The  function  is  a  simplified version of the 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 possi-
ble for because it may allow  accounting  to  be  bypassed.   The
default  printer  is normally though the environment variable may
be used to override this.   Each  spooling  utility  supports  an
option, to allow explicit naming of a destination printer.  Refer
to the for a complete discussion on how setup the database for	a
given  printer.   Refer  to for a description of the file layout.
call) format) format blocks), zero = unlimited style  text  files
If the local line printer driver supports indentation, the daemon
must understand how to invoke it.  The daemon creates a  pipeline
of  to	process  files	for  various  printer types.  The filters
selected depend on the flags passed to 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 filter is invoked with arguments:  The
flag  is  passed only if the flag (pass control characters liter-
ally) is specified to The function and specify the page width and
length (from and respectively) in characters.  The and parameters
specify the login name and host name of  the  owner  of  the  job
respectively.	The  function is passed from the entry.  If no is
specified, is used instead, with the distinction that  is  opened
only  once,  while  is opened for every individual job.  Thus, is
better suited to performing accounting.  The is  only  given  the
and flags.  All other filters are called as: where and are repre-
sented in pixels, specified by the and entries respectively.  All
filters  take  as  the file, as the printer, may log either to or
using and must not ignore Error messages generated  by	the  line
printer programs themselves (that is, the programs) are logged by
using the facility.  Messages printed on of one  of  the  filters
are  sent to the corresponding file.  The filters may, of course,
use themselves.  Error messages sent to the console have  a  car-
riage return and a line feed appended to them, rather than just a
line feed.  The file format appeared in



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