Backup Directory Hierarchy To CDR/DVDR.

I use this on my /home/music directory, which is 23 GiB.

#!/usr/bin/perl

##   Backup Hierarchy.
##
##	Version:  backup-hierarchy.pl v2005-06-24.
##
##	Description:  backup a directory hierarchy to a set 
##	of CDR/DVDRs.
##
##   Copyright (c) 2005 Hal Canary.
##
##	hal at ups dot physics dot wisc dot edu.
##
##   Licence Information:
##
##	This program is free software; you can redistribute it
##	and/or modify it under the terms of version 2 of the
##	GNU General Public License as published by the Free
##	Software Foundation.
##
##	A copy of the licence can be found at:
##			http://www.gnu.org/licenses/gpl.txt
##
##	This program is distributed in the hope that it will
##	be useful, but WITHOUT ANY WARRANTY; without even the
##	implied warranty of MERCHANTABILITY or FITNESS FOR A
##	PARTICULAR PURPOSE.  See the GNU General Public
##	License for more details.
##
##   TO DO: Limit symlink filename length to 64 chars.
##
##   How to use:
##	Change the $backupdir, $startdir, and $originaldir
##	variables.  Maybe also change the $discsize variable.
##
##	After running the program, copy or symlink INDEX.txt
##	into each directory.  Now you can use a single disc to
##	look up files on ALL discs.
##
##	If you want to preserve permissions and such, tar up
##	the files before burning.  "tar --dereference" will
##	dereference those symlinks.  For backing up music and
##	video this is most likey unnessisary.
##
##	mkisofs -V "MUSIC 001" -r -J -f -quiet \
##		-o MUSIC_001.iso MUSIC_001/
##	cdrecord -v -pad -eject MUSIC_001.iso

my $backupdir = "/home/hal/MUSIC_BACKUP"; #abs
my $backupname = "MUSIC" ;
my $startdir = "/home"; #abs
my $originaldir = "music"; #rel
mkdir $backupdir;
#$discsize = 700*1024*1024; # Bytes for CD-R
my $discsize = 4.7*1000*1000*1000; # Bytes for DVD-R

my $num=1;
my $dirnum = &padnum($num);
my $disc = $backupdir."/".$backupname."_".$dirnum;
my $cursize = 0;
mkdir $disc;

chdir $startdir ;
&dealwithdir($originaldir);

chdir $backupdir ;
system ("/bin/ls -shpR . > INDEX.txt");

sub dealwithdir {
    my $dir=shift;
    mkdir $disc."/".$dir ;
    opendir(DH, $dir);
    my @contents = readdir(DH);
    closedir(DH);    #print($dir."\n");
    foreach my $file (@contents) {
	if (-f $dir . "/" . $file ) {
	    dealwithfile($dir, $file);
	} elsif ( -d $dir . "/" . $file ) {
	    &dealwithdir ($dir . "/" . $file)
		unless ($file eq "."
			or $file eq "..");
	}
    }
}

sub dealwithfile {
    my $dir = shift;
    my $file = shift;
    my $size = (stat($dir."/".$file))[7] ;
    $cursize += $size;
    if ($cursize > $discsize) {
	$num++;
 	$dirnum = &padnum($num);
	$cursize = $size ;
	$disc = $backupdir."/"
	    .$backupname."_".$dirnum;
	mkdir $disc;
	system( "mkdir -p ".$disc."/".$dir );
    }
    my $bdir = $disc."/".$dir ;
    symlink( $startdir."/".$dir."/".$file ,
	     $bdir."/".$file )
	or die "HELP";
}

sub padnum {
    $num=shift;
    return "00".$num if $num%lt;10;
    return "0".$num if $num%lt;100;
    return "$num";
}