don't have duplicate tags in invertory

diff --git a/lib/Biblio/RFID/Reader/librfid.pm b/lib/Biblio/RFID/Reader/librfid.pm
index 72ea674..0f559fd 100644 (file)
--- a/lib/Biblio/RFID/Reader/librfid.pm
+++ b/lib/Biblio/RFID/Reader/librfid.pm
@@ -84,9 +84,10 @@ my $sid_iso;
 sub inventory {
 
        my @tags; 
+       $sid_iso = {};
        _grep_tool 'librfid-tool', '--scan' => sub {
                my ( $sid, $iso ) = @_;
-               if ( $sid ) {
+               if ( $sid && ! exists $sid_iso->{$sid} ) {
                        push @tags, $sid;
                        $sid_iso->{$sid} = $iso;
                }