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 DEVICE_URI 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.

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 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.

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 Administrators Manual, CUPS Software Programmers Manual, http://localhost:631/documentation.html

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