Annotation of /trunk/bin/BackupPC_tarIncCreate

#!/usr/bin/perl -w
#============================================================= -*-perl-*-
#
# BackupPC_tarIncCreate: create a tar archive of an existing incremental dump
# 
#
# DESCRIPTION
#  
#   Usage: BackupPC_tarIncCreate [options]
#
#   Flags:
#     Required options:
#
#       -h host         Host from which the tar archive is created.
#       -n dumpNum      Dump number from which the tar archive is created.
#                       A negative number means relative to the end (eg -1
#                       means the most recent dump, -2 2nd most recent etc).
#       -s shareName    Share name from which the tar archive is created.
#
#     Other options:
#       -t              print summary totals
#       -r pathRemove   path prefix that will be replaced with pathAdd
#       -p pathAdd      new path prefix
#       -b BLOCKS       BLOCKS x 512 bytes per record (default 20; same as tar)
#       -w writeBufSz   write buffer size (default 1MB)
#
#     The -h, -n and -s options specify which dump is used to generate
#     the tar archive.  The -r and -p options can be used to relocate
#     the paths in the tar archive so extracted files can be placed
#     in a location different from their original location.
#
# AUTHOR
#   Craig Barratt  <cbarratt@users.sourceforge.net>
#   Ivan Klaric <iklaric@gmail.com>
#   Dobrica Pavlinusic <dpavlin@rot13.org>
#
# COPYRIGHT
#   Copyright (C) 2001-2003  Craig Barratt
#
#   This program is free software; you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation; either version 2 of the License, or
#   (at your option) any later version.
#
#   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.
#
#   You should have received a copy of the GNU General Public License
#   along with this program; if not, write to the Free Software
#   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
#========================================================================
#
# Version 2.1.0, released 20 Jun 2004.
#
# See http://backuppc.sourceforge.net.
#
#========================================================================

use strict;
no  utf8;
use lib "__INSTALLDIR__/lib";
use File::Path;
use Getopt::Std;
use DBI;
use BackupPC::Lib;
use BackupPC::Attrib qw(:all);
use BackupPC::FileZIO;
use BackupPC::View;
use BackupPC::SearchLib;
use Time::HiRes qw/time/;
use POSIX qw/strftime/;
use File::Which;
use File::Path;
use File::Slurp;
use Data::Dumper;       ### FIXME

die("BackupPC::Lib->new failed\n") if ( !(my $bpc = BackupPC::Lib->new) );
my $TopDir = $bpc->TopDir();
my $BinDir = $bpc->BinDir();
my %Conf   = $bpc->Conf();
%BackupPC::SearchLib::Conf = %Conf;
my %opts;
my $in_backup_increment;


if ( !getopts("th:n:p:r:s:b:w:vdf", \%opts) ) {
    print STDERR <<EOF;
usage: $0 [options]
  Required options:
     -h host         host from which the tar archive is created
     -n dumpNum      dump number from which the tar archive is created
                     A negative number means relative to the end (eg -1
                     means the most recent dump, -2 2nd most recent etc).
     -s shareName    share name from which the tar archive is created

  Other options:
     -t              print summary totals
     -r pathRemove   path prefix that will be replaced with pathAdd
     -p pathAdd      new path prefix
     -b BLOCKS       BLOCKS x 512 bytes per record (default 20; same as tar)
     -w writeBufSz   write buffer size (default 1048576 = 1MB)
     -f              overwrite existing parts
     -v              verbose output
     -d              debug output
EOF
    exit(1);
}

if ( $opts{h} !~ /^([\w\.\s-]+)$/ ) {
    die "$0: bad host name '$opts{h}'\n";
}
my $Host = $opts{h};

if ( $opts{n} !~ /^(-?\d+)$/ ) {
    die "$0: bad dump number '$opts{n}'\n";
}
my $Num = $opts{n};

my $bin;
foreach my $c (qw/gzip md5sum tee/) {
        $bin->{$c} = which($c) || die "$0 needs $c, install it\n";
}

