and more efficient than using PPM pipelines, which is
+# what we do if this program doesn't exist.  (We check for "webcollage-helper"
+# on $PATH at startup, and set this variable appropriately.)
+#
+my $webcollage_helper = undef;
 
-my @all_files = ($image_ppm, $image_tmp, $image_jpg, $pending_file, $map_file);
-my $script_date;
 
-# Other Parameters
+# If we have the webcollage-helper program, then it will paste the images
+# together with transparency!  0.0 is invisible, 1.0 is totally opaque.
+#
+my $opacity = 0.85;
 
-my $random_redirector = "http://random.yahoo.com/bin/ryl";
-my $image_randomizer_a = "http://image.altavista.com/";
-my $image_randomizer = $image_randomizer_a . "cgi-bin/avncgi" .
-                       "?do=3&verb=no&oshape=n&oorder=" .
-                       "&ophoto=1&oart=1&ocolor=1&obw=1" .
-                       "&stype=simage&oprem=0&query=";
 
-my $http_timeout = 30;
-my $ppm_to_root_window_cmd = "xv -root -rmode 5 -viewonly" .
-                             " +noresetroot %%PPM%% -quit";
-my $filter_cmd = undef;
-my $post_filter_cmd = undef;
-my $background = undef;
-my $no_output_p = 0;
-my $urls_only_p = 0;
-my $delay = 0;
+# Some sites have  managed to poison the search engines.  These are they.
+# (We auto-detect sites that have poisoned the search engines via excessive
+# keywords or dictionary words,  but these are ones that slip through
+# anyway.)
+#
+# This can contain full host names, or 2 or 3 component domains.
+#
+my %poisoners = (
+  "die.net"                 => 1,  # 'l33t h4ck3r d00dz.
+  "genforum.genealogy.com"  => 1,  # Cluttering avtext with human names.
+  "rootsweb.com"            => 1,  # Cluttering avtext with human names.
+  "akamai.net"              => 1,  # Lots of sites have their images on Akamai.
+  "akamaitech.net"          => 1,  # But those are pretty much all banners.
+                                   # Since Akamai is super-expensive, let's
+                                   # go out on a limb and assume that all of
+                                   # their customers are rich-and-boring.
+  "bartleby.com"            => 1,  # Dictionary, cluttering avtext.
+  "encyclopedia.com"        => 1,  # Dictionary, cluttering avtext.
+  "onlinedictionary.datasegment.com" => 1,  # Dictionary, cluttering avtext.
+  "hotlinkpics.com"         => 1,  # Porn site that has poisoned avimages
+                                   # (I don't see how they did it, though!)
+  "alwayshotels.com"        => 1,  # Poisoned Lycos pretty heavily.
+  "nextag.com"              => 1,  # Poisoned Alta Vista real good.
+);
+
+
+# When verbosity is turned on, we warn about sites that we seem to be hitting
+# a lot: usually this means some new poisoner has made it into the search
+# engines.  But sometimes, the warning is just because that site has a lot
+# of stuff on it.  So these are the sites that are immune to the "frequent
+# site" diagnostic message.
+#
+my %warningless_sites = (
+  "home.earthlink.net"      => 1,  # Lots of home pages here.
+  "www.geocities.com"       => 1,
+  "www.angelfire.com"       => 1,
+  "members.aol.com"         => 1,
+  "img.photobucket.com"     => 1,
+  "pics.livejournal.com"    => 1,
+  "tinypic.com"             => 1,
+  "flickr.com"              => 1,
+
+  "yimg.com"                => 1,  # This is where dailynews.yahoo.com stores
+  "eimg.com"                => 1,  # its images, so pick_from_yahoo_news_text()
+                                   # hits this every time.
+
+  "images.quizfarm.com"     => 1,  # damn those LJ quizzes...
+  "images.quizilla.com"     => 1,
+  "images.quizdiva.net"     => 1,
+
+  "driftnet"                => 1,  # builtin...
+  "local-directory"         => 1,  # builtin...
+);
+
+
+# For decoding HTML-encoded character entities to URLs.
+#
+my %entity_table = (
+   "apos"   => '\'',
+   "quot"   => '"', "amp"    => '&', "lt"     => '<', "gt"     => '>',
+   "nbsp"   => ' ', "iexcl"  => '¡', "cent"   => '¢', "pound"  => '£',
+   "curren" => '¤', "yen"    => '¥', "brvbar" => '¦', "sect"   => '§',
+   "uml"    => '¨', "copy"   => '©', "ordf"   => 'ª', "laquo"  => '«',
+   "not"    => '¬', "shy"    => '­', "reg"    => '®', "macr"   => '¯',
+   "deg"    => '°', "plusmn" => '±', "sup2"   => '²', "sup3"   => '³',
+   "acute"  => '´', "micro"  => 'µ', "para"   => '¶', "middot" => '·',
+   "cedil"  => '¸', "sup1"   => '¹', "ordm"   => 'º', "raquo"  => '»',
+   "frac14" => '¼', "frac12" => '½', "frac34" => '¾', "iquest" => '¿',
+   "Agrave" => 'À', "Aacute" => 'Á', "Acirc"  => 'Â', "Atilde" => 'Ã',
+   "Auml"   => 'Ä', "Aring"  => 'Å', "AElig"  => 'Æ', "Ccedil" => 'Ç',
+   "Egrave" => 'È', "Eacute" => 'É', "Ecirc"  => 'Ê', "Euml"   => 'Ë',
+   "Igrave" => 'Ì', "Iacute" => 'Í', "Icirc"  => 'Î', "Iuml"   => 'Ï',
+   "ETH"    => 'Ð', "Ntilde" => 'Ñ', "Ograve" => 'Ò', "Oacute" => 'Ó',
+   "Ocirc"  => 'Ô', "Otilde" => 'Õ', "Ouml"   => 'Ö', "times"  => '×',
+   "Oslash" => 'Ø', "Ugrave" => 'Ù', "Uacute" => 'Ú', "Ucirc"  => 'Û',
+   "Uuml"   => 'Ü', "Yacute" => 'Ý', "THORN"  => 'Þ', "szlig"  => 'ß',
+   "agrave" => 'à', "aacute" => 'á', "acirc"  => 'â', "atilde" => 'ã',
+   "auml"   => 'ä', "aring"  => 'å', "aelig"  => 'æ', "ccedil" => 'ç',
+   "egrave" => 'è', "eacute" => 'é', "ecirc"  => 'ê', "euml"   => 'ë',
+   "igrave" => 'ì', "iacute" => 'í', "icirc"  => 'î', "iuml"   => 'ï',
+   "eth"    => 'ð', "ntilde" => 'ñ', "ograve" => 'ò', "oacute" => 'ó',
+   "ocirc"  => 'ô', "otilde" => 'õ', "ouml"   => 'ö', "divide" => '÷',
+   "oslash" => 'ø', "ugrave" => 'ù', "uacute" => 'ú', "ucirc"  => 'û',
+   "uuml"   => 'ü', "yacute" => 'ý', "thorn"  => 'þ', "yuml"   => 'ÿ',
+   "ndash"  => '-', "mdash"  => "--"
+);
 
-my $wordlist = "/usr/dict/words";
 
-if (!-r $wordlist) {
-    $wordlist = "/usr/share/lib/dict/words";    # irix
-}
+##############################################################################
+#
+# Various global flags set by command line parameters, or computed
+#
+##############################################################################
+
 
+my $current_state = "???";      # for diagnostics
+my $load_method;
+my $last_search;
+my $image_succeeded = -1;
+my $suppress_audit = 0;
+
+my $verbose_imgmap = 0;         # print out rectangles and URLs only (stdout)
+my $verbose_warnings = 0;       # print out warnings when things go wrong
+my $verbose_load = 0;           # diagnostics about loading of URLs
+my $verbose_filter = 0;         # diagnostics about page selection/rejection
+my $verbose_net = 0;            # diagnostics about network I/O
+my $verbose_pbm = 0;            # diagnostics about PBM pipelines
+my $verbose_http = 0;           # diagnostics about all HTTP activity
+my $verbose_exec = 0;           # diagnostics about executing programs
+
+my $report_performance_interval = 60 * 15;  # print some stats every 15 minutes
+
+my $http_proxy = undef;
+my $http_timeout = 20;
+my $cvt_timeout = 10;
 
 my $min_width = 50;
 my $min_height = 50;
 my $min_ratio = 1/5;
 
-my $DEBUG = 0;
+my $min_gif_area = (120 * 120);
+
 
+my $no_output_p = 0;
+my $urls_only_p = 0;
+my $cocoa_p = 0;
+my $imagemap_base = undef;
+
+my @pids_to_kill = ();  # forked pids we should kill when we exit, if any.
+
+my $driftnet_magic = 'driftnet';
+my $driftnet_dir = undef;
+my $default_driftnet_cmd = "driftnet -a -m 100";
+
+my $local_magic = 'local-directory';
+my $local_dir = undef;
+
+my $wordlist;
+
+my %rejected_urls;
+my @tripwire_words = ("aberrate", "abode", "amorphous", "antioch",
+                      "arrhenius", "arteriole", "blanket", "brainchild",
+                      "burdensome", "carnival", "cherub", "chord", "clever",
+                      "dedicate", "dilogarithm", "dolan", "dryden",
+                      "eggplant");
 
 
 ##############################################################################
@@ -119,1599 +314,3236 @@ my $DEBUG = 0;
 # returns three values: the HTTP response line; the document headers;
 # and the document body.
 #
-sub get_document_1 {
-    my ( $url, $referer, $timeout ) = @_;
+sub get_document_1($$$) {
+  my ($url, $referer, $timeout) = @_;
+
+  if (!defined($timeout)) { $timeout = $http_timeout; }
+  if ($timeout > $http_timeout) { $timeout = $http_timeout; }
+
+  if ($timeout <= 0) {
+    LOG (($verbose_net || $verbose_load), "timed out for $url");
+    return ();
+  }
+
+  LOG ($verbose_net, "get_document_1 $url " . ($referer ? $referer : ""));
+
+  if (! ($url =~ m@^http://@i)) {
+    LOG ($verbose_net, "not an HTTP URL: $url");
+    return ();
+  }
+
+  my ($url_proto, $dummy, $serverstring, $path) = split(/\//, $url, 4);
+  $path = "" unless $path;
+
+  if (!$url_proto || !$serverstring) {
+    LOG (($verbose_net || $verbose_load), "unparsable URL: $url");
+    return ();
+  }
+
+  my ($them,$port) = split(/:/, $serverstring);
+  $port = 80 unless $port;
+
+  my $them2 = $them;
+  my $port2 = $port;
+  if ($http_proxy) {
+    $serverstring = $http_proxy if $http_proxy;
+    $serverstring =~ s@^[a-z]+://@@;
+    ($them2,$port2) = split(/:/, $serverstring);
+    $port2 = 80 unless $port2;
+  }
+
+  my ($remote, $iaddr, $paddr, $proto, $line);
+  $remote = $them2;
+  if ($port2 =~ /\D/) { $port2 = getservbyname($port2, 'tcp') }
+  if (!$port2) {
+    LOG (($verbose_net || $verbose_load), "unrecognised port in $url");
+    return ();
+  }
+  $iaddr   = inet_aton($remote);
+  if (!$iaddr) {
+    LOG (($verbose_net || $verbose_load), "host not found: $remote");
+    return ();
+  }
+  $paddr   = sockaddr_in($port2, $iaddr);
+
+
+  my $head = "";
+  my $body = "";
+
+  @_ =
+    eval {
+      local $SIG{ALRM} = sub {
+        LOG (($verbose_net || $verbose_load), "timed out ($timeout) for $url");
+        die "alarm\n";
+      };
+      alarm $timeout;
+
+      $proto   = getprotobyname('tcp');
+      if (!socket(S, PF_INET, SOCK_STREAM, $proto)) {
+        LOG (($verbose_net || $verbose_load), "socket: $!");
+        return ();
+      }
+      if (!connect(S, $paddr)) {
+        LOG (($verbose_net || $verbose_load), "connect($serverstring): $!");
+        return ();
+      }
+
+      select(S); $| = 1; select(STDOUT);
+
+      my $cookie = $cookies{$them};
+
+      my $user_agent = "$progname/$version";
+
+      if ($url =~ m@^http://www\.altavista\.com/@ ||
+          $url =~ m@^http://random\.yahoo\.com/@ ||
+          $url =~ m@^http://images\.google\.com/@) {
+        # block this, you turkeys.
+        $user_agent = "Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.5)" .
+          " Gecko/20041111 Firefox/1.0";
+      }
+
+      my $hdrs = "GET " . ($http_proxy ? $url : "/$path") . " HTTP/1.0\r\n" .
+                 "Host: $them\r\n" .
+                 "User-Agent: $user_agent\r\n";
+      if ($referer) {
+        $hdrs .= "Referer: $referer\r\n";
+      }
+      if ($cookie) {
+        my @cc = split(/\r?\n/, $cookie);
+        $hdrs .= "Cookie: " . join('; ', @cc) . "\r\n";
+      }
+      $hdrs .= "\r\n";
+
+      foreach (split('\r?\n', $hdrs)) {
+        LOG ($verbose_http, "  ==> $_");
+      }
+      print S $hdrs;
+      my $http = <S> || "";
+
+      # Kludge: the Yahoo Random Link is now returning as its first
+      # line "Status: 301" instead of "HTTP/1.0 301 Found".  Fix it...
+      #
+      $http =~ s@^Status:\s+(\d+)\b@HTTP/1.0 $1@i;
+
+      $_  = $http;
+      s/[\r\n]+$//s;
+      LOG ($verbose_http, "  <== $_");
+
+      while (<S>) {
+        $head .= $_;
+        s/[\r\n]+$//s;
+        last if m@^$@;
+        LOG ($verbose_http, "  <== $_");
+
+        if (m@^Set-cookie:\s*([^;\r\n]+)@i) {
+          set_cookie($them, $1)
+        }
+      }
 
-    if (!defined($timeout)) { $timeout = $http_timeout; }
-    if ($timeout <= 0) { return undef; }
-    if ($timeout > $http_timeout) { $timeout = $http_timeout; }
+      my $lines = 0;
+      while (<S>) {
+        $body .= $_;
+        $lines++;
+      }
 
-    if ( $DEBUG > 3 ) {
-	print STDERR "get_document_1 $url " .
-            ($referer ? $referer : "") . "\n";
-    }
+      LOG ($verbose_http,
+           "  <== [ body ]: $lines lines, " . length($body) . " bytes");
 
-    my($url_proto, $dummy, $serverstring, $path) = split(/\//, $url, 4);
-    if (! ($url_proto && $url_proto =~ m/^http:$/i)) {
-        if ($DEBUG) { print STDERR "not an HTTP URL: $url\n"; }
-        return undef;
-    }
-    my($them,$port) = split(/:/, $serverstring);
-    $port = 80 unless $port;
-    my $size="";
-
-    my ($remote, $iaddr, $paddr, $proto, $line);
-    $remote = $them;
-    if ($port =~ /\D/) { $port = getservbyname($port, 'tcp') }
-    return unless $port;
-    $iaddr   = inet_aton($remote)               || return;
-    $paddr   = sockaddr_in($port, $iaddr);
-
-    @_ =
-    eval {
-        local $SIG{ALRM}  = sub {
-            if ($DEBUG > 0) {
-                print STDERR "timed out ($timeout) for $url\n";
-            }
-            die "alarm\n" };
-        alarm $timeout;
-
-        $proto   = getprotobyname('tcp');
-        socket(S, PF_INET, SOCK_STREAM, $proto)  || return;
-        connect(S, $paddr)    || return;
-
-        select(S); $| = 1; select(STDOUT);
-
-        print S ("GET /$path HTTP/1.0\n" .
-                 "Host: $them\n" .
-                 "User-Agent: $progname/$version\n" .
-                 ($referer ? "Referer: $referer\n" : "") .
-                 "\n");
-
-        my $http = <S>;
-
-        my $head = "";
-        my $body = "";
-        while (<S>) {
-            $head .= $_;
-            last if m@^[\r\n]@;
-        }
-        while (<S>) {
-            $body .= $_;
-        }
+      close S;
 
-        close S;
+      if (!$http) {
+        LOG (($verbose_net || $verbose_load), "null response: $url");
+        return ();
+      }
 
-        return ( $http, $head, $body );
+      $SIG{ALRM} = 'DEFAULT';  # seem to be suffering a race?
+      return ( $http, $head, $body );
     };
-    die if ($@ && $@ ne "alarm\n");       # propagate errors
-    if ($@) {
-        # timed out
-        return undef;
-    } else {
-        # didn't
-        alarm 0;
-        return @_;
-    }
+  die if ($@ && $@ ne "alarm\n");       # propagate errors
+
+  if ($@ && $@ ne "alarm\n") {
+    print STDERR blurb() . "DIE " . join(" ", $@) . "\n";
+    die;
+  }
+
+  if ($@) {
+    # timed out
+    $head = undef;
+    $body = undef;
+    $suppress_audit = 1;
+    return ();
+  } else {
+    # didn't
+    alarm 0;
+    return @_;
+  }
 }
 
 
 # returns two values: the document headers; and the document body.
 # if the given URL did a redirect, returns the redirected-to document.
 #
-sub get_document {
-    my ( $url, $referer, $timeout ) = @_;
-    my $start = time;
+sub get_document($$;$) {
+  my ($url, $referer, $timeout) = @_;
+  my $start = time;
+
+  if (defined($referer) && $referer eq $driftnet_magic) {
+    return get_driftnet_file ($url);
+  }
+
+  if (defined($referer) && $referer eq $local_magic) {
+    return get_local_file ($url);
+  }
+
+  my $orig_url = $url;
+  my $loop_count = 0;
+  my $max_loop_count = 4;
+
+  do {
+    if (defined($timeout) && $timeout <= 0) {
+      LOG (($verbose_net || $verbose_load), "timed out for $url");
+      $suppress_audit = 1;
+      return ();
+    }
 
-    do {
-        if (defined($timeout) && $timeout <= 0) { return undef; }
+    my ( $http, $head, $body ) = get_document_1 ($url, $referer, $timeout);
 
-	my ( $http, $head, $body ) = get_document_1 ($url, $referer, $timeout);
+    if (defined ($timeout)) {
+      my $now = time;
+      my $elapsed = $now - $start;
+      $timeout -= $elapsed;
+      $start = $now;
+    }
 
-        if (defined ($timeout)) {
-            my $now = time;
-            my $elapsed = $now - $start;
-            $timeout -= $elapsed;
-            $start = $now;
-        }
+    return () unless $http; # error message already printed
 
-	return undef if ( ! $body );
+    $http =~ s/[\r\n]+$//s;
 
-	if ( $http =~ m@HTTP/[0-9.]+ 30[23]@ ) {
-	    $_ = $head;
-	    my ( $location ) = m@^location:[ \t]*(.*)$@im;
-	    if ( $location ) {
+    if ( $http =~ m@^HTTP/[0-9.]+ 30[123]@ ) {
+      $_ = $head;
 
-		if ( $DEBUG > 3 ) {
-		    print STDERR "redirect from $url to $location\n";
-		}
-                $referer = $url;
-		$url = $location;
-	    } else {
-		return ( $url, $body );
-	    }
+      my ( $location ) = m@^location:[ \t]*(.*)$@im;
+      if ( $location ) {
+        $location =~ s/[\r\n]$//;
 
-        } elsif ( $http =~ m@HTTP/[0-9.]+ [4-9][0-9][0-9]@ ) {
-            # http errors -- return nothing.
-            return undef;
+        LOG ($verbose_net, "redirect from $url to $location");
+        $referer = $url;
+        $url = $location;
 
-	} else {
+        if ($url =~ m@^/@) {
+          $referer =~ m@^(http://[^/]+)@i;
+          $url = $1 . $url;
+        } elsif (! ($url =~ m@^[a-z]+:@i)) {
+          $_ = $referer;
+          s@[^/]+$@@g if m@^http://[^/]+/@i;
+          $_ .= "/" if m@^http://[^/]+$@i;
+          $url = $_ . $url;
+        }
 
-	    return ( $url, $body );
-	}
+      } else {
+        LOG ($verbose_net, "no Location with \"$http\"");
+        return ( $url, $body );
+      }
 
-    } while (1);
-}
+      if ($loop_count++ > $max_loop_count) {
+        LOG ($verbose_net,
+             "too many redirects ($max_loop_count) from $orig_url");
+        $body = undef;
+        return ();
+      }
 
+    } elsif ( $http =~ m@^HTTP/[0-9.]+ ([4-9][0-9][0-9].*)$@ ) {
 
-# given a URL and the body text at that URL, selects and returns a random
-# image from it.  returns undef if no suitable images found.
-#
-sub pick_image_from_body {
-    my ( $base, $body ) = @_;
+      LOG (($verbose_net || $verbose_load), "failed: $1 ($url)");
 
-    $_ = $base;
+      # http errors -- return nothing.
+      $body = undef;
+      return ();
 
-    # if there's at least one slash after the host, take off the last
-    # pathname component
-    if ( m@^http://[^/]+/@io ) {
-	( $base = $base ) =~ s@[^/]+$@@go;
-    }
+    } elsif (!$body) {
 
