printcap(4)printcap(4)NAMEprintcap - Printer capability data base
SYNOPSIS
/etc/printcap
DESCRIPTION
The printcap file is used to describe printer characteristics. The for‐
mat of the printcap file is a simplified version of the /etc/termcap
database format.
The lpd line printer daemon accesses the /etc/printcap file every time
a file is passed to the spooler for printing. The print spooling system
uses the printcap file to obtain information about each printer
attached to the system and about remote printers. Each entry in the
printcap file describes a single printer.
When the local line printer driver supports indentation, the lpd line
printer daemon must understand how to invoke this capability.
The default printer for your system usually has the device reference
lp, although environment variable PRINTER can be used to override the
default printer reference. The print commands (for example, lpr, lpq,
and lprm) support the -Pprinter option, which enables you to specify a
specific printer.
Note
See the RESTRICTIONS section for information on using printconfig.
Printer Characteristic Symbols
Each printer has various characteristics that tell the lpd line printer
daemon how to communicate with the printing device defined in the /dev
directory. A table in this section lists the printer characteristic
symbols and provides the following information for each: The symbol,
which is a 2-character mnemonic. The symbol must be specified exactly
as it appears in this column. Type of data expressed by the entry as
str, num, or bool. When the characteristic defined by the symbol is
referenced as a string variable (str) in the Type column, it must be
followed by an = (equal sign) together with a string value; when you do
not define the string value, it either remains a NULL string and con‐
tains no data or takes the value specified in the Default column. When
the Type column defines a symbol type as bool, it may only be logically
true (yes) or logically false (no).
When the parameter you define is a numerical variable, it must
be followed with a # (pound sign) together with the numerical
value you assign; when you do not define the numerical parameter
it takes the value specified in the Default column of the table.
A summary of the printer characteristic that the symbol speci‐
fies.
Symbols whose descriptions are followed by "(I18N)" are provided
to meet country-specific printing requirements. Refer to
i18n_printing(5) for information about when these symbols are
valid in a printer entry.
The following is an example of a printcap entry:
myprinter|lp0:\
:af=/usr/adm/lpacct:\
:br#9600:\
:ct=dev:\
:fc#0177777:\
:fs#023:\
:if=/usr/lbin/la75of:\
:lf=/usr/adm/lperr:\
:lp=/dev/tty00:\
:mx#0:\
:of=/usr/lbin/la75of:\
:pl#66:\
:pw#80:\
:sd=/usr/spool/lpd:\
:xc#0177777:\
:xf=/usr/lbin/xf:\
:xs#044000:
Entries can continue onto multiple lines by specifying the back‐
slash (\) as the last character of a line. Empty fields can be
included for readability (here between the last field on a line
and the first field on the next line).
Comments can be included on lines beginning with the pound sign
(#).
Refer to the RESTRICTIONS section for information on blank spa‐
ces and tab characters.
────────────────────────────────────────────────────────────────────
Name Type Default Description
────────────────────────────────────────────────────────────────────
af str NULL Name of accounting file
br num none If lp is a tty, set the baud rate
(ioctl call).
cf str NULL The cifplot data filter.
ct str dev The connection type. The choices
are: dev, LAT (or lat), and tcp
(networked).
df str NULL The tex data filter (DVI format).
fc num 0 If lp is a tty, clear flag bits
(sgtty.h).
ff str \f String to send for a form feed.
fo bool false Print a form feed when the device is
opened.
fs num 0 Like fc, but set bits.
gf str NULL The graph data filter (plot format).
hl bool false Print the burst header page last.
if str NULL Name of text filter that does
accounting.
jj bool NULL Turns on (or restores) the ability
of lpd to keep one connection to a
printer open for all pending jobs in
the queue. Zero (0) is off (one job
per connection), 1 is on (multiple
jobs per connection).
lf str /dev/con‐ Error logging filename.
sole
lo str lock Name of lock file.
lp str /dev/lp Device name to open for output. For
network (TCP/IP) printers, enter the
name a @hostname/servicename. The
servicename is defined in /etc/ser‐
vices with the port number.
mj num 1000 Maximum number of jobs that can be
submitted to a print queue. The
limit is 1,000,000 (ranging from 0
to 999,999).
mx num 1000 Maximum file size (in BUFSIZ
blocks). Zero = unlimited.
nf str NULL The ditroff data filter (for device
independent troff).
of str NULL Name of output filtering program.
on str NULL Supported in clusters only. Valid
entries are localhost and/or a
comma-separated list of cluster mem‐
ber (host) names.
pl num 66 Page length (in lines).
pw num 132 Page width (in columns).
px num 0 Page width in pixels (horizontal).
py num 0 Page length in pixels (vertical).
rf str NULL Filter for printing FORTRAN style
text files.
rm str NULL Machine name for remote printer.
(Required for remote printers.) Use
the string @dpa to define an inbound
gateway for the Advanced Printing
Software.
rp str lp Remote printer name argument.
(Required for remote printers.)
