---
name: "backend"
section: "1"
platform: "linux"
package: "cupsys"
version: "1.0.4-12"
release: "Debian 2.2 (Potato)"
platforms: ["linux"]
url: "https://new.carta.tech/backend"
---

# backend(1)

backend transmission interfaces

## NAME

backend - 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 stdin to a temporary if required by the physical interface.

The command name (argv\[0\]) is set to the device URI of the destination printer.

## 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).

- CONTENT\_TYPE

  The MIME type associated with the file (e.g. application/postscript).

- 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.

- 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).

- SERVER\_ROOT

  The root directory of the server.

- SOFTWARE

  The name and version number of the server (typically CUPS/1.0).

- TZ

  The timezone of the server.

- USER

  The user executing the backend (typically lp).

## SEE ALSO

[cupsd(8)](/cupsd/8.md), [filter(1)](/filter/1.md) CUPS Software Administrators Manual, CUPS Interface Design Description

## COPYRIGHT

Copyright 1993-1999 by Easy Software Products, All Rights Reserved.