CUPS is Common Unix Printing System. Apart from checking the printer queues summary, details and logs in Xinet, we can also perform checks of the printing service directly on the server.
lpstat displays status information about the current classes, jobs, and printers. When it is run with no arguments,
lpstat will list active jobs queued by the current user.
There are a lot more to printing services, then what was is covered here. This information should help to quickly diagnose certain issues.
The files contained in the
/var/spool/cups directory will be used to check the printing jobs. The scheduler stores job files in a spool directory, usually
There are two types of files that will be found in the spool directory, Control Files, and Data Files:
Control files starting with the letter: c ("c00001", "c99999", "c100000", etc.)
- Control files are IPP (Internet Printing Protocol) messages based on the original IPP (Internet Printing Protocol) Print-Job or Create-Job messages.
- Control files are normally cleaned out after the 500th job is submitted.
Data files starting with the letter d ("d00001-001", "d99999-001", "d100000-001", etc.)
- Data files are the original print files that were submitted for printing.
- Data files are removed immediately after a job has successfully printed.
There is one control file for every job known to the system and 0 or more data files for each job. Both behaviors can be configured.
- For more information on CUPS Design Specs
- Checking the printing service status on the server with
lpstat -tcommand. (click to enlarge)
- Checking system default printer with the
lpstat -dcommand (there are no default printers as this is a virtual machine for testing only).
- Checking the active print jobs by using the
- Checking the printing service via
cat /var/log/cups/access_log(click to enlarge)
- Checking the
cat /var/log/cups/error_log(no errors - since nothing was printed).
- Checking the
cat /var/log/cups/page_log(no logs - since nothing was printed).