Administering Print Filters
The LP print service uses filters to complete the following tasks:
Not every print filter can perform all these tasks. Because each task is printer-specific, the tasks can be implemented separately.
The LP print service provides the PostScript filters listed in Table 8-3. The filter programs are located in the /usr/lib/lp/postscript directory. For PostScript printing, you usually only need to install the filter programs when setting up a print server. Solaris Print Manager automatically enables the supplied filters. However, if you administer other printers, you might need to administer print filters for them.
Creating Print Filters
To create a new print filter, you must write a print filter program and create a print filter definition. Filters contain input types, output types, and complex options that provide a language to process command-line arguments within the filter. For more information and step-by-step instructions, see Creating a New Print Filter.
Adding, Changing, Deleting, and Restoring Print Filters
Print filters are added, changed, deleted, or restored on the print server only.
You can use the lpfilter command to manage the list of available filters. System information about filters is stored in the /etc/lp/filter.table file. The lpfilter command gets the information about filters to write to the table from filter descriptor files. The filter descriptor files that are supplied (PostScript only) are located in the /etc/lp/fd directory. The actual filter programs are located in the /usr/lib/lp directory.
The LP print service imposes no fixed limit on the number of print filters you can define. You can remove filters that are no longer used to avoid extra processing by the LP print service. (LP examines all filters to find a filter that works for a specific print request.) If in doubt, do not remove a filter.
As you add, change, or delete filters, you can overwrite or remove some of the original filters provided by the LP print service. You can restore the original set of filters, if necessary. You can also remove any filters you have added.
SunOS software provides a default set of PostScript filters. Solaris Print Manager automatically adds these filters to a print server. Some of the TranScript filters used with LPD-based print services have SunOS equivalents, but other TranScript filters do not. The following table lists the default PostScript filters and identifies the equivalent TranScript filters, where applicable.
Table 8-3 Default PostScript Filters
The SunOS software does not provide the following filters:
The postreverse, postprint, postio, and dpost filters are provided in place of Enscript.
Solaris Print Manager adds the default PostScript filters to a print server. If you have printing needs that are not met by these filters, see How to Create a New Print Filter. This section provides information about writing a custom print filter.
How to Add a Print Filter
Example 8-9 Adding a Print Filter
The following example shows how to add the daisytroff print filter that has the daisytroff.fd print filter definition.
# lpfilter -f daisytroff -F /etc/lp/fd/daisytroff.fd
How to Delete a Print Filter
Example 8-10 Deleting a Print Filter
The following example shows how to delete the daisytroff print filter.
# lpfilter -f daisytroff -x
How to View Information About a Print Filter
Example 8-11 Viewing Information About a Print Filter
This example shows how to request information for the postdaisy print filter. Sample command output follows.
# lpfilter -f postdaisy -l Input types: daisy Output types: postscript Printer types: any Printers: any Filter type: slow Command: /usr/lib/lp/postscript/postdaisy Options: PAGES * = -o* Options: COPIES * = -c* Options: MODES group = -n2 Options: MODES group\=\([2-9]\) = -n\1 Options: MODES portrait = -pp Options: MODES landscape = -pl Options: MODES x\=\(\-*[\.0-9]*\) = -x\1 Options: MODES y\=\(\-*[\.0-9]*\) = -y\1 Options: MODES magnify\=\([\.0-9]*\) = -m\1
Example 8-12 Viewing Information About All Print Filters on a System
This example shows how to display all the print filters that have been added to the system. Sample command output follows.
# lpfilter -f all -l | grep Filter (Filter "download") Filter type: fast (Filter "postio") Filter type: fast (Filter "postior") Filter type: fast (Filter "postreverse") Filter type: slow
Example 8-13 Redirecting Information About a Print Filter
This example shows how to redirect information about the daisytroff filter to a file. This task is useful if a filter definition is removed unintentionally.
# lpfilter -f daisytroff -l > daisytroff.fd