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Diffstat (limited to 'driver/xscreensaver-getimage-file')
| -rwxr-xr-x | driver/xscreensaver-getimage-file | 1316 |
1 files changed, 1316 insertions, 0 deletions
diff --git a/driver/xscreensaver-getimage-file b/driver/xscreensaver-getimage-file new file mode 100755 index 0000000..ba1ef30 --- /dev/null +++ b/driver/xscreensaver-getimage-file @@ -0,0 +1,1316 @@ +#!/usr/bin/perl -w +# Copyright © 2001-2018 Jamie Zawinski <jwz@jwz.org>. +# +# Permission to use, copy, modify, distribute, and sell this software and its +# documentation for any purpose is hereby granted without fee, provided that +# the above copyright notice appear in all copies and that both that +# copyright notice and this permission notice appear in supporting +# documentation. No representations are made about the suitability of this +# software for any purpose. It is provided "as is" without express or +# implied warranty. +# +# This program chooses a random file from under the given directory, and +# prints its name. The file will be an image file whose dimensions are +# larger than a certain minimum size. +# +# If the directory is a URL, it is assumed to be an RSS or Atom feed. +# The images from that feed will be downloaded, cached, and selected from +# at random. The feed will be re-polled periodically, as needed. +# +# The various xscreensaver hacks that manipulate images ("jigsaw", etc.) get +# the image to manipulate by running the "xscreensaver-getimage" program. +# +# Under X11, the "xscreensaver-getimage" program invokes this script, +# depending on the value of the "chooseRandomImages" and "imageDirectory" +# settings in the ~/.xscreensaver file (or .../app-defaults/XScreenSaver). +# The screen savers invoke "xscreensaver-getimage" via utils/grabclient.c, +# which then invokes this script. +# +# Under Cocoa, this script lives inside the .saver bundle, and is invoked +# directly from utils/grabclient.c. +# +# Created: 12-Apr-01. + +require 5; +#use diagnostics; # Fails on some MacOS 10.5 systems +use strict; + +use POSIX; +use Fcntl; + +use Fcntl ':flock'; # import LOCK_* constants + +use POSIX ':fcntl_h'; # S_ISDIR was here in Perl 5.6 +import Fcntl ':mode' unless defined &S_ISUID; # but it is here in Perl 5.8 + # but in Perl 5.10, both of these load, and cause errors! + # So we have to check for S_ISUID instead of S_ISDIR? WTF? + +use Digest::MD5 qw(md5_base64); + +# Some Linux systems don't install LWP by default! +# Only error out if we're actually loading a URL instead of local data. +BEGIN { eval 'use LWP::Simple;' } + + +my $progname = $0; $progname =~ s@.*/@@g; +my ($version) = ('$Revision: 1.52 $' =~ m/\s(\d[.\d]+)\s/s); + +my $verbose = 0; + +# Whether to use MacOS X's Spotlight to generate the list of files. +# When set to -1, uses Spotlight if "mdfind" exists. +# +# (In my experience, this isn't actually any faster, and might not find +# everything if your Spotlight index is out of date, which happens often.) +# +my $use_spotlight_p = 0; + +# Whether to cache the results of the last run. +# +my $cache_p = 1; + +# Regenerate the cache if it is older than this many seconds. +# +my $cache_max_age = 60 * 60 * 3; # 3 hours + +# Re-poll RSS/Atom feeds when local copy is older than this many seconds. +# +my $feed_max_age = $cache_max_age; + + +# This matches files that we are allowed to use as images (case-insensitive.) +# Anything not matching this is ignored. This is so you can point your +# imageDirectory at directory trees that have things other than images in +# them, but it assumes that you gave your images sensible file extensions. +# +my @good_extensions = ('jpg', 'jpeg', 'pjpeg', 'pjpg', 'png', 'gif', + 'tif', 'tiff', 'xbm', 'xpm'); +my $good_file_re = '\.(' . join("|", @good_extensions) . ')$'; + +# This matches file extensions that might occur in an image directory, +# and that are never used in the name of a subdirectory. This is an +# optimization that prevents us from having to stat() those files to +# tell whether they are directories or not. (It speeds things up a +# lot. Don't give your directories stupid names.) +# +my @nondir_extensions = ('ai', 'bmp', 'bz2', 'cr2', 'crw', 'db', + 'dmg', 'eps', 'gz', 'hqx', 'htm', 'html', 'icns', 'ilbm', 'mov', + 'nef', 'pbm', 'pdf', 'php', 'pl', 'ppm', 'ps', 'psd', 'sea', 'sh', + 'shtml', 'tar', 'tgz', 'thb', 'txt', 'xcf', 'xmp', 'Z', 'zip' ); +my $nondir_re = '\.