-    # if there are no slashes after the host at all, put one on the end.
-    if ( m@^http://[^/]+$@io ) {
-	$base .= "/";
-    }
+      LOG (($verbose_net || $verbose_load), "document contains no data: $url");
+      return ();
+
+    } else {
 
-    if ( $DEBUG > 3 ) {
-	print STDERR "base is $base\n";
+      # ok!
+      return ( $url, $body );
     }
 
+  } while (1);
+}
 
-    $_ = $body;
-
-    # strip out newlines, compress whitespace
-    s/[\r\n\t ]+/ /go;
-
-    # nuke comments
-    s/<!--.*?-->//go;
-
-    my @urls;
-    my %unique_urls;
-
-    foreach (split(/ *</)) {
-	if ( m/^(img|a) .*(src|href) ?= ?\"? ?(.*?)[ >\"]/io ) {
-
-	    my $was_inline = ( "$1" eq "a" || "$1" eq "A" );
-	    my $link = $3;
-	    my ( $width )  = m/width ?=[ \"]*([0-9]+)/oi;
-	    my ( $height ) = m/height ?=[ \"]*([0-9]+)/oi;
-	    $_ = $link;
-
-	    if ( m@^/@o ) {
-		my $site;
-		( $site = $base ) =~ s@^(http://[^/]*).*@$1@gio;
-		$_ = "$site$link";
-	    } elsif ( ! m@^[^/:?]+:@ ) {
-		$_ = "$base$link";
-                s@/\./@/@g;
-                while (s@/\.\./@/@g) {
-                }
-	    }
-
-	    # skip non-http
-	    if ( ! m@^http://@io ) {
-		next;
-	    }
-
-	    # skip non-image
-	    if ( ! m@[.](gif|jpg|jpeg|pjpg|pjpeg)$@io ) {
-		next;
-	    }
-
-#	    # skip GIF?
-#	    if ( m@[.](gif)@io ) {
-##		if ( $DEBUG > 2 ) { print STDERR "skip GIF $_\n"; }
-#		next;
-#	    }
-
-	    # skip really short or really narrow images
-	    if ( $width && $width < $min_width) {
-		if ( $DEBUG > 2 ) {
-                    if (!$height) { $height = "?"; }
-		    print STDERR "skip narrow image $_ ($width x $height)\n";
-		}
-		next;
-	    }
-
-	    if ( $height && $height < $min_height) {
-		if ( $DEBUG > 2 ) {
-                    if (!$width) { $width = "?"; }
-		    print STDERR "skip short image $_ ($width x $height)\n";
-		}
-		next;
-	    }
-
-            # skip images with ratios that make them look like banners.
-	    if ( $min_ratio && $width && $height &&
-                ($width * $min_ratio ) > $height ) {
-		if ( $DEBUG > 2 ) {
-                    if (!$height) { $height = "?"; }
-		    print STDERR "skip bad ratio $_ ($width x $height)\n";
-		}
-		next;
-	    }
-
-	    my $url = $_;
-
-	    if ( $unique_urls{$url} ) {
-		if ( $DEBUG > 2 ) { print STDERR "skip duplicate image $_\n"; }
-		next;
-	    }
-
-	    if ( $DEBUG > 2 ) {
-		print STDERR "got $url" . 
-		    ($width && $height ? " (${width}x${height})" : "") .
-		    ($was_inline ? " (inline)" : "") . "\n";
-	    }
-
-	    $urls[++$#urls] = $url;
-	    $unique_urls{$url}++;
-
-	    # jpegs are preferable to gifs.
-            $_ = $url;
-            if ( ! m@[.]gif$@io ) {
-		$urls[++$#urls] = $url;
-            }
-
-	    # pointers to images are preferable to inlined images.
-	    if ( ! $was_inline ) {
-		$urls[++$#urls] = $url;
-		$urls[++$#urls] = $url;
-	    }
-	}
-    }
+# If we already have a cookie defined for this site, and the site is trying
+# to overwrite that very same cookie, let it do so.  This is because nytimes
+# expires its cookies - it lets you upgrade to a new cookie without logging
+# in again, but you have to present the old cookie to get the new cookie.
+# So, by doing this, the built-in cypherpunks cookie will never go "stale".
+#
+sub set_cookie($$) {
+  my ($host, $cookie) = @_;
+  my $oc = $cookies{$host};
+  return unless $oc;
+  $_ = $oc;
+  my ($oc_name, $oc_value) = m@^([^= \t\r\n]+)=(.*)$@;
+  $_ = $cookie;
+  my ($nc_name, $nc_value) = m@^([^= \t\r\n]+)=(.*)$@;
+
+  if ($oc_name eq $nc_name &&
+      $oc_value ne $nc_value) {
+    $cookies{$host} = $cookie;
+    LOG ($verbose_net, "overwrote ${host}'s $oc_name cookie");
+  }
+}
 
-    if ( $#urls == 0 ) {
-	if ( $DEBUG > 2 ) {
-	    print STDERR "no images on $base\n";
-	}
-	return undef;
+
+############################################################################
+#
+# Extracting image URLs from HTML
+#
+############################################################################
+
+# given a URL and the body text at that URL, selects and returns a random
+# image from it.  returns () if no suitable images found.
+#
+sub pick_image_from_body($$) {
+  my ($url, $body) = @_;
+
+  my $base = $url;
+  $_ = $url;
+
+  # if there's at least one slash after the host, take off the last
+  # pathname component
+  if ( m@^http://[^/]+/@io ) {
+    $base =~ s@[^/]+$@@go;
+  }
+
+  # if there are no slashes after the host at all, put one on the end.
+  if ( m@^http://[^/]+$@io ) {
+    $base .= "/";
+  }
+
+  $_ = $body;
+
+  # strip out newlines, compress whitespace
+  s/[\r\n\t ]+/ /go;
+
+  # nuke comments
+  s/<!--.*?-->//go;
+
+
+  # There are certain web sites that list huge numbers of dictionary
+  # words in their bodies or in their <META NAME=KEYWORDS> tags (surprise!
+  # Porn sites tend not to be reputable!)
+  #
+  # I do not want webcollage to filter on content: I want it to select
+  # randomly from the set of images on the web.  All the logic here for
+  # rejecting some images is really a set of heuristics for rejecting
+  # images that are not really images: for rejecting *text* that is in
+  # GIF/JPEG/PNG form.  I don't want text, I want pictures, and I want
+  # the content of the pictures to be randomly selected from among all
+  # the available content.
+  #
+  # So, filtering out "dirty" pictures by looking for "dirty" keywords
+  # would be wrong: dirty pictures exist, like it or not, so webcollage
+  # should be able to select them.
+  #
+  # However, picking a random URL is a hard thing to do.  The mechanism I'm
+  # using is to search for a selection of random words.  This is not
+  # perfect, but works ok most of the time.  The way it breaks down is when
+  # some URLs get precedence because their pages list *every word* as
+  # related -- those URLs come up more often than others.
+  #
+  # So, after we've retrieved a URL, if it has too many keywords, reject
+  # it.  We reject it not on the basis of what those keywords are, but on
+  # the basis that by having so many, the page has gotten an unfair
+  # advantage against our randomizer.
+  #
+  my $trip_count = 0;
+  foreach my $trip (@tripwire_words) {
+    $trip_count++ if m/$trip/i;
+  }
+
+  if ($trip_count >= $#tripwire_words - 2) {
+    LOG (($verbose_filter || $verbose_load),
+         "there is probably a dictionary in \"$url\": rejecting.");
+    $rejected_urls{$url} = -1;
+    $body = undef;
+    $_ = undef;
+    return ();
+  }
+
+
+  my @urls;
+  my %unique_urls;
+
+  foreach (split(/ *</)) {
+    if ( m/^meta /i ) {
+
+      # Likewise, reject any web pages that have a KEYWORDS meta tag
+      # that is too long.
+      #
+      if (m/name ?= ?\"?keywords\"?/i &&
+          m/content ?= ?\"([^\"]+)\"/) {
+        my $L = length($1);
+        if ($L > 1000) {
+          LOG (($verbose_filter || $verbose_load),
+               "excessive keywords ($L bytes) in $url: rejecting.");
+          $rejected_urls{$url} = $L;
+          $body = undef;
+          $_ = undef;
+          return ();
+        } else {
+          LOG ($verbose_filter, "  keywords ($L bytes) in $url (ok)");
+        }
+      }
+
+    } elsif ( m/^(img|a) .*(src|href) ?= ?\"? ?(.*?)[ >\"]/io ) {
+
+      my $was_inline = (! ( "$1" eq "a" || "$1" eq "A" ));
+      my $link = $3;
+      my ( $width )  = m/width ?=[ \"]*(\d+)/oi;
+      my ( $height ) = m/height ?=[ \"]*(\d+)/oi;
+      $_ = $link;
+
+      if ( m@^/@o ) {
+        my $site;
+        ( $site = $base ) =~ s@^(http://[^/]*).*@$1@gio;
+        $_ = "$site$link";
+      } elsif ( ! m@^[^/:?]+:@ ) {
+        $_ = "$base$link";
+        s@/\./@/@g;
+        1 while (s@/[^/]+/\.\./@/@g);
+      }
+
+      # skip non-http
+      if ( ! m@^http://@io ) {
+        next;
+      }
+
+      # skip non-image
+      if ( ! m@[.](gif|jpg|jpeg|pjpg|pjpeg|png)$@io ) {
+        next;
+      }
+
+      # skip really short or really narrow images
+      if ( $width && $width < $min_width) {
+        if (!$height) { $height = "?"; }
+        LOG ($verbose_filter, "  skip narrow image $_ (${width}x$height)");
+        next;
+      }
+
+      if ( $height && $height < $min_height) {
+        if (!$width) { $width = "?"; }
+        LOG ($verbose_filter, "  skip short image $_ (${width}x$height)");
+        next;
+      }
+
+      # skip images with ratios that make them look like banners.
+      if ($min_ratio && $width && $height &&
+          ($width * $min_ratio ) > $height) {
+        if (!$height) { $height = "?"; }
+        LOG ($verbose_filter, "  skip bad ratio $_ (${width}x$height)");
+        next;
+      }
+
+      # skip GIFs with a small number of pixels -- those usually suck.
+      if ($width && $height &&
+          m/\.gif$/io &&
+          ($width * $height) < $min_gif_area) {
+        LOG ($verbose_filter, "  skip small GIF $_ (${width}x$height)");
+        next;
+      }
+      
+      # skip images with a URL that indicates a Yahoo thumbnail.
+      if (m@\.yimg\.com/.*/t/@) {
+        if (!$width)  { $width  = "?"; }
+        if (!$height) { $height = "?"; }
+        LOG ($verbose_filter, "  skip yahoo thumb $_ (${width}x$height)");
+        next;
+      }
+
+      my $url = $_;
+
+      if ($unique_urls{$url}) {
+        LOG ($verbose_filter, "  skip duplicate image $_");
+        next;
+      }
+
+      LOG ($verbose_filter,
+           "  image $url" .
+           ($width && $height ? " (${width}x${height})" : "") .
+           ($was_inline ? " (inline)" : ""));
+
+      $urls[++$#urls] = $url;
+      $unique_urls{$url}++;
+
+      # JPEGs are preferable to GIFs and PNGs.
+      $_ = $url;
+      if ( ! m@[.](gif|png)$@io ) {
+        $urls[++$#urls] = $url;
+      }
+
+      # pointers to images are preferable to inlined images.
+      if ( ! $was_inline ) {
+        $urls[++$#urls] = $url;
+        $urls[++$#urls] = $url;
+      }
     }
+  }
 
-    return undef if ( $#urls < 1 );
+  my $fsp = ($body =~ m@<frameset@i);
 
-    # pick a random element of the table
-    my $i = ((rand() * 99999) % $#urls);
-    my $url = $urls[$i];
+  $_ = undef;
+  $body = undef;
 
-    if ( $DEBUG > 2 ) {
-	print STDERR "picked $url\n";
-    }
+  @urls = depoison (@urls);
+
+  if ( $#urls < 0 ) {
+    LOG ($verbose_load, "no images on $base" . ($fsp ? " (frameset)" : ""));
+    return ();
+  }
+
+  # pick a random element of the table
+  my $i = int(rand($#urls+1));
+  $url = $urls[$i];
+
+  LOG ($verbose_load, "picked image " .($i+1) . "/" . ($#urls+1) . ": $url");
 
-    return $url;
+  return $url;
 }
 
+# Given a URL and the RSS feed from that URL, pick a random image from
+# the feed.  This is a lot simpler than extracting images out of a page:
+# we already know we have reasonable images, so we just pick one.
+# Returns: the real URL of the page (preferably not the RSS version),
+# and the image.
+
+sub pick_image_from_rss($$) {
+  my ( $url, $body ) = @_;
+  my @suitable = ($body =~ m/<enclosure url="(.*?)"/g);
+
+  my ($base) = ($body =~ m@<link>([^<>]+)</link>@i);
+  $base = $url unless $base;
+
+  # pick a random element of the table
+  if (@suitable) {
+    my $i = int(rand(scalar @suitable));
+    my $url = $suitable[$i];
+    LOG ($verbose_load, "picked image " .($i+1) . "/" . 
+                        ($#suitable+1) . ": $url");
+    return ($base, $url);
+  }
+  return;
+}
 
-# Using the URL-randomizer, picks a random image on a random page, and
-# returns two URLs: the page containing the image, and the image.
-# Returns undef if nothing found this time.
+
+############################################################################
 #
-sub pick_from_url_randomizer {
-    my ( $timeout ) = @_;
+# Subroutines for getting pages and images out of search engines
+#
+############################################################################
+
 
-    if ( $DEBUG > 3 ) {
-	print STDERR "\n\npicking from $random_redirector...\n\n";
+sub pick_dictionary() {
+  my @dicts = ("/usr/dict/words",
+               "/usr/share/dict/words",
+               "/usr/share/lib/dict/words");
+  foreach my $f (@dicts) {
+    if (-f $f) {
+      $wordlist = $f;
+      last;
     }
+  }
+  error ("$dicts[0] does not exist") unless defined($wordlist);
+}
 
-    my ( $base, $body ) = get_document ($random_redirector, undef, $timeout);
+# returns a random word from the dictionary
+#
+sub random_word() {
 
-    return if (!$base || !$body);
-    my $img = pick_image_from_body ($base, $body);
+  local *IN;
+  if (! open (IN, "<$wordlist")) {
+    return undef;
+  }
 
-    if ($img) {
-        return ($base, $img);
-    } else {
-        return undef;
+  my $size = (stat(IN))[7];
+  my $word = undef;
+  my $count = 0;
+
+  while (1) {
+    error ("looping ($count) while reading $wordlist")
+      if (++$count > 100);
+
+    my $pos = int (rand ($size));
+    if (seek (IN, $pos, 0)) {
+      $word = <IN>;   # toss partial line
+      $word = <IN>;   # keep next line
     }
+
+    next unless ($word);
+    next if ($word =~ m/^[-\']/);
+
+    $word = lc($word);
+    $word =~ s/^.*-//s;
+    $word =~ s/^[^a-z]+//s;
+    $word =~ s/[^a-z]+$//s;
+    $word =~ s/\'s$//s;
+    $word =~ s/ys$/y/s;
+    $word =~ s/ally$//s;
+    $word =~ s/ly$//s;
+    $word =~ s/ies$/y/s;
+    $word =~ s/ally$/al/s;
+    $word =~ s/izes$/ize/s;
+    $word =~ s/esses$/ess/s;
+    $word =~ s/(.{5})ing$/$1/s;
+
+    next if (length ($word) > 14);
+    last if ($word);
+  }
+
+  close (IN);
+
+  if ( $word =~ s/\s/\+/gs ) {  # convert intra-word spaces to "+".
+    $word = "\%22$word\%22";    # And put quotes (%22) around it.
+  }
+
+  return $word;
 }
 
 
-sub random_word {
-    
-    my $word = 0;
-    if (open (IN, "<$wordlist")) {
-        my $size = (stat(IN))[7];
-        my $pos = rand $size;
-        if (seek (IN, $pos, 0)) {
-            $word = <IN>;   # toss partial line
-            $word = <IN>;   # keep next line
-        }
-        close (IN);
-    }
+sub random_words($) {
+  my ($or_p) = @_;
+  my $sep = ($or_p ? "%20OR%20" : "%20");
+  return (random_word . $sep .
+          random_word . $sep .
+          random_word . $sep .
+          random_word . $sep .
+          random_word);
+}
+
 
-    return 0 if (!$word);
+sub url_quote($) {
+  my ($s) = @_;
+  $s =~ s|([^-a-zA-Z0-9.\@/_\r\n])|sprintf("%%%02X", ord($1))|ge;
+  return $s;
+}
 
-    $word =~ s/^[ \t\n\r]+//;
-    $word =~ s/[ \t\n\r]+$//;
-    $word =~ s/ys$/y/;
-    $word =~ s/ally$//;
-    $word =~ s/ly$//;
-    $word =~ s/ies$/y/;
-    $word =~ s/ally$/al/;
-    $word =~ s/izes$/ize/;
-    $word =~ tr/A-Z/a-z/;
+sub url_unquote($) {
+  my ($s) = @_;
+  $s =~ s/[+]/ /g;
+  $s =~ s/%([a-z0-9]{2})/chr(hex($1))/ige;
+  return $s;
+}
 
-    return $word;
+sub html_quote($) {
+  my ($s) = @_;
+  $s =~ s/&/&amp;/gi;
+  $s =~ s/</&lt;/gi;
+  $s =~ s/>/&gt;/gi;
+  $s =~ s/\"/&quot;/gi;
+  return $s;
 }
 
+sub html_unquote($) {
+  my ($s) = @_;
+  $s =~ s/(&([a-z]+);)/{ $entity_table{$2} || $1; }/gexi;  # e.g., &apos;
+  $s =~ s/(&\#(\d+);)/{ chr($2) }/gexi;                    # e.g., &#39;
+  return $s;
+}
 
 
-# Using the image-randomizer, picks a random image on a random page, and
-# returns two URLs: the page containing the image, and the image.
-# Returns undef if nothing found this time.
+# Loads the given URL (a search on some search engine) and returns:
+# - the total number of hits the search engine claimed it had;
+# - a list of URLs from the page that the search engine returned;
+# Note that this list contains all kinds of internal search engine
+# junk URLs too -- caller must prune them.
 #
-sub pick_from_image_randomizer {
-    my ( $timeout ) = @_;
+sub pick_from_search_engine($$$) {
+  my ( $timeout, $search_url, $words ) = @_;
 
-    my $words = random_word;
-    $words .= "%20" . random_word;
-    $words .= "%20" . random_word;
-    $words .= "%20" . random_word;
-    $words .= "%20" . random_word;
+  $_ = $words;
+  s/%20/ /g;
 
-    my $search_url = $image_randomizer . $words;
+  print STDERR "\n\n" if ($verbose_load);
 
-    if ( $DEBUG > 3 ) {
-        $_ = $words; s/%20/ /g; print STDERR "search words: $_\n";
-    }
+  LOG ($verbose_load, "words: $_");
+  LOG ($verbose_load, "URL: $search_url");
 
-    if ( $DEBUG > 3 ) {
-	print STDERR "\n\npicking from $search_url\n";
-    }
+  $last_search = $search_url;   # for warnings
 
-    my $start = time;
-    my ( $base, $body ) = get_document ($search_url, undef, $timeout);
-    if (defined ($timeout)) {
-        $timeout -= (time - $start);
-        return undef if ($timeout <= 0);
+  my $start = time;
+  my ( $base, $body ) = get_document ($search_url, undef, $timeout);
+  if (defined ($timeout)) {
+    $timeout -= (time - $start);
+    if ($timeout <= 0) {
+      $body = undef;
+      LOG (($verbose_net || $verbose_load),
+           "timed out (late) for $search_url");
+      $suppress_audit = 1;
+      return ();
+    }
+  }
+
+  return () if (! $body);
+
+
+  my @subpages;
+
+  my $search_count = "?";
+  if ($body =~ m@found (approximately |about )?(<B>)?(\d+)(</B>)? image@) {
+    $search_count = $3;
+  } elsif ($body =~ m@<NOBR>((\d{1,3})(,\d{3})*)&nbsp;@i) {
+    $search_count = $1;
+  } elsif ($body =~ m@found ((\d{1,3})(,\d{3})*|\d+) Web p@) {
+    $search_count = $1;
+  } elsif ($body =~ m@found about ((\d{1,3})(,\d{3})*|\d+) results@) {
+    $search_count = $1;
+  } elsif ($body =~ m@\b\d+ - \d+ of (\d+)\b@i) { # avimages
+    $search_count = $1;
+  } elsif ($body =~ m@About ((\d{1,3})(,\d{3})*) images@i) { # avimages
+    $search_count = $1;
+  } elsif ($body =~ m@We found ((\d{1,3})(,\d{3})*|\d+) results@i) { # *vista
+    $search_count = $1;
+  } elsif ($body =~ m@ of about <B>((\d{1,3})(,\d{3})*)<@i) { # googleimages
+    $search_count = $1;
+  } elsif ($body =~ m@<B>((\d{1,3})(,\d{3})*)</B> Web sites were found@i) {
+    $search_count = $1;    # lycos
+  } elsif ($body =~ m@WEB.*?RESULTS.*?\b((\d{1,3})(,\d{3})*)\b.*?Matches@i) {
+    $search_count = $1;                          # hotbot
+  } elsif ($body =~ m@no photos were found containing@i) { # avimages
+    $search_count = "0";
+  } elsif ($body =~ m@found no document matching@i) { # avtext
+    $search_count = "0";
+  }
+  1 while ($search_count =~ s/^(\d+)(\d{3})/$1,$2/);
+
+#  if ($search_count eq "?" || $search_count eq "0") {
+#    local *OUT;
+#    my $file = "/tmp/wc.html";
+#    open(OUT, ">$file") || error ("writing $file: $!");
+#    print OUT $body;
+#    close OUT;
+#    print STDERR  blurb() . "###### wrote $file\n";
+#  }
+
+
+  my $length = length($body);
+  my $href_count = 0;
+
+  $_ = $body;
+
+  s/[\r\n\t ]+/ /g;
+
+
+  s/(<A )/\n$1/gi;
+  foreach (split(/\n/)) {
+    $href_count++;
+    my ($u) = m@<A\s.*\bHREF\s*=\s*([^>]+)>@i;
+    next unless $u;
+
+    if ($u =~ m/^\"([^\"]*)\"/) { $u = $1; }   # quoted string
+    elsif ($u =~ m/^([^\s]*)\s/) { $u = $1; }  # or token
+
+    if ( $rejected_urls{$u} ) {
+      LOG ($verbose_filter, "  pre-rejecting candidate: $u");
+      next;
     }
 
