This file is indexed.

/usr/bin/slack-diff is in slack 0.15.2-4.

This file is owned by root:root, with mode 0o755.

The actual contents of the file can be viewed below.

  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
#!/usr/bin/perl -w
# $Id: slack-diff 122 2006-09-27 07:34:32Z alan $
# vim:sw=2
# vim600:fdm=marker
# Copyright (C) 2004-2006 Alan Sundell <alan@sundell.net>
# All Rights Reserved.  This program comes with ABSOLUTELY NO WARRANTY.
# See the file COPYING for details.
#
# This script is a wrapper for diff that gives output about special files
# and file modes. (diff can only compare regular files)

require 5.006;
use warnings FATAL => qw(all);
use strict;
use sigtrap qw(die untrapped normal-signals
               stack-trace any error-signals);

use Errno;
use File::stat;
use File::Basename;
use File::Find;
use Getopt::Long;
use POSIX qw(SIGPIPE strftime);
use Fcntl qw(:mode);  # provides things like S_IFMT that POSIX does not


my $VERSION = '0.1';
(my $PROG = $0) =~ s#.*/##;
my @diff;       # diff program to use
my $exit = 0;   # our exit code

sub compare ($$);
sub recursive_compare ($$);
sub filetype_to_string ($;$);
sub compare_files ($$);
sub diff ($$);

########################################
# Environment
# Helpful prefix to die messages
$SIG{__DIE__} = sub { die "FATAL[$PROG]: @_"; };
# Set a reasonable umask
umask 077;
# Autoflush on STDOUT
$|=1;
# Autoflush on STDERR
select((select(STDERR), $|=1)[0]);

# Default options
my %opt = (
  fakediff   => 1,
  perms      => 1,
  'new-file' => 1,
  diff       => 'diff',
);

# Config and option parsing
my $usage = <<EOF;
Usage: $PROG [options] <file1> <file2>
       $PROG -r <dir1> <dir2>

Options:
  -u, -U NUM, --unified=NUM
      Tell diff to use unified output format.
  --diff PROG
      Use this program for diffing, instead of "$opt{diff}"
  --fakediff
      Make a fake diff for file modes and other things that are not file
      contents.  Default is on, can be disabled with --nofakediff.
  --perms
      Care about owner, group, and permissions when doing fakediff.
      Default is on, can be disabled with --noperms.
  -r, --recursive
      Recursively compare directories.
  -N, --new-file
      Treat missing files as empty.  Default is on, can be disabled with
      --nonew-file.
  --unidirectional-new-file
      Treat only missing files in the first directory as empty.
  --from-file
      Treat arguments as a list of files from which to read filenames to
      compare, two lines at a time.
  -0, --null
      Use NULLs instead of newlines as the separator in --from-file mode
  --devnullhack
      You have a version of diff that can't deal with -N when not in
      recursive mode, so we need to feed it /dev/null instead of the
      missing file.  Default is on, can be disabled with --nodevnullhack.
  --version
      Output version info
  --help
      Output this help text

Exit codes:
    0   Found no differences
    1   Found a difference
    2   Had a serious error
    3   Found a difference and had a serious error
EOF

{
  Getopt::Long::Configure ("bundling");
  GetOptions(\%opt,
    'help|h|?',
    'version',
    'null|0',
    'devnullhack',
    'new-file|N',
    'u',
    'unified|U=i',
    'recursive|r',
    'from-file',
    'unidirectional-new-file',
    'fakediff!',
    'perms!',
    'diff=s',
    ) or die $usage;
  if ($opt{help}) {
    print $usage;
    exit 0;
  }
  if ($opt{version}) {
    print "$PROG version $VERSION\n";
    exit 0;
  }
}

if ($opt{diff}) {
  # We split on spaces here to be useful -- so that people can give
  # their diff options.
  @diff = split(/\s+/, $opt{diff});
} else {
  die "$PROG: No diff program!\n";
}

if ($opt{'u'}) {
  push @diff, '-u';
} elsif ($opt{'unified'}) {
  $opt{'u'} = 1;  # We use this value later
  push @diff, "--unified=$opt{'unified'}";
}

if (not $opt{'devnullhack'}) {
  push @diff, '-N';
}

# usually, sigpipe would be someone quitting their pager, so don't sweat it
$SIG{PIPE} = sub { exit $exit };

if ($opt{'from-file'}) {
  local $/ = "\0" if $opt{'null'};
  while (my $old = <>) {
    my $new = <>;
    die "Uneven number of lines in --from-file mode!\n"
      if not defined $new;
    chomp($old);
    chomp($new);
    $exit |= compare($old, $new);
  }
} else {
  die $usage unless $#ARGV == 1;
  $exit |= compare($ARGV[0], $ARGV[1]);
}
exit $exit;

##
# Subroutines

sub compare ($$) {
  my ($old, $new) = @_;

  if ($opt{recursive}) {
    return recursive_compare($old, $new);
  } else {
    return compare_files($old, $new);
  }
}

# compare two directories.  We do this by walking down the *new*
# directory, and comparing everything that's there to the stuff in
# the old directory
sub recursive_compare ($$) {
  my ($olddir, $newdir) = @_;
  my ($retval, $basere, $wanted);
  my (%seen);