(' . join("|", @nondir_extensions) . ')$'; + + +# JPEG, GIF, and PNG files that are are smaller than this are rejected: +# this is so that you can use an image directory that contains both big +# images and thumbnails, and have it only select the big versions. +# But, if all of your images are smaller than this, all will be rejected. +# +my $min_image_width = 500; +my $min_image_height = 500; + +my @all_files = (); # list of "good" files we've collected +my %seen_inodes; # for breaking recursive symlink loops + +# For diagnostic messages: +# +my $dir_count = 1; # number of directories seen +my $stat_count = 0; # number of files/dirs stat'ed +my $skip_count_unstat = 0; # number of files skipped without stat'ing +my $skip_count_stat = 0; # number of files skipped after stat + +my $config_file = $ENV{HOME} . "/.xscreensaver"; +my $image_directory = undef; + + +sub find_all_files($); +sub find_all_files($) { + my ($dir) = @_; + + print STDERR "$progname: + reading dir $dir/...\n" if ($verbose > 1); + + my $dd; + if (! opendir ($dd, $dir)) { + print STDERR "$progname: couldn't open $dir: $!\n" if ($verbose); + return; + } + my @files = readdir ($dd); + closedir ($dd); + + my @dirs = (); + + foreach my $file (@files) { + next if ($file =~ m/^\./); # silently ignore dot files/dirs + + if ($file =~ m/[~%\#]$/) { # ignore backup files (and dirs...) + $skip_count_unstat++; + print STDERR "$progname: - skip file $file\n" if ($verbose > 1); + } + + $file = "$dir/$file"; + + if ($file =~ m/$good_file_re/io) { + # + # Assume that files ending in .jpg exist and are not directories. + # + push @all_files, $file; + print STDERR "$progname: - found file $file\n" if ($verbose > 1); + + } elsif ($file =~ m/$nondir_re/io) { + # + # Assume that files ending in .html are not directories. + # + $skip_count_unstat++; + print STDERR "$progname: -- skip file $file\n" if ($verbose > 1); + + } else { + # + # Now we need to stat the file to see if it's a subdirectory. + # + # Note: we could use the trick of checking "nlinks" on the parent + # directory to see if this directory contains any subdirectories, + # but that would exclude any symlinks to directories. + # + my @st = stat($file); + my ($dev,$ino,$mode,$nlink,$uid,$gid,$rdev,$size, + $atime,$mtime,$ctime,$blksize,$blocks) = @st; + + $stat_count++; + + if ($#st == -1) { + if ($verbose) { + my $ll = readlink $file; + if (defined ($ll)) { + print STDERR "$progname: + dangling symlink: $file -> $ll\n"; + } else { + print STDERR "$progname: + unreadable: $file\n"; + } + } + next; + } + + next if ($seen_inodes{"$dev:$ino"}); # break symlink loops + $seen_inodes{"$dev:$ino"} = 1; + + if (S_ISDIR($mode)) { + push @dirs, $file; + $dir_count++; + print STDERR "$progname: + found dir $file\n" if ($verbose > 1); + + } else { + $skip_count_stat++; + print STDERR "$progname: + skip file $file\n" if ($verbose > 1); + } + } + } + + foreach (@dirs) { + find_all_files ($_); + } +} + + +sub spotlight_all_files($) { + my ($dir) = @_; + + my @terms = (); + # "public.image" matches all (indexed) images, including Photoshop, etc. +# push @terms, "kMDItemContentTypeTree == 'public.image'"; + foreach (@good_extensions) { + + # kMDItemFSName hits the file system every time: much worse than "find". +# push @terms, "kMDItemFSName == '*.$_'"; + + # kMDItemDisplayName matches against the name in the Spotlight index, + # but won't find files that (for whatever reason) didn't get indexed. + push @terms, "kMDItemDisplayName == '*.$_'"; + } + + $dir =~ s@([^-_/a-z\d.,])@\\$1@gsi; # quote for sh + my $cmd = "mdfind -onlyin $dir \"" . join (' || ', @terms) . "\""; + + print STDERR "$progname: executing: $cmd\n" if ($verbose > 1); + @all_files = split (/[\r\n]+/, `$cmd`); +} + + +# If we're using cacheing, read the cache file and return its contents, +# if any. This also holds an exclusive lock on the cache file, which +# has the additional benefit that if two copies of this program are +# running at once, one will wait for the other, instead of both of +# them spanking the same file system at the same time. +# +my $cache_fd = undef; +my $cache_file_name = undef; +my $read_cache_p = 0; + +sub read_cache($) { + my ($dir) = @_; + + return () unless ($cache_p); + + my $dd = "$ENV{HOME}/Library/Caches"; # MacOS location + if (-d $dd) { + $cache_file_name = "$dd/org.jwz.xscreensaver.getimage.cache"; + } elsif (-d "$ENV{HOME}/.cache") { # Gnome "FreeDesktop XDG" location + $dd = "$ENV{HOME}/.cache/xscreensaver"; + if (! -d $dd) { mkdir ($dd) || error ("mkdir $dd: $!"); } + $cache_file_name = "$dd/xscreensaver-getimage.cache" + } elsif (-d "$ENV{HOME}/tmp") { # If ~/tmp/ exists, use it. + $cache_file_name = "$ENV{HOME}/tmp/.xscreensaver-getimage.cache"; + } else { + $cache_file_name = "$ENV{HOME}/.xscreensaver-getimage.cache"; + } + + print STDERR "$progname: awaiting lock: $cache_file_name\n" + if ($verbose > 1); + + my $file = $cache_file_name; + open ($cache_fd, '+>>', $file) || error ("unable to write $file: $!"); + flock ($cache_fd, LOCK_EX) || error ("unable to lock $file: $!"); + seek ($cache_fd, 0, 0) || error ("unable to rewind $file: $!"); + + my $mtime = (stat($cache_fd))[9]; + + if ($mtime + $cache_max_age < time) { + print STDERR "$progname: cache is too old\n" if ($verbose); + return (); + } + + my $odir = <$cache_fd>; + $odir =~ s/[\r\n]+$//s if defined ($odir); + if (!defined ($odir) || ($dir ne $odir)) { + print STDERR "$progname: cache is for $odir, not $dir\n" + if ($verbose && $odir); + return (); + } + + my @files = (); + while (<$cache_fd>) { + s/[\r\n]+$//s; + push @files, "$odir/$_"; + } + + print STDERR "$progname: " . ($#files+1) . " files in cache\n" + if ($verbose); + + $read_cache_p = 1; + return @files; +} + + +sub write_cache($) { + my ($dir) = @_; + + return unless ($cache_p); + + # If we read the cache, just close it without rewriting it. + # If we didn't read it, then write it now. + + if (! $read_cache_p) { + + truncate ($cache_fd, 0) || + error ("unable to truncate $cache_file_name: $!"); + seek ($cache_fd, 0, 0) || + error ("unable to rewind $cache_file_name: $!"); + + if ($#all_files >= 0) { + print $cache_fd "$dir\n"; + foreach (@all_files) { + my $f = $_; # stupid Perl. do this to avoid modifying @all_files! + $f =~ s@^\Q$dir/@@so || die; # remove $dir from front + print $cache_fd "$f\n"; + } + } + + print STDERR "$progname: cached " . ($#all_files+1) . " files\n" + if ($verbose); + } + + flock ($cache_fd, LOCK_UN) || + error ("unable to unlock $cache_file_name: $!"); + close ($cache_fd); + $cache_fd = undef; +} + + +sub html_unquote($) { + my ($h) = @_; + + # This only needs to handle entities that occur in RSS, not full HTML. + my %ent = ( 'amp' => '&', 'lt' => '<', 'gt' => '>', + 'quot' => '"', 'apos' => "'" ); + $h =~ s/(&(\#)?([[:alpha:]\d]+);?)/ + { + my ($o, $c) = ($1, $3); + if (! defined($2)) { + $c = $ent{$c}; # for < + } else { + if ($c =~ m@^x([\dA-F]+)$@si) { # for A + $c = chr(hex($1)); + } elsif ($c =~ m@^\d+$@si) { # for A + $c = chr($c); + } else { + $c = undef; + } + } + ($c || $o); + } + /gexi; + return $h; +} + + + +# Figure out what the proxy server should be, either from environment +# variables or by parsing the output of the (MacOS) program "scutil", +# which tells us what the system-wide proxy settings are. +# +sub set_proxy($) { + my ($ua) = @_; + + my $proxy_data = `scutil --proxy 2>/dev/null`; + foreach my $proto ('http', 'https') { + my ($server) = ($proxy_data =~ m/\b${proto}Proxy\s*:\s*([^\s]+)/si); + my ($port) = ($proxy_data =~ m/\b${proto}Port\s*:\s*([^\s]+)/si); + my ($enable) = ($proxy_data =~ m/\b${proto}Enable\s*:\s*([^\s]+)/si); + + if ($server && $enable) { + # Note: this ignores the "ExceptionsList". + my $proto2 = 'http'; + $ENV{"${proto}_proxy"} = ("${proto2}://" . $server . + ($port ? ":$port" : "") . "/"); + print STDERR "$progname: MacOS $proto proxy: " . + $ENV{"${proto}_proxy"} . "\n" + if ($verbose > 2); + } + } + + $ua->env_proxy(); +} + + +sub init_lwp() { + if (! defined ($LWP::Simple::ua)) { + error ("\n\n\tPerl is broken. Do this to repair it:\n" . + "\n\tsudo cpan LWP::Simple LWP::Protocol::https Mozilla::CA\n"); + } + set_proxy ($LWP::Simple::ua); +} + + +sub sanity_check_lwp() { + my $url1 = 'https://www.mozilla.org/'; + my $url2 = 'http://www.mozilla.org/'; + my $body = (LWP::Simple::get($url1) || ''); + if (length($body) < 10240) { + my $err = ""; + $body = (LWP::Simple::get($url2) || ''); + if (length($body) < 10240) { + $err = "Perl is broken: neither HTTP nor HTTPS URLs work."; + } else { + $err = "Perl is broken: HTTP URLs work but HTTPS URLs don't."; + } + $err .= "\nMaybe try: sudo cpan -f Mozilla::CA LWP::Protocol::https"; + $err =~ s/^/\t/gm; + error ("\n\n$err\n"); + } +} + + +# If the URL does not already end with an extension appropriate for the +# content-type, add it after a "#" search. +# +# This is for when we know the content type of the URL, but the URL is +# some crazy thing without an extension. The files on disk need to have +# proper extensions. +# +sub force_extension($$) { + my ($url, $ct) = @_; + return $url unless (defined($url) && defined($ct)); + my ($ext) = ($ct =~ m@^image/([-a-z\d]+)@si); + return $url unless $ext; + $ext = lc($ext); + $ext = 'jpg' if ($ext eq 'jpeg'); + return $url if ($url =~ m/\.