LPFILTER(1M) RISC/os Reference Manual LPFILTER(1M)
NAME
lpfilter - administer filters used with the LP print service
SYNOPSIS
lpfilter -f filter-name -F path-name
lpfilter -f filter-name -
lpfilter -f filter-name -i
lpfilter -f filter-name -x
lpfilter -f filter-name -l
DESCRIPTION
The lpfilter command is used to add, change, delete, and
list a filter used with the LP print service. These filters
are used to convert the content type of a file to a content
type acceptable to a printer. One of the following options
must be used with the lpfilter command: -F path-name (or -
for standard input) to add or change a filter; -i to reset
an original filter to its factory setting; -x to delete a
filter; or -l to list a filter description.
The argument all can be used instead of a filter-name with
any of these options. When all is specified with the -F or
- option, the requested change is made to all filters.
Using all with the -i option has the effect of restoring to
their original settings all filters for which predefined
settings were initially available. Using the all argument
with the -x option results in all filters being deleted, and
using it with the -l option produces a list of all filters.
Adding or Changing a Filter
The filter named in the -f option is added to the filter
table. If the filter already exists, its description is
changed to reflect the new information in the input.
The filter description is taken from the path-name if the -F
option is given, or from the standard input if the - option
is given. One of the two must be given to define or change
a filter. If the filter named is one originally delivered
with the LP print service, the -i option will restore the
original filter description.
When an existing filter is changed with the -F or - option,
items that are not specified in the new information are left
as they were. When a new filter is added with this command,
unspecified items are given default values. (See below.)
Filters are used to convert the content of a request into a
data stream acceptable to a printer. For a given print
request, the LP print service will know the following:
the type of content in the request,
the name of the printer,
the type of the printer,
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the types of content acceptable to the printer, and
the modes of printing asked for by the originator of
the request.
It will use this information to find a filter or a pipeline
of filters that will convert the content into a type accept-
able to the printer.
Below is a list of items that provide input to this command,
and a description of each item. All lists are comma or
space separated.
Input types: content-type-list
Output types: content-type-list
Printer types: printer-type-list
Printers: printer-list
Filter type: filter-type
Command: shell-command
Options: template-list
Input types
This gives the types of content that can be accepted
by the filter. (The default is any.)
Output types
This gives the types of content that the filter can
produce from any of the input content types. (The
default is any.)
Printer types
This gives the type of printers for which the filter
can be used. The LP print service will restrict the
use of the filter to these types of printers. (The
default is any.)
PrintersThis gives the names of the printers for which the
filter can be used. The LP print service will res-
trict the use of the filter to just the printers
named. (The default is any.)
Filter type
This marks the filter as a slow filter or a fast
filter. Slow filters are generally those that take
a long time to convert their input. They are run
unconnected to a printer, to keep the printers from
being tied up while the filter is running. If a
listed printer is on a remote system, the filter
type for it must have the value slow. Fast filters
are generally those that convert their input
quickly, or those that must be connected to the
printer when run. These will be given to the inter-
face program to run connected to the physical
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printer.
Command This specifies the program to run to invoke the
filter. The full program pathname as well as fixed
options must be included in the shell-command; addi-
tional options are constructed, based on the charac-
teristics of each print request and on the Options
field. A command must be given for each filter.
The command must accept a data stream as standard
input and produce the converted data stream on its
standard output. This allows filter pipelines to be
constructed to convert data not handled by a single
filter.
Options This is a comma separated list of templates used by
the LP print service to construct options to the
filter from the characteristics of each print
request listed in the table later.
In general, each template is of the following form:
keyword pattern = replacement
The keyword names the characteristic that the tem-
plate attempts to map into a filter specific option;
each valid keyword is listed in the table below. A
pattern is one of the following: a literal pattern
of one of the forms listed in the table, a single
asterisk (*), or a regular expression. If pattern
matches the value of the characteristic, the tem-
plate fits and is used to generate a filter specific
option. The replacement is what will be used as the
option.
Regular expressions are the same as those found in the ed(1)
or vi(1) commands. This includes the \(...\) and \n con-
structions, which can be used to extract portions of the
pattern for copying into the replacement, and the &, which
can be used to copy the entire pattern into the replacement.
The replacement can also contain a *; it too, is replaced
with the entire pattern, just like the & of ed(1).
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___________________________________________________________________
| lp Option Characteristic keyword Possible patterns|
|__________________________________________________________________|
| |
| -T Content type (input) INPUT content-type |
| N/A Content type (output) OUTPUT content-type |
| N/A Printer type TERM printer-type |
| -d Printer name PRINTER printer-name |
| -f, -o cpi= Character pitch CPI integer |
| -f, -o lpi= Line pitch LPI integer |
| -f, -o length= Page length LENGTH integer |
| -f, -o width= Page width WIDTH integer |
| -P Pages to print PAGES page-list |
| -S Character set CHARSET character-set- |
| Print wheel CHARSET name |
| print-wheel-name |
| -f Form name FORM form-name |
| -y Modes MODES mode |
|_-n______________Number_of_copies_______COPIES___integer__________|
For example, the template
MODES landscape = -l
shows that if a print request is submitted with the -y
landscape option, the filter will be given the option -l.
As another example, the template
TERM * = -T *
shows that the filter will be given the option -T printer-
type for whichever printer-type is associated with a print
request using the filter.
As a last example, consider the template
MODES prwidth\=\(.*\) = -w\1
Suppose a user gives the command
lp -y prwidth=10
From the table above, the LP print service determines that
the -y option is handled by a MODES template. The MODES
template here works because the pattern prwidth\=\(.*\)
matches the prwidth=10 given by the user. The replacement
-w\1 causes the LP print service to generate the filter
option -w10.
If necessary, the LP print service will construct a filter
pipeline by concatenating several filters to handle the
user's file and all the print options. (See sh(1) for a
description of a pipeline.) If the print service constructs
a filter pipeline, the INPUT and OUTPUT values used for each
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filter in the pipeline are the types of the input and output
for that filter, not for the entire pipeline.
Deleting a Filter
The -x option is used to delete the filter specified in
filter-name from the LP filter table.
Listing a Filter Description
The -l option is used to list the description of the filter
named in filter-name. If the command is successful, the
following message is sent to standard output:
Input types: content-type-list
Output types: content-type-list
Printer types: printer-type-list
Printers: printer-list
Filter type: filter-type
Command: shell-command
Options: template-list
If the command fails, an error message is sent to standard
error.
SEE ALSO
lpadmin(1M).
lp(1) in the User's Reference Manual.
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