NAME

dpd, odpd, lpd − HONEYWELL sending daemons, line printer daemon

SYNOPSIS

/usr/lib/dpd
/usr/lib/odpd
/usr/lib/lpd

DESCRIPTION

Dpd and odpd are the daemons for the 200-series DATA-PHONE® set and for the Murray Hill Spider network.  They are designed to submit jobs to the HONEYWELL 6000 computer via the GRTS interface.  For systems with both Spider and DATA-PHONE connections to the MH HONEYWELL 6000 computer, dpd is the Spider daemon, and odpd is the DATA-PHONE set daemon, and is used automatically as a backup when the Spider link is down.  On other systems, there is only one daemon, dpd, which uses the DATA-PHONE set.  Lpd is the daemon for the line printer. 

Dpd and odpd use the directory /usr/spool/dpd.  Lpd uses the directory /usr/spool/lpd.  The file lock in either directory is used to prevent two daemons from becoming active.  After the program 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 submitted 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. 

S directs dpd to generate a unique snumb card. The snumb number is generated from the file snumb in the spooling directory in the case of the DATA-PHONE set daemon, or it is read from the PDP-8 that interfaces to GCOS in the case of the Spider daemon.  This key character is not used by lpd.

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

I is the same as L, but signals the $ IDENT card which is to be mailed back by the mail option. 

B specifies that the rest of the line is a file name.  That file is to be sent as binary cards. 

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

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

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

N is followed by a user file name, to be sent back under the mail option.  (Not used by lpd).

Q is followed by a string of characters, which is a message to be sent back to the user under the mail option.  (Not used by lpd).

Any error encountered will cause the daemon to drop the call, wait up to 20 minutes, (only 10 seconds for lpd), and start over. This means that an improperly constructed “df” file may cause the same job to be submitted every 20 minutes.

Dpd is automatically initiated by all of the GCOS commands, (dpr, gcat, fget, and fsend) and by /etc/rc.  On systems with both dpd daemons, odpd is automatically initiated by dpd on certain errors from Spider.  Lpd is automatically initiated by the line printer command, lpr.

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

FILES

/usr/spool/dpd/∗ spool area for GCOS daemons. 

/usr/spool/lpd/∗ spool area for line printer daemon. 

/etc/passwd to get the user’s name. 

/dev/du?  DATA-PHONE set. 

/dev/dn?  ACU device for use with the DATA-PHONE set. 

/dev/lp line printer device. 

SEE ALSO

dpr(1C), fget(1C), fget.demon(1C), fsend(1C), gcat(1C), lpr(1). 

May 16, 1980