This file is indexed.

postrm is in linux-image-4.13.0-16-generic 4.13.0-16.19~16.04.3.

This file is a maintainer script. It is executed when installing (*inst) or removing (*rm) the package.

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
#! /usr/bin/perl
#                              -*- Mode: Cperl -*- 
# image.postrm --- 
# Author           : Manoj Srivastava ( srivasta@glaurung.green-gryphon.com ) 
# Created On       : Sat May 15 11:05:13 1999
# Created On Node  : glaurung.green-gryphon.com
# Last Modified By : Manoj Srivastava
# Last Modified On : Wed Sep 13 11:26:19 2006
# Last Machine Used: glaurung.internal.golden-gryphon.com
# Update Count     : 57
# Status           : Unknown, Use with caution!
# HISTORY          : 
# Description      : 
# 
#     $Id: image.postrm,v 1.31 2003/10/07 16:24:20 srivasta Exp $
#


# 
#use strict; #for debugging
use Cwd 'abs_path';

$|=1;

# Predefined values:
my $version           = "4.13.0-16-generic";
my $link_in_boot      = "";	# Should be empty, mostly
my $no_symlink        = "";	# Should be empty, mostly
my $reverse_symlink   = "";	# Should be empty, mostly
my $do_symlink        = "Yes";	# target machine defined
my $do_boot_enable    = "Yes";	# target machine defined
my $do_bootfloppy     = "Yes";	# target machine defined
my $do_bootloader     = "Yes";	# target machine defined
my $move_image        = '';       # target machine defined
my $kimage            = "vmlinuz";	# Should be empty, mostly
my $loader            = "grub";     # lilo, silo, quik, palo, vmelilo, or nettrom
my $image_dir         = "/boot";     # where the image is located
my $clobber_modules   = '';       # target machine defined
my $initrd            = "YES";     # initrd kernel
my $do_initrd         = '';       # Normally, we don't
my $warn_initrd       = 'YES';    # Normally we do
my $use_hard_links    = '';       # hardlinks do not work across fs boundaries
my $postinst_hook     = '';       #Normally we do not
my $postrm_hook       = '';       #Normally we do not
my $preinst_hook      = '';       #Normally we do not
my $prerm_hook        = '';       #Normally we do not
my $minimal_swap      = '';       # Do not swap symlinks
my $ignore_depmod_err = '';	# normally we do not
my $relink_build_link = 'YES';	# There is no harm in checking the link
my $force_build_link  = '';	# we shall not create a dangling link
my $kernel_arch       = "x86";
my $ramdisk           = "/usr/sbin/update-initramfs";
my $package_name    = "linux-image-$version";

my $Loader          = "NoLOADER"; # 
$Loader             = "LILO"     if $loader =~ /^lilo/io;
$Loader             = "SILO"     if $loader =~ /^silo/io;
$Loader             = "QUIK"     if $loader =~ /^quik/io;
$Loader             = "yaboot"   if $loader =~ /^yaboot/io;
$Loader             = "PALO"     if $loader =~ /^palo/io;
$Loader             = "NETTROM"  if $loader =~ /^nettrom/io;
$Loader             = "VMELILO"  if $loader =~ /^vmelilo/io;
$Loader             = "ZIPL"     if $loader =~ /^zipl/io;
$Loader             = "ELILO"    if $loader =~ /^elilo/io;


# This should not point to /tmp, because of security risks.
my $temp_file_name = "/var/log/$loader" . "_log.$$";

#known variables
my @boilerplate     = ();
my @silotemplate    = ();
my @quiktemplate    = ();
my @palotemplate    = ();
my @vmelilotemplate = ();
my $bootdevice      = '';
my $rootdevice      = '';
my $rootdisk        = '';
my $rootpartition   = '';
my $image_dest      = "/";
my $realimageloc    = "/$image_dir/";
my $have_conffile   = "";
my $CONF_LOC        = '/etc/kernel-img.conf';
my $relative_links = '';
my $silent_modules  = '';
my $silent_loader   = '';
my $warn_reboot     = 'Yes';     # Warn that we are installing a version of
                                 # the kernel we are running

chdir('/')           or die "could not chdir to /:$!\n";
# remove multiple leading slashes; make sure there is at least one.
$realimageloc  =~ s|^/*|/|o;
$realimageloc  =~ s|/+|/|o;


if (-r "$CONF_LOC" && -f "$CONF_LOC"  ) {
  if (open(CONF, "$CONF_LOC")) {
    while (<CONF>) {
      chomp;
      s/\#.*$//g;
      next if /^\s*$/;