my @Backups = $bpc->BackupInfoRead($Host);
my $FileCnt = 0;
my $ByteCnt = 0;
my $DirCnt = 0;
my $SpecialCnt = 0;
my $ErrorCnt = 0;
my $current_tar_size = 0;
my $total_increment_size = 0;

my $i;
$Num = $Backups[@Backups + $Num]{num} if ( -@Backups <= $Num && $Num < 0 );
for ( $i = 0 ; $i < @Backups ; $i++ ) {
    last if ( $Backups[$i]{num} == $Num );
}
if ( $i >= @Backups ) {
    die "$0: bad backup number $Num for host $Host\n";
}

my $PathRemove = $1 if ( $opts{r} =~ /(.+)/ );
my $PathAdd    = $1 if ( $opts{p} =~ /(.+)/ );
if ( $opts{s} !~ /^([\w\s\.\/\$-]+)$/ && $opts{s} ne "*" ) {
    die "$0: bad share name '$opts{s}'\n";
}
our $ShareName = $opts{s};
our $view = BackupPC::View->new($bpc, $Host, \@Backups);

# database

my $dsn = $Conf{SearchDSN};
my $db_user = $Conf{SearchUser} || '';

my $dbh = DBI->connect($dsn, $db_user, "", { RaiseError => 1, AutoCommit => 0} );

my $sth_inc_size = $dbh->prepare(qq{
        update backups set
                inc_size = ?,
                parts = ?,
                inc_deleted = false
        where id = ?
});
my $sth_backup_parts = $dbh->prepare(qq{
        insert into backup_parts (
                backup_id,
                part_nr,
                tar_size,
                size,
                md5,
                items
        ) values (?,?,?,?,?,?)
});

#
# This constant and the line of code below that uses it are borrowed
# from Archive::Tar.  Thanks to Calle Dybedahl and Stephen Zander.
# See www.cpan.org.
#
# Archive::Tar is Copyright 1997 Calle Dybedahl. All rights reserved.
#                 Copyright 1998 Stephen Zander. All rights reserved.
#
my $tar_pack_header
    = 'a100 a8 a8 a8 a12 a12 A8 a1 a100 a6 a2 a32 a32 a8 a8 a155 x12';
my $tar_header_length = 512;

my $BufSize    = $opts{w} || 1048576;     # 1MB or 2^20
my $WriteBuf   = "";
my $WriteBufSz = ($opts{b} || 20) * $tar_header_length;

my(%UidCache, %GidCache);
my(%HardLinkExtraFiles, @HardLinks);

#
# Write out all the requested files/directories
#

my $max_file_size = $Conf{'MaxArchiveFileSize'} || die "problem with MaxArchiveFileSize parametar";

my $tar_dir = $Conf{InstallDir}.'/'.$Conf{GzipTempDir};
die "problem with $tar_dir, check GzipTempDir in configuration\n" unless (-d $tar_dir && -w $tar_dir);

my $tar_file = BackupPC::SearchLib::getGzipName($Host, $ShareName, $Num) || die "can't getGzipName($Host, $ShareName, $Num)";

my $tar_path_final = $tar_dir . '/' . $tar_file;
my $tar_path = $tar_path_final . '.tmp';

$tar_path =~ s#//#/#g;

my $sth = $dbh->prepare(qq{
        SELECT
                backups.id
        FROM backups 
                JOIN shares on shares.id = shareid
                JOIN hosts on hosts.id = shares.hostid
        WHERE hosts.name = ? and shares.name = ? and backups.num = ?
});
$sth->execute($Host, $ShareName, $Num);
my ($backup_id) = $sth->fetchrow_array;
$sth->finish;


