LPD(1M) Printing Tools LPD(1M)NAMElpd - BSD line printer daemon
SYNOPSIS
/usr/etc/lpd [ -l ] [ port # ]
DESCRIPTION
Lpd is the line printer daemon (spool area handler) and is normally
invoked at boot time from the /etc/init.d/bsdlpr file. chkconfig (1M) can
be used to enable or disable lpd from starting at boot time ("chkconfig
bsdlpr off" or "chkconfig bsdlpr on"). At startup, lpd makes a single
pass through the printcap(4) file to find out about the existing printers
and prints any files left after a crash. It then uses the system calls
listen(2) and accept(2) 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 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(3) but can be changed with the port# argument. The -l flag
causes lpd to log valid requests received from the network. This can be
useful for debugging purposes.
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 those users with accounts on the machine with the printer.
The file minfree in each spool directory contains the number of disk
blocks to leave free so that the line printer queue won't completely fill
the disk. The minfree file can be edited with your favorite text editor.
If lpd receives a request to print to a printer that is not specified in
the printcap file then lpd will forward the print request to lpsched to
allow lpsched to attempt to service the request.
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 lpr(1), lpq(1), and lprm(1). After the daemon has
successfully set the lock, it scans the directory for files beginning
with cf. Lines in each cf file specify files to be printed or non-
printing 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 burst page.
L Literal. The line contains identification info from the password
file and causes the banner page to be printed.
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LPD(1M) Printing Tools LPD(1M)
T Title. String to be used as the title for pr(1).
H Host Name. Name of the machine where lpr 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 to print which is already formatted.
l Like ``f'' but passes control characters and does not make page
breaks.
p Name of a file to print using pr(1) as a filter.
t Troff File. The file contains troff(1) output (cat phototypesetter
commands).
n Ditroff File. The file contains device independent troff output.
d DVI File. The file contains Tex(l) output (DVI format from
Stanford).
g Graph File. The file contains data produced by plot(3X).
c Cifplot File. The file contains data produced by cifplot.
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(1) and the
text filters.
I Indent. The number of characters to indent the output by (in
ascii).
U Unlink. Name of file to remove upon completion of printing.
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LPD(1M) Printing Tools LPD(1M)
N File name. The name of the file which is being printed, or a blank
for the standard input (when lpr is invoked in a pipeline).
If a file can not be opened, a message will be logged via syslog(3) using
the LOG_LPR facility. Lpd will try up to 20 times to reopen a file it
expects to be there, after which it will skip the file to be printed.
Lpd uses flock(2) 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 file name of the current job being printed. The second line is
updated to reflect the current status of lpd for the programs lpq(1) and
lprm(1).
FILES
/etc/printcap printer description file
/usr/spool/* spool directories
/usr/spool/*/minfree minimum free space to leave
/dev/lp* line 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 same administrative control.
SEE ALSOlpc(1M), pac(1), lpr(1), lpq(1), lprm(1), syslog(3), printcap(4)
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