      $do_symlink      = "" if /^\s*do_symlinks\s*=\s*(no|false|0)\s*$/ig;
      $no_symlink      = "" if /^\s*no_symlinks\s*=\s*(no|false|0)\s*$/ig;
      $reverse_symlink = "" if /^\s*reverse_symlinks\s*=\s*(no|false|0)\s*$/ig;
      $link_in_boot    = "" if /^\s*image_in_boot\s*=\s*(no|false|0)\s*$/ig;
      $link_in_boot    = "" if /^\s*link_in_boot\s*=\s*(no|false|0)\s*$/ig;
      $move_image      = "" if /^\s*move_image\s*=\s*(no|false|0)\s*$/ig;
      $clobber_modules = '' if /^\s*clobber_modules\s*=\s*(no|false|0)\s*$/ig;
      $do_boot_enable  = '' if /^\s*do_boot_enable\s*=\s*(no|false|0)\s*$/ig;
      $do_bootfloppy   = '' if /^\s*do_bootfloppy\s*=\s*(no|false|0)\s*$/ig;
      $relative_links  = '' if /^\s*relative_links \s*=\s*(no|false|0)\s*$/ig;
      $do_bootloader   = '' if /^\s*do_bootloader\s*=\s*(no|false|0)\s*$/ig;
      $do_initrd       = '' if /^\s*do_initrd\s*=\s*(no|false|0)\s*$/ig;
      $warn_initrd     = '' if /^\s*warn_initrd\s*=\s*(no|false|0)\s*$/ig;
      $use_hard_links  = '' if /^\s*use_hard_links\s*=\s*(no|false|0)\s*$/ig;
      $silent_modules  = '' if /^\s*silent_modules\s*=\s*(no|false|0)\s*$/ig;
      $silent_loader   = '' if /^\s*silent_loader\s*=\s*(no|false|0)\s*$/ig;
      $warn_reboot     = '' if /^\s*warn_reboot\s*=\s*(no|false|0)\s*$/ig;
      $minimal_swap    = '' if /^\s*minimal_swap\s*=\s*(no|false|0)\s*$/ig;
      $ignore_depmod_err = '' if /^\s*ignore_depmod_err\s*=\s*(no|false|0)\s*$/ig;
      $relink_build_link = '' if /^\s*relink_build_link\s*=\s*(no|false|0)\s*$/ig;
      $force_build_link = '' if /^\s*force_build_link\s*=\s*(no|false|0)\s*$/ig;

      $do_symlink      = "Yes" if /^\s*do_symlinks\s*=\s*(yes|true|1)\s*$/ig;
      $no_symlink      = "Yes" if /^\s*no_symlinks\s*=\s*(yes|true|1)\s*$/ig;
      $reverse_symlink = "Yes" if /^\s*reverse_symlinks\s*=\s*(yes|true|1)\s*$/ig;
      $link_in_boot    = "Yes" if /^\s*image_in_boot\s*=\s*(yes|true|1)\s*$/ig;
      $link_in_boot    = "Yes" if /^\s*link_in_boot\s*=\s*(yes|true|1)\s*$/ig;
      $move_image      = "Yes" if /^\s*move_image\s*=\s*(yes|true|1)\s*$/ig;
      $clobber_modules = "Yes" if /^\s*clobber_modules\s*=\s*(yes|true|1)\s*$/ig;
      $do_boot_enable  = "Yes" if /^\s*do_boot_enable\s*=\s*(yes|true|1)\s*$/ig;
      $do_bootfloppy   = "Yes" if /^\s*do_bootfloppy\s*=\s*(yes|true|1)\s*$/ig;
      $do_bootloader   = "Yes" if /^\s*do_bootloader\s*=\s*(yes|true|1)\s*$/ig;
      $relative_links  = "Yes" if /^\s*relative_links\s*=\s*(yes|true|1)\s*$/ig;
      $do_initrd       = "Yes" if /^\s*do_initrd\s*=\s*(yes|true|1)\s*$/ig;
      $warn_initrd     = "Yes" if /^\s*warn_initrd\s*=\s*(yes|true|1)\s*$/ig;
      $use_hard_links  = "Yes" if /^\s*use_hard_links\s*=\s*(yes|true|1)\s*$/ig;
      $silent_modules  = 'Yes' if /^\s*silent_modules\s*=\s*(yes|true|1)\s*$/ig;
      $silent_loader   = 'Yes' if /^\s*silent_loader\s*=\s*(yes|true|1)\s*$/ig;
      $warn_reboot     = 'Yes' if /^\s*warn_reboot\s*=\s*(yes|true|1)\s*$/ig;
      $minimal_swap    = 'Yes' if /^\s*minimal_swap\s*=\s*(yes|true|1)\s*$/ig;
      $ignore_depmod_err = 'Yes' if /^\s*ignore_depmod_err\s*=\s*(yes|true|1)\s*$/ig;
      $relink_build_link = 'Yes' if /^\s*relink_build_link\s*=\s*(yes|true|1)\s*$/ig;
      $force_build_link = 'Yes' if /^\s*force_build_link\s*=\s*(yes|true|1)\s*$/ig;