$ext$/si); + return "$url#.$ext"; +} + + +# Returns a list of the image enclosures in the RSS or Atom feed. +# Elements of the list are references, [ "url", "guid" ]. +# +sub parse_feed($); +sub parse_feed($) { + my ($url) = @_; + + init_lwp(); + $LWP::Simple::ua->agent ("$progname/$version"); + $LWP::Simple::ua->timeout (10); # bail sooner than the default of 3 minutes + + + # Half the time, random Linux systems don't have Mozilla::CA installed, + # which results in "Can't verify SSL peers without knowning which + # Certificate Authorities to trust". + # + # In xscreensaver-text we just disabled certificate checks. However, + # malicious images really do exist, so for xscreensaver-getimage-file, + # let's actually require that SSL be installed properly. + + print STDERR "$progname: loading $url\n" if ($verbose); + my $body = (LWP::Simple::get($url) || ''); + + if ($body !~ m@^\s*<(\?xml|rss)\b@si) { + # Not an RSS/Atom feed. Try RSS autodiscovery. + + # (Great news, everybody: Flickr no longer provides RSS for "Sets", + # only for "Photostreams", and only the first 20 images of those. + # Thanks, assholes.) + + if ($body =~ m/^\s*$/s) { + sanity_check_lwp(); + error ("null response: $url"); + } + + error ("not an RSS or Atom feed, or HTML: $url") + unless ($body =~ m@<(HEAD|BODY|A|IMG)\b@si); + + # Find the first <link> with RSS or Atom in it, and use that instead. + + $body =~ s@<LINK\s+([^<>]*)>@{ + my $p = $1; + if ($p =~ m! \b REL \s* = \s* ['"]? alternate \b!six && + $p =~ m! \b TYPE \s* = \s* ['"]? application/(atom|rss) !six && + $p =~ m! \b HREF \s* = \s* ['"] ( [^<>'"]+ ) !six + ) { + my $u2 = html_unquote ($1); + if ($u2 =~ m!^/!s) { + my ($h) = ($url =~ m!^([a-z]+://[^/]+)!si); + $u2 = "$h$u2"; + } + print STDERR "$progname: found feed: $u2\n" + if ($verbose); + return parse_feed ($u2); + } + ''; + }@gsexi; + + error ("no RSS or Atom feed for HTML page: $url"); + } + + + $body =~ s@(<ENTRY|<ITEM)@\001$1@gsi; + my @items = split(/\001/, $body); + shift @items; + + my @imgs = (); + my %ids; + + foreach my $item (@items) { + my $iurl = undef; + my $id = undef; + + # First look for <link rel="enclosure" href="..."> + # + if (! $iurl) { + foreach my $link ($item =~ m@<LINK[^<>]*>@gsi) { + last if $iurl; + my ($href) = ($link =~ m/\bHREF\s*=\s*[\"\']([^<>\'\"]+)/si); + my ($type) = ($link =~ m/\bTYPE\s*=\s*[\"\']?([^<>\'\"]+)/si); + my ($rel) = ($link =~ m/\bREL\s*=\s*[\"\']?([^<>\'\"]+)/si); + $href = undef unless (lc($rel || '') eq 'enclosure'); + $href = undef if ($type && $type !~ m@^image/@si); # omit videos + $iurl = html_unquote($href) if $href; + $iurl = force_extension ($iurl, $type); + } + } + + # Then look for <media:content url="..."> + # + if (! $iurl) { + foreach my $link ($item =~ m@<MEDIA:CONTENT[^<>]*>@gsi) { + last if $iurl; + my ($href) = ($link =~ m/\bURL\s*=\s*[\"\']([^<>\'\"]+)/si); + my ($type) = ($link =~ m/\bTYPE\s*=\s*[\"\']?([^<>\'\"]+)/si); + my ($med) = ($link =~ m/\bMEDIUM\s*=\s*[\"\']?([^<>\'\"]+)/si); + $type = 'image/jpeg' if (!$type && lc($med || '') eq 'image'); + $href = undef if ($type && $type !~ m@^image/@si); # omit videos + $iurl = html_unquote($href) if $href; + $iurl = force_extension ($iurl, $type); + } + } + + # Then look for <enclosure url="..."/> + # + if (! $iurl) { + foreach my $link ($item =~ m@<ENCLOSURE[^<>]*>@gsi) { + last if $iurl; + my ($href) = ($link =~ m/\bURL\s*=\s*[\"\']([^<>\'\"]+)/si); + my ($type) = ($link =~ m/\bTYPE\s*=\s*[\"\']?([^<>\'\"]+)/si); + $href = undef if ($type && $type !~ m@^image/@si); # omit videos + $iurl = html_unquote($href) if ($href); + $iurl = force_extension ($iurl, $type); + } + } + + # Ok, maybe there's an image in the <url> field? + # + if (! $iurl) { + foreach my $link ($item =~ m@<URL\b[^<>]*>([^<>]*)@gsi) { + last if $iurl; + my $u2 = $1; + $iurl = html_unquote($u2) if ($u2 =~ m/$good_file_re/io); + if (! $iurl) { + my $u3 = $u2; + $u3 =~ s/#.*$//gs; + $u3 =~ s/[?&].*$//gs; + $iurl = html_unquote($u2) if ($u3 =~ m/$good_file_re/io); + } + } + } + + # Then look for <content:encoded> or <description>... with an + # <img src="..."> inside. If more than one image, take the first. + # + foreach my $t ('content:encoded', 'description') { + last if $iurl; + foreach my $link ($item =~ m@<$t[^<>]*>(.*?)</$t>@gsi) { + last if $iurl; + my $desc = $1; + if ($desc =~ m@<!