--recv 886DDD89 && gpg --export A3C4F0F979CAA22CDBA8F512EE8CBC9E886DDD89 | sudo apt-key add - && sudo aptitude update && sudo aptitude install tor tor-geoipdb polipo http://stackoverflow.com/questions/8...e-command-line Quote: The tee command is called as the superuser via sudo and the -a argument tells tee to append to the file instead of overwriting it. Your original