summaryrefslogtreecommitdiffstats
path: root/driver/xscreensaver-text
blob: eca1fbf7537c56d498110539518a3691a15591d9 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
#!/usr/bin/perl -w
# Copyright © 2005-2019 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 writes some text to stdout, based on preferences in the
# .xscreensaver file.  It may load a file, a URL, run a program, or just
# print the date.
#
# In a native MacOS build of xscreensaver, this script is included in
# the Contents/Resources/ directory of each screen saver .bundle that
# uses it; and in that case, it looks up its resources using
# /usr/bin/defaults instead.
#
# Created: 19-Mar-2005.

require 5;
#use diagnostics;	# Fails on some MacOS 10.5 systems
use strict;

# 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::UserAgent;' }

# Not sure how prevalent this is. Hope it's part of the default install.
BEGIN { eval 'use HTML::Entities;' }

use Socket;
use POSIX qw(strftime);
use Text::Wrap qw(wrap);
#use bytes;  # This breaks shit.

my $progname = $0; $progname =~ s@.*/@@g;
my ($version) = ('$Revision: 1.48 $' =~ m/\s(\d[.\d]+)\s/s);

my $verbose = 0;
my $http_proxy = undef;

my $config_file = $ENV{HOME} . "/.xscreensaver";
my $text_mode     = 'date';
my $text_literal  = '';
my $text_file     = '';
my $text_program  = '';
my $text_url      = 'https://en.wikipedia.org/w/index.php?title=Special:NewPages&feed=rss';
# Default URL needs to be set and match what's in OSX/XScreenSaverView.m

my $wrap_columns   = undef;
my $truncate_lines = undef;
my $latin1_p = 0;
my $nyarlathotep_p = 0;


# Convert any HTML entities to Latin1 characters.
#
sub de_entify($) {
  my ($text) = @_;

  return '' unless defined($text);
  return $text unless ($text =~ m/&/s);

  # Convert any HTML entities to Unicode characters,
  # if the HTML::Entities module is installed.
  eval {
    my $t2 = $text;
    $text = undef;
    $text = HTML::Entities::decode_entities ($t2);
  };
  return $text if defined($text);

  # If it's not installed, just complain instead of trying to halfass it.
  print STDOUT ("\n\tPerl is broken. Do this to repair it:\n" .
                "\n\tsudo cpan HTML::Entities\n\n");
  exit (1);
}


# Convert any Unicode characters to Latin1 if possible.
# Unconvertable bytes are left alone.
#
sub utf8_to_latin1($) {
  my ($text) = @_;

  utf8::encode ($text);  # Unpack Unicode back to multi-byte UTF-8.

  # Maybe it would be better to handle this in the Unicode domain
  # by doing things like s/\x{2018}/\"/g, but without decoding the
  # string back to UTF-8 first, I'm at a loss as to how to have
  # "&aacute;" print as "\340" instead of as "\303\240".

  $text =~ s/ \xC2 ( [\xA0-\xFF] ) / $1 /gsex;
  $text =~ s/ \xC3 ( [\x80-\xFF] ) / chr (ord($1) | 0x40) /gsex;

  # Handles a few 3-byte sequences too.
  $text =~ s/\xE2\x80\x93/--/gs;
  $text =~ s/\xE2\x80\x94/--/gs;
  $text =~ s/\xE2\x80\x98/`/gs;
  $text =~ s/\xE2\x80\x99/'/gs;
  $text =~ s/\xE2\x80\x9C/``/gs;
  $text =~ s/\xE2\x80\x9D/'/gs;
  $text =~ s/\xE2\x80\xA2/&bull;/gs;
  $text =~ s/\xE2\x80\xA6/.../gs;
  $text =~ s/\xE2\x80\xB2/'/gs;
  $text =~ s/\xE2\x84\xA2/&trade;/gs;
  $text =~ s/\xE2\x86\x90/ &larr; /gs;

  return $text;
}


# 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);
  }

  if ($verbose > 1) {
    print STDERR "$progname: mode:    $text_mode\n";
    print STDERR "$progname: literal: $text_literal\n";
    print STDERR "$progname: file:    $text_file\n";
    print STDERR "$progname: program: $text_program\n";
    print STDERR "$progname: url:     $text_url\n";
  }