# delete exising backup_parts
my $sth_delete_backup_parts = $dbh->prepare(qq{
        delete from backup_parts
        where backup_id = ?
});
$sth_delete_backup_parts->execute($backup_id);


print STDERR "backup_id: $backup_id working dir: $tar_dir, max uncompressed size $max_file_size bytes, tar $tar_file\n" if ($opts{d});

if (-e $tar_path_final) {
        if ($opts{f}) {
                rmtree $tar_path_final || die "can't remove $tar_path_final: $!";
        } else {
                die "$tar_path_final allready exists\n";
        }
}

my $fh;
my $part = 0;
my $no_files = 0;
my $items_in_part = 0;

sub new_tar_part {
        my $arg = {@_};

        if ($fh) {
                return if ($current_tar_size == 0);

                print STDERR " $part";

                #
                # Finish with two null 512 byte headers,
                # and then round out a full block.
                # 
                my $data = "\0" x ($tar_header_length * 2);
                TarWrite($fh, \$data);
                TarWrite($fh, undef);

                close($fh) || die "can't close archive part $part: $!";

                my $file = $tar_path . '/' . $part;

                my $md5 = read_file( $file . '.md5' ) || die "can't read md5sum file ${file}.md5";
                $md5 =~ s/\s.*$//;

                my $size = (stat( $file . '.tar.gz' ))[7] || die "can't stat ${file}.tar.gz";

                $sth_backup_parts->execute(
                        $backup_id,
                        $part,
                        $current_tar_size,
                        $size,
                        $md5,
                        $items_in_part,
                );

                $total_increment_size += $size;

                if ($arg->{close}) {

                        sub move($$) {
                                my ($from,$to) = @_;
                                print STDERR "# rename $from -> $to\n" if ($opts{d});
                                rename $from, $to || die "can't move $from -> $to: $!\n";
                        }

                        if ($part == 1) {
                                print STDERR " single" if ($opts{v});
                                move("${tar_path}/1.tar.gz", "${tar_path_final}.tar.gz");
                                move("${tar_path}/1.md5", "${tar_path_final}.md5");
                                rmtree $tar_path or die "can't remove temporary dir $tar_path: $!";
                        } else {
                                print STDERR " [last]" if ($opts{v});
                                move("${tar_path}", "${tar_path_final}");
                        }

                        $sth_inc_size->execute(
                                $total_increment_size,
                                $part,
                                $backup_id
                        );

                        print STDERR ", $total_increment_size bytes\n" if ($opts{v});

                        return;
                }

        }

        $part++;

        # if this is first part, create directory

        if ($part == 1) {
                if (-e $tar_path) {
                        print STDERR "# deleting existing $tar_path\n" if ($opts{d});
                        rmtree($tar_path);
                }
                mkdir($tar_path) || die "can't create directory $tar_path: $!";

                sub abort_cleanup {
                        print STDERR "ABORTED: cleanup temp dir";
                        rmtree($tar_path);
                        $dbh->rollback;
                        exit 1;
                }

                $SIG{'INT'}  = \&abort_cleanup;
                $SIG{'QUIT'} = \&abort_cleanup;
                $SIG{'__DIE__'} = \&abort_cleanup;

        }

        my $file = $tar_path . '/' . $part;

        #
        # create comprex pipe which will pass output through gzip
        # for compression, create file on disk using tee
        # and pipe same output to md5sum to create checksum
        #

        my $cmd = '| ' . $bin->{'gzip'}   . ' ' . $Conf{GzipLevel} .      ' ' .
                  '| ' . $bin->{'tee'}    . ' ' . $file . '.tar.gz' . ' ' .
                  '| ' . $bin->{'md5sum'} . ' - > ' . $file . '.md5';

        print STDERR "## $cmd\n" if ($opts{d});

        open($fh, $cmd) or die "can't open $cmd: $!";
        binmode($fh);

        $current_tar_size = 0;
        $items_in_part = 0;
}

new_tar_part();

if (seedCache($Host, $ShareName, $Num)) {
        archiveWrite($fh, '/');
        archiveWriteHardLinks($fh);
        new_tar_part( close => 1 );
} else {
        print STDERR "NOTE: no files found for $Host:$ShareName, increment $Num\n" if ($opts{v});
        # remove temporary files if there are no files
        rmtree($tar_path);
}