\[CDATA\[\s*(.*?)\s*\]\]>@gs) { + $desc = $1; + } else { + $desc = html_unquote($desc); + } + my ($href) = ($desc =~ m@<IMG[^<>]*\bSRC=[\"\']?([^\"\'<>]+)@si); + $iurl = html_unquote($href) if ($href); + # If IMG SRC has a bogus extension, pretend it's a JPEG. + $iurl = force_extension ($iurl, 'image/jpeg') + if ($iurl && $iurl !~ m/$good_file_re/io); + } + } + + # Find a unique ID for this image, to defeat image farms. + # First look for <id>...</id> + ($id) = ($item =~ m!<ID\b[^<>]*>\s*([^<>]+?)\s*</ID>!si) unless $id; + + # Then look for <guid isPermaLink=...> ... </guid> + ($id) = ($item =~ m!<GUID\b[^<>]*>\s*([^<>]+?)\s*</GUID>!si) unless $id; + + # Then look for <link> ... </link> + ($id) = ($item =~ m!<LINK\b[^<>]*>\s*([^<>]+?)\s*</LINK>!si) unless $id; + + # If we only have a GUID or LINK, but it's an image, use that. + $iurl = $id if (!$iurl && $id && $id =~ m/$good_file_re/io); + + if ($iurl) { + $id = $iurl unless $id; + my $o = $ids{$id}; + if (! $o) { + $ids{$id} = $iurl; + my @P = ($iurl, $id); + push @imgs, \@P; + } elsif ($iurl ne $o) { + print STDERR "$progname: WARNING: dup ID \"$id\"" . + " for \"$o\" and \"$iurl\"\n"; + } + } + } + + return @imgs; +} + + +# Like md5_base64 but uses filename-safe characters. +# +sub md5_file($) { + my ($s) = @_; + $s = md5_base64($s); + $s =~ s@[/]@_@gs; + $s =~ s@[+]@-@gs; + return $s; +} + + +# expands the first URL relative to the second. +# +sub expand_url($$) { + my ($url, $base) = @_; + + $url =~ s/^\s+//gs; # lose whitespace at front and back + $url =~ s/\s+$//gs; + + if (! ($url =~ m/^[a-z]+:/)) { + + $base =~ s@(\#.*)$@@; # strip anchors + $base =~ s@(\?.*)$@@; # strip arguments + $base =~ s@/[^/]*$@/@; # take off trailing file component + + my $tail = ''; + if ($url =~ s@(\#.*)$@@) { $tail = $1; } # save anchors + if ($url =~ s@(\?.*)$@@) { $tail = "$1$tail"; } # save arguments + + my $base2 = $base; + + $base2 =~ s@^([a-z]+:/+[^/]+)/.*@$1@ # if url is an absolute path + if ($url =~ m@^/@); + + my $ourl = $url; + + $url = $base2 . $url; + $url =~ s@/\./@/@g; # expand "." + 1 while ($url =~ s@/[^/]+/\.\./@/@s); # expand ".." + + $url .= $tail; # put anchors/args back + + print STDERR "$progname: relative URL: $ourl --> $url\n" + if ($verbose > 1); + + } else { + print STDERR "$progname: absolute URL: $url\n" + if ($verbose > 2); + } + + return $url; +} + + +# Given the URL of an image, download it into the given directory +# and return the file name. +# +sub download_image($$$) { + my ($url, $uid, $dir) = @_; + + my $url2 = $url; + $url2 =~ s/\#.*$//s; # Omit search terms after file extension + $url2 =~ s/\?.*$//s; + my ($ext) = ($url =~ m@\.([a-z\d]+)$@si); + ($ext) = ($url2 =~ m@\.([a-z\d]+)$@si) unless $ext; + + # If the feed hasn't put a sane extension on their URLs, nothing's going + # to work. This code assumes that file names have extensions, even the + # ones in the cache directory. + # + if (! $ext) { + print STDERR "$progname: skipping extensionless URL: $url\n" + if ($verbose > 1); + return undef; + } + + # Don't bother downloading files that we will reject anyway. + # + if (! ($url =~ m/$good_file_re/io || + $url2 =~ m/$good_file_re/io)) { + print STDERR "$progname: skipping non-image URL: $url\n" + if ($verbose > 1); + return undef; + } + + my $file = md5_file ($uid); + $file .= '.' . lc($ext) if $ext; + + # Don't bother doing If-Modified-Since to see if the URL has changed. + # If we have already downloaded it, assume it's good. + if (-f "$dir/$file") { + print STDERR "$progname: exists: $dir/$file for $uid / $url\n" + if ($verbose > 1); + return $file; + } + + # Special-case kludge for Flickr: + # Their RSS feeds sometimes include only the small versions of the images. + # So if the URL ends in one of the "small-size" letters, change it to "b". + # + # _o orig, 1600 + + # _k large, 2048 max + # _h large, 1600 max + # _b large, 1024 max + # _c medium, 800 max + # _z medium, 640 max + # "" medium, 500 max + # _n small, 320 max + # _m small, 240 max + # _t thumb, 100 max + # _q square, 150x150 + # _s square, 75x75 + # + # Note: if we wanted to get the _k or _o version instead of the _b or _h + # version, we'd need to crack the DRM -- which is easy: see crack_secret + # in "https://www.jwz.org/hacks/galdown". + # + $url =~ s@_[sqtmnzc](\.[a-z]+)$@_b$1@si + if ($url =~ m@^https?://[^/?#&]*?flickr\.com/@si); + + print STDERR "$progname: downloading: $dir/$file for $uid / $url\n" + if ($verbose > 1); + init_lwp(); + $LWP::Simple::ua->agent ("$progname/$version"); + + $url =~ s/\#.