linux/debian/templates/temp.image.plain/preinst

#! /usr/bin/perl
#
#use strict; #for debugging

use Debconf::Client::ConfModule qw(:all);
version('2.0');
my $capb=capb("backup");

$|=1;

# Predefined values:
my $version         = "=V";
my $link_in_boot    = "=IB";     # Should be empty, mostly
my $no_symlink      = "=S";     # Should be empty, mostly
my $do_symlink      = "Yes";	# target machine defined
my $kimage          = "=K";     # Should be empty, mostly
my $image_dir       = "=D";     # where the image is located
my $use_hard_links  = '';       # hardlinks do not wirk across fs boundaries
my $preinst_hook    = '';       #Normally we do not
my $minimal_swap    = '';       # Do not swap symlinks
my $ignore_depmod_err = '';    # normally we do not
my $relink_src_link   = 'YES';	# There is no harm in checking the link
my $relink_build_link = 'YES'; # There is no harm in checking the link
my $force_build_link  = '';	 # There is no harm in checking the link
my $arch              = "=A";  #  should be same as dpkg --print-architecture
my $kernel_arch       = "=B";
my $ramdisk           = "=MK";  # List of tools to create initial ram fs.
my $package_name    = "=ST-image-$version";

#known variables
my $image_dest      = "/";
my $realimageloc    = "/$image_dir/";
my $CONF_LOC        = '/etc/kernel-img.conf';

my $modules_base    = '/lib/modules';

die "Pre inst Internal error. Aborting." unless $version;

exit 0 if $ARGV[0] =~ /abort-upgrade/;
exit 1 unless $ARGV[0] =~ /(install|upgrade)/;

# 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*$/;

      $do_symlink      = "" if /do_symlinks\s*=\s*(no|false|0)\s*$/ig;
      $no_symlink      = "" if /no_symlinks\s*=\s*(no|false|0)\s*$/ig;
      $link_in_boot    = "" if /link_in_boot\s*=\s*(no|false|0)\s*$/ig;
      $use_hard_links  = '' if /use_hard_links\s*=\s*(no|false|0)\s*$/ig;
      $minimal_swap    = '' if /minimal_swap\s*=\s*(no|false|0)\s*$/ig;
      $ignore_depmod_err = '' if /ignore_depmod_err\s*=\s*(no|false|0)\s*$/ig;
      $relink_src_link   = '' if /relink_src_link\s*=\s*(no|false|0)\s*$/ig;
      $relink_build_link = '' if /relink_build_link\s*=\s*(no|false|0)\s*$/ig;
      $force_build_link = '' if /force_build_link\s*=\s*(no|false|0)\s*$/ig;

      $do_symlink      = "Yes" if /do_symlinks\s*=\s*(yes|true|1)\s*$/ig;
      $no_symlink      = "Yes" if /no_symlinks\s*=\s*(yes|true|1)\s*$/ig;
      $link_in_boot    = "Yes" if /link_in_boot\s*=\s*(yes|true|1)\s*$/ig;
      $use_hard_links  = "Yes" if /use_hard_links\s*=\s*(yes|true|1)\s*$/ig;
      $minimal_swap    = 'Yes' if /minimal_swap\s*=\s*(yes|true|1)\s*$/ig;
      $ignore_depmod_err = 'Yes' if /ignore_depmod_err\s*=\s*(yes|true|1)\s*$/ig;
      $relink_src_link   = 'Yes' if /relink_src_link\s*=\s*(yes|true|1)\s*$/ig;
      $relink_build_link = 'Yes' if /relink_build_link\s*=\s*(yes|true|1)\s*$/ig;
      $force_build_link = 'Yes' if /force_build_link\s*=\s*(yes|true|1)\s*$/ig;

      $image_dest      = "$1"  if /image_dest\s*=\s*(\S+)/ig;
      $preinst_hook    = "$1"  if /preinst_hook\s*=\s*(\S+)/ig;
      $ramdisk         = "$1"  if /ramdisk\s*=\s*(.+)$/ig;
    }
    close CONF;
  }
}

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


sub check {
  my $version = shift;
  my $lib_modules="$modules_base/$version";
  my $message = '';

  if (-d "$lib_modules") {
    opendir(DIR, $lib_modules) || die "can’t opendir $lib_modules: $!";
    my @children = readdir(DIR);
    if ($#children > 1) {
      my @dirs  = grep { -d "$lib_modules/$_" } @children;
      if ($#dirs > 1) { # we have subdirs
        my $dir_message='';
        for my $dir (@dirs) {
          if ($dir =~/kernel$/) {
            $dir_message="An older install was detected.\n";
          }
          else {
            $dir_message="Module sub-directories were detected.\n"
              unless $dir_message;
          }
        }
        $message += $dir_message if $dir_message;
      }

      my @links = grep { -l "$lib_modules/$_" } @children;
      if ($#links > -1) {
        my $links_message = '';
        for my $link (@links) {
          next if ($link =~ /^build$/);
          next if ($link =~ /^source$/);
          $links_message = "Symbolic links were detected in $modules_base/$version.\n";
        }
        $message += $links_message if $links_message;
      }
      my @files = grep { -f "$lib_modules/$_" } @children;
      $message += "Additional files also exist in $modules_base/$version.\n"
        if ($#files > -1);
    }
  }
  else { $message .= "$lib_modules does not exist. ";}
  return $message;
}

if (-d "$modules_base/$version") {
  my $errors=check($version);
  warn "Info:\n$errors\n" if $errors;
}

if (-d "$modules_base/$version" && -l "$modules_base/$version/build" ) {
	rename("$modules_base/$version/build", "$modules_base/$version/build.save") ||
	die "failed to move $modules_base/$version/build:$!";
}

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

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;
    }
    exit $? >> 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 {
      die "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";
    die "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 (-x "$preinst_hook") {
  &run_hook("preinst", $preinst_hook);
}
if (-d "/etc/kernel/preinst.d") {
  print STDERR "Examining /etc/kernel/preinst.d/\n";
  system ("run-parts --verbose --exit-on-error --arg=$version" .
          " --arg=$realimageloc$kimage-$version" .
          " /etc/kernel/preinst.d") &&
            die "Failed to process /etc/kernel/preinst.d";
}
if (-d "/etc/kernel/preinst.d/$version") {
  print STDERR "Examining /etc/kernel/preinst.d/$version.\n";
  system ("run-parts --verbose --exit-on-error --arg=$version" .
          " --arg=$realimageloc$kimage-$version" .
          " /etc/kernel/preinst.d/$version") &&
            die "Failed to process /etc/kernel/preinst.d/$version";
}

exit 0;

__END__