CUPS API: subscribe event

[Rytis]

Thank you for your response i've made a huge progress thanks to you! There were a several errors in your code but i've fixed them (the error s are listed in the back of this post if anyone is interested) I have few questions though. The first is how do i tell CUPS that i have already received job-completed notification? I don't need CUPS to remind me forever that job 54 has completed. That i do now is after i receive notification i cancel subscription and create a new one. I'm not sure that's the proper way any guidance on that? And for the second one i'll create a new post :)

in create_subscription()
change:
attr = ippFindAttribute(response, "subscription-id", IPP_TAG_INTEGER);
to:
attr = ippFindAttribute(response, "notify-subscription-id", IPP_TAG_INTEGER);

in show_events()
change:
ippAddInteger(request, IPP_TAG_OPERATION, IPP_TAG_INTEGER,
                      "subscription-id", subscription_id);
to:
ippAddInteger(request, IPP_TAG_OPERATION, IPP_TAG_INTEGER,
                      "notify-subscription-ids", subscription_id);

change:
if (!strcmp(attr->name, "job-id") && attr->value_tag == IPP_TAG_INTEGER)
to:
if (!strcmp(attr->name, "notify-job-id") && attr->value_tag == IPP_TAG_INTEGER)


> Rytis wrote:
> > Uh, it's more complicated than i thought. Anyway, i've rethinked what
> > i whant to do so.. what i need is to get notification whenever
> > printer completes a job. I would also need id of completed job. Is
> > that possible? And how can i achieve that?
>
> OK, to be notified via IPP_GET_NOTIFICATIONS for all printers, use:
>
>      /* Create a subscription for job-completed events and return the
> subscription-id value or 0 on error */
>      int
>      create_subscription(void)
>      {
>        http_t *http;
>        ipp_t *request, *response;
>        ipp_attribute_t *attr;
>        int subscription_id;
>
>
>        http = httpConnectEncrypt(cupsServer(), ippPort(), cupsEncryption());
>
>        request = ippNewRequest(IPP_CREATE_PRINTER_SUBSCRIPTION);
>
>        ippAddString(request, IPP_TAG_OPERATION, IPP_TAG_URI,
>                     "printer-uri", NULL, "ipp://localhost/printers");
>        ippAddString(request, IPP_TAG_OPERATION, IPP_TAG_NAME,
>                     "requesting-user-name", NULL, cupsUser());
>
>        ippAddString(request, IPP_TAG_SUBSCRIPTION, IPP_TAG_KEYWORD,
>                     "notify-pull-method", NULL, "ippget");
>        ippAddString(request, IPP_TAG_SUBSCRIPTION, IPP_TAG_KEYWORD,
>                     "notify-events", NULL, "job-completed");
>
>        response = cupsDoRequest(http, request, "/printers");
>
>        attr = ippFindAttribute(response, "subscription-id",
> IPP_TAG_INTEGER);
>        if (attr)
>          subscription_id = attr->values[0].integer;
>        else
>          subscription_id = 0;
>
>        ippDelete(response);
>        httpClose(http);
>
>        return (subscription_id);
>      }
>
> You can then gather the events using the IPP_GET_NOTIFICATIONS
> operation:
>
>      /* Show job-completed events for the given subscription-id and
> return the number of events seen */
>      int
>      show_events(int subscription_id)
>      {
>        int num_events = 0;
>        http_t *http;
>        ipp_t *request, *response;
>        ipp_attribute_t *attr;
>        int subscription_id;
>
>
>        http = httpConnectEncrypt(cupsServer(), ippPort(), cupsEncryption());
>
>        request = ippNewRequest(IPP_GET_NOTIFICATIONS);
>
>        ippAddString(request, IPP_TAG_OPERATION, IPP_TAG_URI,
>                     "printer-uri", NULL, "ipp://localhost/printers");
>        ippAddString(request, IPP_TAG_OPERATION, IPP_TAG_NAME,
>                     "requesting-user-name", NULL, cupsUser());
>        ippAddInteger(request, IPP_TAG_OPERATION, IPP_TAG_INTEGER,
>                      "subscription-id", subscription_id);
>
>        response = cupsDoRequest(http, request, "/printers");
>
>        if (response)
>        {
>         /*
>          * Loop through the response attributes...
>          */
>
>          for (attr = response->attrs; attr; attr = attr->next)
>          {
>           /*
>            * Skip everything up to the next event notification...
>            */
>
>            if (attr->group_tag != IPP_TAG_EVENT_NOTIFICATION)
>              continue;
>
>           /*
>            * Bump the event counter and then look at the attributes
>            * for this event...
>            */
>
>            num_events ++;
>
>            while (attr && attr->group_tag == IPP_TAG_EVENT_NOTIFICATION)
>            {
>              if (!strcmp(attr->name, "job-id") && attr->value_tag ==
> IPP_TAG_INTEGER)
>                printf("Job %d has completed!\n", attr->values[0].integer);
>
>              attr = attr->next;
>            }
>
>            if (!attr)
>              break;
>          }
>
>          ippDelete(response);
>        }
>
>        httpClose(http);
>
>        return (num_events);
>      }
>
> This code is all untested (just typed it into this email), so there
> might be mistakes, but hopefully it will show you the basics...
>
> --
> ______________________________________________________________________
> Michael Sweet, Easy Software Products           mike at easysw dot com
> Internet Printing and Document Software          http://www.easysw.com