cups-backend1

Usage

Overview

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

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.