  $text_mode =~ tr/A-Z/a-z/;
  $text_literal =~ s@\\n@\n@gs;
  $text_literal =~ s@\\\n@\n@gs;
}


sub get_x11_prefs_1($) {
  my ($body) = @_;

  my $got_any_p = 0;
  $body =~ s@\\\n@@gs;
  $body =~ s@^[ \t]*#[^\n]*$@@gm;

  if ($body =~ m/^[.*]*textMode:[ \t]*([^\s]+)\s*$/im) {
    $text_mode = $1;
    $got_any_p = 1;
  }
  if ($body =~ m/^[.*]*textLiteral:[ \t]*(.*?)[ \t]*$/im) {
    $text_literal = $1;
  }
  if ($body =~ m/^[.*]*textFile:[ \t]*(.*?)[ \t]*$/im) {
    $text_file = $1;
  }
  if ($body =~ m/^[.*]*textProgram:[ \t]*(.*?)[ \t]*$/im) {
    $text_program = $1;
  }
  if ($body =~ m/^[.*]*textURL:[ \t]*(.*?)[ \t]*$/im) {
    $text_url = $1;
  }

  return $got_any_p;
}


sub get_cocoa_prefs($) {
  my ($id) = @_;
  my $v;
 
  print STDERR "$progname: reading Cocoa prefs: \"$id\"\n" if ($verbose > 1);

  $v = get_cocoa_pref_1 ($id, "textMode");
  $text_mode = $v if defined ($v);

  # The "textMode" pref is set to a number instead of a string because I
  # couldn't figure out the black magic to make Cocoa bindings work right.
  #
  # Update: as of 5.33, Cocoa writes strings instead of numbers, but 
  # pre-existing saved preferences might still have numbers in them.
  #
  if    ($text_mode eq '0') { $text_mode = 'date';    }
  elsif ($text_mode eq '1') { $text_mode = 'literal'; }
  elsif ($text_mode eq '2') { $text_mode = 'file';    }
  elsif ($text_mode eq '3') { $text_mode = 'url';     }
  elsif ($text_mode eq '4') { $text_mode = 'program'; }

  $v = get_cocoa_pref_1 ($id, "textLiteral");
  $text_literal = $v if defined ($v);
  $text_literal =~ s@\\n@\n@gs;
  $text_literal =~ s@\\\n@\n@gs;

  $v = get_cocoa_pref_1 ($id, "textFile");
  $text_file = $v if defined ($v);

  $v = get_cocoa_pref_1 ($id, "textProgram");
  $text_program = $v if defined ($v);

  $v = get_cocoa_pref_1 ($id, "textURL");
  $text_url = $v if defined ($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;
}


# like system() but checks errors.
#
sub safe_system(@) {
  my (@cmd) = @_;

  print STDERR "$progname: executing " . join(' ', @cmd) . "\n"
    if ($verbose > 3);

  system @cmd;
  my $exit_value  = $? >> 8;
  my $signal_num  = $? & 127;
  my $dumped_core = $? & 128;
  error ("$cmd[0]: core dumped!") if ($dumped_core);
  error ("$cmd[0]: signal $signal_num!") if ($signal_num);
  error ("$cmd[0]: exited with $exit_value!") if ($exit_value);
}


sub which($) {
  my ($cmd) = @_;

  if ($cmd =~ m@^\./|^/@) {
    error ("cannot execute $cmd") unless (-x $cmd);
    return $cmd;
  }
 
 foreach my $dir (split (/:/, $ENV{PATH})) {
    my $cmd2 = "$dir/$cmd";
    print STDERR "$progname:   checking $cmd2\n" if ($verbose > 3);
    return $cmd2 if (-x "$cmd2");
  }
  error ("$cmd not found on \$PATH");
}


sub output() {

  binmode (STDOUT, ($latin1_p ? ':raw' : ':utf8'));
  binmode (STDERR, ':utf8');

  # Do some basic sanity checking (null text, null file names, etc.)
  #
  if (($text_mode eq 'literal' && $text_literal =~ m/^\s*$/i) ||
      ($text_mode eq 'file'    && $text_file    =~ m/^\s*$/i) ||
      ($text_mode eq 'program' && $text_program =~ m/^\s*$/i) ||
      ($text_mode eq 'url'     && $text_url     =~ m/^\s*$/i)) {
    print STDERR "$progname: falling back to 'date'\n" if ($verbose);
    $text_mode = 'date';
  }

  if ($text_mode eq 'literal') {
    $text_literal = strftime ($text_literal, localtime);
    $text_literal = utf8_to_latin1($text_literal) if ($latin1_p);
    $text_literal =~ y/A-Za-z/N-ZA-Mn-za-m/ if ($nyarlathotep_p);
    print STDOUT $text_literal;
    print STDOUT "\n" unless ($text_literal =~ m/\n$/s);

