filter(1)                             Easy Software Products                            filter(1)



NAME
       filter - cups file conversion filter interfaces

SYNOPSIS
       filter job user title num-copies options [ filename ]

DESCRIPTION
       The  CUPS  filter interface provides a standard method for adding support for new document
       types to CUPS. Each filter is capable of converting from one  or  more  input  formats  to
       another  format that can either be printed directly or piped into another filter to get it
       to a printable format.

       Filters must be capable of reading from a filename on the command-line or from  the  stan-
       dard input, copying the standard input to a temporary file as required by the file format.
       All output must be sent to the standard output.

       The command name (argv[0]) is set to the name of the destination printer.

ENVIRONMENT VARIABLES
       The following environment variables are defined by the CUPS  server  when  executing  each
       filter:

       CHARSET
            The default text character set (typically us-ascii or iso-8859-1).

       CLASS
            When  a  job  is  submitted  to a printer class, contains the name of the destination
            printer class. Otherwise this environment variable will not be set.

       CONTENT_TYPE
            The MIME type associated with the file (e.g. application/postscript).

       CUPS_DATADIR
            The directory where data files can be found.

       CUPS_SERVERROOT
            The root directory of the server.

       DEVICE_URI
            The device-uri associated with the printer.

       LANG
            The default language locale (typically C or en).

       PATH
            The standard execution path for external programs that may be run by the filter.

       PPD
            The full pathname of the PostScript Printer Description (PPD) file for this  printer.

       PRINTER
            The  name of the printer; this is provided for shell scripts which may not be able to
            get the passed argv[0] string.

       RIP_CACHE
            The recommended amount of memory to use for Raster Image Processors (RIPs).

       SOFTWARE
            The name and version number of the server (typically CUPS/1.1).

       TZ
            The timezone of the server.

       USER
            The user executing the filter, typically lp; consult the cupsd.conf file for the cur-
            rent setting.

COMPATIBILITY
       While  the  filter  interface  is compatible with System V interface scripts, it will only
       work with the System V interface script as  the  only  filter.   Typically  the  interface
       script will be provided via the lpadmin(8) command using the -i option.

SEE ALSO
       backend(1), cupsd(8), CUPS Interface Design Description, CUPS Software Administrators Man-
       ual, CUPS Software Programmers Manual, http://localhost:631/documentation.html

COPYRIGHT
       Copyright 1993-2004 by Easy Software Products, All Rights Reserved.



22 June 2000                       Common UNIX Printing System                          filter(1)