aria2/doc/manual-src/en/aria2c.rst

aria2c(1)
=========

SYNOPSIS
--------
**aria2c** [<OPTIONS>] [<URI>|<MAGNET>|<TORRENT_FILE>|<METALINK_FILE>] ...

DESCRIPTION
-----------

aria2 is a utility for downloading files. The supported protocols are
HTTP(S), FTP, SFTP, 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
/SFTP and BitTorrent at the same time, while the data downloaded from
HTTP(S)/FTP/SFTP is uploaded to the BitTorrent swarm. Using Metalink
chunk checksums, aria2 automatically validates chunks of data while
downloading a file.

OPTIONS
-------

.. note::

  Most FTP related options are applicable to SFTP as well.
  Some options are not effective against SFTP (e.g., :option:`--ftp-pasv`)

Basic Options
~~~~~~~~~~~~~
.. option:: -d, --dir=<DIR>

  The directory to store the downloaded file.

.. option:: -i, --input-file=<FILE>

  Downloads the URIs listed in ``FILE``. You can specify multiple sources for a
  single entity by putting multiple URIs on a single line separated by the
  :kbd:`TAB` character.
  Additionally, options can be specified after each URI line. Option lines
  must start with one or more white space characters (:kbd:`SPACE` or :kbd:`TAB`)
  and must only contain one option per line.
  Input files can use gzip compression.
  When ``FILE`` is specified as ``-``, aria2 will read the input from ``stdin``.
  See the `Input File`_ subsection for details.
  See also the :option:`--deferred-input` option.
  See also the :option:`--save-session-file` option.

.. option:: -l, --log=<LOG>

  The file name of the log file. If ``-`` is specified, log is written to
  ``stdout``. If empty string("") is specified, or this option is omitted,
  no log is written to disk at all.

.. option:: -j, --max-concurrent-downloads=<N>

  Set the maximum number of parallel downloads for every queue item.
  See also the :option:`--split <-s>` option.
  Default: ``5``

.. option:: -V, --check-integrity[=true|false]

  Check file integrity by validating piece hashes or a hash of entire
  file.  This option has effect only in BitTorrent, Metalink downloads
  with checksums or HTTP(S)/FTP downloads with
  :option:`--checksum` option.  If
  piece hashes are provided, this option can detect damaged portions
  of a file and re-download them.  If a hash of entire file is
  provided, hash check is only done when file has been already
  download. This is determined by file length. If hash check fails,
  file is re-downloaded from scratch.  If both piece hashes and a hash
  of entire file are provided, only piece hashes are used. Default:
  ``false``

.. option:: -c, --continue[=true|false]

   Continue downloading a partially downloaded file.
   Use this option to resume a download started by a web browser or another
   program which downloads files sequentially from the beginning.
   Currently this option is only applicable to HTTP(S)/FTP downloads.

.. option:: -h, --help[=<TAG>|<KEYWORD>]

   The help messages are classified with tags. A tag starts with
   ``#``. For example, type ``--help=#http`` to get the usage for the
   options tagged with ``#http``. If non-tag word is given, print the
   usage for the options whose name includes that word.  Available
   Values: ``#basic``, ``#advanced``, ``#http``, ``#https``, ``#ftp``,
   ``#metalink``, ``#bittorrent``, ``#cookie``, ``#hook``, ``#file``, ``#rpc``,
   ``#checksum``, ``#experimental``, ``#deprecated``, ``#help``, ``#all``
   Default: ``#basic``

HTTP/FTP/SFTP Options
~~~~~~~~~~~~~~~~~~~~~

.. option:: --all-proxy=<PROXY>

  Use a proxy server for all protocols.  To override a previously
  defined proxy, use "".  You also can override this setting and specify a
  proxy server for a particular protocol using :option:`--http-proxy`,
  :option:`--https-proxy` and :option:`--ftp-proxy` options.  This affects all
  downloads.
  The format of PROXY is ``[http://][USER:PASSWORD@]HOST[:PORT]``.
  See also `ENVIRONMENT`_ section.

  .. note::
    
    If user and password are embedded in proxy URI and they are also
    specified by *--{http,https,ftp,all}-proxy-{user,passwd}* options,
    those specified later override prior options. For example, if you specified
    ``http-proxy-user=myname``, ``http-proxy-passwd=mypass`` in aria2.conf and
    you specified ``--http-proxy="http://proxy"`` on the command-line, then
    you'd get HTTP proxy ``http://proxy`` with user ``myname`` and password
    ``mypass``.

    Another example: if you specified on the command-line
    ``--http-proxy="http://user:pass@proxy" --http-proxy-user="myname"
    --http-proxy-passwd="mypass"``, then you'd get HTTP proxy
    ``http://proxy`` with user ``myname`` and password ``mypass``.

    One more example: if you specified in command-line ``--http-proxy-user="myname"
    --http-proxy-passwd="mypass" --http-proxy="http://user:pass@proxy"``,
    then you'd get HTTP proxy ``http://proxy`` with user ``user`` and password
    ``pass``.

.. option:: --all-proxy-passwd=<PASSWD>

  Set password for :option:`--all-proxy` option.

.. option:: --all-proxy-user=<USER>

  Set user for :option:`--all-proxy` option.

.. option:: --checksum=<TYPE>=<DIGEST>

  Set checksum. TYPE is hash type. The supported hash type is listed
  in ``Hash Algorithms`` in ``aria2c -v``. DIGEST is hex digest.  For
  example, setting sha-1 digest looks like this:
  ``sha-1=0192ba11326fe2298c8cb4de616f4d4140213838`` This option applies
  only to HTTP(S)/FTP downloads.

.. option:: --connect-timeout=<SEC>

  Set the connect timeout in seconds to establish connection to
  HTTP/FTP/proxy server. After the connection is established, this
  option makes no effect and :option:`--timeout <-t>` option is used instead.
  Default: ``60``

.. option:: --dry-run[=true|false]

  If ``true`` is given, aria2 just checks whether the remote file is
  available and doesn't download data. This option has effect on
  HTTP/FTP download.  BitTorrent downloads are canceled if ``true`` is
  specified.  Default: ``false``

.. option:: --lowest-speed-limit=<SPEED>

  Close connection if download speed is lower than or equal to this
  value(bytes per sec).
  ``0`` means aria2 does not have a lowest speed limit.
  You can append ``K`` or ``M`` (1K = 1024, 1M = 1024K).
  This option does not affect BitTorrent downloads.
  Default: ``0``

.. option:: -x, --max-connection-per-server=<NUM>

  The maximum number of connections to one server for each download.
  Default: ``1``

.. option:: --max-file-not-found=<NUM>

  If aria2 receives "file not found" status from the remote HTTP/FTP
  servers NUM times without getting a single byte, then force the
  download to fail. Specify ``0`` to disable this option. This options is
  effective only when using HTTP/FTP servers.
  Default: ``0``

.. option:: -m, --max-tries=<N>

  Set number of tries. ``0`` means unlimited.
  See also :option:`--retry-wait`.
  Default: ``5``

.. option:: -k, --min-split-size=<SIZE>

  aria2 does not split less than 2*SIZE byte range.  For example,
  let's consider downloading 20MiB file. If SIZE is 10M, aria2 can
  split file into 2 range [0-10MiB) and [10MiB-20MiB) and download it
  using 2 sources(if :option:`--split <-s>` >= 2, of course).  If SIZE is 15M,
  since 2*15M > 20MiB, aria2 does not split file and download it using
  1 source.  You can append ``K`` or ``M`` (1K = 1024, 1M = 1024K).
  Possible Values: ``1M`` -``1024M`` Default: ``20M``


.. option:: --netrc-path=<FILE>

   Specify the path to the netrc file.
   Default: ``$(HOME)/.netrc``

   .. note::

       Permission of the .netrc file must be 600.  Otherwise, the file
       will be ignored.

.. option:: -n, --no-netrc[=true|false]

  Disables netrc support. netrc support is enabled by default.

  .. note::
    
    netrc file is only read at the startup if
    :option:`--no-netrc <-n>` is ``false``.
    So if :option:`--no-netrc <-n>` is ``true`` at the startup,
    no netrc is available throughout the session.
    You cannot get netrc enabled even if you send
    :option:`--no-netrc=false <-n>` using
    :func:`aria2.changeGlobalOption`.

.. option:: --no-proxy=<DOMAINS>

  Specify a comma separated list of host names, domains and network addresses
  with or without a subnet mask where no proxy should be used.

  .. note::

    For network addresses with a subnet mask, both IPv4 and IPv6 addresses work.
    The current implementation does not resolve the host name in an URI to compare
    network addresses specified in :option:`--no-proxy`. So it is only effective
    if URI has numeric IP addresses.

.. option:: -o, --out=<FILE>

  The file name of the downloaded file. When the
  :option:`--force-sequential <-Z>` option is used, this option is ignored.

  .. note::

    You cannot specify a file name for Metalink or BitTorrent downloads.
    The file name specified here is only used when the URIs fed to aria2
    are given on the command line directly, but not when using
    :option:`--input-file <-i>`, :option:`--force-sequential <-Z>` option.

    Example:

    .. code-block:: console

      $ aria2c -o myfile.zip "http://mirror1/file.zip" "http://mirror2/file.zip"

.. option:: --proxy-method=<METHOD>

  Set the method to use in proxy request.  METHOD is either ``get`` or
  ``tunnel``. HTTPS downloads always use ``tunnel`` regardless of this
  option.
  Default: ``get``

.. option:: -R, --remote-time[=true|false]

  Retrieve timestamp of the remote file from the remote HTTP/FTP
  server and if it is available, apply it to the local file.
  Default: ``false``

.. option:: --reuse-uri[=true|false]

  Reuse already used URIs if no unused URIs are left.
  Default: ``true``

.. option:: --retry-wait=<SEC>

  Set the seconds to wait between retries. When ``SEC > 0``, aria2 will
  retry downloads when the HTTP server returns a 503 response. Default:
  ``0``

.. option:: --server-stat-of=<FILE>

  Specify the file name to which performance profile of the servers is
  saved. You can load saved data using :option:`--server-stat-if` option. See
  `Server Performance Profile`_
  subsection below for file format.

.. option:: --server-stat-if=<FILE>

  Specify the file name to load performance profile of the servers. The
  loaded data will be used in some URI selector such as ``feedback``.
  See also :option:`--uri-selector` option. See
  `Server Performance Profile`_
  subsection below for file format.

.. option:: --server-stat-timeout=<SEC>

  Specifies timeout in seconds to invalidate performance profile of
  the servers since the last contact to them.
  Default: ``86400`` (24hours)

.. option:: -s, --split=<N>

  Download a file using N connections.  If more than N URIs are given,
  first N URIs are used and remaining URIs are used for backup.  If
  less than N URIs are given, those URIs are used more than once so
  that N connections total are made simultaneously.  The number of
  connections to the same host is restricted by the
  :option:`--max-connection-per-server <-x>` option.
  See also the :option:`--min-split-size <-k>` option.
  Default: ``5``

  .. note::
    
    Some Metalinks regulate the number of servers to connect.  aria2
    strictly respects them.  This means that if Metalink defines the
    ``maxconnections`` attribute lower than N, then aria2 uses the
    value of this lower value instead of N.

.. option:: --stream-piece-selector=<SELECTOR>

  Specify piece selection algorithm used in HTTP/FTP download. Piece
  means fixed length segment which is downloaded in parallel in
  segmented download. If ``default`` is given, aria2 selects piece so
  that it reduces the number of establishing connection. This is
  reasonable default behavior because establishing connection is an
  expensive operation.  If ``inorder`` is given, aria2 selects piece
  which has minimum index. Index=0 means first of the file. This will
  be useful to view movie while downloading it.
  :option:`--enable-http-pipelining` option may
  be useful to reduce re-connection overhead.  Please note that aria2
  honors
  :option:`--min-split-size <-k>` option,
  so it will be necessary to specify a reasonable value to
  :option:`--min-split-size <-k>` option.
  If ``geom`` is given, at the beginning aria2 selects piece which has
  minimum index like ``inorder``, but it exponentially increasingly
  keeps space from previously selected piece. This will reduce the
  number of establishing connection and at the same time it will
  download the beginning part of the file first. This will be useful
  to view movie while downloading it.
  Default: ``default``

.. option:: -t, --timeout=<SEC>

  Set timeout in seconds.
  Default: ``60``

.. option:: --uri-selector=<SELECTOR>

  Specify URI selection algorithm. The possible values are ``inorder``,
  ``feedback`` and ``adaptive``.  If ``inorder`` is given, URI is tried in
  the order appeared in the URI list.  If ``feedback`` is given, aria2
  uses download speed observed in the previous downloads and choose
  fastest server in the URI list. This also effectively skips dead
  mirrors. The observed download speed is a part of performance
  profile of servers mentioned in :option:`--server-stat-of` and
  :option:`--server-stat-if` options.  If ``adaptive`` is given, selects one of
  the best mirrors for the first and reserved connections.  For
  supplementary ones, it returns mirrors which has not been tested
  yet, and if each of them has already been tested, returns mirrors
  which has to be tested again. Otherwise, it doesn't select anymore
  mirrors. Like ``feedback``, it uses a performance profile of servers.
  Default: ``feedback``

HTTP Specific Options
~~~~~~~~~~~~~~~~~~~~~
.. option:: --ca-certificate=<FILE>

  Use the certificate authorities in FILE to verify the peers.
  The certificate file must be in PEM format and can contain multiple CA
  certificates.
  Use :option:`--check-certificate` option to enable verification.

  .. note::

    If you build with OpenSSL or the recent version of GnuTLS which
    has ``gnutls_certificate_set_x509_system_trust()`` function and
    the library is properly configured to locate the system-wide CA
    certificates store, aria2 will automatically load those
    certificates at the startup.

  .. note::

    *WinTLS* and *AppleTLS* do not support this option. Instead you will
    have to import the certificate into the OS trust store.

.. option:: --certificate=<FILE>

  Use the client certificate in FILE. The certificate must be
  either in PKCS12 (.p12, .pfx) or in PEM format.

  PKCS12 files must contain the certificate, a key and optionally a chain
  of additional certificates. Only PKCS12 files with a blank import password
  can be opened!

  When using PEM, you have to specify the private key via :option:`--private-key`
  as well.

  .. note::
    *WinTLS* does not support PEM files at the moment. Users have to use PKCS12
    files.

  .. note::
    *AppleTLS* users should use the KeyChain Access utility to import the client
    certificate and get the SHA-1 fingerprint from the Information dialog
    corresponding to that certificate.
    To start aria2c use `--certificate=<SHA-1>`.
    Alternatively PKCS12 files are also supported. PEM files, however, are not
    supported.

.. option:: --check-certificate[=true|false]

  Verify the peer using certificates specified in :option:`--ca-certificate` option.
  Default: ``true``

.. option:: --http-accept-gzip[=true|false]

  Send ``Accept: deflate, gzip`` request header and inflate response if
  remote server responds with ``Content-Encoding: gzip`` or
  ``Content-Encoding: deflate``.  Default: ``false``

  .. note::
    
    Some server responds with ``Content-Encoding: gzip`` for files which
    itself is gzipped file. aria2 inflates them anyway because of the
    response header.

.. option:: --http-auth-challenge[=true|false]

  Send HTTP authorization header only when it is requested by the
  server. If ``false`` is set, then authorization header is always sent
  to the server.  There is an exception: if user name and password are
  embedded in URI, authorization header is always sent to the server
  regardless of this option.  Default: ``false``

.. option:: --http-no-cache[=true|false]

   Send ``Cache-Control: no-cache`` and ``Pragma: no-cache`` header to avoid
   cached content.  If ``false`` is given, these headers are not sent
   and you can add Cache-Control header with a directive you like
   using :option:`--header` option. Default: ``false``

.. option:: --http-user=<USER>

  Set HTTP user. This affects all URIs.

.. option:: --http-passwd=<PASSWD>

  Set HTTP password. This affects all URIs.

.. option:: --http-proxy=<PROXY>

  Use a proxy server for HTTP.  To override a previously defined proxy,
  use "".
  See also the :option:`--all-proxy` option.  This affects all http downloads.
  The format of PROXY is ``[http://][USER:PASSWORD@]HOST[:PORT]``

.. option:: --http-proxy-passwd=<PASSWD>

  Set password for :option:`--http-proxy`.

.. option:: --http-proxy-user=<USER>

  Set user for :option:`--http-proxy`.

.. option:: --https-proxy=<PROXY>

  Use a proxy server for HTTPS. To override a previously defined proxy,
  use "".
  See also the :option:`--all-proxy` option.  This affects all https download.
  The format of PROXY is ``[http://][USER:PASSWORD@]HOST[:PORT]``

.. option:: --https-proxy-passwd=<PASSWD>

  Set password for :option:`--https-proxy`.

.. option:: --https-proxy-user=<USER>

  Set user for :option:`--https-proxy`.

.. option:: --private-key=<FILE>

  Use the private key in FILE.
  The private key must be decrypted and in PEM format.
  The behavior when encrypted one is given is undefined.
  See also :option:`--certificate` option.

.. option:: --referer=<REFERER>

  Set an http referrer (Referer). This affects all http/https downloads.
  If ``*`` is given, the download URI is also used as the referrer.
  This may be useful when used together with the
  :option:`--parameterized-uri <-P>` option.

.. option:: --enable-http-keep-alive[=true|false]

  Enable HTTP/1.1 persistent connection.
  Default: ``true``

.. option:: --enable-http-pipelining[=true|false]

  Enable HTTP/1.1 pipelining.
  Default: ``false``

  .. note::
    
    In performance perspective, there is usually no advantage to enable
    this option.

.. option:: --header=<HEADER>

  Append HEADER to HTTP request header.
  You can use this option repeatedly to specify more than one header:

  .. code-block:: console

        $ aria2c --header="X-A: b78" --header="X-B: 9J1" "http://host/file"

.. option:: --load-cookies=<FILE>

  Load Cookies from FILE using the Firefox3 format (SQLite3),
  Chromium/Google Chrome (SQLite3) and the
  Mozilla/Firefox(1.x/2.x)/Netscape format.

  .. note::

    If aria2 is built without libsqlite3, then it doesn't support Firefox3
    and Chromium/Google Chrome cookie format.

.. option:: --save-cookies=<FILE>

  Save Cookies to FILE in Mozilla/Firefox(1.x/2.x)/ Netscape
  format. If FILE already exists, it is overwritten. Session Cookies
  are also saved and their expiry values are treated as 0.  Possible
  Values: ``/path/to/file``

.. option:: --use-head[=true|false]

  Use HEAD method for the first request to the HTTP server.
  Default: ``false``


.. option:: -U, --user-agent=<USER_AGENT>

  Set user agent for HTTP(S) downloads.
  Default: ``aria2/$VERSION``, $VERSION is replaced by package version.

FTP/SFTP Specific Options
~~~~~~~~~~~~~~~~~~~~~~~~~
.. option:: --ftp-user=<USER>

  Set FTP user. This affects all URIs.
  Default: ``anonymous``

.. option:: --ftp-passwd=<PASSWD>

  Set FTP password. This affects all URIs.
  If user name is embedded but password is missing in URI, aria2 tries
  to resolve password using .netrc. If password is found in .netrc,
  then use it as password. If not, use the password specified in this
  option.
  Default: ``ARIA2USER@``

.. option:: -p, --ftp-pasv[=true|false]

  Use the passive mode in FTP.
  If ``false`` is given, the active mode will be used.
  Default: ``true``

  .. note::

    This option is ignored for SFTP transfer.

