intent: pass a string into subprocess.Popen
rewritten_intent: set the stdin of the process 'grep f' to be 'one\ntwo\nthree\nfour\nfive\nsix\n'
snippet: p = subprocess.Popen(['grep', 'f'], stdout=subprocess.PIPE, stdin=subprocess.PIPE)
  p.stdin.write('one\ntwo\nthree\nfour\nfive\nsix\n')
  p.communicate()[0]
  p.stdin.close()