backend(1) Easy Software Products backend(1)

NAME
       backend - cups backend transmission interfaces

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

DESCRIPTION
       The CUPS backend interface provides a standard method for sending docu-
       ment 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
       DEVICEURI  environment variable whenever authentication information is
       required.

ENVIRONMENT VARIABLES       The following environment variables are defined by the CUPS server when
       executing 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.

       CONTENTTYPE
            The MIME type associated with  the  file  (e.g.  application/post-
            script).

       CUPSDATADIR
            The directory where data files can be found.

       CUPSSERVERROOT
            The root directory of the server.

       DEVICEURI
            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 informa-
            tion which is not included 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.

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

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

       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
       Administrators  Manual, CUPS Software Programmers Manual, http://local-
       host:631/documentation.html

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



8 October 2004            Common UNIX Printing System               backend(1)