.. option:: --ftp-proxy=<PROXY>

  Use a proxy server for FTP.  To override a previously defined proxy,
  use "".
  See also the :option:`--all-proxy` option.  This affects all ftp downloads.
  The format of PROXY is ``[http://][USER:PASSWORD@]HOST[:PORT]``

.. option:: --ftp-proxy-passwd=<PASSWD>

  Set password for :option:`--ftp-proxy` option.

.. option:: --ftp-proxy-user=<USER>

  Set user for :option:`--ftp-proxy` option.

.. option:: --ftp-type=<TYPE>

  Set FTP transfer type. TYPE is either ``binary`` or ``ascii``.
  Default: ``binary``

  .. note::

    This option is ignored for SFTP transfer.

.. option:: --ftp-reuse-connection[=true|false]

  Reuse connection in FTP.
  Default: ``true``

.. option:: --ssh-host-key-md=<TYPE>=<DIGEST>

  Set checksum for SSH host public key. TYPE is hash type. The
  supported hash type is ``sha-1`` or ``md5``. DIGEST is hex
  digest. For example:
  ``sha-1=b030503d4de4539dc7885e6f0f5e256704edf4c3``.  This option can
  be used to validate server's public key when SFTP is used. If this
  option is not set, which is default, no validation takes place.

BitTorrent/Metalink Options
~~~~~~~~~~~~~~~~~~~~~~~~~~~
.. option:: --select-file=<INDEX>...

  Set file to download by specifying its index.
  You can find the file index using the :option:`--show-files <-S>` option.
  Multiple indexes can be specified by using ``,``, for example: ``3,6``.
  You can also use ``-`` to specify a range: ``1-5``.
  ``,`` and ``-`` can be used together: ``1-5,8,9``.
  When used with the -M option, index may vary depending on the query
  (see *--metalink-\** options).

  .. note::

    In multi file torrent, the adjacent files specified by this option may
    also be downloaded. This is by design, not a bug.
    A single piece may include several files or part of files, and aria2
    writes the piece to the appropriate files.

.. option:: -S, --show-files[=true|false]

  Print file listing of ".torrent", ".meta4" and ".metalink" file and exit.
  In case of ".torrent" file, additional information
  (infohash, piece length, etc) is also printed.

BitTorrent Specific Options
~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. option:: --bt-detach-seed-only[=true|false]

  Exclude seed only downloads when counting concurrent active
  downloads (See :option:`-j` option).  This means that if ``-j3`` is
  given and this option is turned on and 3 downloads are active and
  one of those enters seed mode, then it is excluded from active
  download count (thus it becomes 2), and the next download waiting in
  queue gets started. But be aware that seeding item is still
  recognized as active download in RPC method.  Default: ``false``

.. option:: --bt-enable-lpd[=true|false]

  Enable Local Peer Discovery.  If a private flag is set in a torrent,
  aria2 doesn't use this feature for that download even if ``true`` is
  given.  Default: ``false``

.. option:: --bt-exclude-tracker=<URI>[,...]

  Comma separated list of BitTorrent tracker's announce URI to
  remove. You can use special value ``*`` which matches all URIs, thus
  removes all announce URIs. When specifying ``*`` in shell
  command-line, don't forget to escape or quote it.  See also
  :option:`--bt-tracker` option.

.. option:: --bt-external-ip=<IPADDRESS>

  Specify the external IP address to report to a BitTorrent
  tracker. Although this function is named ``external``, it can accept
  any kind of IP addresses. IPADDRESS must be a numeric IP address.

.. option:: --bt-force-encryption[=true|false]

  Requires BitTorrent message payload encryption with arc4.  This is a
  shorthand of :option:`--bt-require-crypto`
  :option:`--bt-min-crypto-level`\=arc4.  This option does not change
  the option value of those options.  If ``true`` is given, deny
  legacy BitTorrent handshake and only use Obfuscation handshake and
  always encrypt message payload.  Default: ``false``

.. option:: --bt-hash-check-seed[=true|false]

 If ``true`` is given, after hash check using :option:`--check-integrity <-V>` option and
 file is complete, continue to seed file. If you want to check file
 and download it only when it is damaged or incomplete, set this
 option to ``false``.  This option has effect only on BitTorrent download.
 Default: ``true``

.. option:: --bt-lpd-interface=<INTERFACE>

  Use given interface for Local Peer Discovery. If this option is not
  specified, the default interface is chosen. You can specify
  interface name and IP address.  Possible Values: interface, IP
  address

.. option:: --bt-max-open-files=<NUM>

  Specify maximum number of files to open in multi-file
  BitTorrent/Metalink download globally.
  Default: ``100``

.. option:: --bt-max-peers=<NUM>

  Specify the maximum number of peers per torrent.  ``0`` means
  unlimited.  See also :option:`--bt-request-peer-speed-limit` option.
  Default: ``55``

.. option:: --bt-metadata-only[=true|false]

  Download meta data only. The file(s) described in meta data will not
  be downloaded. This option has effect only when BitTorrent Magnet
  URI is used. See also :option:`--bt-save-metadata` option.  Default: ``false``

.. option:: --bt-min-crypto-level=plain|arc4

  Set minimum level of encryption method.
  If several encryption methods are provided by a peer, aria2 chooses the lowest
  one which satisfies the given level.
  Default: ``plain``

.. option:: --bt-prioritize-piece=head[=<SIZE>],tail[=<SIZE>]

  Try to download first and last pieces of each file first. This is
  useful for previewing files. The argument can contain 2 keywords:
  ``head`` and ``tail``. To include both keywords, they must be separated
  by comma. These keywords can take one parameter, SIZE. For example,
  if ``head=<SIZE>`` is specified, pieces in the range of first SIZE bytes
  of each file get higher priority.  ``tail=<SIZE>`` means the range of
  last SIZE bytes of each file. SIZE can include ``K`` or ``M`` (1K = 1024,
  1M = 1024K). If SIZE is omitted, SIZE=1M is used.

.. option:: --bt-remove-unselected-file[=true|false]

   Removes the unselected files when download is completed in
   BitTorrent. To select files, use
   :option:`--select-file` option. If it is
   not used, all files are assumed to be selected. Please use this
   option with care because it will actually remove files from your
   disk.
   Default: ``false``

.. option:: --bt-require-crypto[=true|false]

  If ``true`` is given, aria2 doesn't accept and establish connection with legacy
  BitTorrent handshake(\\19BitTorrent protocol).
  Thus aria2 always uses Obfuscation handshake.
  Default: ``false`` 

.. option:: --bt-request-peer-speed-limit=<SPEED>

  If the whole download speed of every torrent is lower than SPEED,
  aria2 temporarily increases the number of peers to try for more
  download speed. Configuring this option with your preferred download
  speed can increase your download speed in some cases.
  You can append ``K`` or ``M`` (1K = 1024, 1M = 1024K).
  Default: ``50K``

.. option:: --bt-save-metadata[=true|false]

  Save meta data as ".torrent" file. This option has effect only when
  BitTorrent Magnet URI is used.  The file name is hex encoded info
  hash with suffix ".torrent". The directory to be saved is the same
  directory where download file is saved. If the same file already
  exists, meta data is not saved. See also :option:`--bt-metadata-only`
  option. Default: ``false``

.. option:: --bt-seed-unverified[=true|false]

  Seed previously downloaded files without verifying piece hashes.
  Default: ``false``

.. option:: --bt-stop-timeout=<SEC>

  Stop BitTorrent download if download speed is 0 in consecutive SEC
  seconds. If ``0`` is given, this feature is disabled.  Default: ``0``

.. option:: --bt-tracker=<URI>[,...]

  Comma separated list of additional BitTorrent tracker's announce
  URI. These URIs are not affected by :option:`--bt-exclude-tracker` option
  because they are added after URIs in :option:`--bt-exclude-tracker` option are
  removed.

.. option:: --bt-tracker-connect-timeout=<SEC>

  Set the connect timeout in seconds to establish connection to
  tracker. After the connection is established, this option makes no
  effect and :option:`--bt-tracker-timeout` option is used instead.  Default:
  ``60``

.. option:: --bt-tracker-interval=<SEC>

  Set the interval in seconds between tracker requests. This
  completely overrides interval value and aria2 just uses this value
  and ignores the min interval and interval value in the response of
  tracker. If ``0`` is set, aria2 determines interval based on the
  response of tracker and the download progress.  Default: ``0``

.. option:: --bt-tracker-timeout=<SEC>

  Set timeout in seconds. Default: ``60``

.. option:: --dht-entry-point=<HOST>:<PORT>

  Set host and port as an entry point to IPv4 DHT network.

.. option:: --dht-entry-point6=<HOST>:<PORT>

  Set host and port as an entry point to IPv6 DHT network.

.. option:: --dht-file-path=<PATH>

  Change the IPv4 DHT routing table file to PATH.
  Default: ``$HOME/.aria2/dht.dat`` if present, otherwise
  ``$XDG_CACHE_HOME/aria2/dht.dat``.

.. option:: --dht-file-path6=<PATH>

  Change the IPv6 DHT routing table file to PATH.
  Default: ``$HOME/.aria2/dht6.dat`` if present, otherwise
  ``$XDG_CACHE_HOME/aria2/dht6.dat``.

.. option:: --dht-listen-addr6=<ADDR>

  Specify address to bind socket for IPv6 DHT.  It should be a global
  unicast IPv6 address of the host.

.. option:: --dht-listen-port=<PORT>...

  Set UDP listening port used by DHT(IPv4, IPv6) and UDP tracker.
  Multiple ports can be specified by using ``,``, for example:
  ``6881,6885``.  You can also use ``-`` to specify a range:
  ``6881-6999``. ``,`` and ``-`` can be used together.
  Default: ``6881-6999``

  .. note::

    Make sure that the specified ports are open for incoming UDP traffic.

.. option:: --dht-message-timeout=<SEC>

  Set timeout in seconds. Default: ``10``

.. option:: --enable-dht[=true|false]

  Enable IPv4 DHT functionality. It also enables UDP tracker
  support. If a private flag is set in a torrent, aria2 doesn't use
  DHT for that download even if ``true`` is given.  Default: ``true``

.. option:: --enable-dht6[=true|false]

   Enable IPv6 DHT functionality. If a private flag is set in a
   torrent, aria2 doesn't use DHT for that download even if ``true`` is
   given. Use :option:`--dht-listen-port` option to specify port number to
   listen on. See also :option:`--dht-listen-addr6` option.

.. option:: --enable-peer-exchange[=true|false]

  Enable Peer Exchange extension. If a private flag is set in a torrent, this
  feature is disabled for that download even if ``true`` is given.
  Default: ``true``

.. option:: --follow-torrent=true|false|mem

  If ``true`` or ``mem`` is specified, when a file whose suffix is ``.torrent`` or content
  type is ``application/x-bittorrent`` is downloaded, aria2 parses it as a torrent
  file and downloads files mentioned in it.
  If ``mem`` is specified, a torrent file is not written to the disk, but is just
  kept in memory.
  If ``false`` is specified, the ``.torrent`` file is downloaded to the disk, but
  is not parsed as a torrent and its contents are not downloaded.
  Default: ``true``

.. option:: -O, --index-out=<INDEX>=<PATH>

  Set file path for file with index=INDEX. You can find the file index
  using the :option:`--show-files <-S>` option.  PATH is a relative path to the
  path specified in :option:`--dir <-d>` option. You can use this option multiple
  times. Using this option, you can specify the output file names of
  BitTorrent downloads.

.. option:: --listen-port=<PORT>...

  Set TCP port number for BitTorrent downloads.
  Multiple ports can be specified by using ``,``,  for example: ``6881,6885``.
  You can also use ``-`` to specify a range: ``6881-6999``.
  ``,`` and ``-`` can be used together: ``6881-6889,6999``.
  Default: ``6881-6999``

  .. note::

    Make sure that the specified ports are open for incoming TCP traffic.

.. option:: --max-overall-upload-limit=<SPEED>

  Set max overall upload speed in bytes/sec.
  ``0`` means unrestricted.
  You can append ``K`` or ``M`` (1K = 1024, 1M = 1024K).
  To limit the upload speed per torrent, use :option:`--max-upload-limit <-u>` option.
  Default: ``0``

.. option:: -u, --max-upload-limit=<SPEED>

  Set max upload speed per each torrent in bytes/sec.
  ``0`` means unrestricted.
  You can append ``K`` or ``M`` (1K = 1024, 1M = 1024K).
  To limit the overall upload speed, use :option:`--max-overall-upload-limit` option.
  Default: ``0``

.. option:: --peer-id-prefix=<PEER_ID_PREFIX>

  Specify the prefix of peer ID. The peer ID in
  BitTorrent is 20 byte length. If more than 20
  bytes are specified, only first 20 bytes are
  used. If less than 20 bytes are specified, random
  byte data are added to make its length 20 bytes.

  Default: ``A2-$MAJOR-$MINOR-$PATCH-``, $MAJOR, $MINOR and $PATCH are
  replaced by major, minor and patch version number respectively.  For
  instance, aria2 version 1.18.8 has prefix ID ``A2-1-18-8-``.

.. option:: --seed-ratio=<RATIO>

  Specify share ratio. Seed completed torrents until share ratio reaches
  RATIO.
  You are strongly encouraged to specify equals or more than ``1.0`` here.
  Specify ``0.0`` if you intend to do seeding regardless of share ratio.
  If :option:`--seed-time` option is specified along with this option, seeding ends when
  at least one of the conditions is satisfied.
  Default: ``1.0``

.. option:: --seed-time=<MINUTES>

  Specify seeding time in minutes. Also see the :option:`--seed-ratio` option.

  .. note::
    
    Specifying :option:`--seed-time=0 <--seed-time>` disables seeding after download completed.

.. option:: -T, --torrent-file=<TORRENT_FILE>

  The path to the ".torrent" file.  You are not required to use this
  option because you can specify ".torrent" files without :option:`--torrent-file <-T>`.

Metalink Specific Options
~~~~~~~~~~~~~~~~~~~~~~~~~
.. option:: --follow-metalink=true|false|mem

  If ``true`` or ``mem`` is specified, when a file whose suffix is ``.meta4`` or ``.metalink`` or content
  type of ``application/metalink4+xml`` or ``application/metalink+xml`` is downloaded, aria2 parses it as a metalink
  file and downloads files mentioned in it.
  If ``mem`` is specified, a metalink file is not written to the disk, but is just
  kept in memory.
  If ``false`` is specified, the ``.metalink`` file is downloaded to
  the disk, but is not parsed as a metalink file and its contents are not
  downloaded.
  Default: ``true``

.. option:: --metalink-base-uri=<URI>

  Specify base URI to resolve relative URI in metalink:url and
  metalink:metaurl element in a metalink file stored in local disk. If
  URI points to a directory, URI must end with ``/``.

