slackware-current/source/xap/xscreensaver/xscreensaver-getimage-file-5.14

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#!/usr/bin/perl -w
# Copyright <20> 2001-2011 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.
#
# 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 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: 1.29 $ }; $version =~ s/^[^0-9]+([0-9.]+).*$/$1/;
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# everything if your Spotlight index is out of date, which happens often.)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
# 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', '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.
#
my $min_image_width = 255;
my $min_image_height = 255;
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 $skip_count_stat = 0; # number of files skipped after stat
sub find_all_files($);
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}/tmp") {
$cache_file_name = "$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\L/@@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);
$cache_fd = undef;
}
sub find_random_file($) {
my ($dir) = @_;
if ($use_spotlight_p == -1) {
$use_spotlight_p = 0;
if (-x '/usr/bin/mdfind') {
$use_spotlight_p = 1;
}
}
@all_files = read_cache ($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 ($dir);
# @all_files = sort(@all_files);
if ($#all_files < 0) {
print STDERR "$progname: no files in $dir\n";
exit 1;
}
my $max_tries = 50;
for (my $i = 0; $i < $max_tries; $i++) {
my $n = int (rand ($#all_files + 1));
my $file = $all_files[$n];
if (large_enough_p ($file)) {
$file =~ s@^\Q$dir\L/@@so || die; # remove $dir from front
return $file;
}
}
print STDERR "$progname: no suitable images in $dir " .
"(after $max_tries tries)\n";
exit 1;
}
sub large_enough_p($) {
my ($file) = @_;
my ($w, $h) = image_file_size ($file);
if (!defined ($h)) {
print STDERR "$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, '<', $file)) {
print STDERR "$progname: $file: $!\n" if ($verbose);
return undef;
}
binmode ($in); # Larry can take Unicode and shove it up his ass sideways.
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!)
}
sub error($) {
my ($err) = @_;
print STDERR "$progname: $err\n";
exit 1;
}
sub usage() {
print STDERR "usage: $progname [--verbose] directory\n" .
" Prints the name of a randomly-selected image file. The directory\n" .
" is searched recursively. Images smaller than " .
"${min_image_width}x${min_image_height} are excluded.\n";
exit 1;
}
sub main() {
my $dir = undef;
while ($_ = $ARGV[0]) {
shift @ARGV;
if ($_ eq "--verbose") { $verbose++; }
elsif (m/^-v+$/) { $verbose += length($_)-1; }
elsif ($_ eq "--name") { } # ignored, for compatibility
elsif ($_ eq "--spotlight") { $use_spotlight_p = 1; }
elsif ($_ eq "--no-spotlight") { $use_spotlight_p = 0; }
elsif ($_ eq "--cache") { $cache_p = 1; }
elsif ($_ eq "--no-cache") { $cache_p = 0; }
elsif (m/^-./) { usage; }
elsif (!defined($dir)) { $dir = $_; }
else { usage; }
}
usage unless (defined($dir));
$dir =~ s@^~/@$ENV{HOME}/@s; # allow literal "~/"
$dir =~ s@/+$@@s; # omit trailing /
if (! -d $dir) {
print STDERR "$progname: $dir: not a directory\n";
usage;
}
my $file = find_random_file ($dir);
print STDOUT "$file\n";
}
main;
exit 0;