  $retval = 0;

  if (-d $newdir) {
    $basere = qr(^$newdir);
    $wanted = sub {
      my ($newfile) = $_;
      my $oldfile = $newfile;

      $oldfile =~ s#$basere#$olddir#;
      $seen{$oldfile} = 1;
      $retval |= compare_files($oldfile, $newfile);
    };

    eval { find({ wanted => $wanted , no_chdir => 1}, $newdir) };
    if ($@) {
      warn "$PROG: error during find: $@\n";
      $retval |= 2;
    }
  }
  return $retval
    if $opt{'unidirectional-new-file'};

  # If we're not unidirectional, we want to go through the old directory
  # and diff any files we didn't see in the newdir.
  if (-d $olddir) {
    $basere = qr(^$olddir);
    $wanted = sub {
      my ($oldfile) = $_;
      my $newfile;

      return if $seen{$oldfile};
      $newfile = $oldfile;

      $newfile =~ s#$basere#$newdir#;
      $retval |= compare_files($oldfile, $newfile);
    };

    eval { find({ wanted => $wanted , no_chdir => 1}, $olddir) };
    if ($@) {
      warn "$PROG: error during find: $@\n";
      $retval |= 2;
    }
  }
  return $retval;
}

# filetype_to_string(mode)
# filetype_to_string(mode, plural)
#
# Takes a mode returned from stat(), returns a noune describing the filetype,
# e.g. "directory", "symlink".
# If the "plural" argument is provided and true, returns the plural form of
# the noun, e.g. "directories", "symlinks".
sub filetype_to_string ($;$) {
  my ($mode, $plural) = @_;

  if (S_ISREG($mode)) {
    return "regular file".($plural ? "s" : "");
  } elsif (S_ISDIR($mode)) {
    return "director".($plural ? "ies" : "y");
  } elsif (S_ISLNK($mode)) {
    return "symlink".($plural ? "s" : "");
  } elsif (S_ISBLK($mode)) {
    return "block device".($plural ? "s" : "");
  } elsif (S_ISCHR($mode)) {
    return "character device".($plural ? "s" : "");
  } elsif (S_ISFIFO($mode)) {
    return "fifo".($plural ? "s" : "");
  } elsif (S_ISSOCK($mode)) {
    return "socket".($plural ? "s" : "");
  } else {
    return "unknown filetype".($plural ? "s" : "");
  }
}

# compare_files(oldfile, newfile)
# This is the actual diffing routine.  It's quite long because we need to
# deal with all sorts of special cases.  It will print to STDOUT a
# description of the differences between the two files.  For regular files,
# diff(1) will be run to show the differences.
#
# return codes:
#       1 found a difference
#       2 had an error
#       3 found a difference and had an error
sub compare_files ($$) {
  my ($oldname, $newname) = @_;
  my ($old, $new); # stat buffers
  my $return = 0;

  # Get rid of unsightly double slashes
  $oldname =~ s#//#/#g;
  $newname =~ s#//#/#g;
  
  eval { $old = lstat($oldname); };
  if (not defined $old and not $!{ENOENT}) {
    warn "$PROG: Could not stat $oldname: $!\n";
    return 2;
  }
  eval { $new = lstat($newname); };
  if (not defined $new and not $!{ENOENT}) {
    warn "$PROG: Could not stat $newname: $!\n";
    return 2;
  }
  # At this point, $old or $new should only be undefined if the
  # file does not exist.

  if (defined $old and defined $new) {
    if (S_IFMT($old->mode) != S_IFMT($new->mode)) {
      if ($opt{fakediff}) {
        fakediff('filetype',
          $oldname => filetype_to_string($old->mode),
          $newname => filetype_to_string($new->mode),
        );
      } else {
        print "File types differ between ".
          filetype_to_string($old->mode)." $oldname and ".
          filetype_to_string($new->mode)." $newname\n";
      }
      return 1;
    }
    if ($old->nlink != $new->nlink) {
      # In recursive mode, we don't care about link counts in directories,
      # as we'll pick that up with what files do and don't exist.
      unless ($opt{recursive} and S_ISDIR($old->mode)) {
        if ($opt{fakediff}) {
          fakediff('nlink',
            $oldname => $old->nlink,
            $newname => $new->nlink,
          );
        } else {
          print "Link counts differ between ".
            filetype_to_string($old->mode, 1).
            " $oldname and $newname\n";
        }
        $return = 1;
      }
    } 
    if ($old->uid != $new->uid and $opt{perms}) {
      if ($opt{fakediff}) {
        fakediff('uid',
          $oldname => $old->uid,
          $newname => $new->uid,
        );
      } else {
        print "Owner differs between ".
          filetype_to_string($old->mode, 1).
          " $oldname and $newname\n";
      }
      $return = 1;
    } 
    if ($old->gid != $new->gid and $opt{perms}) {
      if ($opt{fakediff}) {
        fakediff('gid',
          $oldname => $old->gid,
          $newname => $new->gid,
        );
      } else {
        print "Group differs between ".
          filetype_to_string($old->mode, 1).
          " $oldname and $newname\n";
      }
      $return = 1;
    }
    if (S_IMODE($old->mode) != S_IMODE($new->mode) and $opt{perms}) {
      if ($opt{fakediff}) {
        fakediff('mode',
          $oldname => sprintf('%04o', S_IMODE($old->mode)),
          $newname => sprintf('%04o', S_IMODE($new->mode)),
        );
      } else {
        print "Modes differ between ".
          filetype_to_string($old->mode, 1).
          " $oldname and $newname\n";
      }
      $return = 1;
    }