.. option:: -M, --metalink-file=<METALINK_FILE>

  The file path to ".meta4" and ".metalink" file. Reads input from ``stdin`` when ``-`` is
  specified.  You are not required to use this option because you can
  specify ".metalink" files without :option:`--metalink-file <-M>`.

.. option:: --metalink-language=<LANGUAGE>

  The language of the file to download.

.. option:: --metalink-location=<LOCATION>[,...]

  The location of the preferred server.
  A comma-delimited list of locations is acceptable, for example, ``jp,us``.

.. option:: --metalink-os=<OS>

  The operating system of the file to download.

.. option:: --metalink-version=<VERSION>

  The version of the file to download.

.. option:: --metalink-preferred-protocol=<PROTO>

  Specify preferred protocol.
  The possible values are ``http``, ``https``, ``ftp`` and ``none``.
  Specify ``none`` to disable this feature.
  Default: ``none``
 
.. option:: --metalink-enable-unique-protocol[=true|false]

  If ``true`` is given and several protocols are available for a mirror in a
  metalink file, aria2 uses one of them.
  Use :option:`--metalink-preferred-protocol` option to specify the preference of
  protocol.
  Default: ``true``

RPC Options
~~~~~~~~~~~

.. option:: --enable-rpc[=true|false]

  Enable JSON-RPC/XML-RPC server.  It is strongly recommended to set
  secret authorization token using :option:`--rpc-secret` option.  See
  also :option:`--rpc-listen-port` option.  Default: ``false``

.. option:: --pause[=true|false]

  Pause download after added. This option is effective only when
  :option:`--enable-rpc=true <--enable-rpc>` is given.
  Default: ``false``

.. option:: --pause-metadata[=true|false]

  Pause downloads created as a result of metadata download. There are
  3 types of metadata downloads in aria2: (1) downloading .torrent
  file. (2) downloading torrent metadata using magnet link. (3)
  downloading metalink file.  These metadata downloads will generate
  downloads using their metadata. This option pauses these subsequent
  downloads. This option is effective only when
  :option:`--enable-rpc=true <--enable-rpc>` is given.
  Default: ``false``

.. option:: --rpc-allow-origin-all[=true|false]

  Add Access-Control-Allow-Origin header field with value ``*`` to the
  RPC response.
  Default: ``false``

.. option:: --rpc-certificate=<FILE>

  Use the certificate in FILE for RPC server. The certificate must be
  either in PKCS12 (.p12, .pfx) or in PEM format.

  PKCS12 files must contain the certificate, a key and optionally a chain
  of additional certificates. Only PKCS12 files with a blank import password
  can be opened!

  When using PEM, you have to specify the private key via :option:`--rpc-private-key`
  as well. Use :option:`--rpc-secure` option to enable encryption.

  .. note::
    *WinTLS* does not support PEM files at the moment. Users have to use PKCS12
    files.

  .. note::
    *AppleTLS* users should use the KeyChain Access utility to first generate a
    self-signed SSL-Server certificate, e.g. using the wizard, and get the
    SHA-1 fingerprint from the Information dialog corresponding to that new
    certificate.
    To start aria2c with :option:`--rpc-secure` use
    `--rpc-certificate=<SHA-1>`.
    Alternatively PKCS12 files are also supported. PEM files, however, are not
    supported.

.. option:: --rpc-listen-all[=true|false]

  Listen incoming JSON-RPC/XML-RPC requests on all network interfaces. If false
  is given, listen only on local loopback interface.  Default: ``false``

.. option:: --rpc-listen-port=<PORT>

  Specify a port number for JSON-RPC/XML-RPC server to listen to.  Possible
  Values: ``1024`` -``65535`` Default: ``6800``

.. option:: --rpc-max-request-size=<SIZE>

  Set max size of JSON-RPC/XML-RPC request. If aria2 detects the request is
  more than SIZE bytes, it drops connection. Default: ``2M``

.. option:: --rpc-passwd=<PASSWD>

  Set JSON-RPC/XML-RPC password.

  .. Warning::

    :option:`--rpc-passwd` option will be deprecated in the future
    release. Migrate to :option:`--rpc-secret` option as soon as
    possible.

.. option:: --rpc-private-key=<FILE>

  Use the private key in FILE for RPC server.  The private key must be
  decrypted and in PEM format. Use :option:`--rpc-secure` option to
  enable encryption. See also :option:`--rpc-certificate` option.

.. option:: --rpc-save-upload-metadata[=true|false]

  Save the uploaded torrent or metalink meta data in the directory
  specified by :option:`--dir` option. The file name consists of SHA-1
  hash hex string of meta data plus extension. For torrent, the
  extension is '.torrent'. For metalink, it is '.meta4'.  If false is
  given to this option, the downloads added by
  :func:`aria2.addTorrent` or :func:`aria2.addMetalink` will not be
  saved by :option:`--save-session` option. Default: ``false``

.. option:: --rpc-secret=<TOKEN>

   Set RPC secret authorization token. Read :ref:`rpc_auth` to know
   how this option value is used.

.. option:: --rpc-secure[=true|false]

  RPC transport will be encrypted by SSL/TLS.  The RPC clients must
  use https scheme to access the server. For WebSocket client, use wss
  scheme. Use :option:`--rpc-certificate` and
  :option:`--rpc-private-key` options to specify the server
  certificate and private key.

.. option:: --rpc-user=<USER>

  Set JSON-RPC/XML-RPC user.

  .. Warning::

    :option:`--rpc-user` option will be deprecated in the future
    release. Migrate to :option:`--rpc-secret` option as soon as
    possible.

Advanced Options
~~~~~~~~~~~~~~~~
.. option:: --allow-overwrite[=true|false]

  Restart download from scratch if the corresponding control file
  doesn't exist.  See also :option:`--auto-file-renaming` option.  Default:
  ``false``

.. option:: --allow-piece-length-change[=true|false]

  If false is given, aria2 aborts download when a piece length is different
  from one in a control file.
  If true is given, you can proceed but some download progress will be lost.
  Default: ``false``

.. option:: --always-resume[=true|false]

  Always resume download. If ``true`` is given, aria2 always tries to
  resume download and if resume is not possible, aborts download.  If
  ``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 :option:`--max-resume-failure-tries` option), aria2
  downloads file from scratch.  See :option:`--max-resume-failure-tries`
  option. Default: ``true``

.. option:: --async-dns[=true|false]

  Enable asynchronous DNS.
  Default: ``true``

.. option:: --async-dns-server=<IPADDRESS>[,...]

  Comma separated list of DNS server address used in asynchronous DNS
  resolver. Usually asynchronous DNS resolver reads DNS server
  addresses from ``/etc/resolv.conf``. When this option is used, it uses
  DNS servers specified in this option instead of ones in
  ``/etc/resolv.conf``. You can specify both IPv4 and IPv6 address. This
  option is useful when the system does not have ``/etc/resolv.conf`` and
  user does not have the permission to create it.

.. option:: --auto-file-renaming[=true|false]

  Rename file name if the same file already exists.
  This option works only in HTTP(S)/FTP download.
  The new file name has a dot and a number(1..9999) appended.
  Default: ``true``

.. option:: --auto-save-interval=<SEC>

  Save a control file(\*.aria2) every SEC seconds.
  If ``0`` is given, a control file is not saved during download. aria2 saves a
  control file when it stops regardless of the value.
  The possible values are between ``0`` to ``600``.
  Default: ``60``

.. option:: --conditional-get[=true|false]

  Download file only when the local file is older than remote
  file. This function only works with HTTP(S) downloads only.  It does
  not work if file size is specified in Metalink. It also ignores
  Content-Disposition header.  If a control file exists, this option
  will be ignored.  This function uses If-Modified-Since header to get
  only newer file conditionally. When getting modification time of
  local file, it uses user supplied file name (see :option:`--out <-o>` option) or
  file name part in URI if :option:`--out <-o>` is not specified.
  To overwrite existing file, :option:`--allow-overwrite` is required.
  Default: ``false``

.. option:: --conf-path=<PATH>

  Change the configuration file path to PATH.
  Default: ``$HOME/.aria2/aria2.conf`` if present, otherwise
  ``$XDG_CONFIG_HOME/aria2/aria2.conf``.

.. option:: --console-log-level=<LEVEL>

  Set log level to output to console.  LEVEL is either ``debug``,
  ``info``, ``notice``, ``warn`` or ``error``.  Default: ``notice``

.. option:: -D, --daemon[=true|false]

  Run as daemon. The current working directory will be changed to ``/``
  and standard input, standard output and standard error will be
  redirected to ``/dev/null``. Default: ``false``

.. option:: --deferred-input[=true|false]

  If ``true`` is given, aria2 does not read all URIs and options from file
  specified by :option:`--input-file <-i>` option at startup,
  but it reads one by one when it
  needs later. This may reduce memory usage if input file contains a
  lot of URIs to download.  If ``false`` is given, aria2 reads all URIs
  and options at startup.
  Default: ``false``

.. option:: --disable-ipv6[=true|false]

  Disable IPv6. This is useful if you have to use broken DNS and want
  to avoid terribly slow AAAA record lookup. Default: ``false``

.. option:: --disk-cache=<SIZE>

  Enable disk cache. If SIZE is ``0``, the disk cache is
  disabled. This feature caches the downloaded data in memory, which
  grows to at most SIZE bytes. The cache storage is created for aria2
  instance and shared by all downloads. The one advantage of the disk
  cache is reduce the disk I/O because the data are written in larger
  unit and it is reordered by the offset of the file.  If hash
  checking is involved and the data are cached in memory, we don't
  need to read them from the disk.  SIZE can include ``K`` or ``M``
  (1K = 1024, 1M = 1024K). Default: ``16M``

.. option:: --download-result=<OPT>

  This option changes the way ``Download Results`` is formatted. If OPT
  is ``default``, print GID, status, average download speed and
  path/URI. If multiple files are involved, path/URI of first
  requested file is printed and remaining ones are omitted.  If OPT is
  ``full``, print GID, status, average download speed, percentage of
  progress and path/URI. The percentage of progress and path/URI are
  printed for each requested file in each row.
  Default: ``default``

.. option:: --dscp=<DSCP>

  Set DSCP value in outgoing IP packets of BitTorrent traffic for
  QoS. This parameter sets only DSCP bits in TOS field of IP packets,
  not the whole field. If you take values from
  */usr/include/netinet/ip.h* divide them by 4 (otherwise values would
  be incorrect, e.g. your ``CS1`` class would turn into ``CS4``). If
  you take commonly used values from RFC, network vendors'
  documentation, Wikipedia or any other source, use them as they are.

.. option:: --rlimit-nofile=<NUM>

  Set the soft limit of open file descriptors.
  This open will only have effect when:

    a) The system supports it (posix)
    b) The limit does not exceed the hard limit.
    c) The specified limit is larger than the current soft limit.

  This is equivalent to setting nofile via ulimit,
  except that it will never decrease the limit.

  This option is only available on systems supporting the rlimit API.

.. option:: --enable-color[=true|false]

  Enable color output for a terminal.
  Default: ``true``

.. option:: --enable-mmap[=true|false]

   Map files into memory. This option may not work if the file space
   is not pre-allocated. See :option:`--file-allocation`.

   Default: ``false``

.. option:: --event-poll=<POLL>

  Specify the method for polling events.  The possible values are
  ``epoll``, ``kqueue``, ``port``, ``poll`` and ``select``.  For each ``epoll``,
  ``kqueue``, ``port`` and ``poll``, it is available if system supports it.
  ``epoll`` is available on recent Linux. ``kqueue`` is available on
  various \*BSD systems including Mac OS X. ``port`` is available on Open
  Solaris. The default value may vary depending on the system you use.

.. option:: --file-allocation=<METHOD>

  Specify file allocation method.
  ``none`` doesn't pre-allocate file space. ``prealloc`` pre-allocates file space
  before download begins. This may take some time depending on the size of the
  file.
  If you are using newer file systems such as ext4
  (with extents support), btrfs, xfs or NTFS(MinGW build only), ``falloc`` is
  your best choice. It allocates large(few GiB)
  files almost instantly. Don't use ``falloc`` with
  legacy file systems such as ext3 and FAT32 because it takes
  almost same time as ``prealloc`` and it blocks aria2
  entirely until allocation finishes. ``falloc`` may
  not be available if your system doesn't have
  :manpage:`posix_fallocate(3)` function.
  ``trunc`` uses :manpage:`ftruncate(2)` system call or
  platform-specific counterpart to truncate a file to a specified
  length.

  Possible Values: ``none``, ``prealloc``, ``trunc``, ``falloc``
  Default: ``prealloc``


.. option:: --force-save[=true|false]

  Save download with :option:`--save-session <--save-session>` option
  even if the download is completed or removed. This option also saves
  control file in that situations. This may be useful to save
  BitTorrent seeding which is recognized as completed state.
  Default: ``false``

.. option:: --gid=<GID>

  Set GID manually. aria2 identifies each download by the ID called
  GID. The GID must be hex string of 16 characters, thus [0-9a-zA-Z]
  are allowed and leading zeros must not be stripped. The GID all 0 is
  reserved and must not be used. The GID must be unique, otherwise
  error is reported and the download is not added.  This option is
  useful when restoring the sessions saved using
  :option:`--save-session <--save-session>` option. If this option is
  not used, new GID is generated by aria2.

.. option:: --hash-check-only[=true|false]

  If ``true`` is given, after hash check using
  :option:`--check-integrity <-V>` option,
  abort download whether or not download is complete.
  Default: ``false``

.. option:: --human-readable[=true|false]

  Print sizes and speed in human readable format (e.g., 1.2Ki, 3.4Mi)
  in the console readout. Default: ``true``

.. option:: --interface=<INTERFACE>

  Bind sockets to given interface. You can specify interface name, IP
  address and host name.
  Possible Values: interface, IP address, host name

  .. note::

    If an interface has multiple addresses, it is highly recommended to
    specify IP address explicitly. See also :option:`--disable-ipv6`.  If your
    system doesn't have :manpage:`getifaddrs(3)`, this option doesn't accept interface
    name.

.. option:: --max-download-result=<NUM>

  Set maximum number of download result kept in memory. The download
  results are completed/error/removed downloads. The download results
  are stored in FIFO queue and it can store at most NUM download
  results. When queue is full and new download result is created,
  oldest download result is removed from the front of the queue and
  new one is pushed to the back. Setting big number in this option may
  result high memory consumption after thousands of
  downloads. Specifying 0 means no download result is kept. Default:
  ``1000``

.. option:: --max-resume-failure-tries=<N>

  When used with :option:`--always-resume=false, <--always-resume>` aria2 downloads file from
  scratch when aria2 detects N number of URIs that does not support
  resume. If N is ``0``, aria2 downloads file from scratch when all
  given URIs do not support resume.  See :option:`--always-resume` option.
  Default: ``0``

.. option:: --min-tls-version=<VERSION>

  Specify minimum SSL/TLS version to enable.
  Possible Values: ``SSLv3``, ``TLSv1``, ``TLSv1.1``, ``TLSv1.2``
  Default: ``TLSv1``

.. option:: --multiple-interface=<INTERFACES>

  Comma separated list of interfaces to bind sockets to. Requests will
  be splited among the interfaces to achieve link aggregation. You can
  specify interface name, IP address and hostname. If
  :option:`--interface` is used, this option will be ignored.
  Possible Values: interface, IP address, hostname

.. option:: --log-level=<LEVEL>

  Set log level to output.
  LEVEL is either ``debug``, ``info``, ``notice``, ``warn`` or ``error``.
  Default: ``debug``

.. option:: --on-bt-download-complete=<COMMAND>

  For BitTorrent, a command specified in :option:`--on-download-complete` is
  called after download completed and seeding is over. On the other
  hand, this option set the command to be executed after download
  completed but before seeding.
  See `Event Hook`_ for more details about COMMAND.
  Possible Values: ``/path/to/command``

.. option:: --on-download-complete=<COMMAND>

  Set the command to be executed after download completed.  See
  See `Event Hook`_ for more details about COMMAND.
  See also :option:`--on-download-stop` option.
  Possible Values: ``/path/to/command``

.. option:: --on-download-error=<COMMAND>

  Set the command to be executed after download aborted due to error.
  See `Event Hook`_ for more details about COMMAND.
  See also :option:`--on-download-stop` option.  Possible Values:
  ``/path/to/command``

.. option:: --on-download-pause=<COMMAND>

  Set the command to be executed after download was paused.
  See `Event Hook`_ for more details about COMMAND.
  Possible Values: ``/path/to/command``

.. option:: --on-download-start=<COMMAND>

  Set the command to be executed after download got started.
  See `Event Hook`_ for more details about COMMAND.
  Possible Values: ``/path/to/command``

.. option:: --on-download-stop=<COMMAND>

  Set the command to be executed after download stopped. You can override
  the command to be executed for particular download result using
  :option:`--on-download-complete` and :option:`--on-download-error`. If they are
  specified, command specified in this option is not executed.
  See `Event Hook`_ for more details about COMMAND.
  Possible Values: ``/path/to/command``

.. option:: --piece-length=<LENGTH>

  Set a piece length for HTTP/FTP downloads. This is the boundary when
  aria2 splits a file. All splits occur at multiple of this
  length. This option will be ignored in BitTorrent downloads.  It
  will be also ignored if Metalink file contains piece hashes.
  Default: ``1M``

  .. note::
    
    The possible use case of :option:`--piece-length`
    option is change the request range in one HTTP pipelined request.
    To enable HTTP pipelining use
    :option:`--enable-http-pipelining`.

