#!/usr/bin/perl -w # Copyright © 2001-2018 Jamie Zawinski . # # Permission to use, copy, modify, distribute, and sell this software and its # documentation for any purpose is hereby granted without fee, provided that # the above copyright notice appear in all copies and that both that # copyright notice and this permission notice appear in supporting # documentation. No representations are made about the suitability of this # software for any purpose. It is provided "as is" without express or # implied warranty. # # 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 # # (In my experience, this isn't actually any faster, and might not find # everything if your Spotlight index is out of date, which happens often.)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 with RSS or Atom in it, and use that instead. $body =~ 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@( # if (! $iurl) { foreach my $link ($item =~ m@]*>@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 # if (! $iurl) { foreach my $link ($item =~ m@]*>@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 # if (! $iurl) { foreach my $link ($item =~ m@]*>@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 field? # if (! $iurl) { foreach my $link ($item =~ m@]*>([^<>]*)@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 or ... with an # inside. If more than one image, take the first. # foreach my $t ('content:encoded', 'description') { last if $iurl; foreach my $link ($item =~ m@<$t[^<>]*>(.*?)@gsi) { last if $iurl; my $desc = $1; if ($desc =~ m@@gs) { $desc = $1; } else { $desc = html_unquote($desc); } my ($href) = ($desc =~ m@]*\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) = ($item =~ m!]*>\s*([^<>]+?)\s*!si) unless $id; # Then look for ... ($id) = ($item =~ m!]*>\s*([^<>]+?)\s*!si) unless $id; # Then look for ... ($id) = ($item =~ m!]*>\s*([^<>]+?)\s*!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;