lpd(8) CLIX lpd(8)
NAME
lpd - Runs the line printer daemon
SYNOPSIS
/usr/lib/lpd [-l] [port#]
FLAGS
-l Turns on logging of requests from the network
DESCRIPTION
The lpd is the line printer daemon (spool area handler) and is normally
invoked at boot time from the rc2.d file. It makes a single pass through
the printcap(4) file to find information on the existing printers, and
prints any files remaining after a crash. It then uses the functions
listen() and accept() to receive requests to print files in the queue,
transfer files to the spooling area, display the queue, or remove jobs
from the queue. In each case, it forks a child process to handle the
request so the parent can continue to listen for more requests.
The Internet port number used to rendezvous with other processes is
normally obtained with getservbyname, but can be changed with the port#
argument.
The -l flag causes lpd to log valid requests received from the network;
this is useful for debugging.
Access control is provided by two means. First, all requests must come
from one of the machines listed in the file /etc/hosts.equiv or
/etc/hosts.lpd. Second, if the rs capability is specified in the printcap
entry for the printer being accessed, lpr requests will only be honored
for users with accounts on the printer's host.
The file minfree in each spool directory contains the number of disk
blocks to leave free so that the line printer queue will not completely
fill the disk. The minfree file can be edited with a text editor.
The file lock in each spool directory is used to prevent multiple daemons
from becoming active simultaneously and to store information about the
daemon process for the lpr lpq, and lprm commands. After the daemon has
successfully set the lock, it scans the directory for files matching the
pattern cf*. Lines in each cf* file specify files to be printed, or
nonprinting actions to be performed. Each such line begins with a key
character to specify what to do with the remainder of the line.
J Job Name. String to be used for the job name on the burst page.
C Classification. String to be used for the classification line on the
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lpd(8) CLIX lpd(8)
burst page.
L Literal. The line contains identification information from the
password file and causes the banner page to be printed.
T Title. String to be used as the title for pr.
H Hostname. Name of the machine where lpr(1) was invoked.
P Person. Login name of the person who invoked lpr. This is used to
verify ownership by lprm.
M Send mail to the specified user when the current print job completes.
f Formatted File. Name of a file that is already formatted to print.
l Like f, but passes control characters and does not make page breaks.
p Name of a file to print using pr as a filter.
t A troff file. The file contains troff output.
n A ditroff file. The file contains device-independent troff output.
g Graph file. The file contains data produced by plot().
v The file contains a raster image.
r The file contains text data with FORTRAN carriage control characters.
1 troff font R. Name of the font file to use instead of the default.
2 troff font I. Name of the font file to use instead of the default.
3 troff font B. Name of the font file to use instead of the default.
4 troff font S. Name of the font file to use instead of the default.
W Width. Changes the page width (in characters) used by pr and the text
filters.
I Indent. The number of characters to indent the output by (in ASCII).
U Unlink. Name of file to remove when printing is complete.
N Filename. The name of the file which is being printed, or a blank for
stdin (when lpr is invoked in a pipeline).
If a file cannot be opened, a message will be logged through the console.
The lpd command will try up to 20 times to reopen a file it expects to be
there. After attempting to reopen the file, it skips the file to be
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lpd(8) CLIX lpd(8)
printed.
The lpd command uses the fcntl() command to provide exclusive access to
the lock file and to prevent multiple daemons from becoming active
simultaneously. If the daemon should be killed or die unexpectedly, the
lock file need not be removed. The lock file is kept in a readable ASCII
form and contains two lines. The first is the process ID of the daemon
and the second is the control filename of the current job being printed.
The second line is updated to reflect the current status of the lpd
command for the programs lpq and lprm.
EXAMPLES
The following starts the line printer daemon with the default options:
lpd
FILES
/etc/printcap Printer description file.
/usr/spool/* Spool directories.
/usr/spool/*/minfree Minimum free space to leave.
/dev/lp* Pine printer devices.
/dev/printer Socket for local requests.
/etc/hosts.equiv Lists machine names allowed printer access.
/etc/hosts.lpd Lists machine names allowed printer access, but not
under the same administrative control.
DIAGNOSTICS
All diagnostic messages for the lpd command appear in the log file.
EXIT VALUES
The lpd command exits with a value of 1 when a fatal error occurs.
RELATED INFORMATION
Commands: lpc(1), lpr, lpq(1), lprm(1)
Files: printcap(4)
Intergraph System and Network Administrator's Guide.
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