ulf(8)
NAME
ulf − universal lineprinter filter
SYNTAX
invokename username
DESCRIPTION
Output is sent through ulf before it is allowed to hit the lineprinter. The ulf program filters out control characters and buffers up lines for devices like diablos. Accounting records are written in /usr/adm/lpacct by ulf at the time of completion of each job.
The ulf program checks to see what name it has been called by so that it will know what entry to look up in /etc/printcap. The account name of the user that was responsible for this invocation of ulf is passed as its one and only argument. This argument is needed to determine who to bill the pages to. The ulf program supports diablos and dumb (LA180, LA120) “lineprinters”.
The ulf program uses a line_structure that is a linked list of arrays to hold enough characters for one physical line on the lineprinter. The first array contains the characters of the line, and all subsequent arrays hold overprinting characters. Blanks are left as zeroes, so that they don’t have to be printed, just move the printhead whatever way is easiest.
DIAGNOSTICS
Are sent to wherever /etc/printcap specifies with the lf field. If the software doesn’t work, the errors should be dumped to disk and examined. After the source of the trouble has been fixed, it is advisable to have the errors routed back to /dev/null.
FILES
/etc/printcap