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 standard input, copying the standard input to a temporary file as
     required by the file format. All output must be sent to the  standard  out-
     put.

     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 ex-
     ecuting 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 current 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  Ad-
     ministrators   Manual,  CUPS  Software  Programmers  Manual,  http://local-
     host:631/documentation.html

COPYRIGHT
     Copyright 1993-2005 by Easy Software Products, All Rights Reserved.