-    return undef if (! $body);
+    LOG ($verbose_http, "    HREF: $u");
 
+    $subpages[++$#subpages] = $u;
+  }
 
-    my @subpages;
-    my $skipped = 0;
+  if ( $#subpages < 0 ) {
+    LOG ($verbose_filter,
+         "found nothing on $base ($length bytes, $href_count links).");
+    return ();
+  }
 
-    $_ = $body;
-    s/(<A )/\n$1/gi;
-    foreach (split(/\n/)) {
+  LOG ($verbose_filter, "" . $#subpages+1 . " links on $search_url");
 
-        if ( m@<A HREF=([^>]+)><IMG SRC=http://image\.altavista\.com@i ) {
+  return ($search_count, @subpages);
+}
 
-            my $u = $1;
-            if (m/^"(.*)"$/) { $u = $1; }
 
-            if (m@\.corbis\.com/@) {
-                $skipped = 1;
-                if ( $DEBUG > 3 ) {
-                    print STDERR "skipping corbis URL: $_\n";
-                }
-                next;
-            } elsif ( $DEBUG > 3 ) {
-                print STDERR "sub-page: $1\n";
-            }
+sub depoison(@) {
+  my (@urls) = @_;
+  my @urls2 = ();
+  foreach (@urls) {
+    my ($h) = m@^http://([^/: \t\r\n]+)@i;
 
-            $subpages[++$#subpages] = $u;
-        }
-    }
+    next unless defined($h);
 
-    if ( $#subpages <= 0 ) {
-        if (!$skipped) {
-            print STDERR "Found nothing on $base\n";
-        }
-	return undef;
+    if ($poisoners{$h}) {
+      LOG (($verbose_filter), "  rejecting poisoner: $_");
+      next;
+    }
+    if ($h =~ m@([^.]+\.[^.]+\.[^.]+)$@ &&
+        $poisoners{$1}) {
+      LOG (($verbose_filter), "  rejecting poisoner: $_");
+      next;
+    }
+    if ($h =~ m@([^.]+\.[^.]+)$@ &&
+        $poisoners{$1}) {
+      LOG (($verbose_filter), "  rejecting poisoner: $_");
+      next;
     }
 
-    # pick a random element of the table
-    my $i = ((rand() * 99999) % $#subpages);
-    my $subpage = $subpages[$i];
+    push @urls2, $_;
+  }
+  return @urls2;
+}
 
-    if ( $DEBUG > 3 ) {
-	print STDERR "picked page $subpage\n";
-    }
 
+# given a list of URLs, picks one at random; loads it; and returns a
+# random image from it.
+# returns the url of the page loaded; the url of the image chosen.
+#
+sub pick_image_from_pages($$$$@) {
+  my ($base, $total_hit_count, $unfiltered_link_count, $timeout, @pages) = @_;
 
+  $total_hit_count = "?" unless defined($total_hit_count);
 
-    my ( $base2, $body2 ) = get_document ($subpage, $base, $timeout);
+  @pages = depoison (@pages);
+  LOG ($verbose_load,
+       "" . ($#pages+1) . " candidates of $unfiltered_link_count links" .
+       " ($total_hit_count total)");
 
-    return undef if (!$base2 || !body2);
+  return () if ($#pages < 0);
 
-    my $img = pick_image_from_body ($base2, $body2);
+  my $i = int(rand($#pages+1));
+  my $page = $pages[$i];
 
-    if ($img) {
-        return ($base2, $img);
-    } else {
-        return undef;
-    }
-}
+  LOG ($verbose_load, "picked page $page");
 
+  $suppress_audit = 1;
 
-# Picks a random image on a random page, and returns two URLs:
-# the page containing the image, and the image. 
-# Returns undef if nothing found this time.
-# Uses the url-randomizer 1 time in 5, else the image randomizer.
-#
-sub pick_image {
-    my ( $timeout ) = @_;
+  my ( $base2, $body2 ) = get_document ($page, $base, $timeout);
 
-    if (int(rand 5) == 0) {
-        return pick_from_url_randomizer ($timeout);
-    } else {
-        return pick_from_image_randomizer ($timeout);
-    }
-}
+  if (!$base2 || !$body2) {
+    $body2 = undef;
+    return ();
+  }
 
+  my $img = pick_image_from_body ($base2, $body2);
+  $body2 = undef;
 
-# Given the raw body of a GIF document, returns the dimensions of the image.
-#
-sub gif_size {
-    my ($body) = @_;
-    my $type = substr($body, 0, 6);
-    my $s;
-    return undef unless ($type =~ /GIF8[7,9]a/);
-    $s = substr ($body, 6, 10);
-    my ($a,$b,$c,$d) = unpack ("C"x4, $s);
-    return (($b<<8|$a), ($d<<8|$c));
+  if ($img) {
+    return ($base2, $img);
+  } else {
+    return ();
+  }
 }
 
-# Given the raw body of a JPEG document, returns the dimensions of the image.
+
+############################################################################
 #
-sub jpeg_size {
-    my ($body) = @_;
-    my $i = 0;
-    my $L = length($body);
-    
-    $c1 = substr($body, $i, 1); $i++;
-    $c2 = substr($body, $i, 1); $i++;
-    return undef unless (ord($c1) == 0xFF && ord($c2) == 0xD8);
-
-    my $ch = "0";
-    while (ord($ch) != 0xDA && $i < $L) {
-        # Find next marker, beginning with 0xFF.
-        while (ord($ch) != 0xFF) {
-            $ch = substr($body, $i, 1); $i++;
-        }
-        # markers can be padded with any number of 0xFF.
-        while (ord($ch) == 0xFF) {
-            $ch = substr($body, $i, 1); $i++;
-        }
-
-        # $ch contains the value of the marker.
-        my $marker = ord($ch);
+# Pick images from random pages returned by the Yahoo Random Link
+#
+############################################################################
 
-        if (($marker >= 0xC0) &&
-            ($marker <= 0xCF) &&
-            ($marker != 0xC4) &&
-            ($marker != 0xCC)) {  # it's a SOFn marker
-            $i += 3;
-            my $s = substr($body, $i, 4); $i += 4;
-            my ($a,$b,$c,$d) = unpack("C"x4, $s);
-            return (($c<<8|$d), ($a<<8|$b));
+# yahoorand
+my $yahoo_random_link = "http://random.yahoo.com/fast/ryl";
 
-        } else {
-            # We must skip variables, since FFs in variable names aren't
-            # valid JPEG markers.
-            my $s = substr($body, $i, 2); $i += 2;
-            my ($c1, $c2) = unpack ("C"x2, $s); 
-            my $length = ($c1 << 8) | $c2;
-            return undef if ($length < 2);
-            $i += $length-2;
-        }
-    }
-    return undef;
-}
 
-# Given the raw body of a GIF or JPEG document, returns the dimensions of
-# the image.
+# Picks a random page; picks a random image on that page;
+# returns two URLs: the page containing the image, and the image.
+# Returns () if nothing found this time.
 #
-sub image_size {
-    my ($body) = @_;
-    my ($w, $h) = gif_size ($body);
-    if ($w && $h) { return ($w, $h); }
-    return jpeg_size ($body);
-}
+sub pick_from_yahoo_random_link($) {
+  my ($timeout) = @_;
 
+  print STDERR "\n\n" if ($verbose_load);
+  LOG ($verbose_load, "URL: $yahoo_random_link");
 
-# returns the full path of the named program, or undef.
-#
-sub which {
-    my ($prog) = @_;
-    foreach (split (/:/, $ENV{PATH})) {
-        if (-x "$_/$prog") {
-            return $prog;
-        }
-    }
-    return undef;
-}
+  $last_search = $yahoo_random_link;   # for warnings
 
-##############################################################################
-#
-# Running as a CGI
-#
-##############################################################################
+  $suppress_audit = 1;
 
-my $body_tag = "<BODY BGCOLOR=\"#000000\" TEXT=\"#DDFFDD\"\n" .
-    "      LINK=\"#00EEEE\" VLINK=\"#EEEE00\" ALINK=\"#FF0000\">\n";
-
-my $html_document =
-    ("" .
-     "<HTML>\n" .
-     "<HEAD>\n" .
-     " <TITLE>WebCollage</TITLE>\n" .
-     "\n" .
-     "</HEAD>\n" .
-     $body_tag .
-     "\n" .
-     "<CENTER><FONT SIZE=1><BR></FONT>" .
-     "<TABLE BORDER=0 CELLPADDING=0 CELLSPACING=0 WIDTH=720>\n" .
-     " <TR>\n" .
-     "  <TD ALIGN=CENTER VALIGN=TOP NOWRAP>\n" .
-     "   <FONT SIZE=\"+3\"><B>WebCollage: </B></FONT>\n" .
-     "   <FONT SIZE=\"-1\"><BR><B>by\n" .
-     "     <A HREF=\"http://www.jwz.org/\">Jamie Zawinski</A></B>\n" .
-     "  </TD>\n" .
-     "  <TD ALIGN=LEFT VALIGN=TOP>\n" .
-     "\n" .
-     "   <P><FONT SIZE=\"+3\"><B>Exterminate All Rational Thought.\n" .
-     "   </B></FONT>\n" .
-     "   <BR>This program creates collages out of random images\n" .
-     "   found on the Web.\n" .
-     "   <P>More images are being added to the\n" .
-     "   collage now: please wait for the image below to load.\n" .
-     "   This will take a minute or two, since it has to contact\n" .
-     "   other web sites to retrieve the images before it can construct\n" .
-     "   the collage.  Once the image below is loaded, you can reload\n" .
-     "   this page to do it again.\n" .
-     "   <P>If you enjoy this, you might also enjoy\n" .
-     "   <A HREF=\"http://www.jwz.org/dadadodo/\">DadaDodo</A>.\n" .
-     "   WebCollage also works as a screen saver, for those of you\n" .
-     "   using Unix: it is included with the\n" .
-     "   <A HREF=\"http://www.jwz.org/xscreensaver/\">XScreenSaver</A>\n" .
-     "   package.<P>\n" .
-     "  </TD>\n" .
-     " </TR>\n" .
-     " <TR>\n" .
-     "  <TD COLSPAN=2 VALIGN=TOP ALIGN=CENTER><TABLE \n" .
-     "      BORDER=2 WIDTH=%%WIDTH%% HEIGHT=%%HEIGHT%% \n" .
-     "      CELLPADDING=0 CELLSPACING=0>\n" .
-     "    <TR><TD BGCOLOR=\"#C0C0C0\">\n" .
-     "      %%MAP%%\n" .
-     "     <A NAME=\"#image\">\n" .
-     "     <IMG SRC=\"%%IMAGE%%\" BORDER=0 \n" .
-     "      WIDTH=%%WIDTH%% HEIGHT=%%HEIGHT%% \n" .
-     "      USEMAP=\"#collage\"></A></TD></TR>\n" .
-     "  </TABLE></TD>\n" .
-     " </TR>\n" .
-     "</TABLE>\n" .
-     "<P>\n" .
-     "</CENTER>\n");
-
-
-my @time_fmt_days = ("Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat");
-my @time_fmt_months = ("Jan", "Feb", "Mar", "Apr", "May", "Jun",
-                       "Jul", "Aug", "Sep", "Oct", "Nov", "Dec");
-
-# Converts a time_t to a string acceptable to HTTP.
-#
-sub format_http_time {
-    my ($time) = @_;
-    my @t = gmtime($time);
-    my ($sec, $min, $hour, $mday, $mon, $year, $wday) = @t;
-    $year += 1900;
-    $wday = $time_fmt_days[$wday];
-    $mon = $time_fmt_months[$mon];
-    return sprintf("%s, %02d %s %d %02d:%02d:%02d GMT",
-                   $wday, $mday, $mon, $year, $hour, $min, $sec);
-}
-
-
-
-# Parses exactly the time format that HTTP requires, no more, no less.
-#
-sub parse_http_time {
-    ($_) = @_;
-
-    if (!m/^[SMTWF][a-z][a-z]+, (\d\d)[- ]([JFMAJSOND][a-z][a-z]+)[- ](\d\d\d?\d?)[- ](\d\d):(\d\d):(\d\d)( GMT)?$/o) {
-        return undef;
-    }
+  my ( $base, $body ) = get_document ($yahoo_random_link, undef, $timeout);
+  if (!$base || !$body) {
+    $body = undef;
+    return;
+  }
 
-    my @moy = qw(Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec);
-    @moy{@moy} = (1..12);
+  LOG ($verbose_load, "redirected to: $base");
 
-    my $t = Time::Local::timegm($6, $5, $4, $1, $moy{$2}-1,
-                                ($3 < 100 ? $3 : $3-1900));
-    return ($t < 0 ? undef : $t);
-}
+  my $img = pick_image_from_body ($base, $body);
+  $body = undef;
 
+  if ($img) {
+    return ($base, $img);
+  } else {
+    return ();
+  }
+}
 
-# Given a modification time, returns a time_t to use as the expiration time
-# of both the HTML and the JPEG.
+
+############################################################################
 #
-sub compute_expires_time {
-    my ($mod_time) = (@_);
-    my $now = time;
-    if ($mod_time < $now) { $mod_time = $now; }
-    return $mod_time + $max_age;
-}
+# Pick images from random pages returned by the Alta Vista Random Link
+#
+############################################################################
+
+# altavista
+my $alta_vista_random_link = "http://www.altavista.com/image/randomlink";
 
 
-# Parse the If-Modified-Since header, and write a response if appropriate.
-# If this returns 1, we're done.
+# Picks a random page; picks a random image on that page;
+# returns two URLs: the page containing the image, and the image.
+# Returns () if nothing found this time.
 #
-sub do_ifmod {
-    # see http://vancouver-webpages.com/proxy/log-tail.pl and
-    # http://mnot.cbd.net.au/cache_docs/ for clues about how to
-    # do cacheing properly with CGI-generated documents.
-    my ($mod_time) = (@_);
-    if ($ENV{HTTP_IF_MODIFIED_SINCE}) {
-        my $ims = $ENV{HTTP_IF_MODIFIED_SINCE};
-        $ims =~ s/;.*// ; # lose trailing "; length=3082"
-        $ims = parse_http_time($ims);
-        if ($ims && $mod_time <= $ims) {
-            print "Status: 304 Not Modified\n\n" ;
-            return 1;
-        }
-    }
-    return 0;
-}
+sub pick_from_alta_vista_random_link($) {
+  my ($timeout) = @_;
 
+  print STDERR "\n\n" if ($verbose_load);
+  LOG ($verbose_load, "URL: $alta_vista_random_link");
 
-# Returns N urls of images (and the pages on which they were found.)
-# Unless there is a significant surplus of URLs in the $pending_file,
-# this will spend $url_generation_time seconds generating as many URLs
-# as it can.  The first N will be returned, and the rest will be left
-# in the file.
-#
-sub get_image_urls {
-    my ($count) = @_;
+  $last_search = $alta_vista_random_link;   # for warnings
 
-    my @urls;
-    my $body = "";
-    my $file_count = 0;
+  $suppress_audit = 1;
 
-    local *PEND;
+  my ( $base, $body ) = get_document ($alta_vista_random_link,
+                                      undef, $timeout);
+  if (!$base || !$body) {
+    $body = undef;
+    return;
+  }
 
-    # Open and lock the file (read/write.)
-    # rewind after locking, in case we had to wait for the lock.
-    #
-    open (PEND, "+<$pending_file") || die "couldn't open $pending_file: $!";
+  LOG ($verbose_load, "redirected to: $base");
 
-    if ($DEBUG > 2) { print STDERR "jpeg: opened $pending_file\n"; }
+  my $img = pick_image_from_body ($base, $body);
+  $body = undef;
 
-    my $flock_wait = time;
-    flock (PEND, LOCK_EX) || die "couldn't lock $pending_file: $!";
-    $flock_wait = (time - $flock_wait);
+  if ($img) {
+    return ($base, $img);
+  } else {
+    return ();
+  }
+}
 
-    seek (PEND, 0, 0)     || die "couldn't rewind $pending_file: $!";
+
+############################################################################
+#
+# Pick images by feeding random words into Alta Vista Image Search
+#
+############################################################################
 
-    if ($DEBUG > 2) { print STDERR "jpeg: locked $pending_file\n"; }
 
+my $alta_vista_images_url = "http://www.altavista.com/image/results" .
+                            "?ipht=1" .       # photos
+                            "&igrph=1" .      # graphics
+                            "&iclr=1" .       # color
+                            "&ibw=1" .        # b&w
+                            "&micat=1" .      # no partner sites
+                            "&sc=on" .        # "site collapse"
+                            "&q=";
 
-    # Take N URLs off the top, and leave the rest.
-    #
-    while (<PEND>) {
-        if (--$count >= 0) {
-            if ($DEBUG > 3) { print STDERR "  <   $_"; }
-            s/[\r\n]+$//;
-            $urls[++$#urls] = $_;
-        } else {
-            $body .= $_;
-            if ($DEBUG > 3) { print STDERR "  -   $_"; }
-            $file_count++;
-        }
-    }
+# avimages
+sub pick_from_alta_vista_images($) {
+  my ($timeout) = @_;
 
-    # rewind and overwrite the file
-    seek (PEND, 0, 0)  || die "couldn't rewind $pending_file: $!";
-    truncate (PEND, 0) || die "couldn't truncate $pending_file: $!";
-    print PEND $body;
+  my $words = random_word();
+  my $page = (int(rand(9)) + 1);
+  my $search_url = $alta_vista_images_url . $words;
 
+  if ($page > 1) {
+    $search_url .= "&pgno=" . $page;		# page number
+    $search_url .= "&stq=" . (($page-1) * 12);  # first hit result on page
+  }
 
-    # If there are fewer than 3x as many URLs as we took left in the file,
-    # then generate as many URLs as we can in N seconds.  Take what we
-    # need from that, and append the rest to the file.  Note that we are
-    # still holding a lock on the file.
-    #
-    # Count the time spent waiting for flock as time spent gathering URLs.
-    # Because that means someone else was doing it.
-    #
-    $body = "";
-    if ($file_count < $count * 3) {
-        my $timeout = $url_generation_time - $flock_wait;
-        my $start = time;
-
-        while (1) {
-            last if ($timeout <= 0);
-
-            if ($DEBUG > 2) { print STDERR "time remaining: $timeout\n"; }
-            my ($base, $img) = pick_image ($timeout);
-
-            if ($img) {
-                $img  =~ s/ /%20/g;
-                $base =~ s/ /%20/g;
-                $_ = "$img $base";
-                if ($count-- >= 0) {
-                    if ($DEBUG > 3) { print STDERR "  <<   $img\n"; }
-                    $urls[++$#urls] = $_;
-                } else {
-                    if ($DEBUG > 3) { print STDERR "  >>   $img\n"; }
-                    print PEND "$_\n"; # append to file
-                    $file_count++;
-                }
-            }
-
-            my $now = time;
-            my $elapsed = $now - $start;
-            $timeout -= $elapsed;
-            $start = $now;
-        }
-    }
+  my ($search_hit_count, @subpages) =
+    pick_from_search_engine ($timeout, $search_url, $words);
 
-    my $of = select(PEND); $| = 1; select($of);		# flush output
-    print PEND "";
+  my @candidates = ();
+  foreach my $u (@subpages) {
 
-    flock (PEND, LOCK_UN) || die "couldn't unlock $pending_file: $!";
-    close (PEND)          || die "couldn't close $pending_file: $!";
+    # avimages is encoding their URLs now.
+    next unless ($u =~ s/^.*\*\*(http%3a.*$)/$1/gsi);
+    $u = url_unquote($u);
 
