23 

    24 # process the arguments before actually calling the

    25 # constructor

    26 

    27 sub BUILDARGS {

    28     my $class = shift;

    29     my ($key, $value) = @_;

    30 

    31     given ($key) {

    32         when ("dev") {

    33 	    $value = "/dev/$value" if $value !~ /^\// and not -e $value and -b "/dev/$value";

    34             -b $value or die "no blockdevice `$value'";

    35             return { dev => $value };

    36         }

    37         when ("dir") {

    38             -d $value or die "`$value' is not a directory";

    39             `df --portability '$value'` =~ /^(?<dev>\/\S+).*?(?<mp>\S+)$/m;

    40             die "$value does not have a real file system"

    41               if not $+{dev};

    42             return { dev => $+{dev} };

    43         }

    44         when (/^m(?:ount)?p(?:oint)?$/) {

    45             -d $value or die "`$value` is not a directory";

    46             open(my $mounts => "/proc/mounts");

    47             join("" => <$mounts>) =~ /^(?<dev>\S+)\s$value\s/m

    48               or die "$value is not a mountpoint";

    49             return { dev => $+{dev} };

    50         }

    51 	when ("uuid") {

    52 	    chomp(my $dev = `blkid -c /dev/null -U '$value'`);

    53 	    die "'$value' does not exist as UUID" if not $dev;

    54 	    return { dev => $dev }

    55 	}

    56 	when ("label") {

    57 	    chomp(my $dev = `blkid -c /dev/null -L '$value'`);

    58 	    die "'$value' does not exist as label" if not $dev;

    59 	    return { dev => $dev }

    60 	}

    61         default { die "unknown initialization" }

    62     }

    63 }

    64 

    65 sub path  { abs_path shift->dev }

    66 sub major { (stat shift->dev)[6] >> 8 }

    67 sub minor { (stat shift->dev)[6] & 0xff }

    68 sub size  {

    69     my $self = shift;

    70     open(my $fh => $self->path);

    71     seek($fh, 0, SEEK_END);

    72     return tell($fh);

    73 }

    74 

    75 

    76 1;

    77 __END__