      $image_dest      = "$1"  if /^\s*image_dest\s*=\s*(\S+)/ig;
      $postinst_hook   = "$1"  if /^\s*postinst_hook\s*=\s*(\S+)/ig;
      $postrm_hook     = "$1"  if /^\s*postrm_hook\s*=\s*(\S+)/ig;
      $preinst_hook    = "$1"  if /^\s*preinst_hook\s*=\s*(\S+)/ig;
      $prerm_hook      = "$1"  if /^\s*prerm_hook\s*=\s*(\S+)/ig;
      $ramdisk         = "$1"  if /^\s*ramdisk\s*=\s*(.+)$/ig;
    }
    close CONF;
    $have_conffile = "Yes";
  }
}

$initrd = '' if (! -x "$ramdisk");

if ($link_in_boot) {
  $image_dest = "/$image_dir/";
  $image_dest =~ s|^/*|/|o;
}

$image_dest = "$image_dest/";
$image_dest =~ s|/+$|/|o;

# The destdir may be gone by now.
if (-d "$image_dest") {
  chdir("$image_dest") or die "could not chdir to $image_dest:$!\n";
}

# Paranoid check to make sure that the correct value is put in there
if (! $kimage)                    {$kimage = "vmlinuz"} # Hmm. empty
elsif ($kimage =~ m/^b?uImage$/o) {$kimage = "vmlinuz"} # these produce vmlinuz
elsif ($kimage =~ m/^b?zImage$/o) {$kimage = "vmlinuz"} # these produce vmlinuz
elsif ($kimage =~ m/^[iI]mage$/o) { my $nop = $kimage;}
elsif ($kimage =~ m/^vmlinux$/o)  { my $nop = $kimage;}
else                              {$kimage = "vmlinuz"} # default

$ENV{KERNEL_ARCH}=$kernel_arch if $kernel_arch;


######################################################################
######################################################################
############
######################################################################
######################################################################
sub remove_sym_link {
  my $bad_image = $_[0];

  warn "Removing symbolic link $bad_image \n";
  if ($loader =~ /lilo/i) 
    {
      warn "Unless you used the optional flag in lilo, \n";
    }
  warn " you may need to re-run your boot loader" . ($loader ? "[$loader]":"")
    . "\n";
  # Remove the dangling link
  unlink "$bad_image";
}

