Transmission, a CLI torrent manager

At home, I have a scrawny HTPC called chimp in my living room connected to the TV —as I don’t own a Smart TV for good reasons—. Even though I have a NAS in the network capable of serving media, I connected a dedicated external disk directly to chimp because my stock router is not the fastest around. Whenever I use the HTPC, I use it remotely from either my desktop, bonobo, or my laptop, simian. Sometimes I need to fetch torrents and download them to the disk connected to the HTPC. Enter Transmission. Transmission is a somewhat popular BitTorrent client that includes a ‘hidden’ command line interface which is very, very useful and simple to use. Learn to use it and you will probably never want to open a GUI torrent client ever again.

This post describes how to set up an use transmission in a remote setup.

First, install it. You know how. Once installed, you will want to have a look at two CLI utilities, transmission-daemon and transmission-remote. The former starts transmission in the background as a daemon. The latter is used to control the daemon: add torrents, remove them, query the state, etc.

Usually, you will want to configure at least the default download location, as well as some speed limits, before starting adding torrents. Check man for the options at your disposal regarding transmission-daemon. At the very least, change the default download directory:

transmission-daemon --download-dir "/path/to/my/downloads"

You can output a JSON listing of all settings with the following command.

$  transmission-daemon --dump-settings
{
    "alt-speed-down": 50,
    "alt-speed-enabled": false,
    "alt-speed-time-begin": 540,
    "alt-speed-time-day": 127,
    "alt-speed-time-enabled": false,
    "alt-speed-time-end": 1020,
    "alt-speed-up": 50,
    "bind-address-ipv4": "0.0.0.0",
    "bind-address-ipv6": "::",
    [...]
    "start-added-torrents": true,
    "trash-original-torrent-files": false,
    "umask": 18,
    "upload-slots-per-torrent": 14,
    "utp-enabled": true
}

Start the daemon by just calling the program with no arguments. Then, you can start adding torrents:

transmission-remote -a "magnet link or torrent file URL"

You can either use magnet links, or the URL of the torrent file directly. Both work.

Then, check the status of your downloads list with:

$  transmission-remote -l 
    ID   Done       Have  ETA           Up    Down  Ratio  Status       Name
     1*  100%    2.26 GB  Done         0.0     0.0    0.0  Stopped      This is an open movie
     3*  100%    1.99 GB  Done         0.0     0.0    0.0  Stopped      Arch Linux x86_64 ISO
     4*  100%   996.9 MB  Done         0.0     0.0    0.0  Stopped      Virtual Box OpenSUSE image
     5*  100%    2.52 GB  Done         0.0     0.0    0.0  Stopped      Manjaro Architect x86_64

Use watch to update the listing automatically every x seconds.

watch -n 3 "transmission-remote -l"

If you made a mistake and need to remove a torrent, note down the ID in the list above and then pass it on to the following command.

transmission-remote -t ID -r

Of course, there are plenty of other options. Use -h to learn about them.

As a final tip, I personally find typing transmission-remote every time far too long. I have aliased it to tr, with an extra tra and trl for adding an listing:

alias tr='transmission-remote'
alias tra='transmission-remote -a'
alias trl='transmission-remote -l'