Installation guide
• Uses specific print filters for print requests. Print filters translate an
input format into a printer-specific output format.
• After a system reboot, prints any files that were not printed when the
system stopped operating.
When you use the lpr command, the lpd daemon is activated, and the
daemon copies the file to the printer’s spooling queue or directory. Requests
are printed in the order in which they enter the queue. A copy of the file to
be printed remains in the queue until the printer is ready to print it; then
the lpd daemon removes the file from the spooling queue and sends it to
the printer.
After you install and boot your system, the lpd daemon is usually started
by the init program. You can start the lpd daemon with the following
command syntax:
/usr/lbin/lpd
[-l]
The −l option causes the lpd daemon to log valid requests from the
network. This option is useful for debugging.
To test whether the line printer daemon is running, enter:
# ps agx |grep /usr/sbin/lpd
10.7.2 Spooling Directories
Each printer must have its own spooling directory located under the
/usr/spool/lpd directory. The spooling directory acts as a printer’s
spooling queue; it contains the files that are queued for printing on that
printer. A printer spooling directory should have the same name as the
printer reference name and must be located on the machine attached to the
printer. The printer reference name is the name that you specify to print on
a particular printer.
If you are using lprsetup, the program supplies the default value
/usr/spool/lpd
n
. The
n
variable specifies the printer number. For
example, the default name of the spooling directory for a second line
printer could be /usr/spool/lpd2. The default spooling directory for any
printer is /usr/spool/lpd.
Each printer entry in the /etc/printcap file should specify a spooling
directory even if the printer is connected to another machine or is on
another network. You specify a spooling directory with the sd symbol. For
example:
sd=/usr/spool/lpd/purple
Spooling directories must have the same parent directory name, which is
normally /usr/spool.
10–20 Administering the Print Services