6.  Line printer Administration

      The lpc program provides local control over line printer activity. The major commands and their intended use will be described. The command format and remaining commands are described in lpc(8).

abort and start

• Abort terminates an active spooling daemon on the local host immediately and then disables printing (preventing new daemons from being started by lpr). This is normally used to forcibly restart a hung line printer daemon (i.e., lpq reports that there is a daemon present but nothing is happening). It does not remove any jobs from the queue (use the lprm command instead). Start enables printing and requests lpd to start printing jobs.

enable and disable

• Enable and disable allow spooling in the local queue to be turned on/off. This will allow/prevent lpr from putting new jobs in the spool queue. It is frequently convenient to turn spooling off while testing new line printer filters since the root user can still use lpr to put jobs in the queue but no one else can. The other main use is to prevent users from putting jobs in the queue when the printer is expected to be unavailable for a long time.

restart

• Restart allows ordinary users to restart printer daemons when lpq reports that there is no daemon present.

stop

• Stop halts a spooling daemon after the current job completes; this also disables printing. This is a clean way to shutdown a printer to do maintenance, etc. Note that users can still enter jobs in a spool queue while a printer is stopped.

topq

• Topq places jobs at the top of a printer queue. This can be used to reorder high priority jobs since lpr only provides first-come-first-serve ordering of jobs.