Transmission

The default BitTorrent client of Ubuntu Desktop, Transmission, has a command line interface (which is not installed by default, the package is transmission-daemon). The daemon can be setup so that it may be interacted with through the terminal and through a web interface.

Transmission is a good bittorrent client because:

• It's lightweight with either interface.


• It's stable, never had it crashing.


• It's easy to understand.


• It has function expected of a modern bittorrent client, e.g. local peer discovery, full encryption, and support for DHT, µTP, PEX and magnet links.

For more info on its features, see this page.

rTorrent

I have written a detailed tutorial about rTorrent, including its installation and configuration. Check it out here or see the official user guide.

rTorrent's pros

• lightweight


• ultra-fast downloading speed


• very effective BitTorrent traffic encryption


• supported by all the private trackers


• very customizable

rTorrent's cons

• might be difficult to set up (configuration file, no GUI), example config file for beginners

Deluge

Deluge is a fully featured, yet lightweight torrent client that is written in Python and utilises libtorrent(rasterbar) C++ library at its core.

• Standalone or Thinclient mode (split core/ui) to enable connecting to daemon (deluged) running remotely or in the background.


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  Multiple user-interfaces, supports access from most platforms:

  
  
  
  
  
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    GTK UI

    
    
    

    
    

    
    
  
  
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    Web UI

    
    
    

    

    
    
  
  
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    Console UI

    
    
    

    

    
    
  
  
  
  



• Many Plugins and application extensions



• Supports all the usual bittorrent client functions: DHT, LPD, PEX, UPNP, Encryption, Proxy, etc.

aria2c

A CLI downloader supporting HTTP, FTP, and Torrents.

To download a torrent:

aria2c file.torrent

You can also point it to a remote torrent file http://some web site here.com/file.torrent so you don't need to download the torrent file first.

Also note you can disable file allocation with this flag: --file-allocation=none.

Aria2c also supports parallel downloading on HTTP. Use the -j flag to determine how many threads. For 3 concurrent downloads of a single HTTP file see the following example:

aria2c -j 3 website.com/file.rar

Azureus

Azureus/Vuse also has a console mode. [disclaimer] I was one of the developers.

To use azureus in console mode, you will need to download a couple of additional libraries from http://svn.vuze.com/public/client/trunk/uis/lib/

• commons-cli.jar


• log4j.jar

If you place these in same the directory as the Vuze jar, you can launch the console ui by running:

java -jar Vuze-xxxx.jar --ui=console

Inside the CLI, type help to view the commands. A couple of useful commands are:

• show torrents


• add [url]


• start [x]


• stop [x]


• remove [x]

Here is example output from a 'show torrents' command

show torrents

> -----

 1 [>] 025.6%   Azureus4.7.0.0.jar (13.26 MB) ETA: 1m 41s

                Speed: 295.1 kB/s / 0 B/s       Amount: 3.56 MB / 0 B   Connections: 11(20) / 0(4)



Total Speed (down/up): 296.6 kB/s / 2.2 kB/s

Transferred Volume (down/up/discarded): 3.56 MB / 0 B / 0 B

Total Connected Peers (seeds/peers): 11 / 0

> -----

Take a look at http://wiki.vuze.com/w/Console_UI for more information :-)

I use it all the time :

sudo apt-get install bittornado

To download torrents :

btdownloadcurses --max_uploads 4 --max_upload_rate 32 to_be_downloaded.torrent

ctorrent

There is a similar question on stackoverflow.com.

The accepted answer there is CTorrent so I thought I should mention it here. The description of ctorrent from packages.debian.org is as follows:

This application is written in the C++ language and doesn't require
any graphical component, such as an X server. Original ctorrent's
upstream has stopped its development and now it's kept updated with
new releases/bug fixes by a new developer. It's built as a console
program and it can be even used remotely in a machine that provides
outside ssh access.

For more info you can visit following sites:
http://packages.debian.org/sid/ctorrent
http://sourceforge.net/projects/ctorrent/

there is also an enhanced version of ctorrent which can be found at http://sourceforge.net/projects/dtorrent/

Try utorrent linux alpha version. Its a headless server which can be controlled from your browser (web UI). http://www.utorrent.com/downloads/linux.

I use tget which is (in the author's words) "wget for torrents". It allows you do download using torrent files or magnet links. It is a node.js application.

tget 'magnet:?xt=urn:btih:0403fb4728bd788fbcb67e87d6feb241ef38c75a'

To install:

npm install -g t-get

I know it's an old question, but nobody mentioned peerflix.

Written in JavaScript, works great, super simple to use, has a nice, informative and colored interface.

Most importantly, it supports streaming of video and audio content through VLC (just launch it with the flag --vlc).