really read data from file for write

diff --git a/nfc-card-dumper.pl b/nfc-card-dumper.pl
index afc3140..37bee84 100755 (executable)
--- a/nfc-card-dumper.pl
+++ b/nfc-card-dumper.pl
@@ -84,7 +84,7 @@ if ($r->init()) {
        my $out_file = write_card_dump $tag => $card;
 
        if ( $opt->write ) {
-               read_file $opt->write;
+               $card = read_file $opt->write;
                foreach my $block ( 0 .. $tag->blocks ) {
                        my $offset = 0x10 * $block;
                        my $data = substr($card,$offset,0x10);