#
# print out totals if requested
#
if ( $opts{t} ) {
    print STDERR "Done: $FileCnt files, $ByteCnt bytes, $DirCnt dirs,",
                 " $SpecialCnt specials, $ErrorCnt errors\n";
}
if ( $ErrorCnt && !$FileCnt && !$DirCnt ) {
    #
    # Got errors, with no files or directories; exit with non-zero
    # status
    #
    die "got errors or no files\n";
}

$sth_inc_size->finish;
$sth_backup_parts->finish;

$dbh->commit || die "can't commit changes to database";
$dbh->disconnect();

exit;

###########################################################################
# Subroutines
###########################################################################

sub archiveWrite
{
    my($fh, $dir, $tarPathOverride) = @_;

    if ( $dir =~ m{(^|/)\.\.(/|$)} ) {
        print(STDERR "$0: bad directory '$dir'\n");
        $ErrorCnt++;
        return;
    }
    $dir = "/" if ( $dir eq "." );
    #print(STDERR "calling find with $Num, $ShareName, $dir\n");
    
    if ( $view->find($Num, $ShareName, $dir, 0, \&TarWriteFile,
                $fh, $tarPathOverride) < 0 ) {
        print(STDERR "$0: bad share or directory '$ShareName/$dir'\n");
        $ErrorCnt++;
        return;
    }
}

#
# Write out any hardlinks (if any)
#
sub archiveWriteHardLinks
{
    my $fh = @_;
    foreach my $hdr ( @HardLinks ) {
        $hdr->{size} = 0;
        if ( defined($PathRemove)
              && substr($hdr->{linkname}, 0, length($PathRemove)+1)
                        eq ".$PathRemove" ) {
            substr($hdr->{linkname}, 0, length($PathRemove)+1) = ".$PathAdd";
        }
        TarWriteFileInfo($fh, $hdr);
    }
    @HardLinks = ();
    %HardLinkExtraFiles = ();
}

sub UidLookup
{
    my($uid) = @_;

    $UidCache{$uid} = (getpwuid($uid))[0] if ( !exists($UidCache{$uid}) );
    return $UidCache{$uid};
}

sub GidLookup
{
    my($gid) = @_;

    $GidCache{$gid} = (getgrgid($gid))[0] if ( !exists($GidCache{$gid}) );
    return $GidCache{$gid};
}

sub TarWrite
{
    my($fh, $dataRef) = @_;


    if ( !defined($dataRef) ) {
        #
        # do flush by padding to a full $WriteBufSz
        #
        my $data = "\0" x ($WriteBufSz - length($WriteBuf));
        $dataRef = \$data;
    }

    # poor man's tell :-)
    $current_tar_size += length($$dataRef);

    if ( length($WriteBuf) + length($$dataRef) < $WriteBufSz ) {
        #
        # just buffer and return
        #
        $WriteBuf .= $$dataRef;
        return;
    }
    my $done = $WriteBufSz - length($WriteBuf);
    if ( syswrite($fh, $WriteBuf . substr($$dataRef, 0, $done))
                                != $WriteBufSz ) {
        die "Unable to write to output file ($!)\n";
    }
    while ( $done + $WriteBufSz <= length($$dataRef) ) {
        if ( syswrite($fh, substr($$dataRef, $done, $WriteBufSz))
                            != $WriteBufSz ) {
            die "Unable to write to output file ($!)\n";
        }
        $done += $WriteBufSz;
    }
    $WriteBuf = substr($$dataRef, $done);
}

sub TarWritePad
{
    my($fh, $size) = @_;

    if ( $size % $tar_header_length ) {
        my $data = "\0" x ($tar_header_length - ($size % $tar_header_length));
        TarWrite($fh, \$data);
    }
}

sub TarWriteHeader
{
    my($fh, $hdr) = @_;

