magicfilter - automatic configurable printer filter
config-file [-c] [-n user] [-h host] [other-options]
is an extensible and customizable automatic printer filter.
It selects an appropriate conversion technique for the input data by seeking
for magic numbers
, and then utilizing the appropriate conversion
is primarily intended for use as the ``input filter'' by the
print spooler. The options accepted by magicfilter
exactly the ones passed to the input filter by lpd
will be invoked by lpd
and hence provided
the right options automatically. This list is included for reference only.
- Copy the input to the output without any conversion whatsoever (used by
lpd whenever the -l option is passed to the lpr
- The login name of the user who submitted the job. Available to subfilters
as $LPUSER. If the user has an associated GECOS entry it will be
available as $LPUSERNAME.
- The host on which the job was submitted. Available to subfilters as
- A numeric option passed by lpd; can be set by the user by the
-i option to lpr. Although nominally used for the amount of
indentation requested, magicfilter makes it available to subfilters
for any useful purpose as $LPINDENT.
- Write debugging output to stdout. Every --debug increases the quantity of
- Tell what version of magicfilter this is.
- Prints out a synopsis of the command-line switches supported.
- other options
- Any other options, such as the -w, -l, -x, and
-y options typically passed by lpd are ignored.
To run magicfilter
it should be entered as one of the
filters in the /etc/printcap
file. Typically, it will be the input
filter (if). Since most version of lpd
do not accept arguments entered
as part of the filter name, typically the filter name entered into the
file will simply be the name of the configuration file,
which is set executable and starts with the line:
Most UNIX kernels will then be able to treat the configuration file itself as if
it was the actual program.
For systems which do not support the ``#!-hack'', the filter set in the if entry
should point to magicfilter
directly, and the accounting file (af)
entry should point to the configuration file. This, however, is a less
general, and hence less desirable solution.
has been extensively modified for the 2.0 release, and has
very little in common with the old 1.2 magicfilter. The config-file
format has changed pretty drastically, and old config files will not
Currently, there is no protection against the pipe
facilities going into an infinite loop.
H. Peter Anvin <firstname.lastname@example.org>, David Parsons <email@example.com>