aria2 に似たアプリケーションはいくつか存在しますが、以下の 2 点 において aria2 は差別化されます: (1) 複数のソース (http/ftp そして BitTorrent) からダウンロードで きる。 (2) aria2 に URL のリストを与えた場合、それらを一つ一つ逐次的にダウンロー ドするのではなく、複数並列でダウンロードすることができます。一つ ずつダウンロードを待つ必要はないのです。これにより aria2 は与え られた帯域をめいいっぱい使用して高速なダウンロードを実現します。
ファイルをHTTP(S)/FTPとBitTorrentの両方から同時にダウンロードする機能を持っています。HTTP(S)/FTPからダウンロードしたデータは、BitTorrentネットワークにアップロードされます.
信頼性 という意味でもっともすぐれたHTTP(S)/FTPダウンロードユーティリティ です。なぜなら、Metalink のチャンクチェックサムをサポートしており、 BitTorrentのようにダウンロードした部分部分のチェックサムを照合す る機能をもつからです。チェックサムが違っていればその部分だけダウ ンロードすればよいのです。従来のようなファイルをすべてダウンロード してからチェックサムをとり、間違っていれば全部ダウンロードしなおすことと較べてください。 その差はファイルサイズが大きくなるにつれて明らかです。
This release adds the ability to save unfinished downloads as text file. aria2 can read the file with -i option on restart. This release also adds the ability to download file from scratch when aria2 sees resume is not supported by remote server. This feature is disabled by default. See --always-resume option for details. --no-proxy option accepts IPv4 network address with CIDR block. aria2 now doesn't send "Accept-Encoding: deflate, gzip" by default. --http-accept-gzip option was added to toggle this behavior. aria2 now treats lines starting "#" in -i list as comments. Several XML-RPC methods were added: aria2.pause, aria2.unpause, aria2.shutdown, and their families. The new exist status code '8' was added. The bug that makes aria2 hang when system time changes while aria2 is running was fixed on MinGW32, Mac OS X and the system which has clock_gettime(). Several other bugs also have been fixed.
本リリースでは, 未完了のダウンロードをテキストファイルに保存する機能を追加しました. aria2 は, このファイルを -i オプションで読み込むことができます. aria2 がレジューム不可能と判断した場合, ダウンロードをやり直す機能を追加しました. デフォルトではこの機能はオフにされています. --always-resume オプションを見てください. --no-proxy オプションが, CIDR 付き IPv4 ネットワークアドレスを受け付けるようになりました. aria2 は "Accept-Encoding: deflate, gzip" を送信しなくなりました. 送信するようにするには, --http-accept-gzip オプションを使用します. -i で指定するテキストファイル内の # で始まる行をコメントとして認識する機能を追加しました. 新しい XML-RPC メソッドを追加しました: aria2.pause, aria2.unpause, aria2.shutdown, 他にもこれらのファミリーのメソッドを追加しました. 終了ステータスコードに 8 を追加しました. aria2 が動いている最中にシステム時刻が変更されると aria2 がハングするバグを, MinGW32, Mac OS X, そして clock_gettime() を持つシステムで修正しました. 他のいくつかのバグも修正しました.
* Updated Ukrainian, Russian, Simplified Chinese, German and Greek
translation. Thanks to all translators.
* Added warning for the system which lacks clock_gettime with
CLOCK_MONOTONIC.
* Fixed the bug that hash check hangs when aria2.pause is issued
while aria2 is checking piece hashes. Fixed the bug that the
download is paused after file allocation completion even if
aria2.pause is issued during file allocation.
* Fixed compile error on opensolaris
* Added aria2.forcePause, aria2.pauseAll, aria2.forcePauseAll and
aria2.unpauseAll XML-RPC method.
* Use clock_gettime(CLOCK_MONOTONIC, ...) if it is available and
usable to prevent from aria2 from being affected by system time
change.
