gistfile1.rb

#!/usr/bin/env ruby

require 'open3'

module TestingStuff
  # return Process::Status, stream through STDOUT and STDERR
  def self.exec(cmd, bytes=1024)
    Open3.popen3(cmd) { |sin, sout, serr, thr|
      sin.close_write
      while !sout.eof or !serr.eof
        ready = IO.select [sout, serr]
        if ready
          ready[0].each { |f| # ready for reading
            begin
              (f == sout ? $stdout : $stderr).print f.read_nonblock(bytes)
            rescue EOFError => e
              # ok
            end
          }
        end
      end
      thr.value # Process::Status
    }
  end
end

cmd = ARGV.shift || raise("please provide a quoted command")

status = TestingStuff.exec(cmd)

puts "DONE: #{status}"