backend(1) Easy Software Products backend(1)NAMEbackend - cups backend transmission interfaces
SYNOPSISbackend 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
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/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; 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.
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/1.1).
TZ
The timezone of the server.
USER
The user executing the backend, typically root; consult the
cupsd.conf file for the current setting.
SEE ALSOcupsd(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)