  } elsif ($text_mode eq 'file') {

    $text_file =~ s@^~/@$ENV{HOME}/@s;     # allow literal "~/"

    if (open (my $in, '<:raw', $text_file)) {
      print STDERR "$progname: reading $text_file\n" if ($verbose);
      binmode (STDOUT, ':raw');

      if (($wrap_columns && $wrap_columns > 0) || $truncate_lines) {
        # read it, then reformat it.
        local $/ = undef;  # read entire file
        my $body = <$in>;
        $body = reformat_text ($body);
        print STDOUT $body;
      } else {
        # stream it by lines
        while (<$in>) { 
          $_ = utf8_to_latin1($_) if ($latin1_p);
          y/A-Za-z/N-ZA-Mn-za-m/ if ($nyarlathotep_p);
          print STDOUT $_;
        }
      }
      close $in;
    } else {
      error ("$text_file: $!");
    }

  } elsif ($text_mode eq 'program') {

    my ($prog, $args) = ($text_program =~ m/^([^\s]+)(.*)$/);
    $text_program = which ($prog) . $args;
    print STDERR "$progname: running $text_program\n" if ($verbose);

    if (($wrap_columns && $wrap_columns > 0) || $truncate_lines) {
      # read it, then reformat it.
      my $lines = 0;
      my $body = "";
      my $cmd = "( $text_program ) 2>&1";
      # $cmd .= " | sed -l"; # line buffer instead of 4k pipe buffer
      open (my $pipe, '-|:unix', $cmd);
      while (my $line = <$pipe>) {
        $body .= $line;
        $lines++;
        last if ($truncate_lines && $lines > $truncate_lines);
      }
      close $pipe;

      # I don't understand why we must do this here, but must not do this
      # in the 'file' branch above, which reads the file with :raw...
      utf8::decode ($body);  # Pack multi-byte UTF-8 back into wide chars.

      $body = reformat_text ($body);
      print STDOUT $body;
    } else {
      # stream it
      safe_system ("$text_program");
    }

  } elsif ($text_mode eq 'url') {

    get_url_text ($text_url);

  } else { # $text_mode eq 'date'

    my $n = `uname -n`;
    $n =~ s/\.local\n/\n/s;
    print $n;

    my $unamep = 1;

    if (-f "/etc/redhat-release") {	    # "Fedora Core release 4 (Stentz)"
      safe_system ("cat", "/etc/redhat-release");
    }

    if (-f "/etc/release") {	    	    # "Solaris 10 3/05 s10_74L2a X86"
      safe_system ("head", "-1", "/etc/release");
    }

    if (-f "/usr/sbin/system_profiler") {   # "Mac OS X 10.4.5 (8H14)"
      my $sp =				    # "iMac G5"
        `/usr/sbin/system_profiler SPSoftwareDataType SPHardwareDataType 2>/dev/null`;
      # system_profiler on OS X 10.10 generates spurious error messages.
      my ($v) = ($sp =~ m/^\s*System Version:\s*(.*)$/mi);
      my ($s) = ($sp =~ m/^\s*(?:CPU|Processor) Speed:\s*(.*)$/mi);
      my ($t) = ($sp =~ m/^\s*(?:Machine|Model) Name:\s*(.*)$/mi);
      print "$v\n" if ($v);
      print "$s $t\n" if ($s && $t);
      $unamep = !defined ($v);
    }

    if ($unamep) {
      safe_system ("uname", "-sr");	    # "Linux 2.6.15-1.1831_FC4"
    }

    print "\n";
    safe_system ("date", "+%c");
    print "\n";
    my $ut = `uptime`;
    $ut =~ s/^[ \d:]*(am|pm)?//i;
    $ut =~ s/,\s*(load)/\n$1/;
    print "$ut\n";
  }

}


# Make an educated guess as to what's in this document.
# We don't necessarily take the Content-Type header at face value.
# Returns 'html', 'rss', or 'text';
#
sub guess_content_type($$) {
  my ($ct, $body) = @_;

