cups remove all print jobs
-- get all outstanding print jobs. Note the printer used
COMMAND: $ lpstat -o
RESULT: HP-Officejet-128 user2 240640 mié 09 mar 2016 11:07:14 CET
-- This result indicates
------------ the printer is: HP-Officejet
------------ The user running the job was: user2
------------ The user the job was: 128
-- Cancel all print jobs for the printer:
$ cancel -a HP-Officejet
-- Cancel the specific print job
$ cancel HP-Officejet-Pro-8620-137
-- Cancel all jobs for that user
$ cancel -u usser2