added read timeout

diff --git a/dialog.pl b/dialog.pl
index 381d1e4..d868ed9 100755 (executable)
--- a/dialog.pl
+++ b/dialog.pl
@@ -47,8 +47,16 @@ die "can't connect" unless $sock;
 sub read_serial {
        my $len = shift;
        my $buffer;
-       $sock->read( $buffer, $len );
-       warn "## read $len ",as_hex($buffer) if $debug;
+       eval {
+               local $SIG{ALRM} = sub { die "read timeout" };
+               alarm 3;
+
+               warn "## read_serial $len" if $debug;
+               $sock->read( $buffer, $len );
+               warn "## read $len ",as_hex($buffer) if $debug;
+       };
+       alarm 0;
+       warn "ERROR: $@" if $@;
        return $buffer;
 }