1 use Fcntl qw/:seek/;

     2 

     3 my $sig_pattern = qr/

     4 	^--\x20\s+	# signature delimiter dash-dash-space

     5 	^Heiko\s+	# signature text

     6 	\Z		# hard end of the signature

     7 /mix;

     8 

     9 sub check_sig {

    10 	my ($file, $sender) = @_;

    11 	

    12 	open(my $fh, $file) or die "Can't open $file: $!\n";

    13 	seek($fh, -1024, SEEK_END) or die "Can't seek to -1024: $!\n"

    14 		if -s $fh > 1024;

    15 

    16 	$_ = join '', <$fh>;

    17 

    18 	return /$sig_pattern/;

    19 }