lprm – cancel/delete specific print jobs 

lprm [ -E ] [ – ] [ -P destination ] [ job ID(s) ]

lprm cancels print jobs that have been queued for printing. The -P option specifies the destination printer or class.

“lprm – ” will delete all jobs

If no arguments are supplied, the current job on the default destination is cancelled. You can specify one or more job ID numbers to cancel those jobs, or use the  option to cancel all jobs.

The -E option forces encryption when connecting to the server.