Public Line Printer Spooler

[papowell at attila.cs.umn.edu]

Soon to come to you VIA comp.unix.sources

              PLP - The Public Line Printer Spooler
               A Portable UNIX Line Printer Spooler
                     Release 2.0, 1 June 1988
                         Patrick Powell
                    Dept. of Computer Science
         University of Minnesota, Minneapolis, Minnesota
     PLP is a public domain version of the Berkeley LPD software.
The  functional  resemblance  between  PLP  and the Berkeley Line
Printer Spooler (LPD) is intentional; the source code was written
without  reference  to the original Berkeley LPD software, except
for  some  very  small sections concerned with networking and the
large  characters used for banner printing.  The PLP software has
the following features:
1).The  PLP  software is intended to be  used in a Networked File
   System  (NFS)  environment,  in which there is a common set of
   spool  queues,  as well as in a loosely coupled environment in
   which  each  host transfers print jobs to a host which has the
   printer.
2).Access  and  permission  to use PLP functions is controlled by
   entries      in      a      printer      permissions      file
   (/usr/spool/lpd/printer_perms.<hostname>)  which  can restrict
   use  by  user  name, host, spooler, page useage, and a host of
   other         factors.         The        printcap        file
   (/usr/spool/lpd/printcap.<hostname>)  is  used  to specify the
   printer queues and their operation.
3).Jobs  can now be prioritized.  The maximum priority a user can
   specify is set in the printer permissions file.
4).In  addition  to  the  general  printer permissions file, each
   spool  queue  can  have  its  own addition printer permissions
   file.
5).Line  printer control functions can be exercised from a remote
   host.   Hosts  and  users  with  remote control permission are
   specified by entries in the printer permissions file.
6).Unspooling  of  jobs  can be performed by a printcap specified
   program, rather than by the PLP unspooler.  This allows PLP to
   be used as a spooler and to have spool queues used for various
   purposes.
7).Extremely  verbose  and chatty error messages have been added.
   These  greatly  ease debugging and installation.  In addition,
   the  checkpc  utility  can be used to set file permissions and
   other items for use by the PLP software.
8).The code is quite portable, with as few system dependencies in
   it as possible.  It has run on a VAX 4.2, 4.3, and ULTRIX, SUN
   3.0, and DG-UX.
____________
* UNIX is a trademark of ATT Bell Laboratories.
Prof. Patrick Powell, Dept. Computer Science, 136 Lind Hall, 207 Church St. SE,
University of Minnesota,  Minneapolis, MN 55455 (612)625-3543/625-4002