#!/usr/bin/perl
#--------------------------------------------------------------------
# Copyright (C) 2000, 2001, 2002 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;

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

my $grub_menu = "/boot/grub/menu.lst";
my ($fastboot, $noreboot, $list);

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

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

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

my @entries;
if ($bootloader =~ /GRUB/) {
    grub_conf();
} elsif ($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 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;
    @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 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;
    @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] <label>
EOF
}

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