lprc—printer-control program

The lprc program is used to control the operation of the line-printer system.

For each printer configured in /etc/printcap, lprc may be used to:

The lprc program gives the root user local control over printer activity. Here are the program's major commands and their intended uses (see the Utilities Reference entry for the command format and full list of commands).

Enable printing and ask lpd to start printing jobs.
Terminate an active spooling daemon on the local host immediately and then disable printing (preventing new daemons from being started by lpr). You typically use the abort command to forcibly restart a hung printer daemon (e.g., when lprq reports that a daemon is present, but nothing is happening).

The abort command doesn't remove any jobs from the spool queue; for this, use lprrm.

enable and disable
Turn spooling in the local queue on or off, in order to allow or prevent lpr from putting new jobs in the spool queue.

For example, you may want to use the disable command when testing new printer filters, because this lets root print, but prevents anyone else from doing so. The other main use of this option is to prevent users from putting jobs in the queue when the printer is expected to be unavailable for a long time.

Allow ordinary users to restart printer daemons when lprq reports that no daemon is present.
Halt a spooling daemon after the current job is completed; this also disables printing. This is a clean way to shut a printer down for maintenance. Note that users can still enter jobs in a spool queue while a printer is stopped.
Place selected jobs at the top of a printer queue. You can use this command to promote high-priority jobs (lpr places jobs in the queue in the order they were received).