.. option:: --show-console-readout[=true|false]

  Show console readout. Default: ``true``

.. option:: --summary-interval=<SEC>

  Set interval in seconds to output download progress summary.
  Setting ``0`` suppresses the output.
  Default: ``60``

  .. note::

    In multi file torrent downloads, the files adjacent forward to the specified files
    are also allocated if they share the same piece.

.. option:: -Z, --force-sequential[=true|false]

  Fetch URIs in the command-line sequentially and download each URI in a
  separate session, like the usual command-line download utilities.
  Default: ``false``

.. option:: --max-overall-download-limit=<SPEED>

  Set max overall download speed in bytes/sec.  ``0`` means
  unrestricted.  You can append ``K`` or ``M`` (1K = 1024, 1M = 1024K).  To
  limit the download speed per download, use :option:`--max-download-limit`
  option.  Default: ``0``

.. option:: --max-download-limit=<SPEED>

  Set max download speed per each download in bytes/sec. ``0`` means
  unrestricted.  You can append ``K`` or ``M`` (1K = 1024, 1M = 1024K).  To
  limit the overall download speed, use :option:`--max-overall-download-limit`
  option.  Default: ``0``

.. option:: --no-conf[=true|false]

  Disable loading aria2.conf file.

.. option:: --no-file-allocation-limit=<SIZE>

  No file allocation is made for files whose size is smaller than SIZE.
  You can append ``K`` or ``M`` (1K = 1024, 1M = 1024K).
  Default: ``5M``

.. option:: -P, --parameterized-uri[=true|false]

  Enable parameterized URI support.
  You can specify set of parts: ``http://{sv1,sv2,sv3}/foo.iso``.
  Also you can specify numeric sequences with step counter:
  ``http://host/image[000-100:2].img``.
  A step counter can be omitted.
  If all URIs do not point to the same file, such as the second example above,
  -Z option is required.
  Default: ``false``

.. option:: -q, --quiet[=true|false]

  Make aria2 quiet (no console output).
  Default: ``false``

.. option:: --realtime-chunk-checksum[=true|false]

   Validate chunk of data by calculating checksum while downloading a file if
   chunk checksums are provided.
   Default: ``true``


.. option:: --remove-control-file[=true|false]

   Remove control file before download. Using with
   :option:`--allow-overwrite=true, <--allow-overwrite>` download always starts from
   scratch. This will be useful for users behind proxy server which
   disables resume.

.. option:: --save-session=<FILE>

  Save error/unfinished downloads to FILE on exit.  You can pass this
  output file to aria2c with :option:`--input-file <-i>` option on
  restart. If you like the output to be gzipped append a .gz extension to
  the file name.
  Please note that downloads added by
  :func:`aria2.addTorrent` and :func:`aria2.addMetalink` RPC method
  and whose meta data could not be saved as a file are not saved.
  Downloads removed using :func:`aria2.remove` and
  :func:`aria2.forceRemove` will not be saved. GID is also saved with
  :option:`gid <--gid>`, but there are some restrictions, see below.

  .. note::

    Normally, GID of the download itself is saved. But some downloads
    use meta data (e.g., BitTorrent and Metalink). In this case, there
    are some restrictions.

    1. magnet URI, and followed by torrent download
        GID of BitTorrent meta data download is saved.
    2. URI to torrent file, and followed by torrent download
        GID of torrent file download is saved.
    3. URI to metalink file, and followed by file downloads described in metalink file
        GID of metalink file download is saved.
    4. local torrent file
        GID of torrent download is saved.
    5. local metalink file
        Any meaningful GID is not saved.

.. option:: --save-session-interval=<SEC>

  Save error/unfinished downloads to a file specified by
  :option:`--save-session` option every SEC seconds. If ``0`` is
  given, file will be saved only when aria2 exits. Default: ``0``

.. option:: --stop=<SEC>

  Stop application after SEC seconds has passed.
  If ``0`` is given, this feature is disabled.
  Default: ``0``

.. option:: --stop-with-process=<PID>

  Stop application when process PID is not running.  This is useful if
  aria2 process is forked from a parent process. The parent process
  can fork aria2 with its own pid and when parent process exits for
  some reason, aria2 can detect it and shutdown itself.

.. option:: --truncate-console-readout[=true|false]

  Truncate console readout to fit in a single line.
  Default: ``true``
 
.. option:: -v, --version

  Print the version number, copyright and the configuration information and
  exit.

Notes for Options
~~~~~~~~~~~~~~~~~

Optional arguments
^^^^^^^^^^^^^^^^^^

The options that have its argument surrounded by square brackets([])
take an optional argument. Usually omitting the argument is evaluated to ``true``.
If you use short form of these options(such as ``-V``) and give
an argument, then the option name and its argument should be concatenated(e.g.
``-Vfalse``). If any spaces are inserted between the option name and the argument,
the argument will be treated as URI and usually this is not what you expect.

Units (K and M)
^^^^^^^^^^^^^^^

Some options takes ``K`` and ``M`` to conveniently represent 1024 and
1048576 respectively.  aria2 detects these characters in
case-insensitive way. In other words, ``k`` and ``m`` can be used as
well as ``K`` and ``M`` respectively.

URI, MAGNET, TORRENT_FILE, METALINK_FILE
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

You can specify multiple URIs in command-line.  Unless you specify
:option:`--force-sequential <-Z>` option, all URIs must point to the same file or downloading will
fail.

You can specify arbitrary number of BitTorrent Magnet URI. Please note
that they are always treated as a separate download.  Both hex encoded
40 characters Info Hash and Base32 encoded 32 characters Info Hash are
supported. The multiple ``tr`` parameters are supported.  Because
BitTorrent Magnet URI is likely to contain ``&`` character, it is highly
recommended to always quote URI with single(``'``) or double(``"``) quotation.
It is strongly recommended to enable DHT especially when ``tr``
parameter is missing. See http://www.bittorrent.org/beps/bep_0009.html
for more details about BitTorrent Magnet URI.

You can also specify arbitrary number of torrent files and Metalink
documents stored on a local drive. Please note that they are always
treated as a separate download. Both Metalink4 and Metalink version
3.0 are supported.

You can specify both torrent file with -T option and URIs. By doing
this, you can download a file from both torrent swarm and
HTTP(S)/FTP/SFTP server at the same time, while the data from
HTTP(S)/FTP/SFTP are uploaded to the torrent swarm.  For single file
torrents, URI can be a complete URI pointing to the resource or if URI
ends with /, name in torrent file in torrent is added. For multi-file
torrents, name and path are added to form a URI for each file.

.. note::

  Make sure that URI is quoted with single(``'``) or double(``"``) quotation if it
  contains ``&`` or any characters that have special meaning in shell.

Resuming Download
~~~~~~~~~~~~~~~~~

Usually, you can resume transfer by just issuing same command (aria2c
URI) if the previous transfer is made by aria2.

If the previous transfer is made by a browser or wget like sequential
download manager, then use :option:`--continue <-c>` option to continue the
transfer.

Event Hook
~~~~~~~~~~

aria2 provides options to specify arbitrary command after specific event
occurred. Currently following options are available:
:option:`--on-bt-download-complete`,
:option:`--on-download-pause`,
:option:`--on-download-complete`.
:option:`--on-download-start`,
:option:`--on-download-error`,
:option:`--on-download-stop`.

aria2 passes 3 arguments to specified command when it is executed.
These arguments are: GID, the number of files and file path.  For
HTTP, FTP, and SFTP downloads, usually the number of files is 1.
BitTorrent download can contain multiple files.  If number of files is
more than one, file path is first one.  In other words, this is the
value of path key of first struct whose selected key is true in the
response of :func:`aria2.getFiles` RPC method.  If you want to get all
file paths, consider to use JSON-RPC/XML-RPC.  Please note that file
path may change during download in HTTP because of redirection or
Content-Disposition header.

Let's see an example of how arguments are passed to command:

.. code-block:: console

  $ cat hook.sh
  #!/bin/sh
  echo "Called with [$1] [$2] [$3]"
  $ aria2c --on-download-complete hook.sh http://example.org/file.iso
  Called with [1] [1] [/path/to/file.iso]

.. _exit-status:

EXIT STATUS
-----------

Because aria2 can handle multiple downloads at once, it encounters
lots of errors in a session.  aria2 returns the following exit status
based on the last error encountered.

0
  If all downloads were successful.

1
  If an unknown error occurred.

2
  If time out occurred.

3
  If a resource was not found.

4
  If aria2 saw the specified number of "resource not found" error.
  See :option:`--max-file-not-found` option.

5
  If a download aborted because download speed was too slow.
  See :option:`--lowest-speed-limit` option.

6
  If network problem occurred.

7
  If there were unfinished downloads. This error is only reported if
  all finished downloads were successful and there were unfinished
  downloads in a queue when aria2 exited by pressing :kbd:`Ctrl-C` by an user
  or sending TERM or INT signal.

8
  If remote server did not support resume when resume was required to
  complete download.

9
  If there was not enough disk space available.

10
  If piece length was different from one in .aria2 control file. See
  :option:`--allow-piece-length-change` option.

11
  If aria2 was downloading same file at that moment.

12
  If aria2 was downloading same info hash torrent at that moment.

13
  If file already existed. See :option:`--allow-overwrite` option.

14
  If renaming file failed. See :option:`--auto-file-renaming` option.

15
  If aria2 could not open existing file.

16
  If aria2 could not create new file or truncate existing file.

17
  If file I/O error occurred.

18
  If aria2 could not create directory.

19
  If name resolution failed.

20
  If aria2 could not parse Metalink document.

21
  If FTP command failed.

22
  If HTTP response header was bad or unexpected.

23
  If too many redirects  occurred.

24
  If HTTP authorization failed.

25
  If aria2 could not parse bencoded file (usually ".torrent" file).

26
  If ".torrent" file was corrupted or missing information that aria2 needed.

27
  If Magnet URI was bad.

28
  If bad/unrecognized option was given or unexpected option argument
  was given.

29
  If the remote server was unable to handle the request due to a
  temporary overloading or maintenance.

30
  If aria2 could not parse JSON-RPC request.

31
  Reserved.  Not used.

32
  If checksum validation failed.

.. note::

  An error occurred in a finished download will not be reported
  as exit status.

ENVIRONMENT
-----------
aria2 recognizes the following environment variables.

``http_proxy [http://][USER:PASSWORD@]HOST[:PORT]``
  Specify proxy server for use in HTTP.
  Overrides http-proxy value in configuration file.
  The command-line option :option:`--http-proxy` overrides this value.

``https_proxy [http://][USER:PASSWORD@]HOST[:PORT]``
  Specify proxy server for use in HTTPS.
  Overrides https-proxy value in configuration file.
  The command-line option :option:`--https-proxy` overrides this value.

``ftp_proxy [http://][USER:PASSWORD@]HOST[:PORT]``
  Specify proxy server for use in FTP.
  Overrides ftp-proxy value in configuration file.
  The command-line option :option:`--ftp-proxy` overrides this value.

``all_proxy [http://][USER:PASSWORD@]HOST[:PORT]``
  Specify proxy server for use if no protocol-specific proxy is specified.
  Overrides all-proxy value in configuration file.
  The command-line option :option:`--all-proxy` overrides this value.

.. note::
  
  Although aria2 accepts ``ftp://`` and ``https://`` scheme in proxy URI, it
  simply assumes that ``http://`` is specified and does not change its
  behavior based on the specified scheme.

``no_proxy [DOMAIN,...]``
  Specify a comma-separated list of host names, domains and network addresses
  with or without a subnet mask where no proxy should be used.  Overrides the
  `no-proxy` value in configuration file.  The command-line option
  :option:`--no-proxy` overrides this value.

FILES
-----
aria2.conf
~~~~~~~~~~

By default, aria2 checks whether the legacy path
``$HOME/.aria2/aria2.conf`` is present, otherwise it parses
``$XDG_CONFIG_HOME/aria2/aria2.conf`` as its configuration file.  You
can specify the path to configuration file using :option:`--conf-path`
option.  If you don't want to use the configuration file, use
:option:`--no-conf` option.

The configuration file is a text file and has 1 option per each
line. In each line, you can specify name-value pair in the format:
``NAME=VALUE``, where name is the long command-line option name without
``--`` prefix. You can use same syntax for the command-line option. The
lines beginning ``#`` are treated as comments::

  # sample configuration file for aria2c
  listen-port=60000
  dht-listen-port=60000
  seed-ratio=1.0
  max-upload-limit=50K
  ftp-pasv=true

.. note::

  The confidential information such as user/password might be included
  in the configuration file. It is recommended to change file mode
  bits of the configuration file (e.g., ``chmod 600 aria2.conf``), so
  that other user cannot see the contents of the file.

dht.dat
~~~~~~~~

Unless the legacy file paths ``$HOME/.aria2/dht.dat`` and
``$HOME/.aria2/dht6.dat`` are pointing to existing files, the routing
table of IPv4 DHT is saved to the path
``$XDG_CACHE_HOME/aria2/dht.dat`` and the routing table of IPv6 DHT is
saved to the path ``$XDG_CACHE_HOME/aria2/dht6.dat``.

Netrc
~~~~~

Netrc support is enabled by default for HTTP(S)/FTP/SFTP.  To disable
netrc support, specify :option:`--no-netrc <-n>` option.  Your .netrc
file should have correct permissions(600).

If machine name starts ``.``, aria2 performs domain-match instead of
exact match. This is an extension of aria2. For example of domain
match, imagine the following .netrc entry::

  machine .example.org login myid password mypasswd


``aria2.example.org`` domain-matches ``.example.org`` and uses ``myid`` and
``mypasswd``.

Some domain-match example follow: ``example.net`` does not domain-match
``.example.org``. ``example.org`` does not domain-match ``.example.org``
because of preceding ``.``. If you want to match ``example.org``, specify
``example.org``.

Control File
~~~~~~~~~~~~

aria2 uses a control file to track the progress of a download.  A
control file is placed in the same directory as the downloading file
and its file name is the file name of downloading file with ``.aria2``
appended.  For example, if you are downloading file.zip, then the
control file should be file.zip.aria2.  (There is a exception for this
naming convention.  If you are downloading a multi torrent, its
control file is the "top directory" name of the torrent with ``.aria2``
appended.  The "top directory" name is a value of "name" key in "info"
directory in a torrent file.)

Usually a control file is deleted once download completed.  If aria2
decides that download cannot be resumed(for example, when downloading
a file from a HTTP server which doesn't support resume), a control
file is not created.

Normally if you lose a control file, you cannot resume download.  But
if you have a torrent or metalink with chunk checksums for the file,
you can resume the download without a control file by giving -V option
to aria2c in command-line.

.. _input-file:

Input File
~~~~~~~~~~

The input file can contain a list of URIs for aria2 to download.  You
can specify multiple URIs for a single entity: separate URIs on a
single line using the TAB character.

Each line is treated as if it is provided in command-line argument.
Therefore they are affected by :option:`--force-sequential <-Z>` and :option:`--parameterized-uri <-P>` options.

Since URIs in the input file are directly read by aria2, they must not
be quoted with single(``'``) or double(``"``) quotation.

Lines starting with ``#`` are treated as comments and skipped.

Additionally, the following options can be specified after each line
of URIs. These optional lines must start with white space(s).