  $body =~ s/^(.{512}).*/$1/s;  # only look in first half K of file

  if ($ct =~ m@^text/.*html@i)          { return 'html'; }
  if ($ct =~ m@\b(atom|rss|xml)\b@i)    { return 'rss';  }

  if ($body =~ m@^\s*<\?xml@is)         { return 'rss';  }
  if ($body =~ m@^\s*<!DOCTYPE RSS@is)  { return 'rss';  }
  if ($body =~ m@^\s*<!DOCTYPE HTML@is) { return 'html'; }

  if ($body =~ m@<(BASE|HTML|HEAD|BODY|SCRIPT|STYLE|TABLE|A\s+HREF)\b@i) {
    return 'html';
  }

  if ($body =~ m@<(RSS|CHANNEL|GENERATOR|DESCRIPTION|CONTENT|FEED|ENTRY)\b@i) {
    return 'rss';
  }

  return 'text';
}


sub reformat_html($$) {
  my ($body, $rss_p) = @_;
  $_ = $body;

  # In HTML, try to preserve newlines inside of PRE.
  #
  if (! $rss_p) {
    s@(<PRE\b[^<>]*>\s*)(.*?)(</PRE)@{
      my ($a, $b, $c) = ($1, $2, $3);
      $b =~ s/[\r\n]/<BR>/gs;
      $a . $b . $c;
     }@gsexi;
  }

  if (! $rss_p) {
    # In HTML, unfold lines.
    # In RSS, assume \n means literal line break.
    s@[\r\n]@ @gsi;
  }

  # This right here is the part where I doom us all to inhuman
  # toil for the One whose Name cannot be expressed in the
  # Basic Multilingual Plane. http://jwz.org/b/yhAT He comes.

  s@<!--.*?-->@@gsi;				 # lose comments
  s@<(STYLE|SCRIPT)\b[^<>]*>.*?</\1\s*>@@gsi;    # lose css and js

  s@</?(BR|TR|TD|LI|DIV)\b[^<>]*>@\n@gsi; # line break at BR, TD, DIV, etc
  s@</?(P|UL|OL|BLOCKQUOTE)\b[^<>]*>@\n\n@gsi; # two line breaks

  s@<lj\s+user=\"?([^<>\"]+)\"?[^<>]*>?@$1@gsi;  # handle <LJ USER=>
  s@</?[BI]>@*@gsi;		                 # bold, italic => asterisks


  s@<[^<>]*>?@@gs;                # lose all other HTML tags
  $_ = de_entify ($_);            # convert HTML entities

  # For Wikipedia: delete anything inside {{ }} and unwrap [[tags]],
  # among other things.
  #
  if ($rss_p eq 'wiki') {

    s@<!--.*?-->@@gsi;				 # lose HTML comments again

    # Creation line is often truncated: screws up parsing with unbalanced {{.
    s@(: +[^a-zA-Z ]* *Created page) with [^\n]+@$1@s;

    s@/\*.*?\*/@@si;				   # /* ... */

    # Try to omit all tables, since they're impossible to read as text.
    #
    1 while (s/\{\{[^{}]*}}/ /gs);		   # {{ ... }}
    1 while (s/\{\|.*?\|\}/\n\n/gs);		   # {| ... |}
    1 while (s/\|-.*?\|/ /gs);			   # |- ... |  (table cell)

    # Convert anchors to something more readable.
    #
    s/\[\[([^\[\]\|]+)\|([^\[\]]+)\]\]/$2/gs;	   # [[link|anchor]]
    s/\[\[([^:\[\]\|]+)\]\]/$1/gs;		   # [[anchor]]
    s/\[https?:[^\[\]\s]+\s+([^\[\]]+)\]/$1/gs;	   # [url anchor]

    # Convert all references to asterisks.
    s@\s*<ref>\s*.*?</ref>@*@gs;		   # <ref> ... <ref> ->  "*"
    s@\n[ \t]*\d+\s*\^\s*http[^\s]+[ \t]*\n@\n@gs; # 1 ^ URL (a Reflist)

    s@\[\[File:([^\|\]]+).*?\]\]@\n$1\n@gs;	  # [[File: X | ... ]]
    s@\[\[Category:.*?\]\]@@gs;			  # omit categories

    s/<[^<>]*>//gs;	# Omit all remaining tags
    s/\'{3,}//gs;	# Omit ''' and ''''
    s/\'\'/\"/gs;	# ''  ->  "
    s/\`\`/\"/gs;	# ``  ->  "
    s/\"\"+/\"/gs;	# ""  ->  "

    s/^[ \t]*[*#]+[ \t]*$//gm;	# Omit lines with just * or # on them

    # Omit trailing headlines with no text after them (e.g. == Notes ==)
    1 while (s/\n==+[ \t]*[^\n=]+[ \t]*==+\s*$/\n/s);

