(root)/
Python-3.12.0/
Lib/
test/
test_pty.py
       1  from test.support import verbose, reap_children
       2  from test.support.import_helper import import_module
       3  
       4  # Skip these tests if termios or fcntl are not available
       5  import_module('termios')
       6  # fcntl is a proxy for not being one of the wasm32 platforms even though we
       7  # don't use this module... a proper check for what crashes those is needed.
       8  import_module("fcntl")
       9  
      10  import errno
      11  import os
      12  import pty
      13  import tty
      14  import sys
      15  import select
      16  import signal
      17  import socket
      18  import io # readline
      19  import unittest
      20  import warnings
      21  
      22  TEST_STRING_1 = b"I wish to buy a fish license.\n"
      23  TEST_STRING_2 = b"For my pet fish, Eric.\n"
      24  
      25  _HAVE_WINSZ = hasattr(tty, "TIOCGWINSZ") and hasattr(tty, "TIOCSWINSZ")
      26  
      27  if verbose:
      28      def debug(msg):
      29          print(msg)
      30  else:
      31      def debug(msg):
      32          pass
      33  
      34  
      35  # Note that os.read() is nondeterministic so we need to be very careful
      36  # to make the test suite deterministic.  A normal call to os.read() may
      37  # give us less than expected.
      38  #
      39  # Beware, on my Linux system, if I put 'foo\n' into a terminal fd, I get
      40  # back 'foo\r\n' at the other end.  The behavior depends on the termios
      41  # setting.  The newline translation may be OS-specific.  To make the
      42  # test suite deterministic and OS-independent, the functions _readline
      43  # and normalize_output can be used.
      44  
      45  def normalize_output(data):
      46      # Some operating systems do conversions on newline.  We could possibly fix
      47      # that by doing the appropriate termios.tcsetattr()s.  I couldn't figure out
      48      # the right combo on Tru64.  So, just normalize the output and doc the
      49      # problem O/Ses by allowing certain combinations for some platforms, but
      50      # avoid allowing other differences (like extra whitespace, trailing garbage,
      51      # etc.)
      52  
      53      # This is about the best we can do without getting some feedback
      54      # from someone more knowledgable.
      55  
      56      # OSF/1 (Tru64) apparently turns \n into \r\r\n.
      57      if data.endswith(b'\r\r\n'):
      58          return data.replace(b'\r\r\n', b'\n')
      59  
      60      if data.endswith(b'\r\n'):
      61          return data.replace(b'\r\n', b'\n')
      62  
      63      return data
      64  
      65  def _readline(fd):
      66      """Read one line.  May block forever if no newline is read."""
      67      reader = io.FileIO(fd, mode='rb', closefd=False)
      68      return reader.readline()
      69  
      70  def expectedFailureIfStdinIsTTY(fun):
      71      # avoid isatty()
      72      try:
      73          tty.tcgetattr(pty.STDIN_FILENO)
      74          return unittest.expectedFailure(fun)
      75      except tty.error:
      76          pass
      77      return fun
      78  
      79  # Marginal testing of pty suite. Cannot do extensive 'do or fail' testing
      80  # because pty code is not too portable.
      81  class ESC[4;38;5;81mPtyTest(ESC[4;38;5;149munittestESC[4;38;5;149m.ESC[4;38;5;149mTestCase):
      82      def setUp(self):
      83          old_alarm = signal.signal(signal.SIGALRM, self.handle_sig)
      84          self.addCleanup(signal.signal, signal.SIGALRM, old_alarm)
      85  
      86          old_sighup = signal.signal(signal.SIGHUP, self.handle_sighup)
      87          self.addCleanup(signal.signal, signal.SIGHUP, old_sighup)
      88  
      89          # isatty() and close() can hang on some platforms. Set an alarm
      90          # before running the test to make sure we don't hang forever.
      91          self.addCleanup(signal.alarm, 0)
      92          signal.alarm(10)
      93  
      94          # Save original stdin window size.
      95          self.stdin_dim = None
      96          if _HAVE_WINSZ:
      97              try:
      98                  self.stdin_dim = tty.tcgetwinsize(pty.STDIN_FILENO)
      99                  self.addCleanup(tty.tcsetwinsize, pty.STDIN_FILENO,
     100                                  self.stdin_dim)
     101              except tty.error:
     102                  pass
     103  
     104      def handle_sig(self, sig, frame):
     105          self.fail("isatty hung")
     106  
     107      @staticmethod
     108      def handle_sighup(signum, frame):
     109          pass
     110  
     111      @expectedFailureIfStdinIsTTY
     112      def test_openpty(self):
     113          try:
     114              mode = tty.tcgetattr(pty.STDIN_FILENO)
     115          except tty.error:
     116              # Not a tty or bad/closed fd.