.. hlist::
  :columns: 3

  * :option:`all-proxy <--all-proxy>`
  * :option:`all-proxy-passwd <--all-proxy-passwd>`
  * :option:`all-proxy-user <--all-proxy-user>`
  * :option:`allow-overwrite <--allow-overwrite>`
  * :option:`allow-piece-length-change <--allow-piece-length-change>`
  * :option:`always-resume <--always-resume>`
  * :option:`async-dns <--async-dns>`
  * :option:`auto-file-renaming <--auto-file-renaming>`
  * :option:`bt-enable-lpd <--bt-enable-lpd>`
  * :option:`bt-exclude-tracker <--bt-exclude-tracker>`
  * :option:`bt-external-ip <--bt-external-ip>`
  * :option:`bt-force-encryption <--bt-force-encryption>`
  * :option:`bt-hash-check-seed <--bt-hash-check-seed>`
  * :option:`bt-max-peers <--bt-max-peers>`
  * :option:`bt-metadata-only <--bt-metadata-only>`
  * :option:`bt-min-crypto-level <--bt-min-crypto-level>`
  * :option:`bt-prioritize-piece <--bt-prioritize-piece>`
  * :option:`bt-remove-unselected-file <--bt-remove-unselected-file>`
  * :option:`bt-request-peer-speed-limit <--bt-request-peer-speed-limit>`
  * :option:`bt-require-crypto <--bt-require-crypto>`
  * :option:`bt-save-metadata <--bt-save-metadata>`
  * :option:`bt-seed-unverified <--bt-seed-unverified>`
  * :option:`bt-stop-timeout <--bt-stop-timeout>`
  * :option:`bt-tracker <--bt-tracker>`
  * :option:`bt-tracker-connect-timeout <--bt-tracker-connect-timeout>`
  * :option:`bt-tracker-interval <--bt-tracker-interval>`
  * :option:`bt-tracker-timeout <--bt-tracker-timeout>`
  * :option:`check-integrity <-V>`
  * :option:`checksum <--checksum>`
  * :option:`conditional-get <--conditional-get>`
  * :option:`connect-timeout <--connect-timeout>`
  * :option:`continue <-c>`
  * :option:`dir <-d>`
  * :option:`dry-run <--dry-run>`
  * :option:`enable-http-keep-alive <--enable-http-keep-alive>`
  * :option:`enable-http-pipelining <--enable-http-pipelining>`
  * :option:`enable-mmap <--enable-mmap>`
  * :option:`enable-peer-exchange <--enable-peer-exchange>`
  * :option:`file-allocation <--file-allocation>`
  * :option:`follow-metalink <--follow-metalink>`
  * :option:`follow-torrent <--follow-torrent>`
  * :option:`force-save <--force-save>`
  * :option:`ftp-passwd <--ftp-passwd>`
  * :option:`ftp-pasv <-p>`
  * :option:`ftp-proxy <--ftp-proxy>`
  * :option:`ftp-proxy-passwd <--ftp-proxy-passwd>`
  * :option:`ftp-proxy-user <--ftp-proxy-user>`
  * :option:`ftp-reuse-connection <--ftp-reuse-connection>`
  * :option:`ftp-type <--ftp-type>`
  * :option:`ftp-user <--ftp-user>`
  * :option:`gid <--gid>`
  * :option:`hash-check-only <--hash-check-only>`
  * :option:`header <--header>`
  * :option:`http-accept-gzip <--http-accept-gzip>`
  * :option:`http-auth-challenge <--http-auth-challenge>`
  * :option:`http-no-cache <--http-no-cache>`
  * :option:`http-passwd <--http-passwd>`
  * :option:`http-proxy <--http-proxy>`
  * :option:`http-proxy-passwd <--http-proxy-passwd>`
  * :option:`http-proxy-user <--http-proxy-user>`
  * :option:`http-user <--http-user>`
  * :option:`https-proxy <--https-proxy>`
  * :option:`https-proxy-passwd <--https-proxy-passwd>`
  * :option:`https-proxy-user <--https-proxy-user>`
  * :option:`index-out <-O>`
  * :option:`lowest-speed-limit <--lowest-speed-limit>`
  * :option:`max-connection-per-server <-x>`
  * :option:`max-download-limit <--max-download-limit>`
  * :option:`max-file-not-found <--max-file-not-found>`
  * :option:`max-resume-failure-tries <--max-resume-failure-tries>`
  * :option:`max-tries <-m>`
  * :option:`max-upload-limit <-u>`
  * :option:`metalink-base-uri <--metalink-base-uri>`
  * :option:`metalink-enable-unique-protocol <--metalink-enable-unique-protocol>`
  * :option:`metalink-language <--metalink-language>`
  * :option:`metalink-location <--metalink-location>`
  * :option:`metalink-os <--metalink-os>`
  * :option:`metalink-preferred-protocol <--metalink-preferred-protocol>`
  * :option:`metalink-version <--metalink-version>`
  * :option:`min-split-size <-k>`
  * :option:`no-file-allocation-limit <--no-file-allocation-limit>`
  * :option:`no-netrc <-n>`
  * :option:`no-proxy <--no-proxy>`
  * :option:`out <-o>`
  * :option:`parameterized-uri <-P>`
  * :option:`pause <--pause>`
  * :option:`pause-metadata <--pause-metadata>`
  * :option:`piece-length <--piece-length>`
  * :option:`proxy-method <--proxy-method>`
  * :option:`realtime-chunk-checksum <--realtime-chunk-checksum>`
  * :option:`referer <--referer>`
  * :option:`remote-time <-R>`
  * :option:`remove-control-file <--remove-control-file>`
  * :option:`retry-wait <--retry-wait>`
  * :option:`reuse-uri <--reuse-uri>`
  * :option:`rpc-save-upload-metadata <--rpc-save-upload-metadata>`
  * :option:`seed-ratio <--seed-ratio>`
  * :option:`seed-time <--seed-time>`
  * :option:`select-file <--select-file>`
  * :option:`split <-s>`
  * :option:`ssh-host-key-md <--ssh-host-key-md>`
  * :option:`stream-piece-selector <--stream-piece-selector>`
  * :option:`timeout <-t>`
  * :option:`uri-selector <--uri-selector>`
  * :option:`use-head <--use-head>`
  * :option:`user-agent <-U>`
  
These options have exactly same meaning of the ones in the
command-line options, but it just applies to the URIs it belongs to.
Please note that for options in input file ``--`` prefix must be
stripped.

For example, the content of uri.txt is::

  http://server/file.iso http://mirror/file.iso
    dir=/iso_images
    out=file.img
  http://foo/bar


If aria2 is executed with ``-i uri.txt -d /tmp`` options, then
``file.iso`` is saved as ``/iso_images/file.img`` and it is downloaded
from ``http://server/file.iso`` and ``http://mirror/file.iso``.  The file
``bar`` is downloaded from ``http://foo/bar`` and saved as ``/tmp/bar``.

In some cases, :option:`out <-o>` parameter has no effect.
See note of :option:`--out <-o>`
option for the restrictions.

Server Performance Profile
~~~~~~~~~~~~~~~~~~~~~~~~~~

This section describes the format of server performance profile.  The
file is plain text and each line has several ``NAME=VALUE`` pair,
delimited by comma.  Currently following NAMEs are recognized:

``host``
  Host name of the server. Required.

``protocol``
  Protocol for this profile, such as ftp, http. Required.

``dl_speed``
  The average download speed observed in the previous download in
  bytes per sec.  Required.

``sc_avg_speed``
  The average download speed observed in the previous download in
  bytes per sec. This value is only updated if the download is done in
  single connection environment and only used by
  AdaptiveURISelector. Optional.

``mc_avg_speed``
  The average download speed observed in the previous download in
  bytes per sec. This value is only updated if the download is done in
  multi connection environment and only used by
  AdaptiveURISelector. Optional.

``counter``
  How many times the server is used. Currently this value is only used
  by AdaptiveURISelector.  Optional.

``last_updated``
  Last contact time in GMT with this server, specified in the seconds
  since the Epoch(00:00:00 on January 1, 1970, UTC). Required.

``status``
  ERROR is set when server cannot be reached or out-of-service or
  timeout occurred. Otherwise, OK is set.

Those fields must exist in one line. The order of the fields is not
significant. You can put pairs other than the above; they are simply
ignored.

An example follows::

  host=localhost, protocol=http, dl_speed=32000, last_updated=1222491640, status=OK
  host=localhost, protocol=ftp, dl_speed=0, last_updated=1222491632, status=ERROR


RPC INTERFACE
-------------

aria2 provides JSON-RPC over HTTP and XML-RPC over HTTP interfaces that offer
basically the same functionality.  aria2 also provides JSON-RPC
over WebSocket. JSON-RPC over WebSocket uses the same method signatures
and response format as JSON-RPC over HTTP, but additionally provides
server-initiated notifications. See `JSON-RPC over WebSocket`_ section for more
information.

The request path of the JSON-RPC interface (for both over HTTP and over
WebSocket) is ``/jsonrpc``.  The request path of the XML-RPC interface is
``/rpc``.

The WebSocket URI for JSON-RPC over WebSocket is
``ws://HOST:PORT/jsonrpc``. If you enabled SSL/TLS encryption, use
``wss://HOST:PORT/jsonrpc`` instead.

The implemented JSON-RPC is based on JSON-RPC 2.0
<http://jsonrpc.org/specification>, and
supports HTTP POST and GET (JSONP).  The WebSocket transport is
an aria2 extension.

The JSON-RPC interface does not support notifications over HTTP, but the
RPC server will send notifications over WebSocket. It also does not
support floating point numbers. The character encoding must be UTF-8.

When reading the following documentation for JSON-RPC, interpret structs as JSON
objects.

Terminology
~~~~~~~~~~~

GID

  The GID (or gid) is a key to manage each download. Each download will be
  assigned a unique GID. The GID is stored as 64-bit binary value in aria2.
  For RPC access, it is represented as a hex string of 16 characters (e.g.,
  ``2089b05ecca3d829``). Normally, aria2 generates this GID for each
  download, but the user can specify GIDs manually using the :option:`--gid
  <--gid>` option. When querying downloads by GID, you can specify only the
  prefix of a GID as long as it is unique among others.

.. _rpc_auth:

RPC authorization secret token
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

As of 1.18.4, in addition to HTTP basic authorization, aria2 provides
RPC method-level authorization. In a future release, HTTP basic
authorization will be removed and RPC method-level authorization will
become mandatory.

To use RPC method-level authorization, the user has to specify an RPC secret
authorization token using the :option:`--rpc-secret` option. For each RPC
method call, the caller has to include the token prefixed with
``token:``. Even when the :option:`--rpc-secret` option is not used, if the
first parameter in the RPC method is a string and starts with ``token:``, it
will removed from the parameter list before the request is being processed.

For example, if the RPC secret authorization token is ``$$secret$$``,
calling `aria2.addUri` RPC method would have to look like this::

  aria2.addUri("token:$$secret$$", ["http://example.org/file"])

The `system.multicall` RPC method is treated specially. Since the XML-RPC
specification only allows a single array as a parameter for this method, we
don't specify the token in the call. Instead, each nested method call has
to provide the token as the first parameter as described above.

.. note::

  The secret token validation in aria2 is designed to take at least a certain
  amount of time to mitigate brute-force/dictionary attacks against the RPC
  interface. Therefore it is recommended to prefer Batch or `system.multicall`
  requests when appropriate.