    $_ = de_entify ($_);            # convert HTML entities, again
  }


  # elide any remaining non-Latin1 binary data.
  if ($latin1_p) {
    utf8::encode ($_);  # Unpack Unicode back to multi-byte UTF-8.
    s/([^\000-\176]+(\s*[^\000-\176]+)[^a-z\d]*)/\xAB...\xBB /g;
  }

  $_ .= "\n";

  s/[ \t]+$//gm;                  # lose whitespace at end of line
  s@\n\n\n+@\n\n@gs;              # compress blank lines

  if (!defined($wrap_columns) || $wrap_columns > 0) {
    $Text::Wrap::columns = ($wrap_columns || 72);
    $Text::Wrap::break = '[\s/|]';  # wrap on slashes for URLs
    $_ = wrap ("", "  ", $_);       # wrap the lines as a paragraph
    s/[ \t]+$//gm;                  # lose whitespace at end of line again
  }

  s/^\n+//gs;

  if ($truncate_lines) {
    s/^(([^\n]*\n){$truncate_lines}).*$/$1/s;
  }

  $_ = utf8_to_latin1($_) if ($latin1_p);
  y/A-Za-z/N-ZA-Mn-za-m/ if ($nyarlathotep_p);

  return $_;
}


sub reformat_rss($) {
  my ($body) = @_;

  my $wiki_p = ($body =~ m@<generator>[^<>]*Wiki@si);

  $body =~ s/(<(ITEM|ENTRY)\b)/\001\001$1/gsi;
  my @items = split (/\001\001/, $body);

  print STDERR "$progname: converting RSS ($#items items)...\n"
    if ($verbose > 2);

  shift @items;

  # Let's skip forward in the stream by a random amount, so that if
  # two copies of ljlatest are running at the same time (e.g., on a
  # multi-headed machine), they get different text.  (Put the items
  # that we take off the front back on the back.)
  #
  if ($#items > 7) {
    my $n = int (rand ($#items - 5));
    print STDERR "$progname: rotating by $n items...\n" if ($verbose > 2);
    while ($n-- > 0) {
      push @items, (shift @items);
    }
  }

  my $out = '';

  my $i = -1;
  foreach (@items) {
    $i++;

    my ($title, $author, $body1, $body2, $body3);
    
    $title = $3 if (m@<((TITLE)       [^<>\s]*)[^<>]*>\s*(.*?)\s*</\1>@xsi);
    $author= $3 if (m@<((DC:CREATOR)  [^<>\s]*)[^<>]*>\s*(.*?)\s*</\1>@xsi);
    $body1 = $3 if (m@<((DESCRIPTION) [^<>\s]*)[^<>]*>\s*(.*?)\s*</\1>@xsi);
    $body2 = $3 if (m@<((CONTENT)     [^<>\s]*)[^<>]*>\s*(.*?)\s*</\1>@xsi);
    $body3 = $3 if (m@<((SUMMARY)     [^<>\s]*)[^<>]*>\s*(.*?)\s*</\1>@xsi);

    # If there are both <description> and <content> or <content:encoded>,
    # use whichever one contains more text.
    #
    if ($body3 && length($body3) >= length($body2 || '')) {
      $body2 = $body3;
    }
    if ($body2 && length($body2) >= length($body1 || '')) {
      $body1 = $body2;
    }

    if (! $body1) {
      if ($title) {
        print STDERR "$progname: no body in item $i (\"$title\")\n"
          if ($verbose > 2);
      } else {
        print STDERR "$progname: no body or title in item $i\n"
          if ($verbose > 2);
        next;
      }
    }

    $title = rss_field_to_html ($title || '');
    $author= rss_field_to_html ($author || '');
    $body1 = rss_field_to_html ($body1 || '');

    $title = '' if ($body1 eq $title);  # Identical in Twitter's atom feed.