Specify a logical printer name, such
as lpr1, for the Advanced Printing
Software.
rs bool false Restrict remote users to those with
local accounts.
rw bool false Open the printer device for reading
and writing.
sb bool false Short banner (one line only).
sc bool false Suppress multiple copies.
sd str /usr/spool/lpd Spool directory. (Required for LAT
and remote printers.)
sf bool false Suppress form feeds.
sh bool false Suppress printing of burst page
header.
st str status Status filename.
tf str NULL The troff data filter (for the cat
phototypesetter).
tr str NULL Trailer string to print when queue
empties.
vf str NULL The raster image filter.
xc num 0 If lp is a tty, clear local mode
bits (tty).
xf str NULL Pass-through filter.
xs num 0 Like xc, but set bits.
ya str NULL Additional parameters for print fil‐
ter (I18N).
yd str NULL Secondary device name for font
faulting (I18N).
yp str NULL Printer ID conforming to Wototo
standard (I18N).
ys num 0 Size of SoftODL character cache
(I18N).
yt str "fifo" SoftODL character replacement strat‐
egy (I18N).
────────────────────────────────────────────────────────────────────
When the local line printer driver supports indentation, the lpd line
printer daemon must understand how to invoke this capability.
LAT Printing Characteristics
The following table lists the LAT printing characteristics:
──────────────────────────────────────────────────────
Name Type Default Description
──────────────────────────────────────────────────────
ct str LAT Remote printing using LAT
as the transport
lp str /dev/ttyWX Device name to open for
output where WX is a LAT
device.
──────────────────────────────────────────────────────
Network (TCP/IP) Printing Characteristics
The following table lists typical TCP/IP printing characteristics for a
DEClaser3500 printer. The entry in the /etc/services file reads:
dlaser35 10001/tcp
Examples of print symbol settings are set as follows: Has a value of
tcp to specify network printing using TCP/IP Has a value of
@prthub/dlaser35 which specifies service name dlaser35 on node prthub
Advanced Printing Software
If Advanced Printing Software is installed you must specify the string
@dpa for the rm characteristic and specify a queue name for the rp
characteristic.
Refer to the Advanced Printing Software documentation for more informa‐
tion on setting up the printing environment.
Filter and Flags
The lpd line printer daemon creates a pipeline of filters to process
files for various different printer device. The filters you select
depend on the flags that are passed to the lpr command. The pipeline
setup is:
───────────────────────────────────
Flag Filter Description
───────────────────────────────────
none if regular text
-p pr | if regular text + pr
-c cf cifplot
-d df DVI (tex)
-g gf plot
-n nf ditroff
-f rf FORTRAN
-t tf troff
-v vf raster image
───────────────────────────────────
The if filter is invoked with arguments according to the following for‐
mat: if [-c] -wwidth -llength -iindent -nlogin -hhost acct-file
The xf pass-through filter is specified when output is preformatted and
does not require special filtering.
The -c flag is passed only when the -l flag (pass control-characters
literally) is specified to the lpr command. The -wwidth and -llength
parameters specify the page width and length (from the assigned or
default values of pw and pl respectively in the printcap file) in char‐
acters. The -n and -h flags specify the login name and hostname of the
owner of the job, respectively. The acct-file is passed from the af
entry in the printcap file.
The if filter is opened for all individual jobs, which makes it suit‐
able for accounting. When the if filter is not specified, the system
uses the of filter as the default value. The of filter however, is
opened only once and is only given the -wwidth and -llength flags.
All other filters are called according to the following format: filter
-xwidth -ylength -nlogin -h host acct-file
In this format, -xwidth and -ylength are represented in pixels as spec‐
ified by the px and py entries, respectively, in the printcap file.
All filters take standard input (stdin) as the source file and standard
output (stdout) as the destination. The printer may log either to stan‐
dard error (stderr) or use syslogd, and must not ignore the SIGINT sig‐
nal.
ERROR LOGGING
Error messages generated by the line printer programs (that is, the lp*
programs) are logged by syslogd using the lpr facility. Messages
printed on the stderr of one of the filters are sent to the correspond‐
ing lf file specified in the printcap file. The filters may, of course,
also use syslogd.
Error messages sent to the console have a carriage return and a line
feed appended to them, rather than just a line feed.
RESTRICTIONS
Editing the /etc/printcap file manually is not recommended. Use the
appropriate configuration utilities to add printers and symbols. If a
printcap file is corrupted, you will see an error message to this
effect. A likely cause of such corruption is the presence of tab or
space characters in a blank line or following a continuation character
(\). Use the following command to find incorrect tabs or spaces in the
printcap file:
$ cat -e /etc/printcap | more
The preceding command marks the end of each line with a dollar sign ($)
so that trailing tabs and spaces are easily visible.
The following restrictions apply when using older versions of printcap
files, at Digital UNIX Version 3.2 or earlier: The system assigns
printers names lp[0-9]*, [0-9]*, and for the default printer, lp. For
example, the default printer may have a name field such as
lp0|0|lp|default|declaser3500:... and another printer may be
lp7|7|some_alias|another alias:.... As a result, the system will have
difficulty with printers that have less than two names or that use
these reserved names as aliases. Some of the attribute value checking
is different. For example, some fields that were not required now are,
and some attributes values that were legal no longer are. The print‐
config utility requires that all comments be associated with a printer.
As a result, comments appearing after the last printer will be trun‐
cated (deleted). As a work around, invoke printconfig with the menu
interface as follows:
printconfig -ui menu
this command invokes lprsetup which is fully compatible with
earlier printcap files.
SEE ALSO
Commands: lpq(1), lpr(1), lprm(1), lpc(8), lpd(8), lprsetup(8), pac(8)
Files: termcap(4)
Others: i18n_printing(5)
System Administration
Network Administration: Connections
printcap(4)