    # We don't want to compare anything more about sockets, fifos, or
    # directories, once we've checked the permissions and link counts
    if (S_ISSOCK($old->mode) or
        S_ISFIFO($old->mode) or
        S_ISDIR($old->mode)) {
      return $return;
    }

    # Check device file devs, and that's it for them
    if (S_ISCHR($old->mode) or
        S_ISBLK($old->mode)) {
      if ($old->rdev != $new->rdev) {
        if ($opt{fakediff}) {
          fakediff('rdev',
            $oldname => $old->rdev,
            $newname => $new->rdev,
          );
        } else {
          print "Device numbers differ between ".
            filetype_to_string($old->mode, 1).
            " $oldname and $newname\n";
        }
        $return = 1;
      }
      return $return;
    }

    # Compare the targets of symlinks
    if (S_ISLNK($old->mode)) {
      my $oldtarget = readlink $oldname
        or (warn("$PROG: Could not readlink($oldname): $!\n"),
            return $return | 2);
      my $newtarget = readlink $newname
        or (warn("$PROG: Could not readlink($newname): $!\n"),
            return $return | 2);
      if ($oldtarget ne $newtarget) {
        if ($opt{fakediff}) {
          fakediff('target',
            $oldname => $oldtarget,
            $newname => $newtarget,
          );
        } else {
          print "Symlink targets differ between $oldname and $newname\n";
        }
        $return = 1;
      }
      return $return;
    }

    if (not S_ISREG($old->mode)) {
      warn "$PROG: Don't know what to do with file mode $old->mode!\n";
      return 2;
    }
  } elsif (not defined $old and not defined $new) {
    print "Neither $oldname nor $newname exists\n";
    return $return;
  } elsif (not defined $old) {
    if (not S_ISREG($new->mode) or not $opt{'new-file'}) {
      print "Only in ".dirname($newname).": ".
            filetype_to_string($new->mode)." ".basename($newname)."\n";
      return 1;
    } elsif ($opt{'devnullhack'}) {
      $oldname = '/dev/null';
    }
  } elsif (not defined $new) {
    if (not S_ISREG($old->mode) or not $opt{'new-file'}) {
      print "Only in ".dirname($oldname).": ".
            filetype_to_string($old->mode)." ".basename($oldname)."\n";
      return 1;
    } elsif ($opt{'devnullhack'}) {
      $newname = '/dev/null';
    }
  }
  # They are regular files!  We can actually run diff!
  return diff($oldname, $newname) | $return;
}

sub diff ($$) {
  my ($oldname, $newname) = @_;
  my @command = (@diff, $oldname, $newname);
  my $status;

  # If we're not specifying unified diff, we need to print a header
  # to indicate what's being diffed.  (I'm not sure if this actually would
  # work for patch, but it does tell our user what's going on).
  # FIXME: We only need to specify this if the files are different
  print "@command\n"
    if not $opt{u};

  {
    # There is a bug in perl with use warnings FATAL => qw(all)
    # that will cause the child process from system() to stick
    # around if there is a warning generated.
    # Shut off warnings -- we'll catch the error below.
    no warnings;
    $status = system(@command);
  }
  return 0 if ($status == 0);
  if ($? == -1) {
    die "$PROG: failed to execute '@command': $!\n";
  }
  if ($? & 128) {
    die "$PROG: '@command' dumped core\n";
  }
  if (my $sig = $? & 127) {
    die "$PROG: '@command' caught sig $sig\n"
      unless ($sig == SIGPIPE);
  }
  if (my $exit = $? >> 8) {
    if ($exit == 1) {
      return 1;
    } else {
      die "$PROG: '@command' returned $exit\n";
    }
  }
  return 0;
}


sub fakediff ($$) {
  my ($type, $oldname, $oldvalue, $newname, $newvalue) = @_;

  return unless $opt{fakediff};
  my $time = strftime('%F %T.000000000 %z', localtime(0));

  # We add a suffix onto the filenames to show we're not actually looking
  # at file contents.  There's no good way to indicate this that's compatible
  # with patch, and this is simple enough.
  $oldname .= '#~~' . $type;
  $newname .= '#~~' . $type;
  
  if ($opt{u}) {
    # fake up a unified diff
    print <<EOF;
--- $oldname\t$time
+++ $newname\t$time
@@ -1 +1 @@
-$oldvalue
+$newvalue
EOF
  } else {
    print <<EOF;
diff $oldname $newname
1c1
< $oldvalue
---
> $newvalue
EOF
  }
}