LPD(8)                                                     LPD(8)

          lpd - line printer daemon


          Lpd is the daemon for the line printer.  Lpd uses the direc-
          tory /usr/spool/lpd. The file lock in that directory is used
          to prevent two daemons from becoming active.  After the pro-
          gram has successfully set the lock, it forks and the main
          path exits, thus spawning the daemon.  The directory is
          scanned for files beginning with df.  Each such file is sub-
          mitted as a job.  Each line of a job file must begin with a
          key character to specify what to do with the remainder of
          the line.

          L    specifies that the remainder of the line is to be sent
               as a literal.

          B    specifies that the rest of the line is a file name.

          F    is the same as B except a form feed is prepended to the

          U    specifies that the rest of the line is a file name.
               After the job has been transmitted, the file is

          M    is followed by a user ID; after the job is sent, a mes-
               sage is mailed to the user via the mail(1) command to
               verify the sending of the job.

          Any error encountered will cause the daemon to wait and
          start over.  This means that an improperly constructed df
          file may cause the same job to be submitted repeatedly.

          Lpd is automatically initiated by the line printer command,

          To restart lpd (in the case of hardware or software malfunc-
          tion), it is necessary to first kill the old daemon (if
          still alive), and remove the lock file before initiating the
          new daemon.  This is done automatically when the system is
          brought up, by /etc/rc, in case there were any jobs left in
          the spooling directory when the system last went down.

          /usr/spool/lpd/* spool area for line printer daemon
          /etc/passwd to get the user's name

     LPD(8)                                                     LPD(8)

          /dev/lp line printer device