    # Omit author if it's in the title or body
    $author = '' if ($author &&
                     ($title =~ m/\Q$author\E/si ||
                      $body1 =~ m/\Q$author\E/si));

    $title = $author if ($author && !$title);
    $title = "$author: $title" if ($author && $title);

    $out .= reformat_html ("$title<P>$body1", $wiki_p ? 'wiki' : 'rss');
    $out .= "\n";
  }

  if ($truncate_lines) {
    $out =~ s/^(([^\n]*\n){$truncate_lines}).*$/$1/s;
  }

  return $out;
}


sub rss_field_to_html($) {
  my ($body) = @_;

  # If <![CDATA[...]]> is present, everything inside that is HTML,
  # and not double-encoded.
  #
  if ($body =~ m/^\s*<!\[CDATA\[(.*?)\]\s*\]/is) {
    $body = $1;
  } else {
    $body = de_entify ($body);      # convert entities to get HTML from XML
  }

  return $body;
}


sub reformat_text($) {
  my ($body) = @_;

  # only re-wrap if --cols was specified.  Otherwise, dump it as is.
  #
  if ($wrap_columns && $wrap_columns > 0) {
    print STDERR "$progname: wrapping at $wrap_columns...\n" if ($verbose > 2);
    $Text::Wrap::columns = $wrap_columns;
    $Text::Wrap::break = '[\s/]';  # wrap on slashes for URLs
    $body = wrap ("", "", $body);
    $body =~ s/[ \t]+$//gm;
  }

  if ($truncate_lines) {
    $body =~ s/^(([^\n]*\n){$truncate_lines}).*$/$1/s;
  }

  $body = utf8_to_latin1($body) if ($latin1_p);
  $body =~ y/A-Za-z/N-ZA-Mn-za-m/ if ($nyarlathotep_p);
  return $body;
}


# 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 get_url_text($) {
  my ($url) = @_;

  my $ua = eval 'LWP::UserAgent->new';

  if (! $ua) {
    print STDOUT ("\n\tPerl is broken. Do this to repair it:\n" .
                  "\n\tsudo cpan LWP::UserAgent" .
                  " LWP::Protocol::https Mozilla::CA\n\n");
    return;
  }

  # 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".
  #
  # I'm going to take a controversial stand here and say that, for the
  # purposes of plain-text being displayed in a screen saver via RSS,
  # the chances of a certificate-based man-in-the-middle attack having
  # a malicious effect on anyone anywhere at any time is so close to
  # zero that it can be discounted.  So, just don't bother validating
  # SSL connections.
  #
  $ENV{'PERL_LWP_SSL_VERIFY_HOSTNAME'} = 0;
  eval {
    $ua->ssl_opts (verify_hostname => 0, SSL_verify_mode => 0);
  };


  set_proxy ($ua);
  $ua->agent ("$progname/$version");
  my $res = $ua->get ($url);
  my $body;
  my $ct;

  if ($res && $res->is_success) {
    $body = $res->decoded_content || '';
    $ct   = $res->header ('Content-Type') || 'text/plain';

  } else {
    my $err = ($res ? $res->status_line : '') || '';
    $err = 'unknown error' unless $err;
    $err = "$url: $err";
    # error ($err);
    $body = "Error loading URL $err\n\n";
    $ct = 'text/plain';
  }

  # This is not necessary, since HTTP::Message::decoded_content() has
  # already done 'decode (<charset-header>, $body)'.
  # utf8::decode ($body);  # Pack multi-byte UTF-8 back into wide chars.

  $ct = guess_content_type ($ct, $body);
  if ($ct eq 'html') {
    print STDERR "$progname: converting HTML...\n" if ($verbose > 2);
    $body = reformat_html ($body, 0);
  } elsif ($ct eq 'rss')  {
    $body = reformat_rss ($body);
  } else {
    print STDERR "$progname: plain text...\n" if ($verbose > 2);
    $body = reformat_text ($body);
  }
  print STDOUT $body;
}



