filter(7)

NAME

       filter - cups file conversion filter interface

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 output.

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

LOG MESSAGES

       Messages  sent  to stderr are generally logged to printer-state-message
       attribute and the current ErrorLog.  Each line begins with  a  standard
       prefix:

       ALERT: message
            Sets  the  printer-state-message  attribute and adds the specified
            message to the current ErrorLog using the "alert" log level.

       ATTR: attribute=value [attribute=value]
            Sets the named job attribute(s). Typically this will  be  used  to
            set the job-remote-id attribute.

       CRIT: message
            Sets  the  printer-state-message  attribute and adds the specified
            message to the current ErrorLog using the "critical" log level.

       DEBUG: message
            Sets the printer-state-message attribute and  adds  the  specified
            message to the current ErrorLog using the "debug" log level.

       DEBUG2: message
            Sets  the  printer-state-message  attribute and adds the specified
            message to the current ErrorLog using the "debug2" log level.

       EMERG: message
            Sets the printer-state-message attribute and  adds  the  specified
            message to the current ErrorLog using the "emergency" log level.

       ERROR: message
            Sets  the  printer-state-message  attribute and adds the specified
            message to the current ErrorLog using the "error" log level.

       INFO: message
            Sets the printer-state-message attribute. If the current  LogLevel
            is set to "debug2", also adds the specified message to the current
            ErrorLog using the "info" log level.

       NOTICE: message
            Sets the printer-state-message attribute and  adds  the  specified
            message to the current ErrorLog using the "notice" log level.

       PAGE: page-number #-copies

       PAGE: total #-pages
            Adds an entry to the current PageLog. The first form adds #-copies
            to the job-media-sheets-completed attribute. The second form  sets
            the job-media-sheets-completed attribute to #-pages.

       STATE: printer-state-reason [printer-state-reason ...]

       STATE: + printer-state-reason [printer-state-reason ...]

       STATE: - printer-state-reason [printer-state-reason ...]
            Sets,  adds,  or removes printer-state-reason keywords to the cur-
            rent queue. Typically this is used to  indicate  media,  ink,  and
            toner conditions on a printer.

       WARNING: message
            Sets  the  printer-state-message  attribute and adds the specified
            message to the current ErrorLog using the "warning" log level.

ENVIRONMENT VARIABLES

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

       CHARSET
            The default text character set, typically utf-8.

       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/post-
            script).

       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.

       FINAL_CONTENT_TYPE
            The  MIME  type  associated  with  the  printer  (e.g.    applica-
            tion/vnd.cups-postscript).

       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.

       RIP_CACHE
            The  recommended  amount of memory to use for Raster Image Proces-
            sors (RIPs).

       SOFTWARE
            The name and version number of the server (typically CUPS/1.2).

       TZ
            The timezone of the server.

       USER
            The user executing the filter, typically "lp" or  "root";  consult
            the cupsd.conf(5) 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),
       http://localhost:631/help

COPYRIGHT

       Copyright 2007 by Apple Inc.

6 July 2007               Common UNIX Printing System                filter(7)