NAME

printcap — printer capability data base

SYNOPSIS

printcap

DESCRIPTION

The printcap data base is used to describe line printers. The spooling system accesses the printcap 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.

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 set up the database for a given printer.

CAPABILITIES

Refer to capfile(5) for a description of the file layout.

Name	Type	Default	Description
af	str	NULL	name of accounting file
br	num	none	if lp is a tty, set the baud rate (ioctl(2) call)
cf	str	NULL	cifplot data filter
df	str	NULL	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 device is opened
fs	num	0	like `fc' but set bits
gf	str	NULL	graph data filter (plot(3) format
hl	bool	false	print the burst header page last
ic	bool	false	driver supports (non standard) ioctl to indent printout
if	str	NULL	name of text filter which does accounting
lf	str	/dev/console	error logging file name
lo	str	lock	name of lock file
lp	str	/dev/lp	device name to open for output to local printer, or port@host for remote printer/printer on print server
ms	str	NULL	list of terminal modes to set or clear
mx	num	1000	maximum file size (in BUFSIZ blocks), zero = unlimited
nd	str	NULL	next directory for list of queues (unimplemented)
nf	str	NULL	ditroff data filter (device independent troff)
of	str	NULL	name of output filtering program
pc	num	200	price per foot or page in hundredths of cents
pf	str	NULL	filter for printing PostScript files
pl	num	66	page length (in lines)
pw	num	132	page width (in characters)
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
rg	str	NULL	restricted group. Only members of group allowed access
rm	str	NULL	machine name for remote printer or port@host for a remote printer on a port other than the standard port. (also suppress the burst page, see NOTES)
rp	str	``lp''	remote printer name argument
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	/var/spool/output/lpd	spool directory
sf	bool	false	suppress form feeds
sh	bool	false	suppress printing of burst page header (local only, see NOTES)
st	str	status	status file name
tf	str	NULL	troff data filter (cat phototypesetter)
tr	str	NULL	trailer string to print when queue empties
vf	str	NULL	raster image filter
xc	num	0	if lp is a tty, clear local mode bits (tty(4))
xs	num	0	like `xc' but set bits

If the local line printer driver supports indentation, the daemon must understand how to invoke it.

FILTERS

If a printer is specified via lp (either local or remote), the lpd(8) daemon creates a pipeline of filters to process files for various printer types. The pipeline is not set up for remote printers specified via rm unless the local host is the same as the remote printer host given. 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 
o	pf	PostScript 
f	rf	Fortran 
t	tf	troff 
v	vf	raster image

The if filter is invoked with arguments:

The -c flag is passed only if the -l flag (pass control characters literally) is specified to lpr(1). The width 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 -j parameter is optional and specifies the name of the print job if available. The acct-file option is passed from the af printcap 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.

All other filters are called as:

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.

Filters can communicate errors to lpd by their exit code and by modifying the mode of the spool lock file as follows:

Exit code

Description

0

Success.

1

An attempt is made to reprint the job and mail is sent if it fails.

2

lpd(8) silently discards the job.

n

lpd(8) discards the job and mail is sent.

lock code

Description

u+x

Stop printing and leave queue disabled (S_IXUSR).

o+x

Rebuild the queue (S_IXOTH).

LOGGING

Error messages generated by the line printer programs themselves (that is, the lp* 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 syslog(3) themselves.

Error messages sent to the console have a carriage return and a line feed appended to them, rather than just a line feed.

SEE ALSO

lpq(1), lpr(1), lprm(1), capfile(5), lpc(8), lpd(8), pac(8)

4.3 BSD Line Printer Spooler Manual.

NOTES

The sh flag is a function of the spooler with the locally attached printer, and so has no effect when used with rm. NetBSD never adds a burst page when used as a remote spooler. To suppress the burst page for other systems or dedicated devices, refer to the documentation for those systems or devices.

HISTORY

The printcap file format appeared in 4.2BSD.