--- a/SI/ptable.pm	Thu Jan 14 20:50:54 2010 +0100
+++ b/SI/ptable.pm	Fri Jan 15 01:16:12 2010 +0100
@@ -2,12 +2,48 @@
 
 use strict;
 use warnings;
+use if $ENV{DEBUG} ~~ "ptable" => "Smart::Comments";
+use File::Find;
+
+$ENV{LC_ALL} = "C";
 
 use SI::tools;
 
-sub save($) {
-	my $file = shift;
-	run "sfdisk -d >$file 2>/dev/null";
+sub info($\%) {
+	my ($file, $part) = @_;
+
+	# find major of devmapper
+	my $devmapper = 0;
+	{
+	local $/ = undef;
+	open(my($i), "/proc/devices") or die "ERR: Can't open /proc/devices: $!\n";
+	($devmapper) =  <$i> =~ /^\s*(\d+)\s+device.mapper\b/m;
+	}
+
+	my ($current, %dev);
+	foreach (`sfdisk -d 2>/dev/null`) {
+		chomp;
+		if (/^# partition table .*?(\/\S+)/) {
+			$current = (stat $1)[6] >> 8 == $devmapper ? undef : $1
+				and push(@{$dev{$current}}, $_);
+			next;
+		}
+		push @{$dev{$current}}, $_;
+	}
+	### partiton tables of useful blockdevices:
+	### %dev
+
+	# process the partition tables
+	# and output the tables for relevant devices
+	foreach my $dev (keys %dev) {
+		($_ = $dev) =~ s/^.*\///;
+		my $file = sprintf $file, $_;
+		die "ERR: $file exists already\n" if -f $file;
+		open(my $o, ">$file") or die "ERR: Can't open $file: $!\n";
+		print $o join "\n", @{$dev{$dev}}, "";
+	}
+
+	# reserve entries in %part, one for each partition
+	@{$part->{physical}}{map { (split)[0] } grep { /^\// } map { @$_ } values %dev} = ();
 }
-
 1;