Methods
~~~~~~~

All code examples are compatible with the Python 2.7 interpreter.
For information on the *secret* parameter, see :ref:`rpc_auth`.

.. function:: aria2.addUri([secret], uris[, options[, position]])

  This method adds a new download. *uris* is an array of
  HTTP/FTP/SFTP/BitTorrent URIs (strings) pointing to the same
  resource.  If you mix URIs pointing to different resources, then the
  download may fail or be corrupted without aria2 complaining.  When
  adding BitTorrent Magnet URIs, *uris* must have only one element and
  it should be BitTorrent Magnet URI.  *options* is a struct and its
  members are pairs of option name and value.  See :ref:`rpc_options`
  below for more details.  If *position* is given, it must be an
  integer starting from 0. The new download will be inserted at
  *position* in the waiting queue. If *position* is omitted or
  *position* is larger than the current size of the queue, the new
  download is appended to the end of the queue.  This method returns
  the GID of the newly registered download.

  **JSON-RPC Example**

  The following example adds ``http://example.org/file``::

    >>> import urllib2, json
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'aria2.addUri',
    ...                       'params':[['http://example.org/file']]})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> c.read()
    '{"id":"qwer","jsonrpc":"2.0","result":"2089b05ecca3d829"}'

  **XML-RPC Example**

  The following example adds ``http://example.org/file``::

    >>> import xmlrpclib
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> s.aria2.addUri(['http://example.org/file'])
    '2089b05ecca3d829'

  The following example adds a new download with two sources and some options::

    >>> s.aria2.addUri(['http://example.org/file', 'http://mirror/file'],
                        dict(dir="/tmp"))
    'd2703803b52216d1'

  The following example adds a download and inserts it to the front of the
  queue::

    >>> s.aria2.addUri(['http://example.org/file'], {}, 0)
    'ca3d829cee549a4d'

.. function:: aria2.addTorrent([secret], torrent[, uris[, options[, position]]])

  This method adds a BitTorrent download by uploading a ".torrent" file.
  If you want to add a BitTorrent Magnet URI, use the :func:`aria2.addUri`
  method instead.  *torrent* must be a base64-encoded string containing the
  contents of the ".torrent" file.
  *uris* is an array of URIs (string). *uris* is used for
  Web-seeding.  For single file torrents, the URI can be a complete URI
  pointing to the resource; if URI ends with /, name in torrent file
  is added. For multi-file torrents, name and path in torrent are
  added to form a URI for each file.
  *options* is a struct and its members are pairs of option name and value.
  See :ref:`rpc_options` below for more details.
  If *position* is given, it must be an integer starting from 0. The new
  download will be inserted at *position* in the waiting queue. If
  *position* is omitted or *position* is larger than the current size of the
  queue, the new download is appended to the end of the queue.
  This method returns the GID of the newly registered download.
  If :option:`--rpc-save-upload-metadata` is ``true``, the
  uploaded data is saved as a file named as the hex string of SHA-1 hash of
  data plus ".torrent" in the directory specified by :option:`--dir
  <-d>` option.  E.g. a file name might be
  ``0a3893293e27ac0490424c06de4d09242215f0a6.torrent``.  If a file with the
  same name already exists, it is overwritten!  If the file cannot be saved
  successfully or :option:`--rpc-save-upload-metadata` is ``false``,
  the downloads added by this method are not saved by :option:`--save-session`.

  The following examples add local file ``file.torrent``.

  **JSON-RPC Example**

  ::

    >>> import urllib2, json, base64
    >>> torrent = base64.b64encode(open('file.torrent').read())
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'asdf',
    ...                       'method':'aria2.addTorrent', 'params':[torrent]})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> c.read()
    '{"id":"asdf","jsonrpc":"2.0","result":"2089b05ecca3d829"}'

  **XML-RPC Example**

  ::

    >>> import xmlrpclib
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> s.aria2.addTorrent(xmlrpclib.Binary(open('file.torrent').read()))
    '2089b05ecca3d829'

.. function:: aria2.addMetalink([secret], metalink[, options[, position]])

  This method adds a Metalink download by uploading a ".metalink" file.
  *metalink* is a base64-encoded string which contains the contents of the
  ".metalink" file.
  *options* is a struct and its members are pairs of option name and value.
  See :ref:`rpc_options` below for more details.
  If *position* is given, it must be an integer starting from 0. The new
  download will be inserted at *position* in the waiting queue. If
  *position* is omitted or *position* is larger than the current size of the
  queue, the new download is appended to the end of the queue.
  This method returns an array of GIDs of newly registered downloads.
  If :option:`--rpc-save-upload-metadata` is ``true``, the uploaded data
  is saved as a file named hex string of SHA-1 hash of data plus
  ".metalink" in the directory specified by :option:`--dir <-d>`
  option.  E.g. a file name might be
  ``0a3893293e27ac0490424c06de4d09242215f0a6.metalink``.  If a file with the
  same name already exists, it is overwritten!  If the file cannot be saved
  successfully or :option:`--rpc-save-upload-metadata` is ``false``,
  the downloads added by this method are not saved by
  :option:`--save-session`.

  The following examples add local file file.meta4.

  **JSON-RPC Example**

  ::

    >>> import urllib2, json, base64
    >>> metalink = base64.b64encode(open('file.meta4').read())
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'aria2.addMetalink',
    ...                       'params':[metalink]})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> c.read()
    '{"id":"qwer","jsonrpc":"2.0","result":["2089b05ecca3d829"]}'

  **XML-RPC Example**

  ::

    >>> import xmlrpclib
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> s.aria2.addMetalink(xmlrpclib.Binary(open('file.meta4').read()))
    ['2089b05ecca3d829']

.. function:: aria2.remove([secret], gid)

  This method removes the download denoted by *gid* (string).  If the specified
  download is in progress, it is first stopped.  The status of the removed
  download becomes ``removed``.
  This method returns GID of removed download.

  The following examples remove a download with GID#2089b05ecca3d829.

  **JSON-RPC Example**

  ::

    >>> import urllib2, json
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'aria2.remove',
    ...                       'params':['2089b05ecca3d829']})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> c.read()
    '{"id":"qwer","jsonrpc":"2.0","result":"2089b05ecca3d829"}'

  **XML-RPC Example**

  ::

    >>> import xmlrpclib
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> s.aria2.remove('2089b05ecca3d829')
    '2089b05ecca3d829'

.. function:: aria2.forceRemove([secret], gid)

  This method removes the download denoted by *gid*.  This method
  behaves just like :func:`aria2.remove` except that this method removes
  the download without performing any actions which take time, such as
  contacting BitTorrent trackers to unregister the download first.

.. function:: aria2.pause([secret], gid)

  This method pauses the download denoted by *gid* (string).  The status of
  paused download becomes ``paused``.  If the download was active, the download
  is placed in the front of waiting queue.  While the status is ``paused``,
  the download is not started.  To change status to ``waiting``, use the
  :func:`aria2.unpause` method.
  This method returns GID of paused download.

.. function:: aria2.pauseAll([secret])

  This method is equal to calling :func:`aria2.pause` for every active/waiting
  download. This methods returns ``OK``.

.. function:: aria2.forcePause([secret], gid)

  This method pauses the download denoted by *gid*.  This method
  behaves just like :func:`aria2.pause` except that this method pauses
  downloads without performing any actions which take time, such as contacting
  BitTorrent trackers to unregister the download first.

.. function:: aria2.forcePauseAll([secret])

  This method is equal to calling :func:`aria2.forcePause` for every
  active/waiting download. This methods returns ``OK``.

.. function:: aria2.unpause([secret], gid)

  This method changes the status of the download denoted by *gid* (string) from
  ``paused`` to ``waiting``, making the download eligible to be restarted.
  This method returns the GID of the unpaused download.

.. function:: aria2.unpauseAll([secret])

  This method is equal to calling :func:`aria2.unpause` for every active/waiting
  download. This methods returns ``OK``.

.. function:: aria2.tellStatus([secret], gid[, keys])

  This method returns the progress of the download denoted by *gid* (string).
  *keys* is an array of strings. If specified, the response contains only keys
  in the *keys* array. If *keys* is empty or omitted, the response contains all
  keys. This is useful when you just want specific keys and avoid unnecessary
  transfers.
  For example, ``aria2.tellStatus("2089b05ecca3d829", ["gid", "status"])``
  returns the *gid* and *status* keys only.  The response is a struct and
  contains following keys. Values are strings.

  ``gid``
    GID of the download.

  ``status``
    ``active`` for currently downloading/seeding downloads.
    ``waiting`` for downloads in the queue; download is not started.
    ``paused`` for paused downloads.
    ``error`` for downloads that were stopped  because of error.
    ``complete`` for stopped and completed downloads.
    ``removed`` for the downloads removed by user.

  ``totalLength``
    Total length of the download in bytes.

  ``completedLength``
    Completed length of the download in bytes.

  ``uploadLength``
    Uploaded length of the download in bytes.

  ``bitfield``
    Hexadecimal representation of the download progress. The highest bit
    corresponds to the piece at index 0. Any set bits indicate loaded pieces,
    while unset bits indicate not yet loaded and/or missing pieces. Any overflow
    bits at the end are set to zero.  When the download was not started yet,
    this key will not be included in the response.

  ``downloadSpeed``
    Download speed of this download measured in bytes/sec.

  ``uploadSpeed``
    Upload speed of this download measured in bytes/sec.

  ``infoHash``
    InfoHash. BitTorrent only.

  ``numSeeders``
    The number of seeders aria2 has connected to. BitTorrent only.

  ``pieceLength``
    Piece length in bytes.

  ``numPieces``
    The number of pieces.

  ``connections``
    The number of peers/servers aria2 has connected to.

  ``errorCode``
    The code of the last error for this item, if any. The value
    is a string. The error codes are defined in the `EXIT STATUS`_ section.
    This value is only available for stopped/completed downloads.

  ``followedBy``
    List of GIDs which are generated as the result of this
    download. For example, when aria2 downloads a Metalink file, it
    generates downloads described in the Metalink (see the
    :option:`--follow-metalink` option). This value is useful to track
    auto-generated downloads. If there are no such downloads, this key will not
    be included in the response.

  ``belongsTo``
    GID of a parent download. Some downloads are a part of another
    download.  For example, if a file in a Metalink has BitTorrent
    resources, the downloads of ".torrent" files are parts of that parent.
    If this download has no parent, this key will not be included in the
    response.

  ``dir``
    Directory to save files.

  ``files``
    Returns the list of files. The elements of this list are the same structs
    used in :func:`aria2.getFiles` method.

  ``bittorrent``
    Struct which contains information retrieved from the .torrent
    (file). BitTorrent only. It contains following keys.

    ``announceList``
      List of lists of announce URIs. If the torrent contains ``announce``
      and no ``announce-list``, ``announce`` is converted to the
      ``announce-list`` format.

    ``comment``
      The comment of the torrent. ``comment.utf-8`` is used if available.

    ``creationDate``
      The creation time of the torrent. The value is an integer since
      the epoch, measured in seconds.

    ``mode``
      File mode of the torrent. The value is either ``single`` or ``multi``.

    ``info``
      Struct which contains data from Info dictionary. It contains
      following keys.

      ``name``
        name in info dictionary. ``name.utf-8`` is used if available.

  **JSON-RPC Example**

  The following example gets information about a download with GID#2089b05ecca3d829::

    >>> import urllib2, json
    >>> from pprint import pprint
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'aria2.tellStatus',
    ...                       'params':['2089b05ecca3d829']})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> pprint(json.loads(c.read()))
    {u'id': u'qwer',
     u'jsonrpc': u'2.0',
     u'result': {u'bitfield': u'0000000000',
                 u'completedLength': u'901120',
                 u'connections': u'1',
                 u'dir': u'/downloads',
                 u'downloadSpeed': u'15158',
                 u'files': [{u'index': u'1',
                             u'length': u'34896138',
                             u'completedLength': u'34896138',
                             u'path': u'/downloads/file',
                             u'selected': u'true',
                             u'uris': [{u'status': u'used',
                                        u'uri': u'http://example.org/file'}]}],
                 u'gid': u'2089b05ecca3d829',
                 u'numPieces': u'34',
                 u'pieceLength': u'1048576',
                 u'status': u'active',
                 u'totalLength': u'34896138',
                 u'uploadLength': u'0',
                 u'uploadSpeed': u'0'}}

  The following example gets only specific keys::

    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'aria2.tellStatus',
    ...                       'params':['2089b05ecca3d829',
    ...                                 ['gid',
    ...                                  'totalLength',
    ...                                  'completedLength']]})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> pprint(json.loads(c.read()))
    {u'id': u'qwer',
     u'jsonrpc': u'2.0',
     u'result': {u'completedLength': u'5701632',
                 u'gid': u'2089b05ecca3d829',
                 u'totalLength': u'34896138'}}

  **XML-RPC Example**

  The following example gets information about a download with GID#2089b05ecca3d829::

    >>> import xmlrpclib
    >>> from pprint import pprint
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> r = s.aria2.tellStatus('2089b05ecca3d829')
    >>> pprint(r)
    {'bitfield': 'ffff80',
     'completedLength': '34896138',
     'connections': '0',
     'dir': '/downloads',
     'downloadSpeed': '0',
     'errorCode': '0',
     'files': [{'index': '1',
                'length': '34896138',
                'completedLength': '34896138',
                'path': '/downloads/file',
                'selected': 'true',
                'uris': [{'status': 'used',
                          'uri': 'http://example.org/file'}]}],
     'gid': '2089b05ecca3d829',
     'numPieces': '17',
     'pieceLength': '2097152',
     'status': 'complete',
     'totalLength': '34896138',
     'uploadLength': '0',
     'uploadSpeed': '0'}

  The following example gets only specific keys::

    >>> r = s.aria2.tellStatus('2089b05ecca3d829', ['gid', 'totalLength', 'completedLength'])
    >>> pprint(r)
    {'completedLength': '34896138', 'gid': '2089b05ecca3d829', 'totalLength': '34896138'}

.. function:: aria2.getUris([secret], gid)

  This method returns the URIs used in the download denoted by *gid* (string).
  The response is an array of structs and it contains following keys.
  Values are string.

  ``uri``
    URI

  ``status``
    'used' if the URI is in use. 'waiting' if the URI is still waiting in the
    queue.

  **JSON-RPC Example**
  ::

    >>> import urllib2, json
    >>> from pprint import pprint
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'aria2.getUris',
    ...                       'params':['2089b05ecca3d829']})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> pprint(json.loads(c.read()))
    {u'id': u'qwer',
     u'jsonrpc': u'2.0',
     u'result': [{u'status': u'used',
                  u'uri': u'http://example.org/file'}]}

  **XML-RPC Example**
  ::

    >>> import xmlrpclib
    >>> from pprint import pprint
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> r = s.aria2.getUris('2089b05ecca3d829')
    >>> pprint(r)
    [{'status': 'used', 'uri': 'http://example.org/file'}]

.. function:: aria2.getFiles([secret], gid)

  This method returns the file list of the download denoted by *gid* (string).
  The response is an array of structs which contain following keys.
  Values are strings.

  ``index``
    Index of the file, starting at 1, in the same order as files appear in the
    multi-file torrent.

  ``path``
    File path.

  ``length``
    File size in bytes.

  ``completedLength``
    Completed length of this file in bytes.  Please note that it is
    possible that sum of ``completedLength`` is less than the
    ``completedLength`` returned by the :func:`aria2.tellStatus` method.
    This is because ``completedLength`` in
    :func:`aria2.getFiles`
    only includes completed pieces. On the other hand, ``completedLength``
    in :func:`aria2.tellStatus` also includes partially completed pieces.

  ``selected``
    ``true`` if this file is selected by :option:`--select-file` option. If
    :option:`--select-file` is not specified or this is single-file torrent or
    not a torrent download at all, this value is always ``true``. Otherwise
    ``false``.

  ``uris``
    Returns a list of URIs for this file. The element type is the same struct
    used in the :func:`aria2.getUris` method.

  **JSON-RPC Example**
  ::

    >>> import urllib2, json
    >>> from pprint import pprint
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'aria2.getFiles',
    ...                       'params':['2089b05ecca3d829']})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> pprint(json.loads(c.read()))
    {u'id': u'qwer',
     u'jsonrpc': u'2.0',
     u'result': [{u'index': u'1',
                  u'length': u'34896138',
                  u'completedLength': u'34896138',
                  u'path': u'/downloads/file',
                  u'selected': u'true',
                  u'uris': [{u'status': u'used',
                             u'uri': u'http://example.org/file'}]}]}

  **XML-RPC Example**
  ::

    >>> import xmlrpclib
    >>> from pprint import pprint
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> r = s.aria2.getFiles('2089b05ecca3d829')
    >>> pprint(r)
    [{'index': '1',
      'length': '34896138',
      'completedLength': '34896138',
      'path': '/downloads/file',
      'selected': 'true',
      'uris': [{'status': 'used',
                'uri': 'http://example.org/file'}]}]

.. function:: aria2.getPeers([secret], gid)

  This method returns a list peers of the download denoted by *gid* (string).
  This method is for BitTorrent only.  The response is an array of structs and
  contains the following keys. Values are strings.

  ``peerId``
    Percent-encoded peer ID.

  ``ip``
    IP address of the peer.

  ``port``
    Port number of the peer.

  ``bitfield``
    Hexadecimal representation of the download progress of the peer. The
    highest bit corresponds to the piece at index 0. Set bits indicate the
    piece is available and unset bits indicate the piece is missing. Any
    spare bits at the end are set to zero.

  ``amChoking``
    ``true`` if aria2 is choking the peer. Otherwise ``false``.

  ``peerChoking``
    ``true`` if the peer is choking aria2. Otherwise ``false``.

  ``downloadSpeed``
    Download speed (byte/sec) that this client obtains from the peer.

  ``uploadSpeed``
    Upload speed(byte/sec) that this client uploads to the peer.

  ``seeder``
    ``true`` is this peer is a seeder. Otherwise ``false``.

  **JSON-RPC Example**
  ::

    >>> import urllib2, json
    >>> from pprint import pprint
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'aria2.getPeers',
    ...                       'params':['2089b05ecca3d829']})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> pprint(json.loads(c.read()))
    {u'id': u'qwer',
     u'jsonrpc': u'2.0',
     u'result': [{u'amChoking': u'true',
                  u'bitfield': u'ffffffffffffffffffffffffffffffffffffffff',
                  u'downloadSpeed': u'10602',
                  u'ip': u'10.0.0.9',
                  u'peerChoking': u'false',
                  u'peerId': u'aria2%2F1%2E10%2E5%2D%87%2A%EDz%2F%F7%E6',
                  u'port': u'6881',
                  u'seeder': u'true',
                  u'uploadSpeed': u'0'},
                 {u'amChoking': u'false',
                  u'bitfield': u'ffffeff0fffffffbfffffff9fffffcfff7f4ffff',
                  u'downloadSpeed': u'8654',
                  u'ip': u'10.0.0.30',
                  u'peerChoking': u'false',
                  u'peerId': u'bittorrent client758',
                  u'port': u'37842',
                  u'seeder': u'false',
                  u'uploadSpeed': u'6890'}]}

  **XML-RPC Example**
  ::

    >>> import xmlrpclib
    >>> from pprint import pprint
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> r = s.aria2.getPeers('2089b05ecca3d829')
    >>> pprint(r)
    [{'amChoking': 'true',
      'bitfield': 'ffffffffffffffffffffffffffffffffffffffff',
      'downloadSpeed': '10602',
      'ip': '10.0.0.9',
      'peerChoking': 'false',
      'peerId': 'aria2%2F1%2E10%2E5%2D%87%2A%EDz%2F%F7%E6',
      'port': '6881',
      'seeder': 'true',
      'uploadSpeed': '0'},
     {'amChoking': 'false',
      'bitfield': 'ffffeff0fffffffbfffffff9fffffcfff7f4ffff',
      'downloadSpeed': '8654',
      'ip': '10.0.0.30',
      'peerChoking': 'false',
      'peerId': 'bittorrent client758',
      'port': '37842',
      'seeder': 'false,
      'uploadSpeed': '6890'}]

.. function:: aria2.getServers([secret], gid)

  This method returns currently connected HTTP(S)/FTP/SFTP servers of
  the download denoted by *gid* (string). The response is an array of
  structs and contains the following keys. Values are strings.

  ``index``
    Index of the file, starting at 1, in the same order as files appear in the
    multi-file metalink.

  ``servers``
    A list of structs which contain the following keys.

    ``uri``
      Original URI.

    ``currentUri``
      This is the URI currently used for downloading. If redirection is
      involved, currentUri and uri may differ.

    ``downloadSpeed``
      Download speed (byte/sec)

  **JSON-RPC Example**
  ::

    >>> import urllib2, json
    >>> from pprint import pprint
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'aria2.getServers',
    ...                       'params':['2089b05ecca3d829']})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> pprint(json.loads(c.read()))
    {u'id': u'qwer',
     u'jsonrpc': u'2.0',
     u'result': [{u'index': u'1',
                  u'servers': [{u'currentUri': u'http://example.org/file',
                                u'downloadSpeed': u'10467',
                                u'uri': u'http://example.org/file'}]}]}

  **XML-RPC Example**
  ::

    >>> import xmlrpclib
    >>> from pprint import pprint
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> r = s.aria2.getServers('2089b05ecca3d829')
    >>> pprint(r)
    [{'index': '1',
      'servers': [{'currentUri': 'http://example.org/dl/file',
                   'downloadSpeed': '20285',
                   'uri': 'http://example.org/file'}]}]

.. function:: aria2.tellActive([secret], [keys])

  This method returns a list of active downloads.  The response is an array of
  the same structs as returned by the :func:`aria2.tellStatus` method.
  For the *keys* parameter, please refer to the :func:`aria2.tellStatus` method.

.. function:: aria2.tellWaiting([secret], offset, num, [keys])

  This method returns a list of waiting downloads, including paused
  ones.
  *offset* is an integer and specifies the offset from
  the download waiting at the front.
  *num* is an integer and specifies the max. number of downloads to be returned.
  For the *keys* parameter, please refer to the :func:`aria2.tellStatus` method.

  If *offset* is a positive integer, this method returns downloads in the
  range of [*offset*, *offset* + *num*).

  *offset* can be a negative integer. *offset* == -1 points last
  download in the waiting queue and *offset* == -2 points the download
  before the last download, and so on. Downloads in the response are
  in reversed order then.

  For example, imagine three downloads "A","B" and "C" are waiting
  in this order. ``aria2.tellWaiting(0, 1)`` returns
  ``["A"]``. ``aria2.tellWaiting(1, 2)`` returns ``["B", "C"]``.
  ``aria2.tellWaiting(-1, 2)`` returns ``["C", "B"]``.

  The response is an array of the same structs as returned by
  :func:`aria2.tellStatus` method.

.. function:: aria2.tellStopped([secret], offset, num, [keys])

  This method returns a list of stopped downloads.
  *offset* is an integer and specifies the offset from the least recently
  stopped download.
  *num* is an integer and specifies the max. number of downloads to be returned.
  For the *keys* parameter, please refer to the :func:`aria2.tellStatus` method.

  *offset* and *num* have the same semantics as described in the
  :func:`aria2.tellWaiting` method.

  The response is an array of the same structs as returned by the
  :func:`aria2.tellStatus` method.

.. function:: aria2.changePosition([secret], gid, pos, how)

  This method changes the position of the download denoted by
  *gid* in the queue.
  *pos* is an integer.
  *how* is a string. If *how* is ``POS_SET``, it moves the download to a
  position relative to the beginning of the queue.  If *how* is ``POS_CUR``, it
  moves the download to a position relative to the current position. If *how* is
  ``POS_END``, it moves the download to a position relative to the end of the
  queue. If the destination position is less than 0 or beyond the end of
  the queue, it moves the download to the beginning or the end of the
  queue respectively. The response is an integer denoting the resulting
  position.

  For example, if GID#2089b05ecca3d829 is currently in position 3,
  ``aria2.changePosition('2089b05ecca3d829', -1, 'POS_CUR')`` will
  change its position to 2. Additionally
  ``aria2.changePosition('2089b05ecca3d829', 0, 'POS_SET')`` will
  change its position to 0 (the beginning of the queue).

  The following examples move the download GID#2089b05ecca3d829 to the
  front of the queue.

  **JSON-RPC Example**

  ::

    >>> import urllib2, json
    >>> from pprint import pprint
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'aria2.changePosition',
    ...                       'params':['2089b05ecca3d829', 0, 'POS_SET']})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> pprint(json.loads(c.read()))
    {u'id': u'qwer', u'jsonrpc': u'2.0', u'result': 0}

  **XML-RPC Example**

  ::

    >>> import xmlrpclib
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> s.aria2.changePosition('2089b05ecca3d829', 0, 'POS_SET')
    0

.. function:: aria2.changeUri([secret], gid, fileIndex, delUris, addUris[, position])

  This method removes the URIs in *delUris* from and appends the URIs in
  *addUris* to download denoted by *gid*. *delUris* and *addUris* are
  lists of strings. A download can contain multiple files and URIs are
  attached to each file.  *fileIndex* is used to select which file to
  remove/attach given URIs. *fileIndex* is 1-based. *position* is used
  to specify where URIs are inserted in the existing waiting URI
  list. *position* is 0-based. When *position* is omitted, URIs are
  appended to the back of the list.  This method first executes the removal
  and then the addition. *position* is the position after URIs are removed,
  not the position when this method is called.  When removing an URI, if
  the same URIs exist in download, only one of them is removed for each URI
  in *delUris*. In other words, if there are three URIs
  ``http://example.org/aria2`` and you want remove them all, you have to
  specify (at least) 3 ``http://example.org/aria2`` in *delUris*.  This
  method returns a list which contains two integers. The first integer is
  the number of URIs deleted. The second integer is the number of URIs
  added.

  The following examples add the URI ``http://example.org/file`` to the
  file whose index is ``1`` and belongs to the download
  GID#2089b05ecca3d829.

  **JSON-RPC Example**

  ::

    >>> import urllib2, json
    >>> from pprint import pprint
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'aria2.changeUri',
    ...                       'params':['2089b05ecca3d829', 1, [],
                                        ['http://example.org/file']]})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> pprint(json.loads(c.read()))
    {u'id': u'qwer', u'jsonrpc': u'2.0', u'result': [0, 1]}

  **XML-RPC Example**

  ::

    >>> import xmlrpclib
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> s.aria2.changeUri('2089b05ecca3d829', 1, [],
                          ['http://example.org/file'])
    [0, 1]

.. function:: aria2.getOption([secret], gid)

  This method returns options of the download denoted by *gid*.  The
  response is a struct where keys are the names of options.
  The values are strings.
  Note that this method does not return options which
  have no default value and have not been set on the command-line, in
  configuration files or RPC methods.

  The following examples get options of the download
  GID#2089b05ecca3d829.

  **JSON-RPC Example**

  ::

    >>> import urllib2, json
    >>> from pprint import pprint
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'aria2.getOption',
    ...                       'params':['2089b05ecca3d829']})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> pprint(json.loads(c.read()))
    {u'id': u'qwer',
     u'jsonrpc': u'2.0',
     u'result': {u'allow-overwrite': u'false',
                 u'allow-piece-length-change': u'false',
                 u'always-resume': u'true',
                 u'async-dns': u'true',
     ...

  **XML-RPC Example**

  ::

    >>> import xmlrpclib
    >>> from pprint import pprint
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> r = s.aria2.getOption('2089b05ecca3d829')
    >>> pprint(r)
    {'allow-overwrite': 'false',
     'allow-piece-length-change': 'false',
     'always-resume': 'true',
     'async-dns': 'true',
     ....

.. function:: aria2.changeOption([secret], gid, options)

  This method changes options of the download denoted by *gid* (string)
  dynamically.  *options* is a struct.
  The following options are available for active downloads:

  * :option:`bt-max-peers <--bt-max-peers>`
  * :option:`bt-request-peer-speed-limit <--bt-request-peer-speed-limit>`
  * :option:`bt-remove-unselected-file <--bt-remove-unselected-file>`
  * :option:`force-save <--force-save>`
  * :option:`max-download-limit <--max-download-limit>`
  * :option:`max-upload-limit <-u>`

  For waiting or paused downloads, in addition to the above options,
  options listed in `Input File`_ subsection are available,
  **except** for following options:
  :option:`dry-run <--dry-run>`,
  :option:`metalink-base-uri <--metalink-base-uri>`,
  :option:`parameterized-uri <-P>`,
  :option:`pause <--pause>`,
  :option:`piece-length <--piece-length>` and
  :option:`rpc-save-upload-metadata <--rpc-save-upload-metadata>` option.
  This method returns ``OK`` for success.

  The following examples set the :option:`max-download-limit
  <--max-download-limit>` option to ``20K`` for the download
  GID#2089b05ecca3d829.

  **JSON-RPC Example**

  ::

    >>> import urllib2, json
    >>> from pprint import pprint
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'aria2.changeOption',
    ...                       'params':['2089b05ecca3d829',
    ...                                 {'max-download-limit':'10K'}]})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> pprint(json.loads(c.read()))
    {u'id': u'qwer', u'jsonrpc': u'2.0', u'result': u'OK'}

  **XML-RPC Example**

  ::

    >>> import xmlrpclib
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> s.aria2.changeOption('2089b05ecca3d829', {'max-download-limit':'20K'})
    'OK'

.. function:: aria2.getGlobalOption([secret])

  This method returns the global options.  The response is a struct. Its keys
  are the names of options.  Values are strings.
  Note that this method does not return options which have no default
  value and have not been set on the command-line, in configuration
  files or RPC methods. Because global options are used as a template
  for the options of newly added downloads, the response contains keys
  returned by the :func:`aria2.getOption` method.

.. function:: aria2.changeGlobalOption([secret], options)

  This method changes global options dynamically.  *options* is a struct.
  The following options are available:

  * :option:`bt-max-open-files <--bt-max-open-files>`
  * :option:`download-result <--download-result>`
  * :option:`log <-l>`
  * :option:`log-level <--log-level>`
  * :option:`max-concurrent-downloads <-j>`
  * :option:`max-download-result <--max-download-result>`
  * :option:`max-overall-download-limit <--max-overall-download-limit>`
  * :option:`max-overall-upload-limit <--max-overall-upload-limit>`
  * :option:`save-cookies <--save-cookies>`
  * :option:`save-session <--save-session>`
  * :option:`server-stat-of <--server-stat-of>`

  In addition, options listed in the `Input File`_ subsection
  are available, **except** for following options:
  :option:`checksum <--checksum>`,
  :option:`index-out <-O>`,
  :option:`out <-o>`,
  :option:`pause <--pause>` and
  :option:`select-file <--select-file>`.

  With the :option:`log <-l>` option, you can dynamically start logging or
  change log file. To stop logging, specify an empty string("") as the parameter
  value. Note that log file is always opened in append mode. This method
  returns ``OK`` for success.

.. function:: aria2.getGlobalStat([secret])

  This method returns global statistics such as the overall download and
  upload speeds. The response is a struct and contains the following
  keys. Values are strings.

  ``downloadSpeed``
    Overall download speed (byte/sec).

  ``uploadSpeed``
    Overall upload speed(byte/sec).

  ``numActive``
    The number of active downloads.

  ``numWaiting``
    The number of waiting downloads.

  ``numStopped``
    The number of stopped downloads in the current session. This value
    is capped by the :option:`--max-download-result` option.

  ``numStoppedTotal``
    The number of stopped downloads in the current session and *not*
    capped by the :option:`--max-download-result` option.

  **JSON-RPC Example**
  ::

    >>> import urllib2, json
    >>> from pprint import pprint
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'aria2.getGlobalStat'})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> pprint(json.loads(c.read()))
    {u'id': u'qwer',
     u'jsonrpc': u'2.0',
     u'result': {u'downloadSpeed': u'21846',
                 u'numActive': u'2',
                 u'numStopped': u'0',
                 u'numWaiting': u'0',
                 u'uploadSpeed': u'0'}}

  **XML-RPC Example**
  ::

    >>> import xmlrpclib
    >>> from pprint import pprint
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> r = s.aria2.getGlobalStat()
    >>> pprint(r)
    {'downloadSpeed': '23136',
     'numActive': '2',
     'numStopped': '0',
     'numWaiting': '0',
     'uploadSpeed': '0'}

.. function:: aria2.purgeDownloadResult([secret])

  This method purges completed/error/removed downloads to free memory.
  This method returns ``OK``.

.. function:: aria2.removeDownloadResult([secret], gid)

  This method removes a completed/error/removed download denoted by *gid*
  from memory. This method returns ``OK`` for success.

  The following examples remove the download result of the download
  GID#2089b05ecca3d829.

  **JSON-RPC Example**

  ::

    >>> import urllib2, json
    >>> from pprint import pprint
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'aria2.removeDownloadResult',
    ...                       'params':['2089b05ecca3d829']})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> pprint(json.loads(c.read()))
    {u'id': u'qwer', u'jsonrpc': u'2.0', u'result': u'OK'}

  **XML-RPC Example**

  ::

    >>> import xmlrpclib
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> s.aria2.removeDownloadResult('2089b05ecca3d829')
    'OK'

.. function:: aria2.getVersion([secret])

  This method returns the version of aria2 and the list of enabled
  features. The response is a struct and contains following keys.

  ``version``
    Version number of aria2 as a string.

  ``enabledFeatures``
    List of enabled features. Each feature is given as a string.

  **JSON-RPC Example**
  ::

    >>> import urllib2, json
    >>> from pprint import pprint
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'aria2.getVersion'})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> pprint(json.loads(c.read()))
    {u'id': u'qwer',
     u'jsonrpc': u'2.0',
     u'result': {u'enabledFeatures': [u'Async DNS',
                                      u'BitTorrent',
                                      u'Firefox3 Cookie',
                                      u'GZip',
                                      u'HTTPS',
                                      u'Message Digest',
                                      u'Metalink',
                                      u'XML-RPC'],
                 u'version': u'1.11.0'}}

  **XML-RPC Example**
  ::

    >>> import xmlrpclib
    >>> from pprint import pprint
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> r = s.aria2.getVersion()
    >>> pprint(r)
    {'enabledFeatures': ['Async DNS',
                         'BitTorrent',
                         'Firefox3 Cookie',
                         'GZip',
                         'HTTPS',
                         'Message Digest',
                         'Metalink',
                         'XML-RPC'],
     'version': '1.11.0'}

.. function:: aria2.getSessionInfo([secret])

  This method returns session information.
  The response is a struct and contains following key.

  ``sessionId``
    Session ID, which is generated each time when aria2 is invoked.

  **JSON-RPC Example**
  ::

    >>> import urllib2, json
    >>> from pprint import pprint
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'aria2.getSessionInfo'})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> pprint(json.loads(c.read()))
    {u'id': u'qwer',
     u'jsonrpc': u'2.0',
     u'result': {u'sessionId': u'cd6a3bc6a1de28eb5bfa181e5f6b916d44af31a9'}}

  **XML-RPC Example**
  ::

    >>> import xmlrpclib
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> s.aria2.getSessionInfo()
    {'sessionId': 'cd6a3bc6a1de28eb5bfa181e5f6b916d44af31a9'}

.. function:: aria2.shutdown([secret])

  This method shuts down aria2.  This method returns ``OK``.

.. function:: aria2.forceShutdown([secret])

  This method shuts down :func:`aria2`. This method behaves like
  :func:'aria2.shutdown` without performing any actions which take time,
  such as contacting BitTorrent trackers to unregister downloads first.
  This method returns ``OK``.


.. function:: aria2.saveSession([secret])

  This method saves the current session to a file specified by the
  :option:`--save-session` option. This method returns ``OK`` if it
  succeeds.

.. function:: system.multicall(methods)

  This methods encapsulates multiple method calls in a single request.
  *methods* is an array of structs.  The structs contain two keys:
  ``methodName`` and ``params``.  ``methodName`` is the
  method name to call and ``params`` is array containing parameters to the
  method call.  This method returns an array of responses.  The elements
  will be either a one-item array containing the return value of the
  method call or a struct of fault element if an encapsulated method call
  fails.

  In the following examples, we add 2 downloads. The first one is
  ``http://example.org/file`` and the second one is ``file.torrent``.

  **JSON-RPC Example**
  ::

    >>> import urllib2, json, base64
    >>> from pprint import pprint
    >>> jsonreq = json.dumps({'jsonrpc':'2.0', 'id':'qwer',
    ...                       'method':'system.multicall',
    ...                       'params':[[{'methodName':'aria2.addUri',
    ...                                   'params':[['http://example.org']]},
    ...                                  {'methodName':'aria2.addTorrent',
    ...                                   'params':[base64.b64encode(open('file.torrent').read())]}]]})
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> pprint(json.loads(c.read()))
    {u'id': u'qwer', u'jsonrpc': u'2.0', u'result': [[u'2089b05ecca3d829'], [u'd2703803b52216d1']]}

  JSON-RPC additionally supports Batch requests as described in the
  JSON-RPC 2.0 Specification::

    >>> jsonreq = json.dumps([{'jsonrpc':'2.0', 'id':'qwer',
    ...                        'method':'aria2.addUri',
    ...                        'params':[['http://example.org']]},
    ...                       {'jsonrpc':'2.0', 'id':'asdf',
    ...                        'method':'aria2.addTorrent',
    ...                        'params':[base64.b64encode(open('file.torrent').read())]}])
    >>> c = urllib2.urlopen('http://localhost:6800/jsonrpc', jsonreq)
    >>> pprint(json.loads(c.read()))
    [{u'id': u'qwer', u'jsonrpc': u'2.0', u'result': u'2089b05ecca3d829'},
     {u'id': u'asdf', u'jsonrpc': u'2.0', u'result': u'd2703803b52216d1'}]

  **XML-RPC Example**
  ::

    >>> import xmlrpclib
    >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
    >>> mc = xmlrpclib.MultiCall(s)
    >>> mc.aria2.addUri(['http://example.org/file'])
    >>> mc.aria2.addTorrent(xmlrpclib.Binary(open('file.torrent').read()))
    >>> r = mc()
    >>> tuple(r)
    ('2089b05ecca3d829', 'd2703803b52216d1')

Error Handling
~~~~~~~~~~~~~~

