journalctl -u cups --since today
-- Logs begin at Thu 2017-02-23 08:47:33 CET, end at Thu 2018-06-07 00:25:47 CEST. --
giu 07 00:00:00 fujitsu cupsd[891]: Expiring subscriptions...
giu 07 00:00:01 fujitsu cupsd[891]: Connection error: Operation now in progress
giu 07 00:00:01 fujitsu cupsd[891]: La stampante non risponde.
giu 07 00:00:01 fujitsu cupsd[891]: Discarding unused job-progress event...
giu 07 00:00:01 fujitsu cupsd[891]: cupsdMarkDirty(----S)
giu 07 00:00:01 fujitsu cupsd[891]: cupsdSetBusyState: newbusy="Printing jobs and dirty files", busy="Printing jobs and dirty files"
giu 07 00:00:01 fujitsu cupsd[891]: Expiring subscriptions...
giu 07 00:00:01 fujitsu cupsd[891]: [Notifier] state=3
giu 07 00:00:01 fujitsu cupsd[891]: [Notifier] PrinterStateChanged
giu 07 00:00:01 fujitsu cupsd[891]: [Client 1] POST / HTTP/1.1
giu 07 00:00:01 fujitsu cupsd[891]: cupsdSetBusyState: newbusy="Active clients, printing jobs, and dirty files", busy="Printing job>
giu 07 00:00:01 fujitsu cupsd[891]: [Client 1] Read: status=200, state=6
giu 07 00:00:01 fujitsu cupsd[891]: [Client 1] No authentication data provided.
giu 07 00:00:01 fujitsu cupsd[891]: [Client 1] 1.1 Get-Notifications 118
giu 07 00:00:01 fujitsu cupsd[891]: Get-Notifications /printers/
giu 07 00:00:01 fujitsu cupsd[891]: cupsdIsAuthorized: requesting-user-name="antonio"
giu 07 00:00:01 fujitsu cupsd[891]: [Client 1] Returning IPP successful-ok for Get-Notifications (/printers/) from localhost
giu 07 00:00:01 fujitsu cupsd[891]: [Client 1] Content-Length: 549
giu 07 00:00:01 fujitsu cupsd[891]: [Client 1] cupsdSendHeader: code=200, type="application/ipp", auth_type=0
giu 07 00:00:01 fujitsu cupsd[891]: [Client 1] con->http=0x5599d71e85c0
giu 07 00:00:01 fujitsu cupsd[891]: [Client 1] cupsdWriteClient error=0, used=0, state=HTTP_STATE_POST_SEND, data_encoding=HTTP_ENC>
giu 07 00:00:01 fujitsu cupsd[891]: [Client 1] Writing IPP response, ipp_state=IPP_STATE_DATA, old wused=0, new wused=0