new_contents: """
  Test that 'stty -a' displays the same output before and after running the lldb command.
  """
  
  import os
  import unittest2
  import lldb
  import pexpect
  from lldbtest import *
  
  class CommandLineCompletionTestCase(TestBase):
  
      mydir = os.path.join("functionalities", "completion")
  
      @classmethod
      def classCleanup(cls):
          """Cleanup the test byproducts."""
          system(["/bin/sh", "-c", "rm -f child_send1.txt"])
          system(["/bin/sh", "-c", "rm -f child_read1.txt"])
          system(["/bin/sh", "-c", "rm -f child_send2.txt"])
          system(["/bin/sh", "-c", "rm -f child_read2.txt"])
  
      def test_stty_dash_a_before_and_afetr_invoking_lldb_command(self):
          """Test that 'stty -a' displays the same output before and after running the lldb command."""
  
          # The expect prompt.
          expect_prompt = "expect.*> "
          # The default lldb prompt.
          lldb_prompt = "(lldb) "
  
          # So that the child gets torn down after the test.
          self.child = pexpect.spawn('expect')
          child = self.child
  
          child.expect(expect_prompt)
          child.setecho(True)
          if self.TraceOn():
              child.logfile = sys.stdout
  
          # Turn on loggings for input/output to/from the child.
          with open('child_send1.txt', 'w') as f_send1:
              with open('child_read1.txt', 'w') as f_read1:
                  child.logfile_send = f_send1
                  child.logfile_read = f_read1
  
                  child.sendline('stty -a')
                  child.expect(expect_prompt)
  
          # Now that the stage1 logging is done, restore logfile to None to
          # stop further logging.
          child.logfile_send = None
          child.logfile_read = None
  
          # Invoke the lldb command.
          child.sendline('%s %s' % (self.lldbHere, self.lldbOption))
          child.expect_exact(lldb_prompt)
  
          # Immediately quit.
          child.sendline('quit')
          child.expect(expect_prompt)
  
          with open('child_send2.txt', 'w') as f_send2:
              with open('child_read2.txt', 'w') as f_read2:
                  child.logfile_send = f_send2
                  child.logfile_read = f_read2
  
                  child.sendline('stty -a')
                  child.expect(expect_prompt)
  
                  child.sendline('exit')
  
          # Now that the stage2 logging is done, restore logfile to None to
          # stop further logging.
          child.logfile_send = None
          child.logfile_read = None
          
          with open('child_send1.txt', 'r') as fs:
              if self.TraceOn():
                  print "\n\nContents of child_send1.txt:"
                  print fs.read()
          with open('child_read1.txt', 'r') as fr:
              from_child1 = fr.read()
              if self.TraceOn():
                  print "\n\nContents of child_read1.txt:"
                  print from_child1
  
          with open('child_send2.txt', 'r') as fs:
              if self.TraceOn():
                  print "\n\nContents of child_send2.txt:"
                  print fs.read()
          with open('child_read2.txt', 'r') as fr:
              from_child2 = fr.read()
              if self.TraceOn():
                  print "\n\nContents of child_read2.txt:"
                  print from_child2
  
          stty_output1_lines = from_child1.splitlines()
          stty_output2_lines = from_child2.splitlines()
          zipped = zip(stty_output1_lines, stty_output2_lines)
          for tuple in zipped:
              if self.TraceOn():
                  print "tuple->%s" % str(tuple)
              # Every line should compare equal until the first blank line.
              if len(tuple[0]) == 0:
                  break
              self.assertTrue(tuple[0] == tuple[1])
  
  
  if __name__ == '__main__':
      import atexit
      lldb.SBDebugger.Initialize()
      atexit.register(lambda: lldb.SBDebugger.Terminate())
      unittest2.main()
  
subject: Add a case to test that 'stty -a' displays the same output before and after running the lldb command.