Log file locations.

The main CUPS log file directory is here:

/var/log/cups

You can follow the access log like this:

tail -f -n 1000 /var/log/cups/access_log

You can follow the error log like this:

tail -f -n 1000 /var/log/cups/error_log

Checking for jobs in progress.

You can check what CUPS printing jobs are in the spool already by checking this spool directory:

sudo ls -la /var/spool/cups/tmp

Remotely manage CUPS.

Just go to this URL on the CUPS server; the key is port 631:

http://localhost:631

Clear out and regenerate the CUPS spool directory.

First, go into the /var/spool/ directory:

cd /var/spool/

Then move/rename cups to cups.old like this:

sudo mv cups cups.old

Now fully restart the server to get CUPS to create a new /var/spool/ directory:

After reboot, go back into the /var/spool/ directory:

cd /var/spool/

And make sure the new cups directory is in place. If it is, all is good

sudo rm cups.old

Restart the CUPS service.

Stop CUPS:

sudo launchctl unload /System/Library/LaunchDaemons/org.cups.cupsd.plist

Start CUPS again:

sudo launchctl load /System/Library/LaunchDaemons/org.cups.cupsd.plist

Restore “Printer & Fax” settings to the default

Stop CUPS:

sudo launchctl stop org.cups.cupsd

Rename cupsd.conf to cupsd.conf.old:

sudo mv /etc/cups/cupsd.conf /etc/cups/cupsd.conf.old

Copy cupsd.conf.default to cupsd.conf:

sudo cp /etc/cups/cupsd.conf.default /etc/cups/cupsd.conf

Rename printers.conf to printers.conf.old:

sudo mv /etc/cups/printers.conf /etc/cups/printers.conf.old

Start CUPS again:

sudo launchctl start org.cups.cupsd