*$//s; # Omit search terms + my $status = LWP::Simple::mirror ($url, "$dir/$file"); + if (!LWP::Simple::is_success ($status)) { + print STDERR "$progname: error $status: $url\n"; # keep going + } + + return $file; +} + + +sub mirror_feed($) { + my ($url) = @_; + + if ($url !~ m/^https?:/si) { # not a URL: local directory. + return (undef, $url); + } + + my $dir = "$ENV{HOME}/Library/Caches"; # MacOS location + if (-d $dir) { + $dir = "$dir/org.jwz.xscreensaver.feeds"; + } elsif (-d "$ENV{HOME}/.cache") { # Gnome "FreeDesktop XDG" location + $dir = "$ENV{HOME}/.cache/xscreensaver"; + if (! -d $dir) { mkdir ($dir) || error ("mkdir $dir: $!"); } + $dir .= "/feeds"; + if (! -d $dir) { mkdir ($dir) || error ("mkdir $dir: $!"); } + } elsif (-d "$ENV{HOME}/tmp") { # If ~/tmp/ exists, use it. + $dir = "$ENV{HOME}/tmp/.xscreensaver-feeds"; + } else { + $dir = "$ENV{HOME}/.xscreensaver-feeds"; + } + + if (! -d $dir) { + mkdir ($dir) || error ("mkdir $dir: $!"); + print STDERR "$progname: mkdir $dir/\n" if ($verbose); + } + + # MD5 for directory name to use for cache of a feed URL. + $dir .= '/' . md5_file ($url); + + if (! -d $dir) { + mkdir ($dir) || error ("mkdir $dir: $!"); + print STDERR "$progname: mkdir $dir/ for $url\n" if ($verbose); + } + + # At this point, we have the directory corresponding to this URL. + # Now check to see if the files in it are up to date, and download + # them if not. + + my $stamp = '.timestamp'; + my $lock = "$dir/$stamp"; + + print STDERR "$progname: awaiting lock: $lock\n" + if ($verbose > 1); + + my $mtime = ((stat($lock))[9]) || 0; + + my $lock_fd; + open ($lock_fd, '+>>', $lock) || error ("unable to write $lock: $!"); + flock ($lock_fd, LOCK_EX) || error ("unable to lock $lock: $!"); + seek ($lock_fd, 0, 0) || error ("unable to rewind $lock: $!"); + + my $poll_p = ($mtime + $feed_max_age < time); + + # --no-cache cmd line arg means poll again right now. + $poll_p = 1 unless ($cache_p); + + # Even if the cache is young, make sure there is at least one file, + # and re-check if not. + # + if (! $poll_p) { + my $count = 0; + opendir (my $dirh, $dir) || error ("$dir: $!"); + foreach my $f (readdir ($dirh)) { + next if ($f =~ m/^\./s); + $count++; + last; + } + closedir $dirh; + + if ($count <= 0) { + print STDERR "$progname: no image files in cache of $url\n" + if ($verbose); + $poll_p = 1; + } + } + + if ($poll_p) { + + print STDERR "$progname: loading $url\n" if ($verbose); + + my %files; + opendir (my $dirh, $dir) || error ("$dir: $!"); + foreach my $f (readdir ($dirh)) { + next if ($f eq '.' || $f eq '..'); + $files{$f} = 0; # 0 means "file exists, should be deleted" + } + closedir $dirh; + + $files{$stamp} = 1; + + # Download each image currently in the feed. + # + my $count = 0; + my @urls = parse_feed ($url); + print STDERR "$progname: " . ($#urls + 1) . " images\n" + if ($verbose > 1); + my %seen_src_urls; + foreach my $p (@urls) { + my ($furl, $id) = @$p; + $furl = expand_url ($furl, $url); + + # No need to download the same image twice, even if it was in the feed + # multiple times under different GUIDs. + next if ($seen_src_urls{$furl}); + $seen_src_urls{$furl} = 1; + + my $f = download_image ($furl, $id, $dir); + next unless $f; + $files{$f} = 1; # Got it, don't delete + $count++; + } + + my $empty_p = ($count <= 0); + + # Now delete any files that are no longer in the feed. + # But if there was nothing in the feed (network failure?) + # then don't blow away the old files. + # + my $kept = 0; + foreach my $f (keys(%files)) { + if ($count <= 0) { + $kept++; + } elsif ($files{$f}) { + $kept++; + } else { + if (unlink ("$dir/$f")) { + print STDERR "$progname: rm $dir/$f\n" if ($verbose > 1); + } else { + print STDERR "$progname: rm $dir/$f: $!\n"; # don't bail + } + } + } + + # Both feed and cache are empty. No files at all. Bail. + error ("empty feed: $url") if ($kept <= 1); + + # Feed is empty, but we have some files from last time. Warn. + print STDERR "$progname: empty feed: using cache: $url\n" + if ($empty_p); + + $mtime = time(); # update the timestamp + + } else { + + # Not yet time to re-check the URL. + print STDERR "$progname: using cache: $url\n" if ($verbose); + + } + + # Unlock and update the write date on the .timestamp file. + # + truncate ($lock_fd, 0) || error ("unable to truncate $lock: $!"); + seek ($lock_fd, 0, 0) || error ("unable to rewind $lock: $!"); + utime ($mtime, $mtime, $lock_fd) || error ("unable to touch $lock: $!"); + flock ($lock_fd, LOCK_UN) || error ("unable to unlock $lock: $!"); + close ($lock_fd); + $lock_fd = undef; + print STDERR "$progname: unlocked $lock\n" if ($verbose > 1); + + # Don't bother using the imageDirectory cache. We know that this directory + # is flat, and we can assume that an RSS feed doesn't contain 100,000 images + # like ~/Pictures/ might. + # + $cache_p = 0; + + # Return the URL and directory name of the files of that URL's local cache. + # + return ($url, $dir); +} + + +sub find_random_file($) { + my ($dir) = @_; + + if ($use_spotlight_p == -1) { + $use_spotlight_p = 0; + if (-x '/usr/bin/mdfind') { + $use_spotlight_p = 1; + } + } + + my $url; + ($url, $dir) = mirror_feed ($dir); + + if ($url) { + $use_spotlight_p = 0; + print STDERR "$progname: $dir is cache for $url\n" if ($verbose > 1); + } + + @all_files = read_cache ($dir); + + if ($#all_files >= 0) { + # got it from the cache... + + } elsif ($use_spotlight_p) { + print STDERR "$progname: spotlighting $dir...\n" if ($verbose); + spotlight_all_files ($dir); + print STDERR "$progname: found " . ($#all_files+1) . + " file" . ($#all_files == 0 ? "" : "s") . + " via Spotlight\n" + if ($verbose); + } else { + print STDERR "$progname: recursively reading $dir...\n" if ($verbose); + find_all_files ($dir); + print STDERR "$progname: " . + "f=" . ($#all_files+1) . "; " . + "d=$dir_count; " . + "s=$stat_count; " . + "skip=${skip_count_unstat}+$skip_count_stat=" . + ($skip_count_unstat + $skip_count_stat) . + ".\n" + if ($verbose); + } + + write_cache ($dir); + + if ($#all_files < 0) { + print STDERR "$progname: no image files in $dir\n"; + exit 1; + } + + my $max_tries = 50; + my $total_files = @all_files; + my $sparse_p = ($total_files < 20); + + # If the directory has a lot of files in it: + # Make a pass through looking for hirez files (assume some are thumbs); + # If we found none, then, select any other file at random. + # Otherwise if there are a small number of files: + # Just select one at random (in case there's like, just one hirez). + + for (my $check_size_p = $sparse_p ? 0 : 1; + $check_size_p >= 0; $check_size_p--) { + + for (my $i = 0; $i < $max_tries; $i++) { + my $n = int (rand ($total_files)); + my $file = $all_files[$n]; + if (!$check_size_p || large_enough_p ($file)) { + if (! $url) { + $file =~ s@^\Q$dir/@@so || die; # remove $dir from front + } + return $file; + } + } + } + + print STDERR "$progname: no suitable images in " . ($url || $dir) . " -- " . + ($total_files <= $max_tries + ? "all $total_files images" + : "$max_tries of $total_files images") . + " are smaller than ${min_image_width}x${min_image_height}.\n"; + + # If we got here, blow away the cache. Maybe it's stale. + unlink $cache_file_name if $cache_file_name; + + exit 1; +} + + +sub large_enough_p($) { + my ($file) = @_; + + my ($w, $h) = image_file_size ($file); + + if (!defined ($h)) { + + # Nonexistent files are obviously too small! + # Already printed $verbose message about the file not existing. + return 0 unless -f $file; + + print STDERR "$progname: $file: unable to determine image size\n" + if ($verbose); + # Assume that unknown files are of good sizes: this will happen if + # they matched $good_file_re, but we don't have code to parse them. + # (This will also happen if the file is junk...) + return 1; + } + + if ($w < $min_image_width || $h < $min_image_height) { + print STDERR "$progname: $file: too small ($w x $h)\n" if ($verbose); + return 0; + } + + print STDERR "$progname: $file: $w x $h\n" if ($verbose); + return 1; +} + + + +# 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, $s); + return (($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|$b)); + + } else { + # We must skip variables, since FFs in variable names aren't + # valid JPEG markers. + return () if (length($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/s); + 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 ($body) = @_; + return () if (length($body) < 10); + my ($w, $h) = gif_size ($body); + if ($w && $h) { return ($w, $h); } + ($w, $h) = jpeg_size ($body); + if ($w && $h) { return ($w, $h); } + # #### TODO: need image parsers for TIFF, XPM, XBM. + return png_size ($body); +} + +# Returns the dimensions of the image file. +# +sub image_file_size($) { + my ($file) = @_; + my $in; + if (! open ($in, '<:raw', $file)) { + print STDERR "$progname: $file: $!