-    if ($DEBUG > 2) {
-        print STDERR "jpeg: closed $pending_file; $file_count urls in file;" .
-            " returning $#urls.\n";
-    }
+    next unless ($u =~ m@^http://@i);    #  skip non-HTTP or relative URLs
+    next if ($u =~ m@[/.]altavista\.com\b@i);     # skip altavista builtins
+    next if ($u =~ m@[/.]yahoo\.com\b@i);         # yahoo and av in cahoots?
+    next if ($u =~ m@[/.]doubleclick\.net\b@i);   # you cretins
+    next if ($u =~ m@[/.]clicktomarket\.com\b@i); # more cretins
+
+    next if ($u =~ m@[/.]viewimages\.com\b@i);    # stacked deck
+    next if ($u =~ m@[/.]gettyimages\.com\b@i);
 
-    return @urls;
+    LOG ($verbose_filter, "  candidate: $u");
+    push @candidates, $u;
+  }
+
+  return pick_image_from_pages ($search_url, $search_hit_count, $#subpages+1,
+                                $timeout, @candidates);
 }
 
 
-sub cgi_reset_all_files {
-    foreach (@all_files) {
-        my $file = $_;
-        local *OUT;
-        open (OUT, "+<$file") || die "couldn't open $file: $!";
-        flock (OUT, LOCK_EX)  || die "couldn't lock $file: $!";
-        truncate (OUT, 0)     || die "couldn't truncate $file: $!";
-        flock (OUT, LOCK_UN)  || die "couldn't unlock $file: $!";
-        close (OUT)           || die "couldn't close $file: $!";
+
+############################################################################
+#
+# Pick images by feeding random words into Google Image Search.
+# By Charles Gales <gales@us.ibm.com>
+#
+############################################################################
+
+
+my $google_images_url =     "http://images.google.com/images" .
+                            "?site=images" .  # photos
+                            "&btnG=Search" .  # graphics
+                            "&safe=off" .     # no screening
+                            "&imgsafe=off" .
+                            "&q=";
+
+# googleimgs
+sub pick_from_google_images($;$$) {
+  my ($timeout, $words, $max_page) = @_;
+
+  if (!defined($words)) {
+    $words = random_word;   # only one word for Google
+  }
+
+  my $page = (int(rand(9)) + 1);
+  my $num = 20;     # 20 images per page
+  my $search_url = $google_images_url . $words;
+
+  if ($page > 1) {
+    $search_url .= "&start=" . $page*$num;	# page number
+    $search_url .= "&num="   . $num;            #images per page
+  }
+
+  my ($search_hit_count, @subpages) =
+    pick_from_search_engine ($timeout, $search_url, $words);
+
+  my @candidates = ();
+  my %referers;
+  foreach my $u (@subpages) {
+    next unless ($u =~ m@imgres\?imgurl@i);    #  All pics start with this
+    next if ($u =~ m@[/.]google\.com\b@i);     # skip google builtins
+
+    if ($u =~ m@^/imgres\?imgurl=(.*?)\&imgrefurl=(.*?)\&@) {
+      my $ref = $2;
+      my $img = $1;
+      $img = "http://$img" unless ($img =~ m/^http:/i);
+
+      LOG ($verbose_filter, "  candidate: $ref");
+      push @candidates, $img;
+      $referers{$img} = $ref;
     }
+  }
+
+  @candidates = depoison (@candidates);
+  return () if ($#candidates < 0);
+  my $i = int(rand($#candidates+1));
+  my $img = $candidates[$i];
+  my $ref = $referers{$img};
 
-    system "ppmmake '#000000' $img_width $img_height > $image_ppm" ||
-        die "failed to create blank $image_ppm file: $!";
-    system "cjpeg -progressive $image_ppm > $image_jpg" ||
-        die "failed to create blank $image_jpg file: $!";
+  LOG ($verbose_load, "picked image " . ($i+1) . ": $img (on $ref)");
+  return ($ref, $img);
 }
 
 
-# Given the URL of an image and the page on which it was found, this will
-# load the image, and paste it at a random spot in $image_ppm and $img_jpg.
-# It will also update $map_file to contain the appropriate referer, and
-# will limit it to $max_map_entries lines.
+
+############################################################################
 #
-sub cgi_paste_image {
-    my ($img, $referer) = @_;
+# Pick images by feeding random numbers into Google Image Search.
+# By jwz, suggested by Ian O'Donnell.
+#
+############################################################################
 
-    my ( $base, $body ) = get_document ($img, $referer);
-    return if (!$base || !$body);
 
-    my ($iw, $ih) = image_size ($body);
-    return if (!$iw || !$ih);
+# googlenums
+sub pick_from_google_image_numbers($) {
+  my ($timeout) = @_;
 
-    if ($DEBUG > 2) { print STDERR "got $base ($iw x $ih)\n"; }
+  my $max = 9999;
+  my $number = int(rand($max));
 
-    my $cmd;
+  $number = sprintf("%04d", $number)
+    if (rand() < 0.3);
 
-    if ($base =~ m/\.gif$/i) {
-        $cmd = "giftopnm";
-    } else {
-        $cmd = "djpeg";
-    }
+  pick_from_google_images ($timeout, "$number");
+}
+
+
+
+############################################################################
+#
+# Pick images by feeding random digital camera file names into 
+# Google Image Search.
+# By jwz, inspired by the excellent Random Personal Picture Finder
+# at http://www.diddly.com/random/
+#
+############################################################################
+
+my @photomakers = (
+  #
+  # Common digital camera file name formats, as described at
+  # http://www.diddly.com/random/about.html
+  #
+  sub { sprintf ("dcp%05d.jpg",  int(rand(4000))); },	# Kodak
+  sub { sprintf ("dsc%05d.jpg",  int(rand(4000))); },	# Nikon
+  sub { sprintf ("dscn%04d.jpg", int(rand(4000))); },	# Nikon
+  sub { sprintf ("mvc-%03d.jpg", int(rand(999)));  },	# Sony Mavica
+  sub { sprintf ("mvc%05d.jpg",  int(rand(9999))); },	# Sony Mavica
+  sub { sprintf ("P101%04d.jpg", int(rand(9999))); },	# Olympus w/ date=101
+  sub { sprintf ("P%x%02d%04d.jpg",			# Olympus
+                 int(rand(0xC)), int(rand(30))+1,
+                 rand(9999)); },
+  sub { sprintf ("IMG_%03d.jpg",  int(rand(999))); },	# ?
+  sub { sprintf ("IMAG%04d.jpg",  int(rand(9999))); },	# RCA and Samsung
+  sub { my $n = int(rand(9999));			# Canon
+          sprintf ("1%02d-%04d.jpg", int($n/100), $n); },
+  sub { my $n = int(rand(9999));			# Canon
+          sprintf ("1%02d-%04d_IMG.jpg",
+                   int($n/100), $n); },
+  sub { sprintf ("IMG_%04d.jpg", int(rand(9999))); },	# Canon
+  sub { sprintf ("dscf%04d.jpg", int(rand(9999))); },	# Fuji Finepix
+  sub { sprintf ("pdrm%04d.jpg", int(rand(9999))); },	# Toshiba PDR
+  sub { sprintf ("IM%06d.jpg", int(rand(9999))); },	# HP Photosmart
+  sub { sprintf ("EX%06d.jpg", int(rand(9999))); },	# HP Photosmart
+#  sub { my $n = int(rand(3));				# Kodak DC-40,50,120
+#        sprintf ("DC%04d%s.jpg", int(rand(9999)),
+#                 $n == 0 ? 'S' : $n == 1 ? 'M' : 'L'); },
+  sub { sprintf ("pict%04d.jpg", int(rand(9999))); },	# Minolta Dimage
+  sub { sprintf ("P%07d.jpg", int(rand(9999))); },	# Kodak DC290
+#  sub { sprintf ("%02d%02d%04d.jpg",			# Casio QV3000, QV4000
+#                 int(rand(12))+1, int(rand(31))+1,
+#                 int(rand(999))); },
+#  sub { sprintf ("%02d%x%02d%04d.jpg",			# Casio QV7000
+#                 int(rand(6)), # year
+#                 int(rand(12))+1, int(rand(31))+1,
+#                 int(rand(999))); },
+  sub { sprintf ("IMGP%04d.jpg", int(rand(9999))); },	# Pentax Optio S
+  sub { sprintf ("PANA%04d.jpg", int(rand(9999))); },	# Panasonic vid still
+  sub { sprintf ("HPIM%04d.jpg", int(rand(9999))); },	# HP Photosmart
+  sub { sprintf ("PCDV%04d.jpg", int(rand(9999))); },	# ?
+ );
+
+
+# googlephotos
+sub pick_from_google_image_photos($) {
+  my ($timeout) = @_;
+
+  my $i = int(rand($#photomakers + 1));
+  my $fn = $photomakers[$i];
+  my $file = &$fn;
+  my $words .= $file . "%20filetype:jpg";
+
+  pick_from_google_images ($timeout, $words);
+}
 
-    if ($iw > $img_width || $ih > $img_height) {
-        while ($iw > $img_width || $ih > $img_height) {
-            $iw = int($iw / 2);
-            $ih = int($ih / 2);
-        }
-        $cmd .= " | pnmscale -xysize $iw $ih";
-    }
 
-    my $x = int (rand() * ($img_width - $iw));
-    my $y = int (rand() * ($img_height - $ih));
+
+############################################################################
+#
+# Pick images by feeding random words into Alta Vista Text Search
+#
+############################################################################
 
-    $cmd .= " | pnmpaste - $x $y $image_ppm";
 
+my $alta_vista_url = "http://www.altavista.com/web/results" .
+                     "?pg=aq" .
+                     "&aqmode=s" .
+                     "&filetype=html" .
+                     "&sc=on" .        # "site collapse"
+                     "&nbq=50" .
+                     "&aqo=";
 
-    local *MAP;
-    local *PIPE_OUT;
+# avtext
+sub pick_from_alta_vista_text($) {
+  my ($timeout) = @_;
 
-    # Open and lock the map (read/write.)
-    # rewind after locking, in case we had to wait for the lock.
-    # This lock doubles as our lock on the image file itself.
-    #
-    open (MAP, "+<$map_file") || die "couldn't open $map_file: $!";
+  my $words = random_words(0);
+  my $page = (int(rand(9)) + 1);
+  my $search_url = $alta_vista_url . $words;
 
-    if ($DEBUG > 2) { print STDERR "jpeg: opened $map_file\n"; }
+  if ($page > 1) {
+    $search_url .= "&pgno=" . $page;
+    $search_url .= "&stq=" . (($page-1) * 10);
+  }
 
-    flock (MAP, LOCK_EX) || die "couldn't lock $map_file: $!";
-    seek (MAP, 0, 0)     || die "couldn't rewind $map_file: $!";
+  my ($search_hit_count, @subpages) =
+    pick_from_search_engine ($timeout, $search_url, $words);
 
-    if ($DEBUG > 2) { print STDERR "jpeg: locked $map_file\n"; }
+  my @candidates = ();
+  foreach my $u (@subpages) {
 
-    # Read in the first hundred lines of the map file.
+    # Those altavista fuckers are playing really nasty redirection games
+    # these days: the filter your clicks through their site, but use
+    # onMouseOver to make it look like they're not!  Well, it makes it
+    # easier for us to identify search results...
     #
-    my $map = "";
-    my $count = 0;
-    while (<MAP>) {
-        last if ($count++ > $max_map_entries);
-        $map .= $_;
-    }
+    next unless ($u =~ s/^.*\*\*(http%3a.*$)/$1/gsi);
+    $u = url_unquote($u);
 
-    # Add this entry to the front of the map data.
-    #
-    $map = "$x $y $iw $ih $referer\n" . $map;
+    next unless ($u =~ m@^http://@i);    #  skip non-HTTP or relative URLs
+    next if ($u =~ m@[/.]altavista\.com\b@i);     # skip altavista builtins
+    next if ($u =~ m@[/.]yahoo\.com\b@i);         # yahoo and av in cahoots?
 
+    LOG ($verbose_filter, "  candidate: $u");
+    push @candidates, $u;
+  }
 
-    # Ensure that the $image_ppm file exists and has a ppm in it.
-    #
-    my $ppm_size = $img_width * $img_height * 3 * 2;
-    my $s = (stat($image_ppm))[7];
-    if ($s < $ppm_size) {
-
-        if ( $DEBUG ) {
-            print STDERR "$image_ppm is $s bytes;" .
-                " should be at least $ppm_size\n";
-            print STDERR "resetting everything.";
-            cgi_reset_all_files();
-        }
-    }
+  return pick_image_from_pages ($search_url, $search_hit_count, $#subpages+1,
+                                $timeout, @candidates);
+}
 
-    # Paste the bits into the image.  Note that the map file is still locked.
-    #
-    local *TMP;
-    open (TMP, ">$image_tmp") || die "couldn't open $image_tmp: $!";
-    close (TMP);
 
-    if (! $DEBUG ) {
-        $cmd = "( $cmd ) 2>/dev/null";
-    }
+
+############################################################################
+#
+# Pick images by feeding random words into Hotbot
+#
+############################################################################
+
+my $hotbot_search_url =("http://hotbot.lycos.com/default.asp" .
+                        "?ca=w" .
+                        "&descriptiontype=0" .
+                        "&imagetoggle=1" .
+                        "&matchmode=any" .
+                        "&nummod=2" .
+                        "&recordcount=50" .
+                        "&sitegroup=1" .
+                        "&stem=1" .
+                        "&cobrand=undefined" .
+                        "&query=");
+
+sub pick_from_hotbot_text($) {
+  my ($timeout) = @_;
+
+  $last_search = $hotbot_search_url;   # for warnings
+
+  # lycos seems to always give us back dictionaries and word lists if
+  # we search for more than one word...
+  #
+  my $words = random_word();
+
+  my $start = int(rand(8)) * 10 + 1;
+  my $search_url = $hotbot_search_url . $words . "&first=$start&page=more";
+
+  my ($search_hit_count, @subpages) =
+    pick_from_search_engine ($timeout, $search_url, $words);
+
+  my @candidates = ();
+  foreach my $u (@subpages) {
+
+    # Hotbot plays redirection games too
+    # (not any more?)
+#    next unless ($u =~ m@/director.asp\?.*\btarget=([^&]+)@);
+#    $u = url_decode($1);
+
+    next unless ($u =~ m@^http://@i);    #  skip non-HTTP or relative URLs
+    next if ($u =~ m@[/.]hotbot\.com\b@i);     # skip hotbot builtins
+    next if ($u =~ m@[/.]lycos\.com\b@i);      # skip hotbot builtins
+    next if ($u =~ m@[/.]inktomi\.com\b@i);    # skip hotbot builtins
+
+    LOG ($verbose_filter, "  candidate: $u");
+    push @candidates, $u;
+  }
+
+  return pick_image_from_pages ($search_url, $search_hit_count, $#subpages+1,
+                                $timeout, @candidates);
+}
 
-    $cmd .= " > $image_tmp";
-    if ($DEBUG > 2) { print STDERR "executing $cmd\n"; }
 
-    if (open(PIPE_OUT, "| $cmd")) {
-        print PIPE_OUT $body;
-        close(PIPE_OUT);
+
+############################################################################
+#
+# Pick images by feeding random words into Lycos
+#
+############################################################################
 
-        if ($DEBUG > 2) { system "ls -ldF $image_tmp >&2"; }
+my $lycos_search_url = "http://search.lycos.com/default.asp" .
+                       "?lpv=1" .
+                       "&loc=searchhp" .
+                       "&tab=web" .
+                       "&query=";
 
-        my @tmp_stat = stat($image_tmp);
-        if (@tmp_stat && $tmp_stat[7] < 200) {
-#            unlink ($image_tmp) || die "couldn't unlink $image_tmp: $!";
-            open (OUT, ">$image_tmp") || die "$image_tmp unwritable: $!";
-            close (OUT);
-            if ($DEBUG > 2) { print STDERR "FAILED writing $image_ppm\n"; }
-        } else {
-#            rename ($image_tmp, $image_ppm) ||
-#                die "couldn't rename $image_tmp to $image_ppm: $!";
-            local *IN;
-            local *OUT;
-            open (IN, "+<$image_tmp") || die "$image_tmp unreadable: $!";
-            open (OUT, ">$image_ppm") || die "$image_ppm unwritable: $!";
-            while (<IN>) { print OUT $_; }
-            truncate (IN, 0) || die "couldn't truncate $image_tmp: $!";
-            close (IN);
-            close (OUT) || die "couldn't write $image_ppm: $!";
-            if ($DEBUG > 2) { print STDERR "wrote $image_ppm\n"; }
-
-
-            # Now convert the PPM to a JPEG.
-            #
-            system "cjpeg -progressive $image_ppm > $image_tmp 2>/dev/null";
-
-            @tmp_stat = stat($image_tmp);
-            if (@tmp_stat && $tmp_stat[7] < 200) {
-#                unlink ($image_tmp) || die "couldn't unlink $image_tmp: $!";
-                open (OUT, ">$image_tmp") || die "$image_tmp unwritable: $!";
-                close (OUT);
-                if ($DEBUG > 2) { print STDERR "FAILED writing $image_jpg\n"; }
-            } else {
-#                rename ($image_tmp, $image_ppm) ||
-#                    die "couldn't rename $image_tmp to $image_ppm: $!";
-                open (IN, "+<$image_tmp") || die "$image_tmp unreadable: $!";
-                open (OUT, ">$image_jpg") || die "$image_jpg unwritable: $!";
-                while (<IN>) { print OUT $_; }
-                truncate (IN, 0) || die "couldn't truncate $image_tmp: $!";
-                close (IN);
-                close (OUT) || die "couldn't write $image_jpg: $!";
-                if ($DEBUG > 2) { print STDERR "wrote $image_jpg\n"; }
-            }
-        }
+sub pick_from_lycos_text($) {
+  my ($timeout) = @_;
 
-        # Overwrite the map data.
-        #
-        seek (MAP, 0, 0)  || die "couldn't rewind $map_file: $!";
-        truncate (MAP, 0) || die "couldn't truncate $map_file: $!";
-        print MAP $map;
-    }
+  $last_search = $lycos_search_url;   # for warnings
 
-    my $of = select(MAP); $| = 1; select($of);		# flush output
-    print MAP "";
+  # lycos seems to always give us back dictionaries and word lists if
+  # we search for more than one word...
+  #
+  my $words = random_word();
 
-    flock (MAP, LOCK_UN) || die "couldn't unlock $map_file: $!";
-    close (MAP)          || die "couldn't close $map_file: $!";
+  my $start = int(rand(8)) * 10 + 1;
+  my $search_url = $lycos_search_url . $words . "&first=$start&page=more";
 
-    if ($DEBUG > 2) { print STDERR "jpeg: closed $map_file\n"; }
-}
+  my ($search_hit_count, @subpages) =
+    pick_from_search_engine ($timeout, $search_url, $words);
 
+  my @candidates = ();
+  foreach my $u (@subpages) {
 
-sub cgi_generate_image {
+    # Lycos plays redirection games.
+    # (not any more?)
+#    next unless ($u =~ m@^http://click.lycos.com/director.asp
+#                         .*
+#                         \btarget=([^&]+)
+#                         .*
+#                        @x);
+#    $u = url_decode($1);
 
-    $SIG{PIPE} = 'IGNORE';
+    next unless ($u =~ m@^http://@i);    #  skip non-HTTP or relative URLs
+    next if ($u =~ m@[/.]hotbot\.com\b@i);     # skip lycos builtins
+    next if ($u =~ m@[/.]lycos\.com\b@i);      # skip lycos builtins
+    next if ($u =~ m@[/.]terralycos\.com\b@i); # skip lycos builtins
+    next if ($u =~ m@[/.]inktomi\.com\b@i);    # skip lycos builtins
 
-    my @urls = get_image_urls ($pastes_per_load);
-    my $end_time = time + $image_retrieval_time;
 
-    if ($DEBUG > 2) {
-        print STDERR "loading $#urls images\n";
-    }
+    LOG ($verbose_filter, "  candidate: $u");
+    push @candidates, $u;
+  }
 
-    foreach (@urls) {
-        my ($img, $referer) = m/^([^ ]+) ([^ ]+)/;
-        if ($img) {
-            cgi_paste_image ($img, $referer);
-        }
-        last if (time > $end_time);
-    }
+  return pick_image_from_pages ($search_url, $search_hit_count, $#subpages+1,
+                                $timeout, @candidates);
 }
 
 
-sub cgi_sanity_check {
-    my $error = undef;
-    foreach (@all_files) {
-        if (! -e $_) { $error = "$_ does not exist.\n"; }
-        elsif (! -r $_) { $error = "$_ is unreadable.\n"; }
-        elsif (! -w $_) { $error = "$_ is unwritable.\n"; }
-        last if ($error);
-    }
+
+############################################################################
+#
+# Pick images by feeding random words into news.yahoo.com
+#
+############################################################################
+
+my $yahoo_news_url = "http://news.search.yahoo.com/search/news" .
+                     "?c=news_photos" .
+                     "&p=";
+
+# yahoonews
+sub pick_from_yahoo_news_text($) {
+  my ($timeout) = @_;
 
-    return unless $error;
+  $last_search = $yahoo_news_url;   # for warnings
 
-    print "Content-Type: text/html\n";
-    print "\n\n<TITLE>Error</TITLE>$body_tag<H1>Error</H1>";
-    print POSIX::getcwd() . "/" . $error . "<P>\n";
+  my $words = random_word();
+  my $search_url = $yahoo_news_url . $words;
 
-    $_ = join("</TT>, <TT>", @all_files);
-    s/,([^,]*)$/, and$1/;
+  my ($search_hit_count, @subpages) =
+    pick_from_search_engine ($timeout, $search_url, $words);
 
-    print "Each of the files: <TT>$_</TT>\n";
-    print " must exist and be readable and writable by the httpd process\n";
-    print "(which probably means they must be globally readable and\n";
-    print "writable, since on most systems, CGI scripts run as the\n";
-    print "user <I>nobody</I>.)\n<P>\n";
+  my @candidates = ();
+  foreach my $u (@subpages) {
 
-    exit (0);
+    # de-redirectize the URLs
+    $u =~ s@^http://rds\.yahoo\.com/.*-http%3A@http:@s;
+
+    # only accept URLs on Yahoo's news site
+    next unless ($u =~ m@^http://dailynews\.yahoo\.com/@i ||
+                 $u =~ m@^http://story\.news\.yahoo\.com/@i);
+    next unless ($u =~ m@&u=/@);
+
+    LOG ($verbose_filter, "  candidate: $u");
+    push @candidates, $u;
+  }
+
+  return pick_image_from_pages ($search_url, $search_hit_count, $#subpages+1,
+                                $timeout, @candidates);
 }
 
 
-# Write the encapsulating HTML document and associated HTTP headers.
-# This is fast -- it just writes out the wrapper document corresponding
-# to the data currently on disk.  It is the loading of the sub-image
-# that does the real work.
+
+############################################################################
+#
+# Pick images from LiveJournal's list of recently-posted images.
 #
-sub cgi_emit_html_document {
+############################################################################
 
-    cgi_sanity_check;
+my $livejournal_img_url = "http://www.livejournal.com/stats/latest-img.bml";
 
-    my $map_file_date;
-    my $doc = $html_document;
+# With most of our image sources, we get a random page and then select
+# from the images on it.  However, in the case of LiveJournal, the page
+# of images tends to update slowly; so we'll remember the last N entries
+# on it and randomly select from those, to get a wider variety each time.
 