* Added aria2.pause and aria2.unpause XML-RPC method. aria2.pause
pauses the download denoted by gid. gid is of type string. The
status of paused download becomes "paused" and the download is
placed on the first position of waiting queue. As long as the
status is "paused", the download is not started. To change status
to "waiting", use aria2.unpause method. This method returns GID of
paused download. aria2.unpause changes the status of the download
denoted by gid from "paused" to "waiting". This makes the download
eligible to restart. gid is of type string. This method returns GID
of unpaused download.
* Added --save-session=FILE option. This option saves
error/unfinished downloads to FILE on exit. You can pass this
output file to aria2c with -i option on restart. Please note that
downloads added by aria2.addTorrent and aria2.addMetalink XML-RPC
method are not saved.
* Fixed the bug that FTP data connection is not established via proxy
when --ftp-proxy is defined and --ftp-pasv=true and
--proxy-method=tunnel.
* Fixed the bug that web-seed URI is not percent-encoded.
* Added aria2.shutdown and aria2.forceShutdown XML-RPC method. These
methods, as their name imply, shutdown aria2. These methods are
useful for Windows because it lacks signal mechanism.
* Don't send "Accept-Encoding: default, gzip" by default. This is
because some servers respond with "Content-Encoding: gzip" for a
file which itself is gzipped file and aria2 inflates them. This is
a problem if user doesn't want to inflate the file. Apparently this
is server configuration error, but we cannot do anything about
this. So we turned this off. Added --http-accept-gzip option. If
true is given to this option, aria2 sends "Accept-Encoding:
deflate, gzip" request header and inflates response if remote
server responds with "Content-Encoding: gzip" or "Content-Encoding:
deflate". We removed extension "tgz" hack in order not to inflate
files with tgz extensions.
* Made aria2 not send
"application/metalink4+xml,application/metalink+xml" in Accept
header for web-seeding URIs and tracker request.
* Added --dht-message-timeout option.
* Added --bt-tracker-connect-timeout and --bt-tracker-timeout
option.
* Documented that specifying --seed-time=0 disables seeding after
download completed.
* Drop connection if same Peer ID has been already seen.
* Fixed the bug that waiting download unintentionally starts when
URIs are added to it using aria2.changeUri XML-RPC method.
* Fixed compile error with g++-4.4 on FreeBSD.
* Fixed the bug that URIs added using aria2.changeUri XML-RPC method
are not used immediately if there is no URI remaining before
calling aria2.changeUri and the number of connection is less than
the value in -s(or -C for Metalink downloads).
* Added --always-resume and --max-resume-failure-tries option. If
--always-resume=false is given, when all given URIs do not
support resume or aria2 encounters N URIs which does not support
resume (N is the value specified using --max-resume-failure-tries
option), aria2 downloads file from scratch. The default behavior is
--always-resume=true, which means if all URIs do not support
resume, download fails. I think this is OK because user normally
doesn't like to see that partially downloaded file is
overwritten(this is particularly true if file size is big). This
option is useful when aria2 is used as a download backend and
graceful falling back to overwritten behavior is preferable. Added
exit status value 8, which means download failed because server did
not support resume.
* Added --remove-control-file option. This option removes control
file(*.aria2 file) before download. Using with
--allow-overwrite=true, download always starts from scratch. This
will be useful for users behind proxy server which disables
resume. For such proxy user, -C1 is also recommended for Metalink
downloads to avoid establishing unnecessary connections.
* Added v key in DHT message. aria2's DHT version is independent of
the package version and we defined it as 1 at the moment. It is
defined as DHT_VERSION in src/DHTConstants.h. aria2's DHT version
scheme is "A2"+2bytes DHT version number in network byte order.
* Fixed the bug that value of numSeeders in aria2.tellStatus XML-RPC
method response is integer, while it should be string. The man
page says it is string. When peer's port is not listening port,
set '0' to port in aria2.getPeers response.
* Lines starting "#" in -i list are treated as comments.
* Accept IPv4 network address with CIDR block in --no-proxy option
and no_proxy environment variable. Current implementation does not
resolve hostname in URI to compare network address. So it is only
effecive if URI has numeric IP address.
