+ client_send ".NOP S $send C 0";
+ client_send ".MSG Please check display of device" if $send == 100;
+
+ # check smtp counters to be sure page is printed
+
+ $credit -= $charge;
+ $total_charged += $charge;
+ $total_pages++;
+
+ client_send ".DONE $nr_jobs $total_pages ".credit($total_charged);
+
+ } elsif ( $line =~ m/^\.NOP/ ) {
+ # XXX it's important to sleep, before sending response or
+ # interface on terminal device will be unresponsive
+ $next_nop_t = time() + 5; # NOP every 5s?