-    my $w2 = int ($img_width  * $scale);
-    my $h2 = int ($img_height * $scale);
-    $doc =~ s/%%WIDTH%%/$w2/g;
-    $doc =~ s/%%HEIGHT%%/$h2/g;
+my $lj_cache_size = 1000;
+my @lj_cache = (); # fifo, for ordering by age
+my %lj_cache = (); # hash, for detecting dups
 
-    local *MAP;
-    open (MAP, "<$map_file") || die "couldn't open $map_file: $!";
-    if ($DEBUG > 2) { print STDERR "html: opened $map_file\n"; }
+# livejournal
+sub pick_from_livejournal_images($) {
+  my ($timeout) = @_;
 
-    flock (MAP, LOCK_SH) || die "couldn't lock $map_file: $!";
-    seek (MAP, 0, 0)     || die "couldn't rewind $map_file: $!";
-    if ($DEBUG > 2) { print STDERR "html: locked $map_file\n"; }
+  $last_search = $livejournal_img_url;   # for warnings
 
-    $map_file_date = (stat(MAP))[9];
+  my ( $base, $body ) = get_document ($livejournal_img_url, undef, $timeout);
+  return () unless $body;
 
-    my $map = "<MAP NAME=\"collage\">\n";
-    while (<MAP>) {
-        my ($x, $y, $w, $h, $url) =
-            m/^([0-9]+) ([0-9]+) ([0-9]+) ([0-9]+) (.*)$/;
-        if ($w && $h) {
-            $x = int($x * $scale);
-            $y = int($y * $scale);
-            $w = int($w * $scale);
-            $h = int($h * $scale);
+  $body =~ s/\n/ /gs;
+  $body =~ s/(<recent-image)\b/\n$1/gsi;
 
-            # protect against URLs that contain <, >, or ".
-            $url =~ s/([<>\"])/uc sprintf("%%%02X",ord($1))/eg;
+  foreach (split (/\n/, $body)) {
+    next unless (m/^<recent-image\b/);
+    next unless (m/\bIMG=[\'\"]([^\'\"]+)[\'\"]/si);
+    my $img = html_unquote ($1);
 
-            my $x2 = $x + $w;
-            my $y2 = $y + $h;
-            $map .=
-                "<AREA SHAPE=RECT COORDS=\"$x,$y,$x2,$y2\" HREF=\"$url\">\n";
-        }
-    }
-    $map .= "</MAP>";
-    flock (MAP, LOCK_UN) || die "couldn't unlock $map_file: $!";
-    close (MAP)          || die "couldn't close $map_file: $!";
+    next if ($lj_cache{$img}); # already have it
 
-    if ($DEBUG > 2) { print STDERR "html: closed $map_file\n"; }
+    next unless (m/\bURL=[\'\"]([^\'\"]+)[\'\"]/si);
+    my $page = html_unquote ($1);
+    my @pair = ($img, $page);
+    LOG ($verbose_filter, "  candidate: $img");
+    push @lj_cache, \@pair;
+    $lj_cache{$img} = \@pair;
+  }
 
-    $doc =~ s/%%MAP%%/$map/g;
+  return () if ($#lj_cache == -1);
 
-    my $img_name = "current";
+  my $n = $#lj_cache+1;
+  my $i = int(rand($n));
+  my ($img, $page) = @{$lj_cache[$i]};
 
-    $doc =~ s@%%IMAGE%%@images/$img_name.jpg@g;
+  # delete this one from @lj_cache and from %lj_cache.
+  #
+  @lj_cache = ( @lj_cache[0 .. $i-1],
+                @lj_cache[$i+1 .. $#lj_cache] );
+  delete $lj_cache{$img};
 
+  # Keep the size of the cache under the limit by nuking older entries
+  #
+  while ($#lj_cache >= $lj_cache_size) {
+    my $pairP = shift @lj_cache;
+    my $img = $pairP->[0];
+    delete $lj_cache{$img};
+  }
 
-    my $mod_time = $map_file_date;
-    if ($script_date > $mod_time) { $mod_time = $script_date; }
+  LOG ($verbose_load, "picked image " .($i+1) . "/$n: $img");
 
-    if (do_ifmod($mod_time)) {
-        return;
-    }
+  return ($page, $img);
+}
 
-    my $exp = compute_expires_time($mod_time);
+
+############################################################################
+#
+# Pick images from ircimages.com (images that have been in the /topic of
+# various IRC channels.)
+#
+############################################################################
 
-    print "Content-Type: text/html\n";
-    print "Content-Length: " . length($doc) . "\n";
-    print "Last-Modified: " . format_http_time($mod_time) . "\n";
+my $ircimages_url = "http://ircimages.com/";
 
-    # This is a suggestion to consider the object invalid after the given
-    # date.  This is sometimes ignored.
-    #
-    print "Expires: " . format_http_time($exp) . "\n";
+# ircimages
+sub pick_from_ircimages($) {
+  my ($timeout) = @_;
 
-    # This may or may not cause a cacheing proxy to pass this stuff along.
-    # It's not standardized, but was historically used for... something.
-    print "Pragma: no-cache\n";
+  $last_search = $ircimages_url;   # for warnings
 
-    # This says the same thing as the Expires header, but it is a stronger
-    # assertion that we're serious and should be listened to.
-    #
-    my $age = $exp - time;
-    print "Cache-Control: max-age=$age, must-revalidate\n";
+  my $n = int(rand(2900));
+  my $search_url = $ircimages_url . "page-$n";
 
-    print "\n";
-    print $doc;
-}
+  my ( $base, $body ) = get_document ($search_url, undef, $timeout);
+  return () unless $body;
 
+  my @candidates = ();
 
-# Write the interior JPEG document and associated HTTP headers.
-#
-sub cgi_emit_jpeg_document {
+  $body =~ s/\n/ /gs;
+  $body =~ s/(<A)\b/\n$1/gsi;
 
-    my $image_data = "";
-    my $jpg_file_date;
-    my $do_ims = 0;
+  foreach (split (/\n/, $body)) {
 
-    # The map file is the means by which we hold write-locks on the image
-    # file.  So first obtain the lock on that file.
-    #
-    local *MAP;
-    open (MAP, "+<$map_file") || die "couldn't open $map_file: $!";
+    my ($u) = m@<A\s.*\bHREF\s*=\s*([^>]+)>@i;
+    next unless $u;
 
-    if ($DEBUG > 2) { print STDERR "jpeg: opened $map_file\n"; }
-    flock (MAP, LOCK_SH) || die "couldn't lock $map_file: $!";
-    if ($DEBUG > 2) { print STDERR "jpeg: locked $map_file\n"; }
+    if ($u =~ m/^\"([^\"]*)\"/) { $u = $1; }   # quoted string
+    elsif ($u =~ m/^([^\s]*)\s/) { $u = $1; }  # or token
 
-    # Now we have exclusive access to the image file.  Read it.
-    #
-    local *IMG;
-    open (IMG, "<$image_jpg") || die "couldn't open $image_jpg: $!";
-
-    $jpg_file_date = (stat(IMG))[9];
-
-    if (do_ifmod($jpg_file_date)) {
-        $do_ims = 1;
-        if ($DEBUG > 2) {
-            my $ims = $ENV{HTTP_IF_MODIFIED_SINCE};
-            $ims =~ s/;.*//;
-            print STDERR "not-modified-since " .
-                localtime(parse_http_time($ims)) . "\n";
-            print STDERR "jpg date: " . localtime($jpg_file_date) . "\n";
-        }
-    }
+    next unless ($u =~ m/^http:/i);
+    next if ($u =~ m@^http://(searchirc\.com\|ircimages\.com)@i);
+    next unless ($u =~ m@[.](gif|jpg|jpeg|pjpg|pjpeg|png)$@i);
 
-    if (!$do_ims) {
-        while (<IMG>) { $image_data .= $_; }
-    }
-    close (IMG) || die "couldn't close $image_jpg: $!";
+    LOG ($verbose_http, "    HREF: $u");
+    push @candidates, $u;
+  }
 
-    # Now free the lock so that others can write to the file.
-    #
-    flock (MAP, LOCK_UN) || die "couldn't unlock $map_file: $!";
-    close (MAP)          || die "couldn't close $map_file: $!";
-    if ($DEBUG > 2) { print STDERR "jpeg: closed $map_file\n"; }
+  LOG ($verbose_filter, "" . $#candidates+1 . " links on $search_url");
 
-    return if ($do_ims);
+  return () if ($#candidates == -1);
 
+  my $i = int(rand($#candidates+1));
+  my $img = $candidates[$i];
 
-    # At this point, we have the image data we will be returning.
-    # However, don't return it yet -- first go off and generate the
-    # *next* image, then we can return *this* one.  If we don't do it
-    # in this order, people will jump the gun hitting reload, and no
-    # image updates will happen.
-    #
-    my $type = "image/jpeg";
-    my $mod_time = $jpg_file_date;
-    if ($script_date > $mod_time) { $mod_time = $script_date; }
-
-    print "Last-Modified: " . format_http_time($mod_time) . "\n";
-    print "Expires: " . format_http_time(compute_expires_time($mod_time))
-        . "\n";
-    print "Content-Type: $type\n";
-    print "Content-Length: " . length($image_data) . "\n";
-    print "\n";
-
-    # Now, before returning the image data, go catatonic for a minute
-    # while we load some URLs and make the next image.
-    #
-    cgi_generate_image;
+  LOG ($verbose_load, "picked image " .($i+1) . "/" . ($#candidates+1) .
+       ": $img");
 
-    # Done setting up for next time -- now finish loading.
-    #
-    print $image_data;
-    $image_data = undef;
+  $search_url = $img;  # hmm...
+  return ($search_url, $img);
 }
 
-
-# Write the source code of this script as a text/plain document.
+
+############################################################################
 #
-sub cgi_emit_source_document {
-    my $mod_time = $script_date;
+# Pick images from Flickr's page of recently-posted photos.
+#
+############################################################################
 
-    if (do_ifmod($mod_time)) {
-        return;
-    }
+my $flickr_img_url = "http://www.flickr.com/photos/";
 
-    print "Content-Type: text/plain\n";
-    print "Last-Modified: " . format_http_time($mod_time) . "\n";
-    print "\n";
-    open (IN, "<$argv0") || die "couldn't open $argv0: $!";
-    while (<IN>) {
-        print;
-    }
-    close (IN);
-}
+# Like LiveJournal, the Flickr page of images tends to update slowly,
+# so remember the last N entries on it and randomly select from those.
 
+# I know that Flickr has an API (http://www.flickr.com/services/api/)
+# but it was easy enough to scrape the HTML, so I didn't bother exploring.
 
-# Parse the various environment variables to decide how we were invoked,
-# and then do something about it.
-#
-sub cgi_main {
+my $flickr_cache_size = 1000;
+my @flickr_cache = (); # fifo, for ordering by age
+my %flickr_cache = (); # hash, for detecting dups
 
-    $DEBUG=4;
 
-    $ENV{PATH} .= ":/usr/local/bin";
+# flickr_recent
+sub pick_from_flickr_recent($) {
+  my ($timeout) = @_;
 
-    # make sure the various programs we execute exist, right up front.
-    foreach ("ppmmake", "cjpeg", "djpeg", "giftopnm", "pnmpaste", "pnmscale") {
-        if (!which ($_)) {
-            print "Content-Type: text/html\n";
-            print "\n\n<TITLE>Error</TITLE>$body_tag<H1>Error</H1>";
-            print "The <TT>$_</TT> program was not found on \$PATH.<BR>\n";
+  my $start = 16 * int(rand(100));
 
-            my $p = $ENV{PATH};
-            $p =~ s/%/%25/g; $p =~ s/\&/%26/g;
-            $p =~ s/</%3C/g; $p =~ s/>/%3E/g;
-            $p =~ s/:/:<WBR>/g;
-            print "\$PATH is: <TT>$p</TT><P>\n";
-            exit (0);
-        }
-    }
+  $last_search = $flickr_img_url;   # for warnings
+  $last_search .= "?start=$start" if ($start > 0);
 
-    $script_date = (stat($argv0))[9];
+  my ( $base, $body ) = get_document ($last_search, undef, $timeout);
+  return () unless $body;
 
-    print "Blat: Foop\n";
+  $body =~ s/[\r\n]/ /gs;
+  $body =~ s/(<a)\b/\n$1/gsi;
 
-    if ($ENV{REQUEST_METHOD} &&
-        $ENV{REQUEST_METHOD} ne "GET" &&
-        $ENV{REQUEST_METHOD} ne "HEAD" ) {
-        print "Content-Type: text/html\n";
-        print "\n\n<TITLE>Error</TITLE>$body_tag<H1>Error</H1>";
-        $_ = $ENV{REQUEST_METHOD};
-        print "bad request method: <TT>$_</TT>\n";
-        exit (0);
+  my $count = 0;
+  my $count2 = 0;
+  foreach (split (/\n/, $body)) {
+    my ($page, $thumb) = m@<A \s [^<>]* \b HREF=\"([^<>\"]+)\" [^<>]* > \s*
+                           <IMG \s [^<>]* \b SRC=\"([^<>\"]+)\" @xsi;
+    next unless defined ($thumb);
+    $page = html_unquote ($page);
+    $thumb = html_unquote ($thumb);
 
-    } elsif ( $ENV{QUERY_STRING} ) {
-        if ( $ENV{QUERY_STRING} eq "reset" ) {
-            cgi_reset_all_files;
+    next unless ($thumb =~ m@^http://photos\d*\.flickr\.com/@);
 
-            print "Content-Type: text/html\n";
-            print "\n\n<TITLE>Collage Reset</TITLE>";
-            print "$body_tag<H1>Collage Reset</H1><P>\n";
-            exit (0);
+    my $base = "http://www.flickr.com/";
+    $page  =~ s@^/@$base@;
+    $thumb =~ s@^/@$base@;
 
-        } else {
-            print "Content-Type: text/html\n";
-            print "\n\n<TITLE>Error</TITLE>$body_tag<H1>Error</H1>";
-            $_ = $ENV{QUERY_STRING};
-            print "malformed URL: <TT>$_</TT>\n";
-            exit (0);
-        }
+    my $img = $thumb;
+    $img =~ s/_[a-z](\.[a-z\d]+)$/$1/si;  # take off "thumb" suffix
 
-    } elsif ( !$ENV{PATH_INFO} || $ENV{PATH_INFO} eq "" ) {
-        # don't allow /webcollage as a URL -- force it to be /webcollage/
-        print "Status: 301 Moved Permanently\n";
-        print "Location: http://" .
-            ($ENV{HTTP_HOST} ? $ENV{HTTP_HOST} : 
-             $ENV{SERVER_NAME} ? $ENV{SERVER_NAME} : "???") .
-            ($ENV{REQUEST_URI} ? $ENV{REQUEST_URI} : "") .
-                "/\n\n";
-        exit (0);
+    $count++;
+    next if ($flickr_cache{$img}); # already have it
 
-    } elsif ( $ENV{PATH_INFO} eq "/" ) {
-	cgi_emit_html_document;
+    my @pair = ($img, $page, $start);
+    LOG ($verbose_filter, "  candidate: $img");
+    push @flickr_cache, \@pair;
+    $flickr_cache{$img} = \@pair;
+    $count2++;
+  }
 
-    } elsif ( $ENV{PATH_INFO} =~ m@^/images/[^/]+\.jpg$@ ) {
-        cgi_emit_jpeg_document;
+  return () if ($#flickr_cache == -1);
 
