| Author: | Tatsuhiro Tsujikawa |
|---|---|
| Email: | t-tujikawa_at_users_dot_sourceforge_dot_net |
This program comes with no warranty. You must use this program at your own risk.
aria2 is a utility for downloading files. The supported protocols are HTTP(S), FTP, BitTorrent, and Metalink. aria2 can download a file from multiple sources/protocols and tries to utilize your maximum download bandwidth. It supports downloading a file from HTTP(S)/FTP and BitTorrent at the same time, while the data downloaded from HTTP(S)/FTP is uploaded to the BitTorrent swarm. Using Metalink's chunk checksums, aria2 automatically validates chunks of data while downloading a file like BitTorrent.
The project page is located at http://aria2.sourceforge.net/.
See aria2 Online Manual (Russian translation) and the usage examples to learn how to use aria2.
Here is a list of features:
We maintain the source code at Github: https://github.com/tatsuhiro-t/aria2
To get the latest source code, run following command:
$ git clone git://github.com/tatsuhiro-t/aria2.git
This will create aria2 directory in your current directory and source files are stored there.
| features | dependency |
|---|---|
| HTTPS | GnuTLS or OpenSSL |
| BitTorrent | libnettle+libgmp or libgcrypt or OpenSSL |
| Metalink | libxml2 or Expat. |
| Checksum | libnettle or libgcrypt or OpenSSL |
| gzip, deflate in HTTP | zlib |
| Async DNS | C-Ares |
| Firefox3/Chromium cookie | libsqlite3 |
| XML-RPC | libxml2 or Expat. |
| JSON-RPC over WebSocket | libnettle or libgcrypt or OpenSSL |
Note
libxml2 has precedence over Expat if both libraries are installed. If you prefer Expat, run configure with --without-libxml2.
Note
GnuTLS has precedence over OpenSSL if both libraries are installed. If you prefer OpenSSL, run configure with --without-gnutls --with-openssl.
Note
libnettle has precedence over libgcrypt if both libraries are installed. If you prefer libgcrypt, run configure with --without-libnettle --with-libgcrypt. If OpenSSL is selected over GnuTLS, neither libnettle nor libgcrypt will be used.
A user can have one of the following configurations for SSL and crypto libraries:
You can disable BitTorrent and Metalink support by providing --disable-bittorrent and --disable-metalink to the configure script respectively.
In order to enable async DNS support, you need c-ares.
In order to build aria2 from the source package, you need following development packages(package name may vary depending on the distribution you use):
You can use libgcrypt-dev instead of nettle-dev and libgmp-dev:
You can use libssl-dev instead of libgnutls-dev, nettle-dev, libgmp-dev, libgpg-error-dev and libgcrypt-dev:
You can use libexpat1-dev instead of libxml2-dev:
You may also need pkg-config to detect the above mentioned libraries.
On Fedora you need the following packages: gcc, gcc-c++, kernel-devel, libgcrypt-devel, libgcrypt-devel, libxml2-devel, openssl-devel
If you downloaded source code from git repository, you have to run following command to generate configure script and other files necessary to build the program:
$ autoreconf -i
Also you need Sphinx to build man page.
If you are building aria2 for Mac OS X, take a look at build_osx_release.sh, which builds OSX universal binary DMG.
The quickest way to build aria2 is just type following commands:
$ ./configure $ make
The configure script checks available libraries and enables the features as much as possible because all the features are enabled by default.
Since 1.1.0, aria2 checks the certificate of HTTPS servers by default. If you build with HTTPS support, I recommend to supply the path to the CA bundle file. For example, in Debian the path to CA bundle file is '/etc/ssl/certs/ca-certificates.crt' (in ca-certificates package). This may vary depending on your distribution. You can give it to configure script using --with-ca-bundle option:
$ ./configure --with-ca-bundle='/etc/ssl/certs/ca-certificates.crt' $ make
Without --with-ca-bundle option, you will encounter the error when accessing HTTPS servers because the certificate cannot be verified without CA bundle. In such case, you can specify the CA bundle file using aria2's --ca-certificate option. If you don't have CA bundle file installed, then the last resort is disable the certificate validation using --check-certificate=false.
By default, bash_completion file named aria2c is installed to the directory $prefix/share/doc/aria2/bash_completion. To change the install directory of the file, use --with-bashcompletiondir option.
The executable is 'aria2c' in src directory.
aria2 uses CppUnit for automated unit testing. To run the unit test:
$ make check
Sphinx is used to build the documentation. aria2 man pages will be build when you run make if they are not up-to-date. You can also build HTML version of aria2 man page by make html. The HTML version manual is also available at online (Russian translation).
The filename of the downloaded file is determined as follows:
Before download starts, a complete directory structure is created if needed. By default, aria2 opens at most 100 files mentioned in .torrent file, and directly writes to and reads from these files. The number of files to open simultaneously can be controlled by --bt-max-open-files option.
aria2 supports mainline compatible DHT. By default, the routing table for IPv4 DHT is saved to $HOME/.aria2/dht.dat and the routing table for IPv6 DHT is saved to $HOME/.aria2/dht6.dat. aria2 uses same port number to listen on for both IPv4 and IPv6 DHT.
The current implementation supports HTTP(S)/FTP/BitTorrent. The other P2P protocols are ignored. Both Metalink4 and Metalink version 3.0 documents are supported.
For checksum verification, md5, sha-1, sha-224, sha-256, sha-384 and sha-512 are supported. If multiple hash algorithms are provided, aria2 uses stronger one. If whole file checksum verification fails, aria2 doesn't retry the download and just exits with non-zero return code.
The supported user preferences are version, language, location, protocol and os.
If chunk checksums are provided in Metalink file, aria2 automatically validates chunks of data during download. This behavior can be turned off by a command-line option.
If signature is included in a Metalink file, aria2 saves it as a file after the completion of the download. The filename is download filename + ".sig". If same file already exists, the signature file is not saved.
In Metalink4, multi-file torrent could appear in metalink:metaurl element. Since aria2 cannot download 2 same torrents at the same time, aria2 groups files in metalink:file element which has same BitTorrent metaurl and downloads them from a single BitTorrent swarm. This is basically multi-file torrent download with file selection, so the adjacent files which is not in Metalink document but shares same piece with selected file are also created.
If relative URI is specified in metalink:url or metalink:metaurl element, aria2 uses the URI of Metalink file as base URI to resolve the relative URI. If relative URI is found in Metalink file which is read from local disk, aria2 uses the value of --metalink-base-uri option as base URI. If this option is not specified, the relative URI will be ignored.
The current implementation only uses rel=duplicate links only. aria2 understands Digest header fields and check whether it matches the digest value from other sources. If it differs, drop connection. aria2 also uses this digest value to perform checksum verification after download finished. aria2 recognizes geo value. To tell aria2 which location you prefer, you can use --metalink-location option.
netrc support is enabled by default for HTTP(S)/FTP. To disable netrc support, specify -n command-line option. Your .netrc file should have correct permissions(600).
The WebSocket server embedded in aria2 implements the specification defined in RFC 6455. The supported protocol version is 13.