LPD(8-BSD)          RISC/os Reference Manual           LPD(8-BSD)



NAME
     lpd - line printer daemon

SYNOPSIS
     /bsd43/bin/lpd [ -l ] [ port # ]

DESCRIPTION
     lpd is the line printer daemon (spool area handler).  It
     makes a single pass through the printcap(5) file to find out
     about the existing printers and prints any files left after
     a crash. It then uses the system calls listen(2) and
     accept(2) to receive requests to print files in the queue,
     transfer files to the spooling area, display the queue, or
     remove jobs from the queue.  In each case, it forks a child
     to handle the request so the parent can continue to listen
     for more requests.  The Internet port number used to rendez-
     vous with other processes is normally obtained with get-
     servbyname (see getservent(3N)) but can be changed with the
     port# argument.  The -l flag causes lpd to log valid
     requests received from the network. This can be useful for
     debugging purposes.

     Access control is provided by two means. First, all requests
     must come from one of the machines listed in the file
     /etc/hosts.equiv.  Second, if the ``rs'' capability is
     specified in the printcap entry for the printer being
     accessed, lpr requests will only be honored for those users
     with accounts on the machine with the printer.

     The file minfree in each spool directory contains the number
     of disk blocks to leave free so that the line printer queue
     won't completely fill the disk.  The minfree file can be
     edited with your favorite text editor.

     The file lock in each spool directory is used to prevent
     multiple daemons from becoming active simultaneously, and to
     store information about the daemon process for lpr(1),
     lpq(1), and lprm(1).  After the daemon has successfully set
     the lock, it scans the directory for files beginning with
     cf.  Lines in each cf file specify files to be printed or
     non-printing actions to be performed.  Each such line begins
     with a key character to specify what to do with the
     remainder of the line.

     J    Job Name.  String to be used for the job name on the
          burst page.

     C    Classification.  String to be used for the classifica-
          tion line on the burst page.

     L    Literal.  The line contains identification info from
          the password file and causes the banner page to be



                         Printed 1/15/91                   Page 1

LPD(8-BSD)          RISC/os Reference Manual           LPD(8-BSD)



          printed.

     T    Title.  String to be used as the title for pr(1).

     H    Host Name.  Name of the machine where lpr was invoked.

     P    Person.  Login name of the person who invoked lpr.
          This is used to verify ownership by lprm.

     M    Send mail to the specified user when the current print
          job completes.

     f    Formatted File.  Name of a file to print which is
          already formatted.

     l    Like ``f'' but passes control characters and does not
          make page breaks.

     p    Name of a file to print using pr(1) as a filter.

     t    Troff File.  The file contains troff(1) output (cat
          phototypesetter commands).

     n    Ditroff File.  The file contains device independent
          troff output.

     d    DVI File.  The file contains Tex output (DVI format
          from Stanford).

     g    Graph File.  The file contains data produced by
          plot(3X).

     c    Cifplot File. The file contains data produced by cif-
          plot.

     v    The file contains a raster image.

     r    The file contains text data with FORTRAN carriage con-
          trol characters.

     1    Troff Font R. Name of the font file to use instead of
          the default.

     2    Troff Font I. Name of the font file to use instead of
          the default.

     3    Troff Font B. Name of the font file to use instead of
          the default.

     4    Troff Font S. Name of the font file to use instead of
          the default.




 Page 2                  Printed 1/15/91

LPD(8-BSD)          RISC/os Reference Manual           LPD(8-BSD)



     W    Width. Changes the page width (in characters) used by
          pr(1) and the text filters.

     I    Indent.  The number of characters to indent the output
          by (in ascii).

     U    Unlink.  Name of file to remove upon completion of
          printing.

     N    File name.  The name of the file which is being
          printed, or a blank for the standard input (when lpr is
          invoked in a pipeline).

     If a file can not be opened, a message will be logged via
     syslog(3) using the LOG_LPR facility.  lpd will try up to 20
     times to reopen a file it expects to be there, after which
     it will skip the file to be printed.

     lpd uses flock(2) to provide exclusive access to the lock
     file and to prevent multiple deamons from becoming active
     simultaneously.  If the daemon should be killed or die unex-
     pectedly, the lock file need not be removed.  The lock file
     is kept in a readable ASCII form and contains two lines.
     The first is the process id of the daemon and the second is
     the control file name of the current job being printed.  The
     second line is updated to reflect the current status of lpd
     for the programs lpq(1) and lprm(1).

FILES
     /etc/printcap            printer description file
     /usr/spool/*             spool directories
     /usr/spool/*/minfree     minimum free space to leave
     /dev/lp*                 line printer devices
     /dev/printer             socket for local requests
     /etc/hosts.equiv         lists machine names allowed printer
                              access

SEE ALSO
     lpc(8).
     lpq(1), lpr(1), lprm(1) in the User's Reference Manual.
     syslog(3), printcap(5) in the Programmer's Reference Manual.
     4.3 BSD Printer Spooler, Chapter 13 in the RISC/os System
     Administrator's Guide.












                         Printed 1/15/91                   Page 3