Listing 2: mrestore

#!/usr/bin/perl
# restore files from a tape created using mdump
#
# usage:    mrestore [options] path path...
#
# Options:
#    -f dev    tape device        default back:/dev/nrst24
#    -e    eject tape when finish    default no eject
#    -l    list contents only
#
# The path should be in the form of host:path. If host is omitted,
# the local host name is assumed
#
# Multiple path can be given in any order. mrestore will sort the
# pathes to suite the order
#
#
# mrestore uses hostname, rsh, dd, mt, restore. Make sure the path include all
# directories on all systems you want to do backup
# On SunOS 4.1.3, restore is in /usr/etc
# On Linux RedHat 5.1, restore is in /sbin.
# Add other directory to suite your needs

$ENV{'PATH'} = '/bin:/usr/etc:/sbin:/usr/bin:/usr/ucb';

#default options
$opt_f        = "back:/dev/nrst24";
$opt_i        = 1;
$opt_l        = 0;
$magic        =     '###mdump###';

chop( $localhost = `hostname` );

$localhost || die "Unable to determine the local host name: $!\n";

# get the options
use Getopt::Std;
&getopts('fedl');

$opt_f =~ s/^$localhost://;
$opt_f =~ s/^localhost://;

# collect path to restore

while( $path = shift @ARGV )
{
$host = '';
($host, $path) = split(':',$path) if $path =~ /:/;
$host || ($host = $localhost);
$paths{"$host:$path"} = 1;
}

@paths = keys %paths;
$| = 1;
$opt_l || @paths || die "No file or directory to restore\n";


# decide the dump device name and host
($dump_host, $dump_dev) = split(':', $opt_f);
$dump_dev || do { $dump_dev = $dump_host; $dump_host = "localhost"; };
($dump_dev && $dump_host) || die "Please supply dump device using -f option\n";
$dump_host eq $localhost && ($dump_host = 'localhost');

print "Restore device: $dump_dev on $dump_host\n" if $opt_d;

$opt_d && print join("\n\t", 'Restoring:',@paths), "\n";


# decide the mt command
$mt = "mt -f $dump_dev";
$mt = "rsh $dump_host $mt" unless $dump_host eq 'localhost';

# rewind the tape
do_system("$mt rewind");

# decide the dd command to use
$dd = "dd";
$dd = "rsh $dump_host $dd" unless $dump_host eq 'localhost';

# get the configuration information stored at the beginning of the tape

open( DD, " $dd if=$dump_dev|" ) || die "Cannot run $dd: $!\n";
$conf = <DD>;
if( $conf !~ /^$magic/ )
{
close DD;
print "The tape may not be a mdump tape\nQuiting\n";
system("$mt offline");
exit;
}

@filesys = ();
while(<DD>)
{
/;/ || next;
push( @filesys, split(';', $_ ) );
}
close DD;

print join("\n\t", "File systems on the tape:", @filesys), "\n" if ($opt_d || $opt_l);

if($opt_l)
{
do_system("$mt rewind");
exit;
}


# sort out the order of requests

foreach $p ( @paths )
{
my($last) = ();
foreach $fs ( @filesys )
{
if( $p =~ /^$fs/ )
{
$last && ($fs !~ /^$last/ )  && next;
# if the last one used is shorter than the current one
# use the current one
$order{$last} && delete $order{$last};
$order{$fs} = $p;
$last = $fs;
}
}

}


if( %order )
{
print "In the order:\n" if $opt_d;
$curpos = 1;
foreach $fs ( @filesys )
{
$opt_d && $order{$fs} && print "\t", $order{$fs}, "\n";
}
}

$curpos = 1;
$fspos  = 1;

$opt_i && ($opt_i = 'i');

foreach $fs ( @filesys )
{
$order{$fs} || next;
$move = $fspos - $curpos;
next if $move < 0;
print "Restoring from $fs at segment $fspos\n";
do_system("$mt fsf $move") if $move > 0;
do_system("restore -f$opt_i $opt_f");
$curpos = $fspos;
}
continue
{
$fspos++;
}

sub do_system {
my($cmd) = @_;

print "$cmd ...." if $opt_d;
my($system) = system($cmd);
print "successed\n" if $system == 0 && $opt_d;
print "failed\n" if $system && $opt_d;
}

# End of File