sub error($) {
  my ($err) = @_;
  print STDERR "$progname: $err\n";
  exit 1;
}

sub usage() {
  print STDERR "usage: $progname [ --options ... ]\n" .
   ("\n" .
    "       Prints out some text for use by various screensavers,\n" .
    "       according to the options in the ~/.xscreensaver file.\n" .
    "       This may dump the contents of a file, run a program,\n" .
    "       or load a URL.\n".
    "\n" .
    "   Options:\n" .
    "\n" .
    "       --date           Print the host name and current time.\n" .
    "\n" .
    "       --text STRING    Print out the given text.  It may contain %\n" .
    "                        escape sequences as per strftime(2).\n" .
    "\n" .
    "       --file PATH      Print the contents of the given file.\n" .
    "                        If --cols is specified, re-wrap the lines;\n" .
    "                        otherwise, print them as-is.\n" .
    "\n" .
    "       --program CMD    Run the given program and print its output.\n" .
    "                        If --cols is specified, re-wrap the output.\n" .
    "\n" .
    "       --url HTTP-URL   Download and print the contents of the HTTP\n" .
    "                        document.  If it contains HTML, RSS, or Atom,\n" .
    "                        it will be converted to plain-text.\n" .
    "\n" .
    "       --cols N         Wrap lines at this column.  Default 72.\n" .
    "\n" .
    "       --lines N        No more than N lines of output.\n" .
    "\n" .
    "       --latin1         Emit Latin1 instead of UTF-8.\n" .
    "\n");
  exit 1;
}

sub main() {

  my $load_p = 1;
  my $cocoa_id = undef;

  while ($#ARGV >= 0) {
    $_ = shift @ARGV;
    if ($_ eq "--verbose") { $verbose++; }
    elsif (m/^-v+$/) { $verbose += length($_)-1; }
    elsif (m/^--?date$/)    { $text_mode = 'date';
                              $load_p = 0; }
    elsif (m/^--?text$/)    { $text_mode = 'literal';
                              $text_literal = shift @ARGV || '';
                              $text_literal =~ s@\\n@\n@gs;
                              $text_literal =~ s@\\\n@\n@gs;
                              $load_p = 0; }
    elsif (m/^--?file$/)    { $text_mode = 'file';
                              $text_file = shift @ARGV || '';
                              $load_p = 0; }
    elsif (m/^--?program$/) { $text_mode = 'program';
                              $text_program = shift @ARGV || '';
                              $load_p = 0; }
    elsif (m/^--?url$/)     { $text_mode = 'url';
                              $text_url = shift @ARGV || '';
                              $load_p = 0; }
    elsif (m/^--?col(umn)?s?$/) { $wrap_columns = 0 + shift @ARGV; }
    elsif (m/^--?lines?$/)  { $truncate_lines = 0 + shift @ARGV; }
    elsif (m/^--?cocoa$/)   { $cocoa_id = shift @ARGV; }
    elsif (m/^--?latin1$/)  { $latin1_p++; }
    elsif (m/^--?nyarlathotep$/) { $nyarlathotep_p++; }
    elsif (m/^-./) { usage; }
    else { usage; }
  }

  if ($load_p) {

    if (!defined ($cocoa_id)) {
      # see OSX/XScreenSaverView.m
      $cocoa_id = $ENV{XSCREENSAVER_CLASSPATH};
    }

    if (defined ($cocoa_id)) {
      get_cocoa_prefs($cocoa_id);
    } else {
      get_x11_prefs();
    }
  }

  output();


  if (defined ($cocoa_id)) {
    #
    # On MacOS, sleep for 10 seconds between when the last output is
    # printed, and when this process exits.  This is because MacOS
    # 10.5.0 and later broke ptys in a new and exciting way: basically,
    # once the process at the end of the pty exits, you have exactly
    # 1 second to read all the queued data off the pipe before it is
    # summarily flushed.
    #
    # Many of the screen savers were written to depend on being able
    # to read a small number of bytes, and continue reading until they
    # reached EOF.  This is no longer possible.
    #
    # Note that the current MacOS behavior has all four of these
    # awesome properties: 1) Inconvenient; 2) Has no sane workaround;
    # 3) Different behavior than MacOS 10.1 through 10.4; and 4)
    # Different behavior than every other Unix in the world.
    #
    # See http://jwz.org/b/DHke, and for those of you inside Apple,
    # "Problem ID 5606018".
    #
    # One workaround would be to rewrite the savers to have an
    # internal buffer, and always read as much data as possible as
    # soon as a pipe has input available.  However, that's a lot more
    # work, so instead, let's just not exit right away, and hope that
    # 10 seconds is enough.
    #
    # This will solve the problem for invocations of xscreensaver-text
    # that produce little output (e.g., date-mode); and won't solve it
    # in cases where a large amount of text is generated in a short
    # amount of time (e.g., url-mode.)
    #
    sleep (10);
  }
}

main();
exit 0;