>Perhaps this isn't as neat as you'd like, but you can do something like ...
>
>   system("...").each do |line|
>       # Do something with the each line
>   end

There shouldn't be any .each here, just system("...") will do it. The
command gets executed in a subshell and prints its output to stdout. 

If you want to process the output before printing it you need popen
(see Dave Thomas's post).

// Niklas