NAME

lpd − line printer daemon
lpdrestart − restart downed daemons at reboot time

SYNOPSIS

/usr/lib/lpd printer

DESCRIPTION

lpd is the line printer daemon (spool area handler) invoked by opr(1), lpr(1), print(1). It uses the printer name passed it to determine the spooling directory, and other pertinent information.  The file lock in that directory is used to prevent multiple daemons from becoming active simultaneously, and to store information about the daemon process for lpq(1) and lprm(1). After the daemon has succesfully set the lock, it scans the directory for files beginning with df.  Lines in each df 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. 

LLiteral.  The line contains identification info from the password file. 

IIndent.  Changes the default indents for output.  Device driver must have ioctl(2) capability.

MSend mail to the specified user when the current print job completes. 

FFormatted File.  Name of a file which is already formatted for printing. 

UUnlink.  Name of file to remove upon completion of printing. 

RPrint file with pr(1).

HHeader title passed to pr(1).

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

CClassification.  String to be used for the classification line on the burst page. 

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

An inability to open a file will result in a message being printed in the log file (normally the console).  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. 

The lock file is maintained in a binary format and holds two numbers.  The first is the process id of the daemon and the second is the job nuber of the current job being printed.  The latter value 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/*            spooling areas
/dev/lp*                line printer devices

SEE ALSO

lpr(1), lpq(1), lprm(1), printcap(5).

7th Edition