ULF(8) — Unix Programmer’s Manual
NAME
ulf − universal lineprinter filter
SYNOPSIS
“invokename” username
DESCRIPTION
Output is sent through ulf before it is allowed to hit the lineprinter.
Ulf 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.
Ulf 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. Ulf supports diablos and dumb (LA180, LA120) “lineprinters”
Ulf 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 zero’s, so that they don’t have to be printed, just move the printhead whatever way is easiest.
AUTHOR
Cliff Matthews, University of New Mexico
FILES
/etc/printcap
DIAGNOSTICS
Are sent to wherever /etc/printcap specifies with the lf field. I like to see them go to /dev/null, because they tend to be generated in large quantities, and can fill up a filesystem very quickly. 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.
SEE ALSO
7th Edition