-    } elsif ( $ENV{PATH_INFO} eq "/webcollage.pl" ) {
-        cgi_emit_source_document;
+  my $n = $#flickr_cache+1;
+  my $i = int(rand($n));
+  my ($img, $page) = @{$flickr_cache[$i]};
+
+  # delete this one from @flickr_cache and from %flickr_cache.
+  #
+  @flickr_cache = ( @flickr_cache[0 .. $i-1],
+                    @flickr_cache[$i+1 .. $#flickr_cache] );
+  delete $flickr_cache{$img};
+
+  # Keep the size of the cache under the limit by nuking older entries
+  #
+  while ($#flickr_cache >= $flickr_cache_size) {
+    my $pairP = shift @flickr_cache;
+    my $img = $pairP->[0];
+    delete $flickr_cache{$img};
+  }
+
+  LOG ($verbose_load, "picked image " .($i+1) . "/$n: $img");
+
+  return ($page, $img);
+}
+
+
+############################################################################
+#
+# Pick images from a random RSS feed on Flickr.
+#
+############################################################################
+
+my $flickr_rss_base = ("http://www.flickr.com/services/feeds/photos_public.gne" .
+                       "?format=rss_200_enc&tags=");
+
+# Picks a random RSS feed; picks a random image from that feed;
+# returns 2 URLs: the page containing the image, and the image.
+# Mostly by Joe Mcmahon <mcmahon@yahoo-inc.com>
+#
+# flickr_random
+sub pick_from_flickr_random($) {
+  my $timeout = shift;
+
+  my $rss = $flickr_rss_base . random_word();
+  $last_search = $rss;
+
+  print STDERR "\n\n" if ($verbose_load);
+  LOG ($verbose_load, "URL: $last_search");
+
+  $suppress_audit = 1;
+
+  my ( $base, $body ) = get_document ($last_search, undef, $timeout);
+  if (!$base || !$body) {
+    $body = undef;
+    return;
+  }
+
+  my $img;
+  ($base, $img) = pick_image_from_rss ($base, $body);
+  $body = undef;
+  return () unless defined ($img);
+
+  LOG ($verbose_load, "redirected to: $base");
+  return ($base, $img);
+}
+
+
+############################################################################
+#
+# Pick images by waiting for driftnet to populate a temp dir with files.
+# Requires driftnet version 0.1.5 or later.
+# (Driftnet is a program by Chris Lightfoot that sniffs your local ethernet
+# for images being downloaded by others.)
+# Driftnet/webcollage integration by jwz.
+#
+############################################################################
+
+# driftnet
+sub pick_from_driftnet($) {
+  my ($timeout) = @_;
+
+  my $id = $driftnet_magic;
+  my $dir = $driftnet_dir;
+  my $start = time;
+  my $now;
+
+  error ("\$driftnet_dir unset?") unless ($dir);
+  $dir =~ s@/+$@@;
+
+  error ("$dir unreadable") unless (-d "$dir/.");
+
+  $timeout = $http_timeout unless ($timeout);
+  $last_search = $id;
+
+  while ($now = time, $now < $start + $timeout) {
+    local *DIR;
+    opendir (DIR, $dir) || error ("$dir: $!");
+    while (my $file = readdir(DIR)) {
+      next if ($file =~ m/^\./);
+      $file = "$dir/$file";
+      closedir DIR;
+      LOG ($verbose_load, "picked file $file ($id)");
+      return ($id, $file);
+    }
+    closedir DIR;
+  }
+  LOG (($verbose_net || $verbose_load), "timed out for $id");
+  return ();
+}
+
+
+sub get_driftnet_file($) {
+  my ($file) = @_;
+
+  error ("\$driftnet_dir unset?") unless ($driftnet_dir);
+
+  my $id = $driftnet_magic;
+  my $re = qr/$driftnet_dir/;
+  error ("$id: $file not in $driftnet_dir?")
+    unless ($file =~ m@^$re@o);
+
+  local *IN;
+  open (IN, $file) || error ("$id: $file: $!");
+  my $body = '';
+  while (<IN>) { $body .= $_; }
+  close IN || error ("$id: $file: $!");
+  unlink ($file) || error ("$id: $file: rm: $!");
+  return ($id, $body);
+}
+
+
+sub spawn_driftnet($) {
+  my ($cmd) = @_;
+
+  # make a directory to use.
+  while (1) {
+    my $tmp = $ENV{TEMPDIR} || "/tmp";
+    $driftnet_dir = sprintf ("$tmp/driftcollage-%08x", rand(0xffffffff));
+    LOG ($verbose_exec, "mkdir $driftnet_dir");
+    last if mkdir ($driftnet_dir, 0700);
+  }
+
+  if (! ($cmd =~ m/\s/)) {
+    # if the command didn't have any arguments in it, then it must be just
+    # a pointer to the executable.  Append the default args to it.
+    my $dargs = $default_driftnet_cmd;
+    $dargs =~ s/^[^\s]+//;
+    $cmd .= $dargs;
+  }
+
+  # point the driftnet command at our newly-minted private directory.
+  #
+  $cmd .= " -d $driftnet_dir";
+  $cmd .= ">/dev/null" unless ($verbose_exec);
+
+  my $pid = fork();
+  if ($pid < 0) { error ("fork: $!\n"); }
+  if ($pid) {
+    # parent fork
+    push @pids_to_kill, $pid;
+    LOG ($verbose_exec, "forked for \"$cmd\"");
+  } else {
+    # child fork
+    nontrapping_system ($cmd) || error ("exec: $!");
+  }
+
+  # wait a bit, then make sure the process actually started up.
+  #
+  sleep (1);
+  error ("pid $pid failed to start \"$cmd\"")
+    unless (1 == kill (0, $pid));
+}
+
+# local-directory
+sub pick_from_local_dir {
+  my ( $timeout ) = @_;
+
+  my $id = $local_magic;
+  $last_search = $id;
+
+  my $dir = $local_dir;
+  error ("\$local_dir unset?") unless ($dir);
+  $dir =~ s@/+$@@;
+
+  error ("$dir unreadable") unless (-d "$dir/.");
+
+  my $v = ($verbose_exec ? "-v" : "");
+  my $pick = `xscreensaver-getimage-file $v "$dir"`;
+
+  LOG ($verbose_load, "picked file $pick ($id)");
+  return ($id, $pick);
+}
+
+
+sub get_local_file {
+  my ($file) = @_;
+
+  error ("\$local_dir unset?") unless ($local_dir);
+
+  my $id = $local_magic;
+  my $re = qr/$local_dir/;
+  error ("$id: $file not in $local_dir?")
+    unless ($file =~ m@^$re@o);
+
+  local *IN;
+  open (IN, $file) || error ("$id: $file: $!");
+  my $body = '';
+  while (<IN>) { $body .= $_; }
+  close IN || error ("$id: $file: $!");
+  return ($id, $body);
+}
+
+
+
+############################################################################
+#
+# Pick a random image in a random way
+#
+############################################################################
+
+
+# Picks a random image on a random page, and returns two URLs:
+# the page containing the image, and the image.
+# Returns () if nothing found this time.
+#
+
+sub pick_image(;$) {
+  my ($timeout) = @_;
+
+  $current_state = "select";
+  $load_method = "none";
+
+  my $n = int(rand(100));
+  my $fn = undef;
+  my $total = 0;
+  my @rest = @search_methods;
+
+  while (@rest) {
+    my $pct  = shift @rest;
+    my $name = shift @rest;
+    my $tfn  = shift @rest;
+    $total += $pct;
+    if ($total > $n && !defined($fn)) {
+      $fn = $tfn;
+      $current_state = $name;
+      $load_method = $current_state;
+    }
+  }
+
+  if ($total != 100) {
+    error ("internal error: \@search_methods totals to $total%!");
+  }
+
+  record_attempt ($current_state);
+  return $fn->($timeout);
+}
+
+
+
+############################################################################
+#
+# Statistics and logging
+#
+############################################################################
+
+sub timestr() {
+  return strftime ("%H:%M:%S: ", localtime);
+}
+
+sub blurb() {
+  return "$progname: " . timestr() . "$current_state: ";
+}
+
+sub error($) {
+  my ($err) = @_;
+  print STDERR blurb() . "$err\n";
+  exit 1;
+}
+
+sub stacktrace() {
+  my $i = 1;
+  print STDERR "$progname: stack trace:\n";
+  while (1) {
+    my ($package, $filename, $line, $subroutine) = caller($i++);
+    last unless defined($package);
+    $filename =~ s@^.*/@@;
+    print STDERR "  $filename#$line, $subroutine\n";
+  }
+}
+
+
+my $lastlog = "";
+
+sub clearlog() {
+  $lastlog = "";
+}
+
+sub showlog() {
+  my $head = "$progname: DEBUG: ";
+  foreach (split (/\n/, $lastlog)) {
+    print STDERR "$head$_\n";
+  }
+  $lastlog = "";
+}
+
+sub LOG($$) {
+  my ($print, $msg) = @_;
+  my $blurb = timestr() . "$current_state: ";
+  $lastlog .= "$blurb$msg\n";
+  print STDERR "$progname: $blurb$msg\n" if $print;
+}
+
+
+my %stats_attempts;
+my %stats_successes;
+my %stats_elapsed;
+
+my $last_state = undef;
+sub record_attempt($) {
+  my ($name) = @_;
+
+  if ($last_state) {
+    record_failure($last_state) unless ($image_succeeded > 0);
+  }
+  $last_state = $name;
+
+  clearlog();
+  report_performance();
+
+  start_timer($name);
+  $image_succeeded = 0;
+  $suppress_audit = 0;
+}
+
+sub record_success($$$) {
+  my ($name, $url, $base) = @_;
+  if (defined($stats_successes{$name})) {
+    $stats_successes{$name}++;
+  } else {
+    $stats_successes{$name} = 1;
+  }
+
+  stop_timer ($name, 1);
+  my $o = $current_state;
+  $current_state = $name;
+  save_recent_url ($url, $base);
+  $current_state = $o;
+  $image_succeeded = 1;
+  clearlog();
+}
+
+
+sub record_failure($) {
+  my ($name) = @_;
+
+  return if $image_succeeded;
+
+  stop_timer ($name, 0);
+  if ($verbose_load && !$verbose_exec) {
+
+    if ($suppress_audit) {
+      print STDERR "$progname: " . timestr() . "(audit log suppressed)\n";
+      return;
+    }
+
+    my $o = $current_state;
+    $current_state = "DEBUG";
+
+    my $line =  "#" x 78;
+    print STDERR "\n\n\n";
+    print STDERR ("#" x 78) . "\n";
+    print STDERR blurb() . "failed to get an image.  Full audit log:\n";
+    print STDERR "\n";
+    showlog();
+    print STDERR ("-" x 78) . "\n";
+    print STDERR "\n\n";
+
+    $current_state = $o;
+  }
+  $image_succeeded = 0;
+}
+
+
+
+sub stats_of($) {
+  my ($name) = @_;
+  my $i = $stats_successes{$name};
+  my $j = $stats_attempts{$name};
+  $i = 0 unless $i;
+  $j = 0 unless $j;
+  return "" . ($j ? int($i * 100 / $j) : "0") . "%";
+}
+
+
+my $current_start_time = 0;
+
+sub start_timer($) {
+  my ($name) = @_;
+  $current_start_time = time;
+
+  if (defined($stats_attempts{$name})) {
+    $stats_attempts{$name}++;
+  } else {
+    $stats_attempts{$name} = 1;
+  }
+  if (!defined($stats_elapsed{$name})) {
+    $stats_elapsed{$name} = 0;
+  }
+}
+
+sub stop_timer($$) {
+  my ($name, $success) = @_;
+  $stats_elapsed{$name} += time - $current_start_time;
+}
+
+
+my $last_report_time = 0;
+sub report_performance() {
+
+  return unless $verbose_warnings;
+
+  my $now = time;
+  return unless ($now >= $last_report_time + $report_performance_interval);
+  my $ot = $last_report_time;
+  $last_report_time = $now;
+
+  return if ($ot == 0);
+
+  my $blurb = "$progname: " . timestr();
+
+  print STDERR "\n";
+  print STDERR "${blurb}Current standings:\n";
+
+  foreach my $name (sort keys (%stats_attempts)) {
+    my $try = $stats_attempts{$name};
+    my $suc = $stats_successes{$name} || 0;
+    my $pct = int($suc * 100 / $try);
+    my $secs = $stats_elapsed{$name};
+    my $secs_link = int($secs / $try);
+    print STDERR sprintf ("$blurb   %-12s %4s (%d/%d);\t %2d secs/link\n",
+                          "$name:", "$pct%", $suc, $try, $secs_link);
+  }
+}
+
+
+
+my $max_recent_images = 400;
+my $max_recent_sites  = 20;
+my @recent_images = ();
+my @recent_sites = ();
+
+sub save_recent_url($$) {
+  my ($url, $base) = @_;
+
+  return unless ($verbose_warnings);
+
+  $_ = $url;
+  my ($site) = m@^http://([^ \t\n\r/:]+)@;
+  return unless defined ($site);
+
+  if ($base eq $driftnet_magic || $base eq $local_magic) {
+    $site = $base;
+    @recent_images = ();
+  }
+
+  my $done = 0;
+  foreach (@recent_images) {
+    if ($_ eq $url) {
+      print STDERR blurb() . "WARNING: recently-duplicated image: $url" .
+        " (on $base via $last_search)\n";
+      $done = 1;
+      last;
+    }
+  }
+
+  # suppress "duplicate site" warning via %warningless_sites.
+  #
+  if ($warningless_sites{$site}) {
+    $done = 1;
+  } elsif ($site =~ m@([^.]+\.[^.]+\.[^.]+)$@ &&
+           $warningless_sites{$1}) {
+    $done = 1;
+  } elsif ($site =~ m@([^.]+\.[^.]+)$@ &&
+           $warningless_sites{$1}) {
+    $done = 1;
+  }
+
+  if (!$done) {
+    foreach (@recent_sites) {
+      if ($_ eq $site) {
+        print STDERR blurb() . "WARNING: recently-duplicated site: $site" .
+        " ($url on $base via $last_search)\n";
+        last;
+      }
+    }
+  }
+
+  push @recent_images, $url;
+  push @recent_sites,  $site;
+  shift @recent_images if ($#recent_images >= $max_recent_images);
+  shift @recent_sites  if ($#recent_sites  >= $max_recent_sites);
+}
+
+
+
+##############################################################################
+#
+# other utilities
+#
+##############################################################################
+
+# Does %-decoding.
+#
+sub url_decode($) {
+  ($_) = @_;
+  tr/+/ /;
+  s/%([a-fA-F0-9][a-fA-F0-9])/pack("C", hex($1))/eg;
+  return $_;
+}
+
+
+# Given the raw body of a GIF document, returns the dimensions of the image.
+#
+sub gif_size($) {
+  my ($body) = @_;
+  my $type = substr($body, 0, 6);
+  my $s;
+  return () unless ($type =~ /GIF8[7,9]a/);
+  $s = substr ($body, 6, 10);
+  my ($a,$b,$c,$d) = unpack ("C"x4, $s);
+  return () unless defined ($d);
+  return (($b<<8|$a), ($d<<8|$c));
+}
+
+# Given the raw body of a JPEG document, returns the dimensions of the image.
+#
+sub jpeg_size($) {
+  my ($body) = @_;
+  my $i = 0;
+  my $L = length($body);
+
+  my $c1 = substr($body, $i, 1); $i++;
+  my $c2 = substr($body, $i, 1); $i++;
+  return () unless (ord($c1) == 0xFF && ord($c2) == 0xD8);
+
+  my $ch = "0";
+  while (ord($ch) != 0xDA && $i < $L) {
+    # Find next marker, beginning with 0xFF.
+    while (ord($ch) != 0xFF) {
+      return () if (length($body) <= $i);
+      $ch = substr($body, $i, 1); $i++;
+    }
+    # markers can be padded with any number of 0xFF.
+    while (ord($ch) == 0xFF) {
+      return () if (length($body) <= $i);
+      $ch = substr($body, $i, 1); $i++;
+    }
+
+    # $ch contains the value of the marker.
+    my $marker = ord($ch);
+
+    if (($marker >= 0xC0) &&
+        ($marker <= 0xCF) &&
+        ($marker != 0xC4) &&
+        ($marker != 0xCC)) {  # it's a SOFn marker
+      $i += 3;
+      return () if (length($body) <= $i);
+      my $s = substr($body, $i, 4); $i += 4;
+      my ($a,$b,$c,$d) = unpack("C"x4, $s);
+      return (($c<<8|$d), ($a<<8|$b));
 
     } else {
-        print "Content-Type: text/html\n";
-        print "\n\n<TITLE>Error</TITLE>$body_tag<H1>Error</H1>";
-        $_ = $ENV{PATH_INFO};
-        print "malformed URL: <TT>$_</TT>\n";
-        exit (0);
+      # We must skip variables, since FFs in variable names aren't
+      # valid JPEG markers.
+      return () if (length($body) <= $i);
+      my $s = substr($body, $i, 2); $i += 2;
+      my ($c1, $c2) = unpack ("C"x2, $s);
+      my $length = ($c1 << 8) | $c2;
+      return () if ($length < 2);
+      $i += $length-2;
+    }
+  }
+  return ();
+}
+
+# Given the raw body of a PNG document, returns the dimensions of the image.
+#
+sub png_size($) {
+  my ($body) = @_;
+  return () unless ($body =~ m/^\211PNG\r/);
+  my ($bits) = ($body =~ m/^.{12}(.{12})/s);
+  return () unless defined ($bits);
+  return () unless ($bits =~ /^IHDR/);
+  my ($ign, $w, $h) = unpack("a4N2", $bits);
+  return ($w, $h);
+}
+
+
+# Given the raw body of a GIF, JPEG, or PNG document, returns the dimensions
+# of the image.
+#
+sub image_size($) {
+  my ($body) = @_;
+  my ($w, $h) = gif_size ($body);
+  if ($w && $h) { return ($w, $h); }
+  ($w, $h) = jpeg_size ($body);
+  if ($w && $h) { return ($w, $h); }
+  return png_size ($body);
+}
+
+
+# returns the full path of the named program, or undef.
+#
+sub which($) {
+  my ($prog) = @_;
+  foreach (split (/:/, $ENV{PATH})) {
+    if (-x "$_/$prog") {
+      return $prog;
     }
+  }
+  return undef;
+}
+
+
+# Like rand(), but chooses numbers with a bell curve distribution.
+sub bellrand(;$) {
+  ($_) = @_;
+  $_ = 1.0 unless defined($_);
+  $_ /= 3.0;
+  return (rand($_) + rand($_) + rand($_));
+}
+
+
+sub exit_cleanup() {
+  x_cleanup();
+  print STDERR "$progname: exiting\n" if ($verbose_warnings);
+  if (@pids_to_kill) {
+    print STDERR blurb() . "killing: " . join(' ', @pids_to_kill) . "\n";
+    kill ('TERM', @pids_to_kill);
+  }
+}
+
+sub signal_cleanup($) {
+  my ($sig) = @_;
+  print STDERR blurb() . (defined($sig)
+                          ? "caught signal $sig."
+                          : "exiting.")
+                       . "\n"
+    if ($verbose_exec || $verbose_warnings);
+  exit 1;
 }
 
 
+
 ##############################################################################
 #
 # Generating a list of urls only
 #
 ##############################################################################
 
-sub url_only_output {
-    $| = 1;
-    do {
-        my ($base, $img) = pick_image;
-        if ($img) {
-            $base =~ s/ /%20/g;
-            $img  =~ s/ /%20/g;
-            print "$img $base\n";
-        }
-    } while (1);
+sub url_only_output() {
+  do {
+    my ($base, $img) = pick_image;
+    if ($img) {
+      $base =~ s/ /%20/g;
+      $img  =~ s/ /%20/g;
+      print "$img $base\n";
+    }
+  } while (1);
 }
 
 ##############################################################################
 #
-# Running as an xscreensaver module
+# Running as an xscreensaver module, or as a web page imagemap
 #
 ##############################################################################
 
-my $image_tmp2;
-my $image_tmp3;
+my $image_ppm   = sprintf ("%s/webcollage-%08x",
+                           ($ENV{TMPDIR} ? $ENV{TMPDIR} : "/tmp"),
+                           rand(0xFFFFFFFF));
+my $image_tmp1  = sprintf ("%s/webcollage-1-%08x",
+                           ($ENV{TMPDIR} ? $ENV{TMPDIR} : "/tmp"),
+                           rand(0xFFFFFFFF));
+my $image_tmp2  = sprintf ("%s/webcollage-2-%08x",
+                           ($ENV{TMPDIR} ? $ENV{TMPDIR} : "/tmp"),
+                           rand(0xFFFFFFFF));
 
-sub x_cleanup {
-    if ($DEBUG > 0) { print STDERR "caught signal\n"; }
-    unlink $image_ppm, $image_tmp, $image_tmp2, $image_tmp3;
-    exit 1;
+my $filter_cmd = undef;
+my $post_filter_cmd = undef;
+my $background = undef;
+
+my @imagemap_areas = ();
+my $imagemap_html_tmp = undef;
+my $imagemap_jpg_tmp = undef;
+
+
+my $img_width;            # size of the image being generated.
+my $img_height;
+
+my $delay = 2;
+
+sub x_cleanup() {
+  unlink $image_ppm, $image_tmp1, $image_tmp2;
+  unlink $imagemap_html_tmp, $imagemap_jpg_tmp
+    if (defined ($imagemap_html_tmp));
 }
 
 
-sub x_output {
+# Like system, but prints status about exit codes, and kills this process
+# with whatever signal killed the sub-process, if any.
+#
+sub nontrapping_system(@) {
+  $! = 0;
+
+  $_ = join(" ", @_);
+  s/\"[^\"]+\"/\"...\"/g;
 
-    my $win_cmd = $ppm_to_root_window_cmd;
-    $win_cmd =~ s/^([^ \t\r\n]+).*$/$1/;
+  LOG ($verbose_exec, "executing \"$_\"");
 
-    # make sure the various programs we execute exist, right up front.
-    foreach ("ppmmake", "giftopnm", "djpeg", "pnmpaste", "pnmscale",
-             $win_cmd) {
-        which ($_) || die "$progname: $_ not found on \$PATH.\n";
+  my $rc = system @_;
+
+  if ($rc == 0) {
+    LOG ($verbose_exec, "subproc exited normally.");
+  } elsif (($rc & 0xff) == 0) {
+    $rc >>= 8;
+    LOG ($verbose_exec, "subproc exited with status $rc.");
+  } else {
+    if ($rc & 0x80) {
+      LOG ($verbose_exec, "subproc dumped core.");
+      $rc &= ~0x80;
     }
+    LOG ($verbose_exec, "subproc died with signal $rc.");
+    # die that way ourselves.
+    kill $rc, $$;
+  }
+
+  return $rc;
+}
 
-    $SIG{HUP}  = \&x_cleanup;
-    $SIG{INT}  = \&x_cleanup;
-    $SIG{QUIT} = \&x_cleanup;
-    $SIG{ABRT} = \&x_cleanup;
-    $SIG{KILL} = \&x_cleanup;
-    $SIG{TERM} = \&x_cleanup;
-
-    # Need this so that if giftopnm dies, we don't die.
-    $SIG{PIPE} = 'IGNORE';
-
-    if (!$img_width || !$img_height) {
-        $_ = "xdpyinfo";
-        which ($_) || die "$progname: $_ not found on \$PATH.\n";
-        $_ = `$_`;
-        ($img_width, $img_height) = m/dimensions: *([0-9]+)x([0-9]+) /;
+
+# Given the URL of a GIF, JPEG, or PNG image, and the body of that image,
+# writes a PPM to the given output file.  Returns the width/height of the
+# image if successful.
+#
+sub image_to_pnm($$$) {
+  my ($url, $body, $output) = @_;
+  my ($cmd, $cmd2, $w, $h);
+
+  if ((@_ = gif_size ($body))) {
+    ($w, $h) = @_;
+    $cmd = "giftopnm";
+  } elsif ((@_ = jpeg_size ($body))) {
+    ($w, $h) = @_;
+    $cmd = "djpeg";
+  } elsif ((@_ = png_size ($body))) {
+    ($w, $h) = @_;
+    $cmd = "pngtopnm";
+  } else {
+    LOG (($verbose_pbm || $verbose_load),
+         "not a GIF, JPG, or PNG" .
+         (($body =~ m@<(base|html|head|body|script|table|a href)\b@i)
+          ? " (looks like HTML)" : "") .
+         ": $url");
+    $suppress_audit = 1;
+    return ();
+  }
+
+  $cmd2 = "exec $cmd";        # yes, this really is necessary.  if we don't
+                              # do this, the process doesn't die properly.
+  if (!$verbose_pbm) {
+    #
+    # We get a "giftopnm: got a 'Application Extension' extension"
+    # warning any time it's an animgif.
+    #
+    # Note that "giftopnm: EOF / read error on image data" is not
+    # always a fatal error -- sometimes the image looks fine anyway.
+    #
+    $cmd2 .= " 2>/dev/null";
+  }
+
+  # There exist corrupted GIF and JPEG files that can make giftopnm and
+  # djpeg lose their minds and go into a loop.  So this gives those programs
+  # a small timeout -- if they don't complete in time, kill them.
+  #
+  my $pid;
+  @_ = eval {
+    my $timed_out;
+
+    local $SIG{ALRM}  = sub {
+      LOG ($verbose_pbm,
+           "timed out ($cvt_timeout) for $cmd on \"$url\" in pid $pid");
+      kill ('TERM', $pid) if ($pid);
+      $timed_out = 1;
+      $body = undef;
+    };
+
+    if (($pid = open(PIPE, "| $cmd2 > $output"))) {
+      $timed_out = 0;
+      alarm $cvt_timeout;
+      print PIPE $body;
+      $body = undef;
+      close PIPE;
+
+      LOG ($verbose_exec, "awaiting $pid");
+      waitpid ($pid, 0);
+      LOG ($verbose_exec, "$pid completed");
+
+      my $size = (stat($output))[7];
+      $size = -1 unless defined($size);
+      if ($size < 5) {
+        LOG ($verbose_pbm, "$cmd on ${w}x$h \"$url\" failed ($size bytes)");
+        return ();
+      }
+
+      LOG ($verbose_pbm, "created ${w}x$h $output ($cmd)");
+      return ($w, $h);
+    } else {
+      print STDERR blurb() . "$cmd failed: $!\n";
+      return ();
     }
+  };
+  die if ($@ && $@ ne "alarm\n");       # propagate errors
+  if ($@) {
+    # timed out
+    $body = undef;
+    return ();
+  } else {
+    # didn't
+    alarm 0;
+    $body = undef;
+    return @_;
+  }
+}
 