Over JSON-RPC, aria2 returns a JSON object which contains an error code in
``code`` and the error message in ``message``.

Over XML-RPC, aria2 returns ``faultCode=1`` and the error message in
``faultString``.

.. _rpc_options:

Options
~~~~~~~

The same options as for :option:`--input-file <-i>` are available. See the
`Input File`_ subsection for a complete list of options.

In the option struct, the name element is the option name (without the preceding
``--``) and the value element is the argument as a string.

JSON-RPC Example
^^^^^^^^^^^^^^^^
::

  {'split':'1', 'http-proxy':'http://proxy/'}


XML-RPC Example
^^^^^^^^^^^^^^^
.. code-block:: xml

  <struct>
    <member>
      <name>split</name>
      <value><string>1</string></value>
    </member>
    <member>
      <name>http-proxy</name>
      <value><string>http://proxy/</string></value>
    </member>
  </struct>


The :option:`header <--header>` and :option:`index-out <-O>`
options are allowed multiple times on the command-line. Since the name should be
unique in a struct (many XML-RPC library implementations use a hash or dict for
struct), a single string is not enough. To overcome this limitation, you may use
an array as the value as well as a string.

JSON-RPC Example
^^^^^^^^^^^^^^^^
::

  {'header':['Accept-Language: ja', 'Accept-Charset: utf-8']}


XML-RPC Example
^^^^^^^^^^^^^^^
.. code-block:: xml

  <struct>
    <member>
      <name>header</name>
      <value>
        <array>
          <data>
            <value><string>Accept-Language: ja</string></value>
            <value><string>Accept-Charset: utf-8</string></value>
          </data>
        </array>
      </value>
    </member>
  </struct>


The following example adds a download with two options: ``dir`` and ``header``.
The ``header`` option requires two values, so it uses a list::

  >>> import xmlrpclib
  >>> s = xmlrpclib.ServerProxy('http://localhost:6800/rpc')
  >>> opts = dict(dir='/tmp',
  ...             header=['Accept-Language: ja',
  ...                     'Accept-Charset: utf-8'])
  >>> s.aria2.addUri(['http://example.org/file'], opts)
  '1'


JSON-RPC using HTTP GET
~~~~~~~~~~~~~~~~~~~~~~~

The JSON-RPC interface also supports requests via HTTP GET.
The encoding scheme in GET parameters is based on JSON-RPC over HTTP Specification [2008-1-15(RC1)].
The encoding of GET parameters are follows::

  /jsonrpc?method=METHOD_NAME&id=ID&params=BASE64_ENCODED_PARAMS


The ``method`` and ``id`` are always treated as JSON string and their
encoding must be UTF-8.

