Can't Find MacPorts (installed on OS 10.8.5
For run MacPort you have to write sudo /opt/local/bin/port in your Terminal window.

Alias in .zshrc :

alias port='sudo /opt/local/bin/port'


However, a .torrent file can be open with uTorrent or Transmission without using MacPorts. 

.torrent files explained : http://en.wikipedia.org/wiki/Torrent_file