######################################################################
######################################################################
############
######################################################################
######################################################################
sub CanonicalizePath {
  my $path = join '/', @_;
  my @work = split '/', $path;
  my @out;
  my $is_absolute;

  if (@work && $work[0] eq "") { $is_absolute = 1; shift @work; }

  while (@work) {
    my $seg = shift @work;
    if ($seg eq "." || $seg eq "") {
    } elsif ($seg eq "..") {
      if (@out && $out[-1] ne "..") {
        pop @out;
      } else {
        # Leading "..", or "../..", etc.
        push @out, $seg;
      }
    } else {
      push @out, $seg;
    }
  }

  unshift @out, "" if $is_absolute;
  return join('/', @out);
}

######################################################################
######################################################################
############
######################################################################
######################################################################
# This removes dangling symlinks. What do we do about hard links? Surely a 
# something with the nane $image_dest . "$kimage" ought not to be left behind? 
sub image_magic {
  my $kimage = $_[0];
  my $image_dest = $_[1];

  if (-l "$kimage") {
    # There is a symbolic link
    my $force_move = 0;
    my $vmlinuz_target = readlink "$kimage";
    my $real_target = '';
    $real_target = abs_path($vmlinuz_target) if defined ($vmlinuz_target);
    if (!defined($vmlinuz_target) || ! -f "$real_target") {
      # what, a dangling symlink?
      warn "The link "  . $image_dest . "$kimage is a damaged link\n";
      # Remove the dangling link
      &remove_sym_link("$kimage");
    }
    else {
      my $canonical_target = CanonicalizePath("$vmlinuz_target");
      if (! -e $canonical_target) {
	warn "The link "  . $image_dest . "$kimage is a dangling link\n";
	&remove_sym_link("$kimage");
      }
    }
  }
}

# set the env var stem
$ENV{'STEM'} = "linux";

sub exec_script {
  my $type   = shift;
  my $script = shift;
  print STDERR "Running $type hook script $script.\n";
  system ("$script $version $realimageloc$kimage-$version") &&
    print STDERR "User $type hook script [$script] ";
  if ($?) {
    if ($? == -1) {
      print STDERR "failed to execute: $!\n";
    }
    elsif ($? & 127) {
      printf STDERR "died with signal %d, %s coredump\n",
        ($? & 127),  ($? & 128) ? 'with' : 'without';
    }
    else {
      printf STDERR "exited with value %d\n", $? >> 8;
    }
  }
}
sub run_hook {
  my $type   = shift;
  my $script = shift;
  if ($script =~ m,^/,) {
    # Full path provided for the hook script
    if (-x "$script") {
      &exec_script($type,$script);
    }
    else {
      warn "The provided $type hook script [$script] could not be run.\n";
    }
  }
  else {
    # Look for it in a safe path
    for my $path ('/bin', '/sbin', '/usr/bin', '/usr/sbin') {
      if (-x "$path/$script") {
        &exec_script($type, "$path/$script");
        return 0;
      }
    }
    # No luck
    print STDERR "Could not find $type hook script [$script].\n";
    warn "Looked in: '/bin', '/sbin', '/usr/bin', '/usr/sbin'\n";
  }
}

my $options;
for (@ARGV) {
	s,','\\'',g;
	$options .= " '$_'";
}
$ENV{'DEB_MAINT_PARAMS'}="$options";

## Run user hook script here, if any
if ($postrm_hook) {
  &run_hook("postrm", $postrm_hook);
}
if (-d "/etc/kernel/postrm.d") {
  warn "Examining /etc/kernel/postrm.d .\n";
  system ("run-parts --verbose --exit-on-error --arg=$version " .
          "--arg=$realimageloc$kimage-$version " .
          "/etc/kernel/postrm.d") &&
            die "Failed to process /etc/kernel/postrm.d";
}
if (-d "/etc/kernel/postrm.d/$version") {
  warn "Examining /etc/kernel/postrm.d/$version .\n";
  system ("run-parts --verbose --exit-on-error --arg=$version " .
          "--arg=$realimageloc$kimage-$version " .
          "/etc/kernel/postrm.d/$version") &&
            die "Failed to process /etc/kernel/postrm.d/$version";
}

# check and remove damaged and dangling symlinks
if ($ARGV[0] !~ /upgrade/) {
  system("$ramdisk -d -k " . $version . " > /dev/null 2>&1");
  if (-f $realimageloc . "initrd.img-$version.bak") {
    unlink $realimageloc . "initrd.img-$version.bak";
  }
  image_magic($kimage,          $image_dest);
  image_magic($kimage . ".old", $image_dest);
  image_magic("initrd.img",     $image_dest) if $initrd;
  image_magic("initrd.img.old", $image_dest) if $initrd;
}

exit 0;

__END__