printcap ? printer capability data base

printcap

DESCRIPTION

The Printcap function is a simplified version of the termcap(5) data base 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. This data base may not be substituted for, as is possible for termcap, 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 setup the database for a given printer.

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

Name

Type

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 ’

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
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
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
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/lpd spool directory
sf bool false suppress form feeds
sh bool false suppress printing of burst page header
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

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

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)

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 if filter is invoked with arguments:

if [?c] ?wwidth ?llength ?iindent ?n login ?h host acct-file

The ?c flag is passed only if the ?l flag (pass control characters literally) is specified to lpr. 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 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:

filter ?xwidth ?ylength ?n login ?h host acct-file

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.

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 themselves.

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

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

The printcap file format appeared in 4.2BSD ..

4.2 Berkeley Distribution May 10, 1991 4.2 Berkeley Distribution