-    my $bgcolor = "#000000";
-    my $bgimage = undef;
-
-    if ($background) {
-        if ($background =~ m/^\#[0-9a-f]+$/i) {
-            $bgcolor = $background;
-        } elsif (-r $background) {
-            $bgimage = $background;
-            
-        } elsif (! $background =~ m@^[-a-z0-9 ]+$@i) {
-            print STDERR "not a color or readable file: $background\n";
-            exit 1;
-        } else {
-            # default to assuming it's a color
-            $bgcolor = $background;
-        }
+
+# Same as the "ppmmake" command: creates a solid-colored PPM.
+# Does not understand the rgb.txt color names except "black" and "white".
+#
+sub ppmmake($$$$) {
+  my ($outfile, $bgcolor, $w, $h) = @_;
+
+  my ($r, $g, $b);
+  if ($bgcolor =~ m/^\#?([\dA-F][\dA-F])([\dA-F][\dA-F])([\dA-F][\dA-F])$/i ||
+      $bgcolor =~ m/^\#?([\dA-F])([\dA-F])([\dA-F])$/i) {
+    ($r, $g, $b) = (hex($1), hex($2), hex($3));
+  } elsif ($bgcolor =~ m/^black$/i) {
+    ($r, $g, $b) = (0, 0, 0);
+  } elsif ($bgcolor =~ m/^white$/i) {
+    ($r, $g, $b) = (0xFF, 0xFF, 0xFF);
+  } else {
+    error ("unparsable color name: $bgcolor");
+  }
+
+  my $pixel = pack('CCC', $r, $g, $b);
+  my $bits = "P6\n$w $h\n255\n" . ($pixel x ($w * $h));
+
+  local *OUT;
+  open (OUT, ">$outfile") || error ("$outfile: $!");
+  print OUT $bits;
+  close OUT;
+}
+
+
+sub pick_root_displayer() {
+  my @names = ();
+
+  if ($cocoa_p) {
+    # see "xscreensaver/hacks/webcollage-cocoa.m"
+    return "echo COCOA LOAD ";
+  }
+
+  foreach my $cmd (@root_displayers) {
+    $_ = $cmd;
+    my ($name) = m/^([^ ]+)/;
+    push @names, "\"$name\"";
+    LOG ($verbose_exec, "looking for $name...");
+    foreach my $dir (split (/:/, $ENV{PATH})) {
+      LOG ($verbose_exec, "  checking $dir/$name");
+      return $cmd if (-x "$dir/$name");
     }
+  }
 
-    # Create the sold-colored base image.
-    #
-    $_ = "ppmmake '$bgcolor' $img_width $img_height";
-    if ($DEBUG > 1) {
-        print STDERR "creating base image: $_\n";
+  $names[$#names] = "or " . $names[$#names];
+  error "none of: " . join (", ", @names) . " were found on \$PATH.";
+}
+
+
+my $ppm_to_root_window_cmd = undef;
+
+
+sub x_or_pbm_output($) {
+  my ($window_id) = @_;
+
+  # Check for our helper program, to see whether we need to use PPM pipelines.
+  #
+  $_ = "webcollage-helper";
+  if (defined ($webcollage_helper) || which ($_)) {
+    $webcollage_helper = $_ unless (defined($webcollage_helper));
+    LOG ($verbose_pbm, "found \"$webcollage_helper\"");
+    $webcollage_helper .= " -v";
+  } else {
+    LOG (($verbose_pbm || $verbose_load), "no $_ program");
+  }
+
+  if ($cocoa_p && !defined ($webcollage_helper)) {
+    error ("webcollage-helper not found in Cocoa-mode!");
+  }
+
+
+  # make sure the various programs we execute exist, right up front.
+  #
+  my @progs = ();
+
+  if (!defined($webcollage_helper)) {
+    # Only need these others if we don't have the helper.
+    @progs = (@progs,
+              "giftopnm", "pngtopnm", "djpeg",
+              "pnmpaste", "pnmscale", "pnmcut");
+  }
+
+  foreach (@progs) {
+    which ($_) || error "$_ not found on \$PATH.";
+  }
+
+  # find a root-window displayer program.
+  #
+  $ppm_to_root_window_cmd = pick_root_displayer();
+
+  if (defined ($window_id)) {
+    error ("-window-id only works if xscreensaver-getimage is installed")
+      unless ($ppm_to_root_window_cmd =~ m/^xscreensaver-getimage\b/);
+
+    error ("unparsable window id: $window_id")
+      unless ($window_id =~ m/^\d+$|^0x[\da-f]+$/i);
+    $ppm_to_root_window_cmd =~ s/--?root\b/$window_id/ ||
+      error ("unable to munge displayer: $ppm_to_root_window_cmd");
+  }
+
+  if (!$img_width || !$img_height) {
+
+    if (!defined ($window_id) &&
+        defined ($ENV{XSCREENSAVER_WINDOW})) {
+      $window_id = $ENV{XSCREENSAVER_WINDOW};
     }
-    system "$_ > $image_ppm";
 
-    # Paste the default background image in the middle of it.
-    #
-    if ($bgimage) {
-        my ($iw, $ih);
-        if (open(IMG, "<$bgimage")) {
-            $_ = <IMG>;
-            $_ = <IMG>;
-            ($iw, $ih) = m/^([0-9]+) ([0-9]+)$/;
-            close (IMG);
-        }
-        my $x = int (($img_width - $iw) / 2);
-        my $y = int (($img_height - $ih) / 2);
-        if ($DEBUG > 1) {
-            print STDERR "pasting $bgimage into base image at $x, $y\n";
-        }
-        system "pnmpaste $bgimage $x $y $image_ppm > $image_tmp2" .
-            " && mv $image_tmp2 $image_ppm";
+    if (!defined ($window_id)) {
+      $_ = "xdpyinfo";
+      which ($_) || error "$_ not found on \$PATH.";
+      $_ = `$_`;
+      ($img_width, $img_height) = m/dimensions: *(\d+)x(\d+) /;
+      if (!defined($img_height)) {
+        error "xdpyinfo failed.";
+      }
+    } else {  # we have a window id
+      $_ = "xwininfo";
+      which ($_) || error "$_ not found on \$PATH.";
+      $_ .= " -id $window_id";
+      $_ = `$_`;
+      ($img_width, $img_height) = m/^\s*Width:\s*(\d+)\n\s*Height:\s*(\d+)\n/m;
+
+      if (!defined($img_height)) {
+        error "xwininfo failed.";
+      }
     }
+  }
 
+  my $bgcolor = "#000000";
+  my $bgimage = undef;
 
-    do {
-        my ($base, $img) = pick_image;
+  if ($background) {
+    if ($background =~ m/^\#[0-9a-f]+$/i) {
+      $bgcolor = $background;
 
-        my ($headers, $body);
-        if ($img) {
-            ($headers, $body) = get_document ($img, $base);
-        }
+    } elsif (-r $background) {
+      $bgimage = $background;
 
-        if ($body) {
-
-            if ($DEBUG > 0) {
-                print STDERR "got $img (" . length($body) . ")\n";
-            }
-
-            my $cmd;
-            if ($img =~ m/\.gif/i) {
-                $cmd = "giftopnm";
-            } else {
-                $cmd = "djpeg";
-            }
-
-            if ($DEBUG == 0) {
-                $cmd .= " 2>/dev/null";
-            }
-
-            if (open(PIPE, "| $cmd > $image_tmp")) {
-                print PIPE $body;
-                close PIPE;
-
-                if ($DEBUG > 1) {
-                    print STDERR "created $image_tmp ($cmd)\n";
-                }
-            }
-
-            if (-s $image_tmp) {
-
-                if ($filter_cmd) {
-                    if ($DEBUG > 1) {
-                        print STDERR "running $filter_cmd\n";
-                    }
-                    system "($filter_cmd) < $image_tmp > $image_tmp3" .
-                        " && mv $image_tmp3 $image_tmp";
-                }
-
-                my ($iw, $ih);
-                if (open(IMG, "<$image_tmp")) {
-                    $_ = <IMG>;
-                    $_ = <IMG>;
-                    ($iw, $ih) = m/^([0-9]+) ([0-9]+)$/;
-                    close (IMG);
-                }
-
-                if ($iw && $ih) {
-
-                    if ($DEBUG > 1) {
-                        print STDERR "image size is $iw x $ih\n";
-                    }
-
-                    if ($iw > $img_width || $ih > $img_height) {
-                        while ($iw > $img_width ||
-                               $ih > $img_height) {
-                            $iw = int($iw / 2);
-                            $ih = int($ih / 2);
-                        }
-                        if ($DEBUG > 1) {
-                            print STDERR "scaling to $iw x $ih\n";
-                        }
-                        system "pnmscale -xysize $iw $ih $image_tmp" .
-                            " > $image_tmp2" .
-                            " 2>/dev/null && mv $image_tmp2 $image_tmp";
-                    }
-
-                    my $x = int (rand() * ($img_width - $iw));
-                    my $y = int (rand() * ($img_height - $ih));
-
-                    if ($DEBUG > 1) {
-                        print STDERR "pasting at $x, $y in $image_ppm\n";
-                    }
-
-                    system "pnmpaste $image_tmp $x $y $image_ppm" .
-                        " > $image_tmp2" .
-                        " && mv $image_tmp2 $image_ppm";
-
-
-                    my $target = $image_ppm;
-                    if ($post_filter_cmd) {
-                        if ($DEBUG > 1) {
-                            print STDERR "running $post_filter_cmd\n";
-                        }
-                        system "($post_filter_cmd) < $image_ppm > $image_tmp3";
-                        $target = $image_tmp3;
-                    }
-
-                    if (!$no_output_p) {
-
-                        my $tsize = (stat($target))[7];
-                        if ($tsize > 200) {
-                            $_ = $ppm_to_root_window_cmd;
-                            s/%%PPM%%/$target/;
-
-                            if ($DEBUG > 1) {
-                                print STDERR "running $_\n";
-                            }
-                            system $_;
-
-                        } elsif ($DEBUG > 1) {
-                            print STDERR "$target size is $tsize\n";
-                        }
-                    }
-                }
-            }
-            unlink $image_tmp, $image_tmp2, $image_tmp3;
-        }
+    } elsif (! $background =~ m@^[-a-z0-9 ]+$@i) {
+      error "not a color or readable file: $background";
+
+    } else {
+      # default to assuming it's a color
+      $bgcolor = $background;
+    }
+  }
+
+  # Create the sold-colored base image.
+  #
+  LOG ($verbose_pbm, "creating base image: ${img_width}x${img_height}");
+  $_ = ppmmake ($image_ppm, $bgcolor, $img_width, $img_height);
 
-        sleep $delay;
+  # Paste the default background image in the middle of it.
+  #
+  if ($bgimage) {
+    my ($iw, $ih);
 
-    } while (1);
+    my $body = "";
+    local *IMG;
+    open(IMG, "<$bgimage") || error "couldn't open $bgimage: $!";
+    my $cmd;
+    while (<IMG>) { $body .= $_; }
+    close (IMG);
+
+    if ((@_ = gif_size ($body))) {
+      ($iw, $ih) = @_;
+      $cmd = "giftopnm |";
+
+    } elsif ((@_ = jpeg_size ($body))) {
+      ($iw, $ih) = @_;
+      $cmd = "djpeg |";
+
+    } elsif ((@_ = png_size ($body))) {
+      ($iw, $ih) = @_;
+      $cmd = "pngtopnm |";
+
+    } elsif ($body =~ m/^P\d\n(\d+) (\d+)\n/) {
+      $iw = $1;
+      $ih = $2;
+      $cmd = "";
+
+    } else {
+      error "$bgimage is not a GIF, JPEG, PNG, or PPM.";
+    }
+
+    my $x = int (($img_width  - $iw) / 2);
+    my $y = int (($img_height - $ih) / 2);
+    LOG ($verbose_pbm,
+         "pasting $bgimage (${iw}x$ih) into base image at $x,$y");
+
+    $cmd .= "pnmpaste - $x $y $image_ppm > $image_tmp1";
+    open (IMG, "| $cmd") || error "running $cmd: $!";
+    print IMG $body;
+    $body = undef;
+    close (IMG);
+    LOG ($verbose_exec, "subproc exited normally.");
+    rename ($image_tmp1, $image_ppm) ||
+      error "renaming $image_tmp1 to $image_ppm: $!";
+  }
+
+  clearlog();
+
+  while (1) {
+    my ($base, $img) = pick_image();
+    my $source = $current_state;
+    $current_state = "loadimage";
+    if ($img) {
+      my ($headers, $body) = get_document ($img, $base);
+      if ($body) {
+        paste_image ($base, $img, $body, $source);
+        $body = undef;
+      }
+    }
+    $current_state = "idle";
+    $load_method = "none";
+
+    unlink $image_tmp1, $image_tmp2;
+    sleep $delay;
+  }
 }
 
+sub paste_image($$$$) {
+  my ($base, $img, $body, $source) = @_;
 
-sub x_main {
+  $current_state = "paste";
 
-    # Unlike CGI, when running in X mode, the various tmp files should be
-    # in the /tmp directory and should have gensymed names.
-    #
-    $image_ppm = ($ENV{TMPDIR} ? $ENV{TMPDIR} : "/tmp") . "/webcollage." . $$;
-    $image_tmp   = $image_ppm . "-1";
-    $image_tmp2  = $image_ppm . "-2";
-    $image_tmp3  = $image_ppm . "-3";
+  $suppress_audit = 0;
 
-    # In X mode, these aren't used.  Set them to undef to error if we try.
-    #
-    $data_dir = undef;
-    $image_jpg = undef;
-    $pending_file = undef;
-    $map_file = undef;
-    $url_generation_time = undef;
-    $image_retrieval_time = undef;
-    $max_map_entries = undef;
-    $pastes_per_load = undef;
-    $max_age = undef;
-    $script_date = undef;
-    @all_files = undef;
-
-    # In X mode, these come either from the command line, or from the X server.
-    $img_width = undef;
-    $img_height = undef;
-
-
-    my $root_p = 0;
-
-    while ($_ = $ARGV[0]) {
-        shift @ARGV;
-        if ($_ eq "-display" ||
-            $_ eq "-displ" ||
-            $_ eq "-disp" ||
-            $_ eq "-dis" ||
-            $_ eq "-dpy" ||
-            $_ eq "-d") {
-            $ENV{DISPLAY} = shift @ARGV;
-        } elsif ($_ eq "-root") {
-            $root_p = 1;
-        } elsif ($_ eq "-no-output") {
-            $no_output_p = 1;
-        } elsif ($_ eq "-urls-only") {
-            $urls_only_p = 1;
-            $no_output_p = 1;
-        } elsif ($_ eq "-verbose") {
-            $DEBUG++;
-        } elsif (m/^-v+$/) {
-            $DEBUG += length($_)-1;
-        } elsif ($_ eq "-delay") {
-            $delay = shift @ARGV;
-        } elsif ($_ eq "-timeout") {
-            $http_timeout = shift @ARGV;
-        } elsif ($_ eq "-filter") {
-            $filter_cmd = shift @ARGV;
-        } elsif ($_ eq "-filter2") {
-            $post_filter_cmd = shift @ARGV;
-        } elsif ($_ eq "-background" || $_ eq "-bg") {
-            $background = shift @ARGV;
-        } elsif ($_ eq "-size") {
-            $_ = shift @ARGV;
-            if (m@^([0-9]+)x([0-9]+)$@) {
-                $img_width = $1;
-                $img_height = $2;
-            } else {
-                die "$progname: argument to \"-size\" must be" .
-                    " of the form \"640x400\"\n";
-            }
-        } else {
-            die "$copyright\nusage: $progname [-root]" .
-                " [-display dpy] [-root] [-verbose] [-timeout secs]\n" .
-                "\t\t  [-delay secs] [-filter cmd] [-filter2 cmd]\n";
-        }
+  LOG ($verbose_pbm, "got $img (" . length($body) . ")");
+
+  my ($iw, $ih);
+
+  # If we are using the webcollage-helper, then we do not need to convert this
+  # image to a PPM.  But, if we're using a filter command, we still must, since
+  # that's what the filters expect (webcollage-helper can read PPMs, so that's
+  # fine.)
+  #
+  if (defined ($webcollage_helper) &&
+      !defined ($filter_cmd)) {
+
+    ($iw, $ih) = image_size ($body);
+    if (!$iw || !$ih) {
+      LOG (($verbose_pbm || $verbose_load),
+           "not a GIF, JPG, or PNG" .
+           (($body =~ m@<(base|html|head|body|script|table|a href)>@i)
+            ? " (looks like HTML)" : "") .
+           ": $img");
+      $suppress_audit = 1;
+      $body = undef;
+      return 0;
+    }
+
+    local *OUT;
+    open (OUT, ">$image_tmp1") || error ("writing $image_tmp1: $!");
+    print OUT $body || error ("writing $image_tmp1: $!");
+    close OUT || error ("writing $image_tmp1: $!");
+
+  } else {
+    ($iw, $ih) = image_to_pnm ($img, $body, $image_tmp1);
+    $body = undef;
+    if (!$iw || !$ih) {
+      LOG ($verbose_pbm, "unable to make PBM from $img");
+      return 0;
+    }
+  }
+
+  record_success ($load_method, $img, $base);
+
+
+  my $ow = $iw;  # used only for error messages
+  my $oh = $ih;
+
+  # don't just tack this onto the front of the pipeline -- we want it to
+  # be able to change the size of the input image.
+  #
+  if ($filter_cmd) {
+    LOG ($verbose_pbm, "running $filter_cmd");
+
+    my $rc = nontrapping_system "($filter_cmd) < $image_tmp1 >$image_tmp2";
+    if ($rc != 0) {
+      LOG(($verbose_pbm || $verbose_load), "failed command: \"$filter_cmd\"");
+      LOG(($verbose_pbm || $verbose_load), "failed URL: \"$img\" (${ow}x$oh)");
+      return;
+    }
+    rename ($image_tmp2, $image_tmp1);
+
+    # re-get the width/height in case the filter resized it.
+    local *IMG;
+    open(IMG, "<$image_tmp1") || return 0;
+    $_ = <IMG>;
+    $_ = <IMG>;
+    ($iw, $ih) = m/^(\d+) (\d+)$/;
+    close (IMG);
+    return 0 unless ($iw && $ih);
+  }
+
+  my $target_w = $img_width;   # max rectangle into which the image must fit
+  my $target_h = $img_height;
+
+  my $cmd = "";
+  my $scale = 1.0;
+
+
+  # Usually scale the image to fit on the screen -- but sometimes scale it
+  # to fit on half or a quarter of the screen.  (We do this by reducing the
+  # size of the target rectangle.)  Note that the image is not merely scaled
+  # to fit; we instead cut the image in half repeatedly until it fits in the
+  # target rectangle -- that gives a wider distribution of sizes.
+  #
+  if (rand() < 0.3) { $target_w /= 2; $target_h /= 2; } # reduce target rect
+  if (rand() < 0.3) { $target_w /= 2; $target_h /= 2; }
+
+  if ($iw > $target_w || $ih > $target_h) {
+    while ($iw > $target_w ||
+           $ih > $target_h) {
+      $iw = int($iw / 2);
+      $ih = int($ih / 2);
+      $scale /= 2;
+    }
+    if ($iw <= 10 || $ih <= 10) {
+      LOG ($verbose_pbm, "scaling to ${iw}x$ih would have been bogus.");
+      return 0;
+    }
+
+    LOG ($verbose_pbm, "scaling to ${iw}x$ih ($scale)");
+
+    $cmd .= " | pnmscale -xsize $iw -ysize $ih";
+  }
+
+
+  my $src = $image_tmp1;
+
+  my $crop_x = 0;     # the sub-rectangle of the image
+  my $crop_y = 0;     # that we will actually paste.
+  my $crop_w = $iw;
+  my $crop_h = $ih;
+
+  # The chance that we will randomly crop out a section of an image starts
+  # out fairly low, but goes up for images that are very large, or images
+  # that have ratios that make them look like banners (we try to avoid
+  # banner images entirely, but they slip through when the IMG tags didn't
+  # have WIDTH and HEIGHT specified.)
+  #
+  my $crop_chance = 0.2;
+  if ($iw > $img_width * 0.4 || $ih > $img_height * 0.4) {
+    $crop_chance += 0.2;
+  }
+  if ($iw > $img_width * 0.7 || $ih > $img_height * 0.7) {
+    $crop_chance += 0.2;
+  }
+  if ($min_ratio && ($iw * $min_ratio) > $ih) {
+    $crop_chance += 0.7;
+  }
+
+  if ($crop_chance > 0.1) {
+    LOG ($verbose_pbm, "crop chance: $crop_chance");
+  }
+
+  if (rand() < $crop_chance) {
+
+    my $ow = $crop_w;
+    my $oh = $crop_h;
+
+    if ($crop_w > $min_width) {
+      # if it's a banner, select the width linearly.
+      # otherwise, select a bell.
+      my $r = (($min_ratio && ($iw * $min_ratio) > $ih)
+               ? rand()
+               : bellrand());
+      $crop_w = $min_width + int ($r * ($crop_w - $min_width));
+      $crop_x = int (rand() * ($ow - $crop_w));
+    }
+    if ($crop_h > $min_height) {
+      # height always selects as a bell.
+      $crop_h = $min_height + int (bellrand() * ($crop_h - $min_height));
+      $crop_y = int (rand() * ($oh - $crop_h));
+    }
+
+    if ($crop_x != 0   || $crop_y != 0 ||
+        $crop_w != $iw || $crop_h != $ih) {
+      LOG ($verbose_pbm,
+           "randomly cropping to ${crop_w}x$crop_h \@ $crop_x,$crop_y");
     }
+  }
+
+  # Where the image should logically land -- this might be negative.
+  #
+  my $x = int((rand() * ($img_width  + $crop_w/2)) - $crop_w*3/4);
+  my $y = int((rand() * ($img_height + $crop_h/2)) - $crop_h*3/4);
+
+  # if we have chosen to paste the image outside of the rectangle of the
+  # screen, then we need to crop it.
+  #
+  if ($x < 0 ||
+      $y < 0 ||
+      $x + $crop_w > $img_width ||
+      $y + $crop_h > $img_height) {
+
+    LOG ($verbose_pbm,
+         "cropping for effective paste of ${crop_w}x$crop_h \@ $x,$y");
+
+    if ($x < 0) { $crop_x -= $x; $crop_w += $x; $x = 0; }
+    if ($y < 0) { $crop_y -= $y; $crop_h += $y; $y = 0; }
+
+    if ($x + $crop_w >= $img_width)  { $crop_w = $img_width  - $x - 1; }
+    if ($y + $crop_h >= $img_height) { $crop_h = $img_height - $y - 1; }
+  }
+
+  # If any cropping needs to happen, add pnmcut.
+  #
+  if ($crop_x != 0   || $crop_y != 0 ||
+      $crop_w != $iw || $crop_h != $ih) {
+    $iw = $crop_w;
+    $ih = $crop_h;
+    $cmd .= " | pnmcut $crop_x $crop_y $iw $ih";
+    LOG ($verbose_pbm, "cropping to ${crop_w}x$crop_h \@ $crop_x,$crop_y");
+  }
+
+  LOG ($verbose_pbm, "pasting ${iw}x$ih \@ $x,$y in $image_ppm");
+
+  $cmd .= " | pnmpaste - $x $y $image_ppm";
+
+  $cmd =~ s@^ *\| *@@;
+
+  if (defined ($webcollage_helper)) {
+    $cmd = "$webcollage_helper $image_tmp1 $image_ppm " .
+                              "$scale $opacity " .
+                              "$crop_x $crop_y $x $y " .
+                              "$iw $ih";
+    $_ = $cmd;
+
+  } else {
+    # use a PPM pipeline
+    $_ = "($cmd)";
+    $_ .= " < $image_tmp1 > $image_tmp2";
+  }
+
+  if ($verbose_pbm) {
+    $_ = "($_) 2>&1 | sed s'/^/" . blurb() . "/'";
+  } else {
+    $_ .= " 2> /dev/null";
+  }
+
+  my $rc = nontrapping_system ($_);
+
+  if (defined ($webcollage_helper) && -z $image_ppm) {
+    LOG (1, "failed command: \"$cmd\"");
+    print STDERR "\naudit log:\n\n\n";
+    print STDERR ("#" x 78) . "\n";
+    print STDERR blurb() . "$image_ppm has zero size\n";
+    showlog();
+    print STDERR "\n\n";
+    exit (1);
+  }
+
+  if ($rc != 0) {
+    LOG (($verbose_pbm || $verbose_load), "failed command: \"$cmd\"");
+    LOG (($verbose_pbm || $verbose_load), "failed URL: \"$img\" (${ow}x$oh)");
+    return;
+  }
+
+  if (!defined ($webcollage_helper)) {
+    rename ($image_tmp2, $image_ppm) || return;
+  }
+
+  my $target = "$image_ppm";
+
+  # don't just tack this onto the end of the pipeline -- we don't want it
+  # to end up in $image_ppm, because we don't want the results to be
+  # cumulative.
+  #
+  if ($post_filter_cmd) {
 