For example, The encoded string of
``aria2.tellStatus('2089b05ecca3d829')`` with ``id='foo'`` looks like
this::

  /jsonrpc?method=aria2.tellStatus&id=foo&params=WyIyMDg5YjA1ZWNjYTNkODI5Il0%3D


The ``params`` parameter is Base64-encoded JSON array which usually
appears in ``params`` attribute in JSON-RPC request object.  In the
above example, the params is ``["2089b05ecca3d829"]``, therefore::

  ["2089b05ecca3d829"] --(Base64)--> WyIyMDg5YjA1ZWNjYTNkODI5Il0=
               --(Percent Encode)--> WyIyMDg5YjA1ZWNjYTNkODI5Il0%3D


The JSON-RPC interface also supports JSONP. You can specify the callback
function in the ``jsoncallback`` parameter::

  /jsonrpc?method=aria2.tellStatus&id=foo&params=WyIyMDg5YjA1ZWNjYTNkODI5Il0%3D&jsoncallback=cb

For Batch requests, the ``method`` and ``id`` parameters must not be specified.
The whole request must be specified in the ``params`` parameter. For example,
a Batch request::

  [{'jsonrpc':'2.0', 'id':'qwer', 'method':'aria2.getVersion'},
   {'jsonrpc':'2.0', 'id':'asdf', 'method':'aria2.tellActive'}]


must be encoded like this::

  /jsonrpc?params=W3sianNvbnJwYyI6ICIyLjAiLCAiaWQiOiAicXdlciIsICJtZXRob2QiOiAiYXJpYTIuZ2V0VmVyc2lvbiJ9LCB7Impzb25ycGMiOiAiMi4wIiwgImlkIjogImFzZGYiLCAibWV0aG9kIjogImFyaWEyLnRlbGxBY3RpdmUifV0%3D


JSON-RPC over WebSocket
~~~~~~~~~~~~~~~~~~~~~~~

JSON-RPC over WebSocket uses same method signatures and response
format as JSON-RPC over HTTP. The supported WebSocket version is 13
which is detailed in :rfc:`6455`.

To send a RPC request to the RPC server, send a serialized JSON string
in a Text frame. The response from the RPC server is delivered also in
a Text frame.

Notifications
^^^^^^^^^^^^^
The RPC server might send notifications to the client. Notifications is
unidirectional, therefore the client which receives the notification must not
respond to it. The method signature of a notification is much like a normal
method request but lacks the id key. The value of the params key is the data
which this notification carries. The format of the value varies depending on the
notification method. Following notification methods are defined.


.. function:: aria2.onDownloadStart(event)

  This notification will be sent when a download is started.
  The *event* is of type struct and it contains following keys.
  The value type is string.
  
  ``gid``
    GID of the download.
  

.. function:: aria2.onDownloadPause(event)

  This notification will be sent when a download is paused.  The *event*
  is the same struct as the *event* argument of
  :func:`aria2.onDownloadStart` method.
  

.. function:: aria2.onDownloadStop(event)

  This notification will be sent when a download is stopped by the user.
  The *event* is the same struct as the *event* argument of
  :func:`aria2.onDownloadStart` method.
  

.. function:: aria2.onDownloadComplete(event)

  
  This notification will be sent when a download is complete.  For
  BitTorrent downloads, this notification is sent when the download is
  complete and seeding is over. The *event* is the same struct of the
  *event* argument of 
  :func:`aria2.onDownloadStart` method.
  

.. function:: aria2.onDownloadError(event)

  
  This notification will be sent when a download is stopped due to an error.
  The *event* is the same struct as the *event* argument of
  :func:`aria2.onDownloadStart` method.
  

.. function:: aria2.onBtDownloadComplete(event)

  
  This notification will be sent when a torrent download is complete but seeding
  is still going on.  The *event* is the same struct as the *event* argument of
  :func:`aria2.onDownloadStart` method.
  
Sample XML-RPC Client Code
~~~~~~~~~~~~~~~~~~~~~~~~~~

The following Ruby script adds ``http://localhost/aria2.tar.bz2`` to
aria2c (running on localhost) with option :option:`--dir=/downloads <-d>` and
prints the RPC response:

.. code-block:: ruby

  #!/usr/bin/env ruby
  
  require 'xmlrpc/client'
  require 'pp'
  
  client=XMLRPC::Client.new2("http://localhost:6800/rpc")
  
  options={ "dir" => "/downloads" }
  result=client.call("aria2.addUri", [ "http://localhost/aria2.tar.bz2" ], options)
  
  pp result


If you are a Python lover, you can use xmlrpclib (Python3 uses
xmlrpc.client instead) to interact with aria2::

  import xmlrpclib
  from pprint import pprint
  
  s = xmlrpclib.ServerProxy("http://localhost:6800/rpc")
  r = s.aria2.addUri(["http://localhost/aria2.tar.bz2"], {"dir":"/downloads"})
  pprint(r)

MISC
----

Console Readout
~~~~~~~~~~~~~~~

While downloading files, aria2 prints a readout to the console to show the
progress of the downloads. The console readout looks like this::

    [#2089b0 400.0KiB/33.2MiB(1%) CN:1 DL:115.7KiB ETA:4m51s]

This section describes what these numbers and strings mean.

``#NNNNNN``
  The first 6 characters of the GID as a hex string. The GID is an unique ID for
  each download, internal to aria2. The GID is particularly useful when
  interacting with aria2 using the RPC interface.

``X/Y(Z%)``
  Completed length, the total file length and its progress. If
  :option:`--select-file` is used, this is the sum of selected files.

``SEED``
  Share ratio when the aria2 is seeding a finished torrent.

``CN``
  The number of connections aria2 has established.

``SD``
  The number of seeders aria2 is connected to.

``DL``
  Download speed (bytes per second).

``UL``
  Upload speed (bytes per second) and the number of uploaded bytes.

``ETA``
  Expected time to finish the download.

When more than one download is in progress, some of the information
described above will be omitted in order to show information for several
downloads. And the overall download and upload speeds are shown at
the beginning of the line.

When aria2 is allocating file space or validating checksums, it
additionally prints the progress of these operations:

FileAlloc
  GID, already allocated length and total length in bytes.

Checksum
  GID, already validated length and total length in bytes.

EXAMPLE
-------

HTTP/FTP Segmented Downloads
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Download a file
^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c "http://host/file.zip"


.. note::

  To stop a download, press :kbd:`Ctrl-C`. You can resume the transfer by
  running aria2c with the same argument in the same directory. You can change
  URIs as long as they are pointing to the same file.

Download a file from two different HTTP servers
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c "http://host/file.zip" "http://mirror/file.zip"


Download a file from one host using multiple connections
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c -x2 -k1M "http://host/file.zip"

.. note::

  The -x option specified the number of allowed connections, while the -k option
  specified the size of chunks.


Download a file from HTTP and FTP servers at the same time
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c "http://host1/file.zip" "ftp://host2/file.zip"


Download files listed in a text file concurrently
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c -ifiles.txt -j2

.. note::

  -j option specifies the number of parallel downloads.

Using a proxy
^^^^^^^^^^^^^
For HTTP:

.. code-block:: console

  $ aria2c --http-proxy="http://proxy:8080" "http://host/file"


.. code-block:: console

  $ aria2c --http-proxy="http://proxy:8080" --no-proxy="localhost,127.0.0.1,192.168.0.0/16" "http://host/file"


For FTP:

.. code-block:: console

  $ aria2c --ftp-proxy="http://proxy:8080" "ftp://host/file"

.. note::
  
  See :option:`--http-proxy`, :option:`--https-proxy`, :option:`--ftp-proxy`,
  :option:`--all-proxy` and :option:`--no-proxy` for details.  You can specify
  proxy in the environment variables. See `ENVIRONMENT`_ section.

Using a Proxy with authorization
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c --http-proxy="http://username:password@proxy:8080" "http://host/file"

.. code-block:: console

  $ aria2c --http-proxy="http://proxy:8080" --http-proxy-user="username" --http-proxy-passwd="password" "http://host/file"


Metalink Download
~~~~~~~~~~~~~~~~~
Download files with remote Metalink
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c --follow-metalink=mem "http://host/file.metalink"


Download using a local metalink file
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c -p --lowest-speed-limit=4000 file.metalink

.. note::

  To stop a download, press :kbd:`Ctrl-C`.
  You can resume the transfer by running aria2c with the same argument in the same
  directory.

Download several local metalink files
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c -j2 file1.metalink file2.metalink


Download only selected files
^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c --select-file=1-4,8 file.metalink

.. note::

  The index is printed to the console using -S option.

Download a file using a local metalink file with user preference
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c --metalink-location=jp,us --metalink-version=1.1 --metalink-language=en-US file.metalink


BitTorrent Download
~~~~~~~~~~~~~~~~~~~
Download files using a remote BitTorrent file
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c --follow-torrent=mem "http://host/file.torrent"


Download using a local torrent file
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c --max-upload-limit=40K file.torrent

.. note::

  --max-upload-limit specifies the max of upload rate.

.. note::

  To stop a download, press :kbd:`Ctrl-C`. You can resume the transfer later by
  running aria2c with the same argument in the same directory.

Download using BitTorrent Magnet URI
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c "magnet:?xt=urn:btih:248D0A1CD08284299DE78D5C1ED359BB46717D8C&dn=aria2"


.. note::

  Don't forget to quote BitTorrent Magnet URIs which include ``&``
  characters with single(``'``) or double(``"``) quotes when specifying URIs on
  the command-line.

Download 2 torrents
^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c -j2 file1.torrent file2.torrent


Download a file via torrent and HTTP/FTP server in parallel
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c -Ttest.torrent "http://host1/file" "ftp://host2/file"

.. note::

  Downloading a multi-file torrent while also using HTTP/FTP is not supported.

Only download specific files (usually called "selected download")
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c --select-file=1-4,8 file.torrent

.. note::

  The index is printed to the console using -S option.

Download a .torrent file, but do not download the torrent
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c --follow-torrent=false "http://host/file.torrent"

Specify the output file name
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

To specify the output file name for BitTorrent downloads, you need to know
the index of file in the torrent (see :option:`--show-files <-S>`). For
example, the output looks like this::

  idx|path/length
  ===+======================
    1|dist/base-2.6.18.iso
     |99.9MiB
  ---+----------------------
    2|dist/driver-2.6.18.iso
     |169.0MiB
  ---+----------------------


To save 'dist/base-2.6.18.iso' in '/tmp/mydir/base.iso' and
'dist/driver-2.6.18.iso' in '/tmp/dir/driver.iso', use the following
command:

.. code-block:: console

  $ aria2c --dir=/tmp --index-out=1=mydir/base.iso --index-out=2=dir/driver.iso file.torrent


Change the listening ports for incoming peer connections
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c --listen-port=7000-7001,8000 file.torrent

.. note::

  Since aria2 doesn't configure firewalls or routers for port forwarding, it's
  up to you to do so manually.

Specify conditions to stop seeding after torrent downloads finish
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c --seed-time=120 --seed-ratio=1.0 file.torrent

.. note::

  In the above example, the program stops seeding after 120 minutes since
  download completed or seed ratio reaches 1.0.

Throttle upload speed
^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c --max-upload-limit=100K file.torrent

Enable IPv4 DHT
^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c --enable-dht --dht-listen-port=6881 file.torrent

.. note::

  DHT uses UDP. Since aria2 doesn't configure firewalls or routers for port
  forwarding, it's up to you to do it manually.

Enable IPv6 DHT
^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c --enable-dht6 --dht-listen-port=6881 --dht-listen-addr6=YOUR_GLOBAL_UNICAST_IPV6_ADDR

.. note::

  aria2 uses the same ports as IPv4 for IPv6.

Add and remove tracker URIs
^^^^^^^^^^^^^^^^^^^^^^^^^^^

Ignore all tracker announce URIs defined in file.torrent and use
``http://tracker1/announce`` and ``http://tracker2/announce`` instead:

.. code-block:: console

  $ aria2c --bt-exclude-tracker="*" --bt-tracker="http://tracker1/announce,http://tracker2/announce" file.torrent


More advanced HTTP features
~~~~~~~~~~~~~~~~~~~~~~~~~~~
Load cookies
^^^^^^^^^^^^
.. code-block:: console

  $ aria2c --load-cookies=cookies.txt "http://host/file.zip"

.. note::

  You can use Firefox/Mozilla/Chromium's cookie files without modification.

Resume download started by web browsers or other programs
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c -c -s2 "http://host/partiallydownloadedfile.zip"

.. note::

  This will only work when the initial download was not multi-segmented.

Client certificate authorization for SSL/TLS
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Specify a PKCS12 file as follows:

.. code-block:: console

  $ aria2c --certificate=/path/to/mycert.p12

.. note::

  The file specified in :option:`--certificate` must be contain one PKCS12 encoded
  certificate and key. The password must be blank.

Alternatively, if PEM files are supported, use a command like the following:

.. code-block:: console

  $ aria2c --certificate=/path/to/mycert.pem --private-key=/path/to/mykey.pem https://host/file

.. note::

  The file specified in :option:`--private-key` must be decrypted. The behavior when
  encrypted one is given is undefined.

Verify SSL/TLS servers using given CA certificates
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c --ca-certificate=/path/to/ca-certificates.crt --check-certificate https://host/file

.. note::

  This option is only available when aria2 was compiled against GnuTLS or
  OpenSSL.
  WinTLS and AppleTLS will always use the system certificate store. Instead of
  ```--ca-certificate`` install the certificate in that store.

RPC
~~~

Encrypt RPC traffic with SSL/TLS
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Specify a server PKC12 file:

.. code-block:: console

  $ aria2c --enable-rpc --rpc-certificate=/path/to/server.p12 --rpc-secure

.. note::

  The file specified in :option:`--rpc-certificate` must be contain one PKCS12
  encoded certificate and key. The password must be blank.

Alternatively, when PEM files are supported (GnuTLS and OpenSSL), specify the
server certificate file and private key file as follows:

.. code-block:: console

  $ aria2c --enable-rpc --rpc-certificate=/path/to/server.crt --rpc-private-key=/path/to/server.key --rpc-secure

And more advanced features
~~~~~~~~~~~~~~~~~~~~~~~~~~
Throttle the download speed
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Per-download:

.. code-block:: console

  $ aria2c --max-download-limit=100K file.metalink

Overall:

.. code-block:: console

  $ aria2c --max-overall-download-limit=100K file.metalink


Repair a damaged download
^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c -V file.metalink

.. note::
  
  Repairing damaged downloads can be done efficiently when used with
  BitTorrent or Metalink with chunk checksums.

Drop connections if download speed is lower than a specified limit
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c --lowest-speed-limit=10K file.metalink


Parameterized URI support
^^^^^^^^^^^^^^^^^^^^^^^^^
You can specify set of parts:

.. code-block:: console

  $ aria2c -P "http://{host1,host2,host3}/file.iso"


You can specify numeric sequence:

.. code-block:: console

  $ aria2c -Z -P "http://host/image[000-100].png"


.. note::

  The -Z option is required if the URIs don't point to the same file, such as in
  the above example.

You can specify step counter:

.. code-block:: console

  $ aria2c -Z -P "http://host/image[A-Z:2].png"


Verifying checksums
^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c --checksum=sha-1=0192ba11326fe2298c8cb4de616f4d4140213837 http://example.org/file


Parallel downloads of an arbitrary number of URIs, metalink, torrent
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
.. code-block:: console

  $ aria2c -j3 -Z "http://host/file1" file2.torrent file3.metalink


BitTorrent Encryption
^^^^^^^^^^^^^^^^^^^^^
Encrypt the whole payload using ARC4 (obfuscation):

.. code-block:: console

  $ aria2c --bt-min-crypto-level=arc4 --bt-require-crypto=true file.torrent


SEE ALSO
--------
Project Web Site: http://aria2.sourceforge.net/

Metalink Homepage: http://www.metalinker.org/

The Metalink Download Description Format: :rfc:`5854`

COPYRIGHT
---------
Copyright (C) 2006, 2014 Tatsuhiro Tsujikawa

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

In addition, as a special exception, the copyright holders give
permission to link the code of portions of this program with the
OpenSSL library under certain conditions as described in each
individual source file, and distribute linked combinations
including the two.
You must obey the GNU General Public License in all respects
for all of the code used other than OpenSSL.  If you modify
file(s) with this exception, you may extend this exception to your
version of the file(s), but you are not obligated to do so.  If you
do not wish to do so, delete this exception statement from your
version.  If you delete this exception statement from all source
files in the program, then also delete it here.