Metalink
| Metalink | |
|---|---|
|
|
| File extension : |
.metalink
|
| MIME type : | application / metalink + xml |
| Extended by: | XML |
| Website : | metalinker.org |
Metalink is a cross-platform, cross-application, open standard that defines a format for files that can be used to provide a list of sources and other meta information for downloading a particular file.
In 2008 the format was presented to the Internet Engineering Task Force for standardization, which resulted in the Metalink 4.0 specification in RFC 5854 in June 2010 .
technology
Metalinks are XML text files that describe the physical properties (file size, checksums) of files and list their locations. The format is open and expandable.
The locations of each file can be listed in the form of URLs for various protocols, such as: B. HTTP , FTP or rsync servers or - to localize the file in peer-to-peer networks such as BitTorrent or eDonkey2000 - the URLs of .torrent files, magnet or eD2k links are available. These links or addresses can be evaluated by downloading software and thus resolve to possibly several redundant sources for the desired file. This increases the reliability of a download on the one hand, but also accelerates it, as several parts of the same file can be downloaded from several different sources ( mirrors ) at the same time.
In addition to the list of sources of supply, checksums in MD5 , SHA- 1 or SHA-256 format are also included for the file as a whole or for individual sections of the file, which means that errors can be detected and, in this case, if there are several checksums, not the whole file has to be reloaded.
Furthermore, OpenPGP - signatures are specified with which the authenticity of the file received can be checked.
Metalink 3.0 (with the .metalink extension) and Metalink 4.0 files (with the .meta4 extension) are not compatible with each other.
Metalink 4.0 example
<?xml version="1.0" encoding="UTF-8"?>
<metalink xmlns="urn:ietf:params:xml:ns:metalink">
<published>2009-05-15T12:23:23Z</published>
<file name="example.ext">
<size>14471447</size>
<identity>Example</identity>
<version>1.0</version>
<language>en</language>
<description>A description of the example file for download.</description>
<hash type="sha-256">3d6fece8033d146d8611eab4f032df738c8c1283620fd02a1f2bfec6e27d590d</hash>
<url location="de" priority="1">ftp://ftp.example.com/example.ext</url>
<url location="fr" priority="1">http://example.com/example.ext</url>
<metaurl mediatype="torrent" priority="2">http://example.com/example.ext.torrent</metaurl>
</file>
</metalink>
Metalink 4.0 files are delivered using the application/metalink4+xml Internet Media Type . There is a whole range of software for generating the Metalinks.
support
Download managers or software package administrations support the standard, although the level of support varies. In particular, downloads via the rsync protocol and OpenPGP signatures are rarely offered by any program.
Programs
- aria2 (GPL) in Debian repositories . A Unix / Windows command line download utility that supports BitTorrent and Metalink (HTTP / FTP / BitTorrent).
- DownThemAll! ( GPL ), a download manager as a Firefox add-on that offers simple Metalink functions.
- FlashGot ( GPL ), a Firefox add-on for starting downloads in various, independent, external download managers.
- Free Download Manager ( GPL ), a free Windows download manager with Metalink (HTTP / FTP) support since v2.5.
- GetRight 6, a Windows download manager with Metalink (HTTP / FTP / BitTorrent) support.
- jDownloader is an open source download manager written in Java .
- KGet ( GPL ), KDE 's own download manager, with Metalink functionality since KDE 4 .
- Metalink Access is an extension for the Opera - web browser , which enables direct download files to Metalink.
- Net Transport , a Windows download manager.
- Orbit Downloader , a Windows download manager with Metalink (HTTP / FTP) functionality.
- Phex ( GPL ), a Mac / Unix / Windows gnutella P2P program; In addition to Metalink downloads, it also supports the export of entire file collections as Metalink, for B. to share with others.
- Retriever is a closed-source multi-platform Java download manager that supports Metalink and BitTorrent.
- SmartFTP , is a Windows GUI FTP program that allows files to be added to the FTP queue via Metalink and to verify files by checksum.
- VeryCDs easyMule (Version 1 according to GPL , Ver.2 possibly violates the GPL) is an eMule version with Metalink support.
- wxDownload Fast (GPL) is a Mac / Unix / Windows download manager with Metalink (HTTP / FTP) support.
Package management
yum and ZYpp make use of it for everyday software updates from Linux distributions such as Mandriva, Fedora and openSUSE. The Ubuntu installation program Wubi also uses it to dissolve its data sources. Debian Metalink's package management also supports HTTP headers.
providers
It is used in numerous Linux distributions (as well as some BSDs ) including Ubuntu , Fedora, Mandriva and openSUSE in the distribution of CD images . It is also offered for downloading the program packages for other software: B. at OpenOffice.org and Sage or at the UniProt Consortium for the transfer of their large protein database.