    $hdr->{uname} = UidLookup($hdr->{uid}) if ( !defined($hdr->{uname}) );
    $hdr->{gname} = GidLookup($hdr->{gid}) if ( !defined($hdr->{gname}) );
    my $devmajor = defined($hdr->{devmajor}) ? sprintf("%07o", $hdr->{devmajor})
                                             : "";
    my $devminor = defined($hdr->{devminor}) ? sprintf("%07o", $hdr->{devminor})
                                             : "";
    my $sizeStr;
    if ( $hdr->{size} >= 2 * 65536 * 65536 ) {
        #
        # GNU extension for files >= 8GB: send size in big-endian binary
        #
        $sizeStr = pack("c4 N N", 0x80, 0, 0, 0,
                                  $hdr->{size} / (65536 * 65536),
                                  $hdr->{size} % (65536 * 65536));
    } elsif ( $hdr->{size} >= 1 * 65536 * 65536 ) {
        #
        # sprintf octal only handles up to 2^32 - 1
        #
        $sizeStr = sprintf("%03o", $hdr->{size} / (1 << 24))
                 . sprintf("%08o", $hdr->{size} % (1 << 24));
    } else {
        $sizeStr = sprintf("%011o", $hdr->{size});
    }
    my $data = pack($tar_pack_header,
                     substr($hdr->{name}, 0, 99),
                     sprintf("%07o", $hdr->{mode}),
                     sprintf("%07o", $hdr->{uid}),
                     sprintf("%07o", $hdr->{gid}),
                     $sizeStr,
                     sprintf("%011o", $hdr->{mtime}),
                     "",        #checksum field - space padded by pack("A8")
                     $hdr->{type},
                     substr($hdr->{linkname}, 0, 99),
                     $hdr->{magic} || 'ustar ',
                     $hdr->{version} || ' ',
                     $hdr->{uname},
                     $hdr->{gname},
                     $devmajor,
                     $devminor,
                     ""         # prefix is empty
                 );
    substr($data, 148, 7) = sprintf("%06o\0", unpack("%16C*",$data));
    TarWrite($fh, \$data);
}

sub TarWriteFileInfo
{
    my($fh, $hdr) = @_;

    #
    # Handle long link names (symbolic links)
    #
    if ( length($hdr->{linkname}) > 99 ) {
        my %h;
        my $data = $hdr->{linkname} . "\0";
        $h{name} = "././\@LongLink";
        $h{type} = "K";
        $h{size} = length($data);
        TarWriteHeader($fh, \%h);
        TarWrite($fh, \$data);
        TarWritePad($fh, length($data));
    }
    #
    # Handle long file names
    #
    if ( length($hdr->{name}) > 99 ) {
        my %h;
        my $data = $hdr->{name} . "\0";
        $h{name} = "././\@LongLink";
        $h{type} = "L";
        $h{size} = length($data);
        TarWriteHeader($fh, \%h);
        TarWrite($fh, \$data);
        TarWritePad($fh, length($data));
    }
    TarWriteHeader($fh, $hdr);
}

#
# seed cache of files in this increment
#
sub seedCache($$$) {
        my ($host, $share, $dumpNo) = @_;

        print STDERR curr_time(), "$host:$share #$dumpNo" if ($opts{v});
        my $sql = q{
                SELECT path,size
                FROM files
                        JOIN shares on shares.id = shareid
                        JOIN hosts on hosts.id = shares.hostid
                WHERE hosts.name = ? and shares.name = ? and backupnum = ?
        };

        my $sth = $dbh->prepare($sql);  
        $sth->execute($host, $share, $dumpNo);
        my $count = $sth->rows;
        print STDERR " $count items, parts:" if ($opts{v});
        while (my $row = $sth->fetchrow_arrayref) {
#print STDERR "+ ", $row->[0],"\n";
                $in_backup_increment->{ $row->[0] } = $row->[1];
        }
        
