The
Printcap
function
is a simplified version of the
termcap(5)
data base
used to describe line printers.
The spooling system accesses the
file every time it is used, allowing dynamic
addition and deletion of printers.
Each entry in the data base
is used to describe one printer.
This data base may not be
substituted for, as is possible for
termcap(5),
because it may allow accounting to be bypassed.
The default printer is normally
lp
though the environment variable
PRINTER
may be used to override this.
Each spooling utility supports an option,
-P printer
to allow explicit naming of a destination printer.
Refer to the
"4.3 BSD Line Printer Spooler Manual"
for a complete discussion on how to setup the database for a given printer.
CAPABILITIES
Refer to
termcap(5)
for a description of the file layout.
NameTypeDefaultDescription
"afstr" Ta NULL Ta name of accounting file
"brnumnoneif lp is a tty, set the baud rate"
(ioctl2
call)
"cfstr" Ta NULL Ta cifplot data filter
"ctnum120TCP connection timeout in seconds"
"dfstr" Ta NULL Ta tex data filter
( DVI
format)
"ffstr" Ta So \f Sc Ta string to send for a form feed
"foboolfalseprint a form feed when device is opened"
"gfstr" Ta NULL Ta graph data filter
(plot3
format
"hlboolfalseprint the burst header page last"
"icboolfalsedriver supports (non standard) ioctl to indent printout"
"ifstr" Ta NULL Ta name of text filter which does accounting
"lfstr" Ta /dev/console Ta error logging file name
"lostr" Ta lock Ta name of lock file
"lpstr" Ta /dev/lp Ta device name to open for output, or port @ machine to open a TCP socket
"mcnum0maximum number of copies which can be requested on"
"ndstr" Ta NULL Ta next directory for list of queues (unimplemented)
"nfstr" Ta NULL Ta ditroff data filter (device independent troff)
"ofstr" Ta NULL Ta name of output filtering program
"pcnum200price per foot or page in hundredths of cents"
"plnum66page length (in lines)"
"pwnum132page width (in characters)"
"pxnum0page width in pixels (horizontal)"
"pynum0page length in pixels (vertical)"
"rcboolfalsewhen sending to a remote host, resend copies (see below)"
"rfstr" Ta NULL Ta filter for printing
FORTRAN
style text files
"rgstr" Ta NULL Ta restricted group. Only members of group allowed access
"rmstr" Ta NULL Ta machine name for remote printer
"rpstr" Ta lp Ta remote printer name argument
"rsboolfalserestrict remote users to those with local accounts"
"rwboolfalseopen the printer device for reading and writing"
"sbboolfalseshort banner (one line only)"
"scboolfalsesuppress multiple copies"
"sdstr" Ta /var/spool/lpd Ta spool directory
"sfboolfalsesuppress form feeds"
"shboolfalsesuppress printing of burst page header"
"srstr" Ta NULL Ta file name to hold statistics of each datafile as it is received
"ssstr" Ta NULL Ta file name to hold statistics of each datafile as it is sent
"ststr" Ta status Ta status file name
"tfstr" Ta NULL Ta troff data filter (cat phototypesetter)
"trstr" Ta NULL Ta trailer string to print when queue empties
"vfstr" Ta NULL Ta raster image filter
Each two-letter capability has a human-readable alternate name.
Short formLong form
"afacct.file"
"brtty.rate"
"cffilt.cifplot"
"ctremote.timeout"
"dffilt.dvi"
"dudaemon.user"
"ffjob.formfeed"
"fojob.topofform"
"gffilt.plot"
"hlbanner.last"
"iffilt.input"
"lfspool.log"
"lospool.lock"
"lptty.device"
"mcmax.copies"
"mstty.mode"
"mxmax.blocks"
"nffilt.ditroff"
"offilt.output"
"pcacct.price"
"plpage.length"
"pwpage.width"
"pxpage.pwidth"
"pypage.plength"
"rcremote.resend_copies"
"rffilt.fortran"
"rgdaemon.restrictgrp"
"rmremote.host"
"rpremote.queue"
"rsdaemon.restricted"
"rwtty.rw"
"sbbanner.short"
"scjob.no_copies"
"sdspool.dir"
"sfjob.no_formfeed"
"shbanner.disable"
"srstat.recv"
"ssstat.send"
"stspool.status"
"tffilt.troff"
"trjob.trailer"
"vffilt.raster"
If the local line printer driver supports indentation, the daemon
must understand how to invoke it.
