+my $fn_t= "_update.$$-xxxxxxxxxxxxxxxx.tmp";
+open F, "> $fn_t" or die "$fn_t $!";
+(stat F) or die $!;
+my $fn_i= sprintf "_update.$$-%016x.rdy", (stat _)[1];
+
+print F $whole or die $!;
+close F or die $!;
+rename $fn_t, $fn_i or die "$fn_t $fn_i $!";
+
+__END__
+