When you send a print job to the printer daemon such as printing files from OpenOffice.org applications or printing an image from The GIMP, the print job is added to the print spool queue.
The print spool queue is a list of print jobs that have been sent to the printer and information about each print request, such as:
The status of the request
The username of the person who sent the request
The hostname of the system that sent the request
The job number
To view the list of print jobs in the print spool, open a shell prompt and type the command lpq. The last few lines will look similar to the following:
Rank Owner/ID Class Job Files Size Time active user@localhost+902 A 902 sample.txt 2050 01:20:46
If you want to cancel a print job, find the job number of the request with the command lpq (see the previous section) and then use the command lprm job_number. For example, typing the command lprm 902 would cancel the print job shown in the example in the previous section.
You must have proper permissions to cancel a print job. You cannot cancel print jobs that were started by other users unless you are logged in as root on the machine to which the printer is attached.
You can also print a file directly from a shell prompt. For example, the command lpr sample.txt will print the text file sample.txt. The print filter determines what type of file it is and converts it to a format the printer can understand.