As an administrator for your printers, you have had to install, set up, and test them. Using the lpc command, you can interact with your printers in yet more ways. With
lpc, you can
First, a note about terminology: if a printer is stopped, it will not print anything in its queue. Users can still submit jobs, which will wait in the queue until the printer is started or the queue is cleared.
If a queue is disabled, no user (except root) can submit jobs for the printer. An enabled queue allows jobs to be submitted. A printer can be started for a disabled queue, in which case it will continue to print jobs in the queue until the queue is empty.
In general, you have to have root privileges to use the
lpc command. Ordinary users can use the lpc command to get printer status and to restart a hung printer only.
Here is a summary of the
lpc commands. Most of the
commands takes a printer-name argument to tell on which
printer to operate. You can use all
for the
printer-name to mean all printers listed in
/etc/printcap
.
abort printer-name
Cancel the current job and stop the printer. Users can still submit jobs if the queue's enabled.
clean printer-name
Remove old files from the printer's spooling directory. Occasionally, the files that make up a job are not properly removed by LPD, particularly if there have been errors during printing or a lot of administrative activity. This command finds files that do not belong in the spooling directory and removes them.
disable printer-name
Disable queuing of new jobs. If the printer's started, it will continue to print any jobs remaining in the queue. The superuser (root) can always submit jobs, even to a disabled queue.
This command is useful while you are testing a new
printer or filter installation: disable the queue and
submit jobs as root. Other users will not be able to
submit jobs until you complete your testing and re-enable
the queue with the enable
command.
down printer-name message...
Take a printer down. Equivalent to disable
followed by stop
. The message appears as the
printer's status whenever a user checks the printer's
queue with
lpq or status with lpc status
.
enable printer-name
Enable the queue for a printer. Users can submit jobs but the printer will not print anything until it is started.
help command-name
Print help on the command command-name. With no command-name, print a summary of the commands available.
restart printer-name
Start the printer. Ordinary users can use this command
if some extraordinary circumstance hangs LPD, but they
cannot start a printer stopped with either the stop
or down
commands. The restart
command is
equivalent to abort
followed by start
.
start printer-name
Start the printer. The printer will print jobs in its queue.
stop printer-name
Stop the printer. The printer will finish the current job and will not print anything else in its queue. Even though the printer is stopped, users can still submit jobs to an enabled queue.
topq printer-name job-or-username...
Rearrange the queue for printer-name by placing the
jobs with the listed job numbers or the jobs
belonging to username at the top of the queue. For
this command, you cannot use all
as the
printer-name.
up printer-name
Bring a printer up; the opposite of the down
command. Equivalent to start
followed by
enable
.
lpc accepts the above commands on the command line. If
you do not enter any commands,
lpc enters an interactive
mode, where you can enter commands until you type exit
,
quit
, or end-of-file.