backend(1)

NAME
     backend - cups backend transmission interfaces

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

DESCRIPTION
     The  CUPS backend interface provides a standard method for sending document
     files to different physical interfaces.

     Backends 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 if
     required by the physical interface.

     The command name (argv[0]) is set to the  device  URI  of  the  destination
     printer.  Starting  with  CUPS  1.1.22,  any  authentication information in
     argv[0] will be removed, so backend developers are urged  to  use  the  DE-
     VICE_URI  environment  variable  whenever authentication information is re-
     quired.

ENVIRONMENT VARIABLES
     The following environment variables are defined by the CUPS server when ex-
     ecuting the backend:

     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; this is provided for shell
          scripts which may not be able to get the passed argv[0] string and for
          backends that require any authentication information which is not  in-
          cluded in argv[0].

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

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

     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/1.1).

     TZ
          The timezone of the server.

     USER
          The user executing the backend, typically root; consult the cupsd.conf
          file for the current setting.

SEE ALSO
     cupsd(8), filter(1) CUPS Interface Design Description, CUPS Software Admin-
     istrators   Manual,   CUPS   Software   Programmers  Manual,  http://local-
     host:631/documentation.html

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