Provided by: cups_1.4.1-5ubuntu2_i386 bug

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 but is also available in the PRINTER environment variable.

OPTIONS

       Options passed on the command-line typically do not include the default
       choices the printer’s PPD  file.  In  addition,  some  options  may  be
       specified in multiple ways - "landscape" is a synonym for "orientation-
       requested=4",  "media"  is  a  synonym  for  "PageSize",  "PageRegion",
       "InputSlot",  and "MediaType", and "sides" is a synonym for the various
       "Duplex" options. Non-raster filters must  support  both  explicit  and
       implicit  specification  of  PPD  options - use the ppdMarkDefaults and
       cupsMarkOptions functions in  the  CUPS  library  to  use  the  correct
       mapping, and ppdFindMarkedChoice to get the user-selected choice.

       Raster  filters  should  use option choices set through the raster page
       header, as those reflect the  options  in  effect  for  a  given  page.
       Options  specified on the command-line determine the default values for
       the entire job, which can be overridden on a per-page basis.

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.

       PPD: Keyword=Value ... KeywordN=Value
            Sets the named  keywords  in  the  printer’s  PPD  file.  This  is
            typically   used   to  update  default  option  keywords  such  as
            DefaultPageSize and the various installable  options  in  the  PPD
            file.

       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
            current 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/postscript).

       CUPS_CACHEDIR
            The directory for semi-persistent cache files can be found.

       CUPS_DATADIR
            The directory where data files can be found.

       CUPS_FILETYPE
            The type of file being printed: "job-sheet" for a banner page  and
            "document" for a regular print file.

       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.
            application/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
            Processors (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(7), cupsd(8),
       http://localhost:631/help

COPYRIGHT

       Copyright 2007-2009 by Apple Inc.