-    if (!$root_p && !$no_output_p) {
-        die "$copyright" .
-            "$progname: the -root argument is manditory (for now.)\n";
+    my $cmd;
+
+    $target = $image_tmp1;
+    if (!defined ($webcollage_helper)) {
+      $cmd = "($post_filter_cmd) < $image_ppm > $target";
+    } else {
+      # Blah, my scripts need the JPEG data, but some other folks need
+      # the PPM data -- what to do?  Ignore the problem, that's what!
+#     $cmd = "djpeg < $image_ppm | ($post_filter_cmd) > $target";
+      $cmd = "($post_filter_cmd) < $image_ppm > $target";
     }
 
-    if (!$no_output_p && !$ENV{DISPLAY}) {
-        die "$progname: \$DISPLAY is not set.\n";
+    $rc = nontrapping_system ($cmd);
+    if ($rc != 0) {
+      LOG ($verbose_pbm, "filter failed: \"$post_filter_cmd\"\n");
+      return;
     }
+  }
+
+  if (!$no_output_p) {
+    my $tsize = (stat($target))[7];
+    if ($tsize > 200) {
+      $cmd = "$ppm_to_root_window_cmd $target";
+
+      # xv seems to hate being killed.  it tends to forget to clean
+      # up after itself, and leaves windows around and colors allocated.
+      # I had this same problem with vidwhacker, and I'm not entirely
+      # sure what I did to fix it.  But, let's try this: launch xv
+      # in the background, so that killing this process doesn't kill it.
+      # it will die of its own accord soon enough.  So this means we
+      # start pumping bits to the root window in parallel with starting
+      # the next network retrieval, which is probably a better thing
+      # to do anyway.
+      #
+      $cmd .= " &";
+
+      $rc = nontrapping_system ($cmd);
+
+      if ($rc != 0) {
+        LOG (($verbose_pbm || $verbose_load), "display failed: \"$cmd\"");
+        return;
+      }
 
-    if ($urls_only_p) {
-        url_only_output;
     } else {
-        x_output;
+      LOG ($verbose_pbm, "$target size is $tsize");
     }
+  }
+
+  $source .= "-" . stats_of($source);
+  print STDOUT "image: ${iw}x${ih} @ $x,$y $base $source\n"
+    if ($verbose_imgmap);
+  if ($imagemap_base) {
+    update_imagemap ($base, $x, $y, $iw, $ih,
+                     $image_ppm, $img_width, $img_height);
+  }
+
+  clearlog();
+
+  return 1;
 }
 
 
-##############################################################################
-#
-# Decide if we're in X or CGI mode, and dispatch.
-#
-##############################################################################
+sub update_imagemap($$$$$$$$) {
+  my ($url, $x, $y, $w, $h, $image_ppm, $image_width, $image_height) = @_;
+
+  $current_state = "imagemap";
+
+  my $max_areas = 200;
+
+  $url = html_quote ($url);
+  my $x2 = $x + $w;
+  my $y2 = $y + $h;
+  my $area = "<AREA SHAPE=RECT COORDS=\"$x,$y,$x2,$y2\" HREF=\"$url\">";
+  unshift @imagemap_areas, $area;	# put one on the front
+  if ($#imagemap_areas >= $max_areas) {
+    pop @imagemap_areas;		# take one off the back.
+  }
+
+  LOG ($verbose_pbm, "area: $x,$y,$x2,$y2 (${w}x$h)");
+
+  my $map_name = $imagemap_base;
+  $map_name =~ s@^.*/@@;
+  $map_name = 'collage' if ($map_name eq '');
+
+  my $imagemap_html = $imagemap_base . ".html";
+  my $imagemap_jpg  = $imagemap_base . ".jpg";
+
+  if (!defined ($imagemap_html_tmp)) {
+    $imagemap_html_tmp = $imagemap_html . sprintf (".%08x", rand(0xffffffff));
+    $imagemap_jpg_tmp  = $imagemap_jpg  . sprintf (".%08x", rand(0xffffffff));
+  }
+
+  # Read the imagemap html file (if any) to get a template.
+  #
+  my $template_html = '';
+  {
+    local *IN;
+    if (open (IN, "<$imagemap_html")) {
+      while (<IN>) { $template_html .= $_; }
+      close IN;
+      LOG ($verbose_pbm, "read template $imagemap_html");
+    }
+
+    if ($template_html =~ m/^\s*$/s) {
+      $template_html = ("<MAP NAME=\"$map_name\"></MAP>\n" .
+                        "<IMG SRC=\"$imagemap_base.jpg\"" .
+                        " USEMAP=\"$map_name\">\n");
+      LOG ($verbose_pbm, "created dummy template");
+    }
+  }
+
+  # Write the jpg to a tmp file
+  #
+  {
+    my $cmd;
+    if (defined ($webcollage_helper)) {
+      $cmd = "cp -p $image_ppm $imagemap_jpg_tmp";
+    } else {
+      $cmd = "cjpeg < $image_ppm > $imagemap_jpg_tmp";
+    }
+    my $rc = nontrapping_system ($cmd);
+    if ($rc != 0) {
+      error ("imagemap jpeg failed: \"$cmd\"\n");
+    }
+  }
+
+  # Write the html to a tmp file
+  #
+  {
+    my $body = $template_html;
+    my $areas = join ("\n\t", @imagemap_areas);
+    my $map = ("<MAP NAME=\"$map_name\">\n\t$areas\n</MAP>");
+    my $img = ("<IMG SRC=\"$imagemap_base.jpg\" " .
+               "BORDER=0 " .
+               "WIDTH=$image_width HEIGHT=$image_height " .
+               "USEMAP=\"#$map_name\">");
+    $body =~ s@(<MAP\s+NAME=\"[^\"]*\"\s*>).*?(</MAP>)@$map@is;
+    $body =~ s@<IMG\b[^<>]*\bUSEMAP\b[^<>]*>@$img@is;
+
+    # if there are magic webcollage spans in the html, update those too.
+    #
+    {
+      my @st = stat ($imagemap_jpg_tmp);
+      my $date = strftime("%d-%b-%Y %l:%M:%S %p %Z", localtime($st[9]));
+      my $size = int(($st[7] / 1024) + 0.5) . "K";
+      $body =~ s@(<SPAN\s+CLASS=\"webcollage_date\">).*?(</SPAN>)@$1$date$2@si;
+      $body =~ s@(<SPAN\s+CLASS=\"webcollage_size\">).*?(</SPAN>)@$1$size$2@si;
+    }
+
+    local *OUT;
+    open (OUT, ">$imagemap_html_tmp") || error ("$imagemap_html_tmp: $!");
+    print OUT $body                   || error ("$imagemap_html_tmp: $!");
+    close OUT                         || error ("$imagemap_html_tmp: $!");
+    LOG ($verbose_pbm, "wrote $imagemap_html_tmp");
+  }
+
+  # Rename the two tmp files to the real files
+  #
+  rename ($imagemap_html_tmp, $imagemap_html) ||
+    error "renaming $imagemap_html_tmp to $imagemap_html";
+  LOG ($verbose_pbm, "wrote $imagemap_html");
+  rename ($imagemap_jpg_tmp,  $imagemap_jpg) ||
+    error "renaming $imagemap_jpg_tmp to $imagemap_jpg";
+  LOG ($verbose_pbm, "wrote $imagemap_jpg");
+}
+
+
+sub init_signals() {
+
+  $SIG{HUP}  = \&signal_cleanup;
+  $SIG{INT}  = \&signal_cleanup;
+  $SIG{QUIT} = \&signal_cleanup;
+  $SIG{ABRT} = \&signal_cleanup;
+  $SIG{KILL} = \&signal_cleanup;
+  $SIG{TERM} = \&signal_cleanup;
+
+  # Need this so that if giftopnm dies, we don't die.
+  $SIG{PIPE} = 'IGNORE';
+}
+
+END { exit_cleanup(); }
+
+
+sub main() {
+  $| = 1;
+  srand(time ^ $$);
+
+  my $verbose = 0;
+  my $dict;
+  my $driftnet_cmd = 0;
+
+  $current_state = "init";
+  $load_method = "none";
+
+  my $root_p = 0;
+  my $window_id = undef;
+
+  # historical suckage: the environment variable name is lower case.
+  $http_proxy = $ENV{http_proxy} || $ENV{HTTP_PROXY};
+
+  while ($_ = $ARGV[0]) {
+    shift @ARGV;
+    if ($_ eq "-display" ||
+        $_ eq "-displ" ||
+        $_ eq "-disp" ||
+        $_ eq "-dis" ||
+        $_ eq "-dpy" ||
+        $_ eq "-d") {
+      $ENV{DISPLAY} = shift @ARGV;
+    } elsif ($_ eq "-root") {
+      $root_p = 1;
+    } elsif ($_ eq "-window-id" || $_ eq "--window-id") {
+      $window_id = shift @ARGV;
+      $root_p = 1;
+    } elsif ($_ eq "-no-output") {
+      $no_output_p = 1;
+    } elsif ($_ eq "-urls-only") {
+      $urls_only_p = 1;
+      $no_output_p = 1;
+    } elsif ($_ eq "-cocoa") {
+      $cocoa_p = 1;
+    } elsif ($_ eq "-imagemap") {
+      $imagemap_base = shift @ARGV;
+      $no_output_p = 1;
+    } elsif ($_ eq "-verbose") {
+      $verbose++;
+    } elsif (m/^-v+$/) {
+      $verbose += length($_)-1;
+    } elsif ($_ eq "-delay") {
+      $delay = shift @ARGV;
+    } elsif ($_ eq "-timeout") {
+      $http_timeout = shift @ARGV;
+    } elsif ($_ eq "-filter") {
+      $filter_cmd = shift @ARGV;
+    } elsif ($_ eq "-filter2") {
+      $post_filter_cmd = shift @ARGV;
+    } elsif ($_ eq "-background" || $_ eq "-bg") {
+      $background = shift @ARGV;
+    } elsif ($_ eq "-size") {
+      $_ = shift @ARGV;
+      if (m@^(\d+)x(\d+)$@) {
+        $img_width = $1;
+        $img_height = $2;
+      } else {
+        error "argument to \"-size\" must be of the form \"640x400\"";
+      }
+    } elsif ($_ eq "-proxy" || $_ eq "-http-proxy") {
+      $http_proxy = shift @ARGV;
+    } elsif ($_ eq "-dictionary" || $_ eq "-dict") {
+      $dict = shift @ARGV;
+    } elsif ($_ eq "-opacity") {
+      $opacity = shift @ARGV;
+      error ("opacity must be between 0.0 and 1.0")
+        if ($opacity <= 0 || $opacity > 1);
+    } elsif ($_ eq "-driftnet" || $_ eq "--driftnet") {
+      @search_methods = ( 100, "driftnet", \&pick_from_driftnet );
+      if (! ($ARGV[0] =~ m/^-/)) {
+        $driftnet_cmd = shift @ARGV;
+      } else {
+        $driftnet_cmd = $default_driftnet_cmd;
+      }
+    } elsif ($_ eq "-directory" || $_ eq "--directory") {
+      @search_methods = ( 100, "local", \&pick_from_local_dir );
+      if (! ($ARGV[0] =~ m/^-/)) {
+        $local_dir = shift @ARGV;
+      } else {
+        error ("local directory path must be set")
+      }
+    } elsif ($_ eq "-debug" || $_ eq "--debug") {
+      my $which = shift @ARGV;
+      my @rest = @search_methods;
+      my $ok = 0;
+      while (@rest) {
+        my $pct  = shift @rest;
+        my $name = shift @rest;
+        my $tfn  = shift @rest;
+
+        if ($name eq $which) {
+          @search_methods = (100, $name, $tfn);
+          $ok = 1;
+          last;
+        }
+      }
+      error "no such search method as \"$which\"" unless ($ok);
+      LOG (1, "DEBUG: using only \"$which\"");
 
-sub main {
-    srand(time ^ $$);
-    if ( $progname =~ m/\.cgi$/i || $ENV{REQUEST_METHOD} ) {
-        cgi_main;
     } else {
-        x_main;
+      print STDERR "$copyright\nusage: $progname " .
+              "[-root] [-display dpy] [-verbose] [-debug which]\n" .
+        "\t\t  [-timeout secs] [-delay secs] [-size WxH]\n" .
+        "\t\t  [-no-output] [-urls-only] [-imagemap filename]\n" .
+        "\t\t  [-filter cmd] [-filter2 cmd] [-background color]\n" .
+        "\t\t  [-dictionary dictionary-file] [-http-proxy host[:port]]\n" .
+        "\t\t  [-driftnet [driftnet-program-and-args]]\n" .
+        "\t\t  [-directory local-image-directory]\n" .
+        "\n";
+      exit 1;
     }
+  }
+
+  if ($http_proxy && $http_proxy eq "") {
+    $http_proxy = undef;
+  }
+  if ($http_proxy && $http_proxy =~ m@^http://([^/]*)/?$@ ) {
+    # historical suckage: allow "http://host:port" as well as "host:port".
+    $http_proxy = $1;
+  }
+
+  if (!$root_p && !$no_output_p && !$cocoa_p) {
+    print STDERR $copyright;
+    error "the -root argument is mandatory (for now.)";
+  }
+
+  if (!$no_output_p && !$cocoa_p && !$ENV{DISPLAY}) {
+    error "\$DISPLAY is not set.";
+  }
+
+
+  if ($verbose == 1) {
+    $verbose_imgmap   = 1;
+    $verbose_warnings = 1;
+
+  } elsif ($verbose == 2) {
+    $verbose_imgmap   = 1;
+    $verbose_warnings = 1;
+    $verbose_load     = 1;
+
+  } elsif ($verbose == 3) {
+    $verbose_imgmap   = 1;
+    $verbose_warnings = 1;
+    $verbose_load     = 1;
+    $verbose_filter   = 1;
+
+  } elsif ($verbose == 4) {
+    $verbose_imgmap   = 1;
+    $verbose_warnings = 1;
+    $verbose_load     = 1;
+    $verbose_filter   = 1;
+    $verbose_net      = 1;
+
+  } elsif ($verbose == 5) {
+    $verbose_imgmap   = 1;
+    $verbose_warnings = 1;
+    $verbose_load     = 1;
+    $verbose_filter   = 1;
+    $verbose_net      = 1;
+    $verbose_pbm      = 1;
+
+  } elsif ($verbose == 6) {
+    $verbose_imgmap   = 1;
+    $verbose_warnings = 1;
+    $verbose_load     = 1;
+    $verbose_filter   = 1;
+    $verbose_net      = 1;
+    $verbose_pbm      = 1;
+    $verbose_http     = 1;
+
+  } elsif ($verbose >= 7) {
+    $verbose_imgmap   = 1;
+    $verbose_warnings = 1;
+    $verbose_load     = 1;
+    $verbose_filter   = 1;
+    $verbose_net      = 1;
+    $verbose_pbm      = 1;
+    $verbose_http     = 1;
+    $verbose_exec     = 1;
+  }
+
+  if ($dict) {
+    error ("$dict does not exist") unless (-f $dict);
+    $wordlist = $dict;
+  } else {
+    pick_dictionary();
+  }
+
+  if ($imagemap_base && !($img_width && $img_height)) {
+    error ("-size WxH is required with -imagemap");
+  }
+
+  if (defined ($local_dir)) {
+    $_ = "xscreensaver-getimage-file";
+    which ($_) || error "$_ not found on \$PATH.";
+  }
+
+  init_signals();
+
+  spawn_driftnet ($driftnet_cmd) if ($driftnet_cmd);
+
+  if ($urls_only_p) {
+    url_only_output ();
+  } else {
+    x_or_pbm_output ($window_id);
+  }
 }
 
-main;
+main();
 exit (0);