        $sth->finish();

        return $count;
}

#
# calculate overhad for one file in tar
#
sub tar_overhead($) {
        my $name = shift || '';

        # header, padding of file and two null blocks at end
        my $len = 4 * $tar_header_length;

        # if filename is longer than 99 chars subtract blocks for
        # long filename
        if ( length($name) > 99 ) {
                $len += int( ( length($name) + $tar_header_length ) / $tar_header_length ) * $tar_header_length;
        }

        return $len;
}

my $Attr;
my $AttrDir;

sub TarWriteFile
{
    my($hdr, $fh, $tarPathOverride) = @_;

    my $tarPath = $hdr->{relPath};
    $tarPath = $tarPathOverride if ( defined($tarPathOverride) );

    $tarPath =~ s{//+}{/}g;

    #print STDERR "? $tarPath\n" if ($opts{d});
    my $size = $in_backup_increment->{$tarPath};
    return unless (defined($size));

    # is this file too large to fit into MaxArchiveFileSize?

    if ( ($current_tar_size + tar_overhead($tarPath) + $size) > $max_file_size ) {
        print STDERR "# tar file $current_tar_size + $tar_header_length + $size > $max_file_size, splitting\n" if ($opts{d});
        new_tar_part();
    }

    #print STDERR "A $tarPath [$size] tell: $current_tar_size\n" if ($opts{d});
    $items_in_part++;

    if ( defined($PathRemove)
            && substr($tarPath, 0, length($PathRemove)) eq $PathRemove ) {
        substr($tarPath, 0, length($PathRemove)) = $PathAdd;
    }
    $tarPath = "./" . $tarPath if ( $tarPath !~ /^\.\// );
    $tarPath =~ s{//+}{/}g;
    $hdr->{name} = $tarPath;

    if ( $hdr->{type} == BPC_FTYPE_DIR ) {
        #
        # Directory: just write the header
        #
        $hdr->{name} .= "/" if ( $hdr->{name} !~ m{/$} );
        TarWriteFileInfo($fh, $hdr);
        $DirCnt++;
    } elsif ( $hdr->{type} == BPC_FTYPE_FILE ) {
        #
        # Regular file: write the header and file
        #
        my $f = BackupPC::FileZIO->open($hdr->{fullPath}, 0, $hdr->{compress});
        if ( !defined($f) ) {
            print(STDERR "Unable to open file $hdr->{fullPath}\n");
            $ErrorCnt++;
            return;
        }
        # do we need to split file?
        if ($hdr->{size} < $max_file_size) {
                TarWriteFileInfo($fh, $hdr);
                my($data, $size);
                while ( $f->read(\$data, $BufSize) > 0 ) {
                    TarWrite($fh, \$data);
                    $size += length($data);
                }
                $f->close;
                TarWritePad($fh, $size);
                $FileCnt++;
                $ByteCnt += $size;
        } else {
                my $full_size = $hdr->{size};
                my $orig_name = $hdr->{name};
                my $max_part_size = $max_file_size - tar_overhead($hdr->{name});

                my $parts = int(($full_size + $max_part_size - 1) / $max_part_size);
                print STDERR "# splitting $orig_name [$full_size bytes] into $parts parts\n" if ($opts{d});
                foreach my $subpart ( 1 .. $parts ) {
                        new_tar_part();
                        if ($subpart < $parts) {
                                $hdr->{size} = $max_part_size;
                        } else {
                                $hdr->{size} = $full_size % $max_part_size;
                        }
                        $hdr->{name} = $orig_name . '/' . $subpart;
                        print STDERR "## creating part $subpart ",$hdr->{name}, " [", $hdr->{size}," bytes]\n";

                        TarWriteFileInfo($fh, $hdr);
                        my($data, $size);
if (0) {
                        for ( 1 .. int($hdr->{size} / $BufSize) ) {
                                my $r_size = $f->read(\$data, $BufSize);
                                die "expected $BufSize bytes read, got $r_size bytes!" if ($r_size != $BufSize);
                                TarWrite($fh, \$data);
                                $size += length($data);
                        }
}
                        my $size_left = $hdr->{size} % $BufSize;
                        my $r_size = $f->read(\$data, $size_left);
                        die "expected $size_left bytes last read, got $r_size bytes!" if ($r_size != $size_left);

