File update_UUID_in_grub.pl of Package Vj_Latesttar

#!/usr/bin/env perl
# Author: Vijay Tripathi <v-vijayt@microsoft.com>
use File::Basename;
use File::Copy;

#
# Declare subroutines.
#

sub update_grub_file;
sub GetUUID;
#
# Declare globals.
#
my $grubfile = "/boot/grub/grub.conf";
my $kernel_ver = `uname -r`;
my $matchkernel = "vmlinuz-" . $kernel_ver;


#
# main entry point
#
chomp $matchkernel;

if (-e "/etc/SuSE-release") {
	$grubfile = "/boot/grub/menu.lst";

}

update_grub_file();

print "\tDone.\n";
#
# Subroutine Update Grub File
#
sub update_grub_file() {
	my $grubfiletmp = $grubfile . ".tmp123";
	my $modified = 0;

	if ( -e $grubfiletmp) {
		die "\tError $grubfiletmp exists. Please rename the file and rerun this.\n";
	}
	
	if (!open(GRUB_CONF_FILE_TMP, ">$grubfiletmp")) {
		die "\tError opening $grubfiletmp. Running as root?\n";
	}
	
	if (!open(GRUB_CONF_FILE, "<$grubfile")) {
		close GRUB_CONF_FILE_TMP;
		unlink $grubfiletmp;
		die "\tError opening $grubfile. Running as root?\n";
	}
		
	#print "\tLooking for kernel match - $matchkernel.\n";
		
	while ($line =  <GRUB_CONF_FILE>) {
		if ($line =~ /$matchkernel/) {
			#print "\tKernel match found - $matchkernel.\n";

			if ($line =~ /\/dev\/*/) {
				$tmp=$line;
				chomp $line;
				@disk = split(/  */,$line);
				@alldevs = ();
				foreach(@disk)
				{
					if($_ =~ /\/dev\//){
					push(@alldevs,$_);
				}
				}
				foreach(@alldevs){
					@var = split(/=/,$_);
					$uuid=GetUUID($var[1]);
                           		$line =~ s/$var[1]/$uuid/gi;
					}
					printf GRUB_CONF_FILE_TMP $line."\n";
					$modified = 1;
						
			}
		} else {
			printf GRUB_CONF_FILE_TMP $line;
		}		
	}
	
	close GRUB_CONF_FILE;
	close GRUB_CONF_FILE_TMP;
		
	if ($modified == 1) {
		move($grubfiletmp, $grubfile);
	} else {
		unlink $grubfiletmp;
	}
}

#Subroutine to get uuid of device
sub GetUUID{
#BLKID COMMAND OUTPUT
$uuidfstr=`blkid $_[0]`;
#SPLITTING O/P IN THE STRINGS
@uuid_arr = split(/  */,$uuidfstr);
$uuid = 0;
#REMOVING "" FROM UUID STRING
foreach(@uuid_arr){
if($_ =~ /^U/){
$uuid = $_;
$uuid =~ s/"//gi;

}
}
$uuid;
}