I usually try to avoid administering printers whenever possible. As a result I end of flailing around the CUPS web interface before I figure out how to re-enable a printer. And, when I get a call to help debug a printer, I can't easily tell people what to do.

When I try to do what I need via the command line, I end up spending at least 10 or 15 minutes re-reading man pages before I piece together the steps.

Here's my attempt to document the steps so I don't have to re-read man pages.

Setup

In these examples, the printer name in question is: stability and it is a network printer, with local DNS that properly resolves the hostname stability to an IP address.

The cups commands in these examples can be run as a non-root user if that user is in the lpadmin group.

Type:

groups

To see if lpadmin is listed. If not:

sudo adduser <your-user-name> lpadmin

Then, to gain access to the new group without logging out and logging in again:

newgrp lpadmin

Network access

First, try to ping the printer:

ping stability

If this fails, restart the printer and/or check network cables. No point in doing anything else until it responds to pings.

Can't submit new jobs to the printer

Next, if the problem is that the printer is greyed out when you try to print a document or your application tells you that the printer is rejecting jobs, confirm this status with:

lpstat -a stability

It will either output:

stability accepting requests since Mon 20 May 2013 10:28:57 AM EDT

Or

stability not accepting requests since Mon 20 May 2013 10:28:57 AM EDT -
  Rejecting Jobs

If it is rejecting jobs, try:

/usr/sbin/cupsaccept stability

Accepts new jobs, but just doesn't print

On the other hand, if the printer is accepting jobs, but the jobs are not printing, find out if the printer is enabled with:

lpstat -p stability

You should get either:

printer stability is idle.  enabled since Mon 20 May 2013 10:28:57 AM EDT

Or:

printer stability disabled since Mon 20 May 2013 10:35:10 AM EDT -
  Paused

If it is disabled, you should first see what queued jobs there are:

lpq

If you have a list of duplicate pending jobs, be sure to delete the duplicates to avoid having your print job come out multiple times.

To delete a queued job, type the following (n should be the number in the Job column of the lpq output):

cancel <n>

After you have deleted duplicate jobs, try "enabling" it:

/usr/sbin/cupsenable stability

Then, re-rerun the lpq command and see if it's now "ready." At this point, the jobs should start printing.

Review of concepts

For review... a few important concepts:

  • cupsaccept/cupsreject: controls whether a printer will accept or reject new jobs. It doesn't matter whether the printer is enabled or disabled.
  • cupsenable/cupsdisable: controls whether a printer will print existing jobs. It doesn't matter whether the print is accepting or rejecting new jobs.