Adding, Changing, Removing, and Restoring Print Filters

Print filters are added, changed, or removed on the print server only.

You 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 supplied (PostScript only) are located in the /etc/lp/fd directory. The actual filter programs are located under /usr/lib/lp.

The LP print service imposes no fixed limit on the number of print filters you can define. You may remove filters that are no longer used to avoid extra processing by the LP print service. (LP examines all filters to find one that works for a specific print request.) If in doubt, do not remove a filter.

As you add, change, or delete filters, you may overwrite or remove some of the original filters provided by the LP print service. You can restore the original set of filters, if necessary, and remove any filters you have added.

SunOS 5.x system software provides a default set of PostScript filters, which Admintool automatically adds to a print server. Some of the TranScript filters used with SunOS 4.1 have SunOS 5.x equivalents, but others do not. Table 43-1 lists the default PostScript filters and identifies the TranScript filters, where applicable.

SunOS 5.x does not provide the following filters:

• TEX

• oscat (NeWSprint opost)

• Enscript

The postreverse, postprint, postio, and dpost filters are provided in place of Enscript.

Admintool 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" for information about writing a custom print filter.