command-line tool for a single download of a torrent (like wget or curl)

I'm interested in a single command that would download the contents of a torrent (and perhaps participate as a seed following the download, until I stop it). Usually, there is a torrent-client daemon which should be started separately beforehand, and a client to control (like transmission-remote). But I'm looking for the simplicity of wget or curl: give one command, get the result after a while.