\n" if ($verbose); + return (); + } + my $body = ''; + sysread ($in, $body, 1024 * 50); # The first 50k should be enough. + close $in; # (It's not for certain huge jpegs... + return image_size ($body); # but we know they're huge!) +} + + +# Reads the prefs we use from ~/.xscreensaver +# +sub get_x11_prefs() { + my $got_any_p = 0; + + if (open (my $in, '<', $config_file)) { + print STDERR "$progname: reading $config_file\n" if ($verbose > 1); + local $/ = undef; # read entire file + my $body = <$in>; + close $in; + $got_any_p = get_x11_prefs_1 ($body); + + } elsif ($verbose > 1) { + print STDERR "$progname: $config_file: $!\n"; + } + + if (! $got_any_p && defined ($ENV{DISPLAY})) { + # We weren't able to read settings from the .xscreensaver file. + # Fall back to any settings in the X resource database + # (/usr/X11R6/lib/X11/app-defaults/XScreenSaver) + # + print STDERR "$progname: reading X resources\n" if ($verbose > 1); + my $body = `appres XScreenSaver xscreensaver -1`; + $got_any_p = get_x11_prefs_1 ($body); + } +} + + +sub get_x11_prefs_1($) { + my ($body) = @_; + + my $got_any_p = 0; + $body =~ s@\\\n@@gs; + $body =~ s@^[ \t]*#[^\n]*$@@gm; + + if ($body =~ m/^[.*]*imageDirectory:[ \t]*([^\s]+)\s*$/im) { + $image_directory = $1; + $got_any_p = 1; + } + return $got_any_p; +} + + +sub get_cocoa_prefs($) { + my ($id) = @_; + print STDERR "$progname: reading Cocoa prefs: \"$id\"\n" if ($verbose > 1); + my $v = get_cocoa_pref_1 ($id, "imageDirectory"); + $v = '~/Pictures' unless defined ($v); # Match default in XScreenSaverView + $image_directory = $v if defined ($v); +} + + +sub get_cocoa_pref_1($$) { + my ($id, $key) = @_; + # make sure there's nothing stupid/malicious in either string. + $id =~ s/[^-a-z\d. ]/_/gsi; + $key =~ s/[^-a-z\d. ]/_/gsi; + my $cmd = "defaults -currentHost read \"$id\" \"$key\""; + + print STDERR "$progname: executing $cmd\n" + if ($verbose > 3); + + my $val = `$cmd 2>/dev/null`; + $val =~ s/^\s+//s; + $val =~ s/\s+$//s; + + print STDERR "$progname: Cocoa: $id $key = \"$val\"\n" + if ($verbose > 2); + + $val = undef if ($val =~ m/^$/s); + + return $val; +} + + +sub error($) { + my ($err) = @_; + print STDERR "$progname: $err\n"; + exit 1; +} + +sub usage() { + print STDERR "usage: $progname [--verbose] [ directory-or-feed-url ]\n\n" . + " Prints the name of a randomly-selected image file. The directory\n" . + " is searched recursively. Images smaller than " . + "${min_image_width}x${min_image_height} are excluded.\n" . + "\n" . + " The directory may also be the URL of an RSS/Atom feed. Enclosed\n" . + " images will be downloaded and cached locally.\n" . + "\n"; + exit 1; +} + +sub main() { + my $cocoa_id = undef; + my $abs_p = 0; + + while ($_ = $ARGV[0]) { + shift @ARGV; + if (m/^--?verbose$/s) { $verbose++; } + elsif (m/^-v+$/s) { $verbose += length($_)-1; } + elsif (m/^--?name$/s) { } # ignored, for compatibility + elsif (m/^--?spotlight$/s) { $use_spotlight_p = 1; } + elsif (m/^--?no-spotlight$/s) { $use_spotlight_p = 0; } + elsif (m/^--?cache$/s) { $cache_p = 1; } + elsif (m/^--?no-?cache$/s) { $cache_p = 0; } + elsif (m/^--?cocoa$/) { $cocoa_id = shift @ARGV; } + elsif (m/^--?abs(olute)?$/) { $abs_p = 1; } + elsif (m/^-./) { usage; } + elsif (!defined($image_directory)) { $image_directory = $_; } + else { usage; } + } + + # Most hacks (X11 and Cocoa) pass a --directory value on the command line, + # but if they don't, look it up from the resources. Currently this only + # happens with "glitchpeg" which invokes xscreensaver-getimage-file + # directly instead of going through the traditional path. + # + if (! $image_directory) { + if (!defined ($cocoa_id)) { + # see OSX/XScreenSaverView.m + $cocoa_id = $ENV{XSCREENSAVER_CLASSPATH}; + } + + if (defined ($cocoa_id)) { + get_cocoa_prefs($cocoa_id); + error ("no imageDirectory in $cocoa_id") unless $image_directory; + } else { + get_x11_prefs(); + error ("no imageDirectory in X11 resources") unless $image_directory; + } + } + + usage unless (defined($image_directory)); + + $image_directory =~ s@^feed:@http:@si; + + if ($image_directory =~ m/^https?:/si) { + # ok + } else { + $image_directory =~ s@^~/@$ENV{HOME}/@s; # allow literal "~/" + $image_directory =~ s@/+$@@s; # omit trailing / + + if (! -d $image_directory) { + print STDERR "$progname: $image_directory not a directory or URL\n"; + usage; + } + } + + my $file = find_random_file ($image_directory); + + # With --absolute return fully qualified paths instead of relative to --dir. + if ($abs_p && + $file !~ m@^/@ && + $image_directory =~ m@^/@s) { + $file = "$image_directory/$file"; + $file =~ s@//+@/@gs; + } + + print STDOUT "$file\n"; +} + +main; +exit 0; |