#!/usr/bin/perl
#--------------------------------------------------------------------
# Copyright (C) 2000-2010 by Mandriva,
# Pixel <pixel@mandriva.com>,
# Chmouel Boudjnah <chmouel@mandriva.com>,
# Redistribution of this file is permitted under the terms of the GNU
# Public License (GPL)
#--------------------------------------------------------------------
# $Id: rebootin 109033 2007-01-15 09:40:20Z pixel $
#--------------------------------------------------------------------
## description:
#		Reboot once on a specified image for grub or lilo

use strict;
use MDK::Common;

my $lilo_conf = "/etc/lilo.conf";

my $grub_menu = "/boot/grub/menu.lst";
my $grub2_menu = "/boot/grub2/grub.cfg";
my $grub2_cfg = "/etc/default/grub";
my ($fastboot, $noreboot, $list, $menu);

while ($ARGV[0] =~ /^-/) {
    local $_ = shift;
    if (/^-f/) {
	$fastboot++;
    } elsif (/^-l/) {
	$list++;
    } elsif (/^-n/) {
	$noreboot++;
    } elsif (/^-m/) {
	$menu++;
    } else {
	die "Unknown switch $_\n";
    }
}

$menu || $list || @ARGV == 1 && $ARGV[0] or usage();
!$menu || @ARGV == 0 or usage();

my ($wanted_entry) = @ARGV;

my $bootloader  = `/usr/sbin/detectloader -q` or die "Can't detect your bootloader\n";chomp $bootloader;

my @entries;
if ($bootloader =~ /GRUB2/) {
    grub2_conf();
} elsif ($bootloader =~ /GRUB/) {
    grub_conf();
} elsif ($bootloader =~ /LILO/) {
    lilo_conf();
} elsif ($bootloader =~ /YABOOT/) {
    die "Sorry, can't do this with yaboot...\n";
} else {
    die "Can't detect your bootloader\n";
}
exec "reboot" unless $noreboot;


sub list_entries() { print "$_\n" foreach @entries; exit(0) }
sub select_entry() {
    my $i = 1;
    print $i++ . ") $_\n" foreach @entries;
    print "0) exit\n";
    my $userinput;
    do {
	print "> ";
        $userinput = <STDIN>;
	chomp $userinput;
    } while ($userinput > $i);
    exit(1) unless $userinput;
    $entries[$userinput-1];
}

sub lilo_conf() {
    open(my $F, $lilo_conf) or die "lilo is not installed ($lilo_conf is missing)\n";
    @entries = map { /="?([^"\n]+)/ } grep { /\s*label=\S*/ } <$F>;
    list_entries() if $list;
    $wanted_entry = select_entry() if $menu;
    @entries > 0 or die "Bad lilo.conf (no entry found)\n";
    grep { $_ eq $wanted_entry } @entries or usage();
    write_fast_boot() if $fastboot;
    system("lilo -R $wanted_entry"); die "error while wanting to reboot on $wanted_entry\n" if $?;
}

sub grub2_conf() {
    open(my $F, $grub2_menu) or die "grub2 is not installed ($grub2_menu is missing)\n";

    # Update menu if needed:
    if (cat_($grub2_cfg) !~ /^GRUB_DEFAULT="saved"/sm) {
	append_to_file($grub2_cfg, qq(GRUB_DEFAULT="saved"\n));
	system('updates-grub2');
    }

    foreach (<$F>) {
	if (/^[^#]*menuentry\s+'([^']*)/) {
	    push @entries, $1;
	}
    }
    list_entries() if $list;
    $wanted_entry = select_entry() if $menu;
    @entries > 0 or die "bad menu.lst (no entry found)\n";

    if (member($wanted_entry, @entries)) {
	system('grub2-reboot', $wanted_entry);
	write_fast_boot() if $fastboot;
	return;
    }

    print STDERR "$wanted_entry not found\n";
    usage(); # not found
}

sub grub_conf() {
    open(my $F, $grub_menu) or die "grub is not installed ($grub_menu is missing)\n";
    my @short_entries;
    foreach (<$F>) {
	if (/^title\s+(.*)/) {
	    push @entries, $1;
	} elsif (/BOOT_IMAGE=(\S+)/) {
	    $short_entries[$#entries] = $1;
	}
    }
    list_entries() if $list;
    $wanted_entry = select_entry() if $menu;
    @entries > 0 or die "bad menu.lst (no entry found)\n";

    for (my $i = 0; $i < @entries; $i++) {
	if ($wanted_entry eq $entries[$i] || $wanted_entry eq $short_entries[$i]) {
	    set_grub($i);
	    return;
	}
    }

    print STDERR "$wanted_entry not found\n";
    usage(); # not found
}

sub set_grub {
    open(my $F, "| grub --device-map=/boot/grub/device.map --batch");
    print $F "savedefault --default=$_[0] --once\nquit\n";
    write_fast_boot() if $fastboot;
}

sub usage() {
    my $entries = @entries ? "  where <label> is one of " . join(", ", @entries) . "\n" : '';
    die <<'EOF' . $entries;
usage: rebootin -l 
       rebootin [-n] [-f] -m
       rebootin [-n] [-f] <label>
EOF
}

sub write_fast_boot() {
    open(my $_F, ">/fastboot");
}