FILTERS
The
lpd(8)
daemon creates a pipeline of
filters
to process files for various printer types.
The filters selected depend on the flags passed to
lpr(1).
The pipeline set up is:
p pr | if regular text + pr(1)
none if regular text
c cf cifplot
d df DVI (tex)
g gf plot(3)
n nf ditroff
f rf Fortran
t tf troff
v vf raster image
The
-c
flag is passed only if the
-l
flag (pass control characters literally)
is specified to
lpr(1).
The
Width
function
and
length
specify the page width and length
(from
pw
and
pl
respectively) in characters.
The
-n
and
-h
parameters specify the login name and host name of the owner
of the job respectively.
The
Acct-file
function
is passed from the
af
entry.
If no
if
is specified,
of
is used instead,
with the distinction that
of
is opened only once,
while
if
is opened for every individual job.
Thus,
if
is better suited to performing accounting.
The
of
is only given the
width
and
length
flags.
where
width
and
length
are represented in pixels,
specified by the
px
and
py
entries respectively.
All filters take
stdin
as the file,
stdout
as the printer,
may log either to
stderr
or using
syslog(3),
and must not ignore
SIGINT
REMOTE PRINTING
When printing to a remote printer using
rm
it is possible to use either
if
or
of
If both are specified,
of
is ignored.
Both filters behave the same except that they are passed
different arguments as above.
Specifically, the output filter is
terminated and restarted for each file transmitted.
This is necessary
in order to pass the resulting size to the remote
lpd(8).
If the
-p
flag was passed to
lpr(1),
pr(1)
is not executed locally, but is requested of the remote
lpd(8).
Any input filtering via
if
will therefore happen before
pr(1)
is executed rather than afterwards.
There are some models of network printers which accept jobs from
lpd(8),
but they ignore the control file for a job and simply print
each data file as it arrives at the printer.
One side-effect of this behavior is that the printer will ignore any request
for multiple copies as given with the
-#
flag on the
lpr(1)
command.
The
rc
entry will cause
lpd(8)
to resend each data file for each copy that the user
originally requested.
Note that the
rc
entry should only be specified on hosts which send jobs directly to
the printer.
If
lp
is specified as
port @ machine
(and
rm
is not in use), print data will be sent directly to the given
port
on the given
machine
TRANSFER STATISTICS
When a print job is transfered to a remote machine (which might be
another unix box, or may be a network printer), it may be useful
to keep statistics on each transfer.
The
sr
and
ss
options indicate filenames that lpd should use to store such
statistics.
A statistics line is written for each datafile of a
job as the file is successfully transferred.
The format of the
line is the same for both the sending and receiving side of a
transfer.
Statistics on datafiles being received would be used on a print
server, if you are interested in network performance between a
variety of machines which are sending jobs to that print server.
The print server could collect statistics on the speed of each
print job as it arrived on the server.
Statistics on datafiles being sent might be used as a minimal
accounting record, when you want to know who sent which jobs to a
remote printer, when they were sent, and how large (in bytes) the
files were.
This will not give include any idea of how many pages
were printed, because there is no standard way to get that information
back from a remote (network) printer in this case.
LOGGING
Error messages generated by the line printer programs themselves
(that is, the
lpd(8)
and related programs)
are logged by
syslog(3)
using the
LPR
facility.
Messages printed on
stderr
of one of the filters
are sent to the corresponding
lf
file.
The filters may, of course, use
syslogd(8)
themselves.
Error messages sent to the console have a carriage return and a line
feed appended to them, rather than just a line feed.