                        TarWrite($fh, \$data);
                        $size += length($data);
                        TarWritePad($fh, $size);

                        $items_in_part++;
                }
                $f->close;
                $FileCnt++;
                $ByteCnt += $full_size;
                new_tar_part();
        }
    } elsif ( $hdr->{type} == BPC_FTYPE_HARDLINK ) {
        #
        # Hardlink file: either write a hardlink or the complete file
        # depending upon whether the linked-to file will be written
        # to the archive.
        #
        # Start by reading the contents of the link.
        #
        my $f = BackupPC::FileZIO->open($hdr->{fullPath}, 0, $hdr->{compress});
        if ( !defined($f) ) {
            print(STDERR "Unable to open file $hdr->{fullPath}\n");
            $ErrorCnt++;
            return;
        }
        my $data;
        while ( $f->read(\$data, $BufSize) > 0 ) {
            $hdr->{linkname} .= $data;
        }
        $f->close;
        my $done = 0;
        my $name = $hdr->{linkname};
        $name =~ s{^\./}{/};
        if ( $HardLinkExtraFiles{$name} ) {
            #
            # Target file will be or was written, so just remember
            # the hardlink so we can dump it later.
            #
            push(@HardLinks, $hdr);
            $SpecialCnt++;
        } else {
            #
            # Have to dump the original file.  Just call the top-level
            # routine, so that we save the hassle of dealing with
            # mangling, merging and attributes.
            #
            $HardLinkExtraFiles{$hdr->{linkname}} = 1;
            archiveWrite($fh, $hdr->{linkname}, $hdr->{name});
        }
    } elsif ( $hdr->{type} == BPC_FTYPE_SYMLINK ) {
        #
        # Symbolic link: read the symbolic link contents into the header
        # and write the header.
        #
        my $f = BackupPC::FileZIO->open($hdr->{fullPath}, 0, $hdr->{compress});
        if ( !defined($f) ) {
            print(STDERR "Unable to open symlink file $hdr->{fullPath}\n");
            $ErrorCnt++;
            return;
        }
        my $data;
        while ( $f->read(\$data, $BufSize) > 0 ) {
            $hdr->{linkname} .= $data;
        }
        $f->close;
        $hdr->{size} = 0;
        TarWriteFileInfo($fh, $hdr);
        $SpecialCnt++;
    } elsif ( $hdr->{type} == BPC_FTYPE_CHARDEV
           || $hdr->{type} == BPC_FTYPE_BLOCKDEV
           || $hdr->{type} == BPC_FTYPE_FIFO ) {
        #
        # Special files: for char and block special we read the
        # major and minor numbers from a plain file.
        #
        if ( $hdr->{type} != BPC_FTYPE_FIFO ) {
            my $f = BackupPC::FileZIO->open($hdr->{fullPath}, 0,
                                                $hdr->{compress});
            my $data;
            if ( !defined($f) || $f->read(\$data, $BufSize) < 0 ) {
                print(STDERR "Unable to open/read char/block special file"
                           . " $hdr->{fullPath}\n");
                $f->close if ( defined($f) );
                $ErrorCnt++;
                return;
            }
            $f->close;
            if ( $data =~ /(\d+),(\d+)/ ) {
                $hdr->{devmajor} = $1;
                $hdr->{devminor} = $2;
            }
        }
        $hdr->{size} = 0;
        TarWriteFileInfo($fh, $hdr);
        $SpecialCnt++;
    } else {
        print(STDERR "Got unknown type $hdr->{type} for $hdr->{name}\n");
        $ErrorCnt++;
    }
}

my $t_fmt = '%Y-%m-%d %H:%M:%S';
sub curr_time {
        return strftime($t_fmt,localtime());
}