#!/usr/bin/perl -w
# virt-list-filesystems
# Copyright (C) 2009 Red Hat Inc.
#
# 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., 675 Mass Ave, Cambridge, MA 02139, USA.

use warnings;
use strict;

use Sys::Guestfs;
use Sys::Guestfs::Lib qw(open_guest get_partitions);
use Pod::Usage;
use Getopt::Long;
use Locale::TextDomain 'libguestfs';

=encoding utf8

=head1 NAME

virt-list-filesystems - List filesystems in a virtual machine or disk image

=head1 SYNOPSIS

 virt-list-filesystems [--options] domname

 virt-list-filesystems [--options] disk.img [disk.img ...]

=head1 DESCRIPTION

C<virt-list-filesystems> is a command line tool to list
the filesystems that are contained in a virtual machine or
disk image.

C<virt-list-filesystems> is just a simple wrapper around
L<libguestfs(3)> functionality.  For more complex cases you should
look at the L<guestfish(1)> tool.

=head1 OPTIONS

=over 4

=cut

my $help;

=item B<--help>

Display brief help.

=cut

my $version;

=item B<--version>

Display version number and exit.

=cut

my $uri;

=item B<--connect URI> | B<-c URI>

If using libvirt, connect to the given I<URI>.  If omitted, then we
connect to the default libvirt hypervisor.

If you specify guest block devices directly, then libvirt is not used
at all.

=cut

my $long;

=item B<-l> | B<--long>

With this option, C<virt-list-filesystems> displays the type of
each filesystem too (where "type" means C<ext3>, C<xfs> etc.)

=cut

my $all;

=item B<-a> | B<--all>

Normally we only show mountable filesystems.  If this option
is given then swap devices are shown too.

=back

=cut

# Configure bundling, otherwise '-al' is treated as '--all'.
Getopt::Long::Configure ("bundling");

GetOptions ("help|?" => \$help,
            "version" => \$version,
            "connect|c=s" => \$uri,
            "long|l" => \$long,
            "all|a" => \$all,
    ) or pod2usage (2);
pod2usage (1) if $help;
if ($version) {
    my $g = Sys::Guestfs->new ();
    my %h = $g->version ();
    print "$h{major}.$h{minor}.$h{release}$h{extra}\n";
    exit
}

pod2usage (__"virt-list-filesystems: no image or VM name given")
    if @ARGV <= 0;

my $g;
if ($uri) {
    $g = open_guest (\@ARGV, address => $uri);
} else {
    $g = open_guest (\@ARGV);
}

$g->launch ();

# List of partitions, LVs etc.
my @partitions = get_partitions ($g);

my @fses;
my @not_mountable;
my $dev;

# Try and mount each one, to see what's mountable.
foreach $dev (@partitions) {
    eval { $g->mount_ro ($dev, "/"); };
    my $mountable = $@ ? 0 : 1;
    $g->umount_all ();
    if ($mountable) {
        push @fses, $dev;
    } else {
        push @not_mountable, $dev;
    }
}

foreach $dev (@fses) {
    print canonicalize($dev);
    if ($long) {
        my $fstype;
        eval { $fstype = $g->vfs_type ($dev); };
        if ($fstype) {
            print " $fstype";
        } else {
            print " unknown";
        }
    }
    print "\n";
}

# If asked, look in the not_mountable list for potential swap devices.
if ($all) {
    foreach $dev (@not_mountable) {
        my $file;
        eval { $file = $g->file ($dev); };
        if ($file && $file =~ /\bswap\b/) {
            print canonicalize($dev);
            print " swap" if $long;
            print "\n"
        }
    }
}

# The reverse of device name translation, see
# BLOCK DEVICE NAMING in guestfs(3).
sub canonicalize
{
    local $_ = shift;

    if (m{^/dev/[hv]d([a-z]\d)$}) {
        return "/dev/sd$1";
    }
    $_;
}

=head1 SEE ALSO

L<guestfs(3)>,
L<guestfish(1)>,
L<virt-cat(1)>,
L<virt-tar(1)>,
L<virt-list-partitions(1)>,
L<Sys::Guestfs(3)>,
L<Sys::Guestfs::Lib(3)>,
L<Sys::Virt(3)>,
L<http://libguestfs.org/>.

=head1 AUTHOR

Richard W.M. Jones L<http://et.redhat.com/~rjones/>

=head1 COPYRIGHT

Copyright (C) 2009 Red Hat Inc.

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., 675 Mass Ave, Cambridge, MA 02139, USA.