HP-UX System Administrator's Guide: Overview

Interface files (written as shell scripts) near the end of the data flow serve as pumps that
“pump” the orderly flow of data to the printers.
The line printer scheduler:
• prevents intermixed listings
• monitors printer/print request priorities
• adjusts printer status and availability
• logs spooler activities
If one printer’s “drain gets clogged”, you can reroute a print request from that printer
to another by using the lpmove command. Unwanted data can be “flushed” from the
spooling system with the cancel command.
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