Lprm without any arguments will delete the currently active job if it is owned by the user who invoked lprm.
If the - flag is specified, lprm will remove all jobs which a user owns. If the super-user employs this flag, the spool queue will be emptied entirely. The owner is determined by the user's login name and host name on the machine where the lpr command was invoked.
Specifying a user's name, or list of user names, will cause lprm to attempt to remove any jobs queued belonging to that user (or users). This form of invoking lprm is useful only to the super-user.
A user may dequeue an individual job by specifying its job number. This number may be obtained from the lpq(1) program, e.g.
% lpq -l
1st: ken [job #013ucbarpa]
(standard input) 100 bytes
% lprm 13
Lprm will announce the names of any files it removes and is silent if there are no jobs in the queue which match the request list.
Lprm will kill off an active daemon, if necessary, before removing any spooling files. If a daemon is killed, a new one is automatically restarted upon completion of file removals.
The -P option may be usd to specify the queue associated with a specific printer (otherwise the default printer, or the value of the PRINTER variable in the environment is used).
/etc/printcap printer characteristics file
/usr/spool/* spooling directories
/usr/spool/*/lock lock file used to obtain the pid of the current
daemon and the job number of the currently active job