     117              debug("tty.tcgetattr(pty.STDIN_FILENO) failed")
     118              mode = None
     119  
     120          new_dim = None
     121          if self.stdin_dim:
     122              try:
     123                  # Modify pty.STDIN_FILENO window size; we need to
     124                  # check if pty.openpty() is able to set pty slave
     125                  # window size accordingly.
     126                  debug("Setting pty.STDIN_FILENO window size.")
     127                  debug(f"original size: (row, col) = {self.stdin_dim}")
     128                  target_dim = (self.stdin_dim[0] + 1, self.stdin_dim[1] + 1)
     129                  debug(f"target size: (row, col) = {target_dim}")
     130                  tty.tcsetwinsize(pty.STDIN_FILENO, target_dim)
     131  
     132                  # Were we able to set the window size
     133                  # of pty.STDIN_FILENO successfully?
     134                  new_dim = tty.tcgetwinsize(pty.STDIN_FILENO)
     135                  self.assertEqual(new_dim, target_dim,
     136                                   "pty.STDIN_FILENO window size unchanged")
     137              except OSError:
     138                  warnings.warn("Failed to set pty.STDIN_FILENO window size.")
     139                  pass
     140  
     141          try:
     142              debug("Calling pty.openpty()")
     143              try:
     144                  master_fd, slave_fd, slave_name = pty.openpty(mode, new_dim,
     145                                                                True)
     146              except TypeError:
     147                  master_fd, slave_fd = pty.openpty()
     148                  slave_name = None
     149              debug(f"Got {master_fd=}, {slave_fd=}, {slave_name=}")
     150          except OSError:
     151              # " An optional feature could not be imported " ... ?
     152              raise unittest.SkipTest("Pseudo-terminals (seemingly) not functional.")
     153  
     154          # closing master_fd can raise a SIGHUP if the process is
     155          # the session leader: we installed a SIGHUP signal handler
     156          # to ignore this signal.
     157          self.addCleanup(os.close, master_fd)
     158          self.addCleanup(os.close, slave_fd)
     159  
     160          self.assertTrue(os.isatty(slave_fd), "slave_fd is not a tty")
     161  
     162          if mode:
     163              self.assertEqual(tty.tcgetattr(slave_fd), mode,
     164                               "openpty() failed to set slave termios")
     165          if new_dim:
     166              self.assertEqual(tty.tcgetwinsize(slave_fd), new_dim,
     167                               "openpty() failed to set slave window size")
     168  
     169          # Ensure the fd is non-blocking in case there's nothing to read.
     170          blocking = os.get_blocking(master_fd)
     171          try:
     172              os.set_blocking(master_fd, False)
     173              try:
     174                  s1 = os.read(master_fd, 1024)
     175                  self.assertEqual(b'', s1)
     176              except OSError as e:
     177                  if e.errno != errno.EAGAIN:
     178                      raise
     179          finally:
     180              # Restore the original flags.
     181              os.set_blocking(master_fd, blocking)
     182  
     183          debug("Writing to slave_fd")
     184          os.write(slave_fd, TEST_STRING_1)
     185          s1 = _readline(master_fd)
     186          self.assertEqual(b'I wish to buy a fish license.\n',
     187                           normalize_output(s1))
     188  
     189          debug("Writing chunked output")
     190          os.write(slave_fd, TEST_STRING_2[:5])
     191          os.write(slave_fd, TEST_STRING_2[5:])
     192          s2 = _readline(master_fd)
     193          self.assertEqual(b'For my pet fish, Eric.\n', normalize_output(s2))
     194  
     195      def test_fork(self):
     196          debug("calling pty.fork()")
     197          pid, master_fd = pty.fork()
     198          self.addCleanup(os.close, master_fd)
     199          if pid == pty.CHILD:
     200              # stdout should be connected to a tty.
     201              if not os.isatty(1):
     202                  debug("Child's fd 1 is not a tty?!")
     203                  os._exit(3)
     204  
     205              # After pty.fork(), the child should already be a session leader.
     206              # (on those systems that have that concept.)
     207              debug("In child, calling os.setsid()")
     208              try:
     209                  os.setsid()
     210              except OSError:
     211                  # Good, we already were session leader
     212                  debug("Good: OSError was raised.")
     213                  pass
     214              except AttributeError:
     215                  # Have pty, but not setsid()?
     216                  debug("No setsid() available?")
     217                  pass
     218              except:
     219                  # We don't want this error to propagate, escaping the call to
     220                  # os._exit() and causing very peculiar behavior in the calling
     221                  # regrtest.py !
     222                  # Note: could add traceback printing here.
     223                  debug("An unexpected error was raised.")
     224                  os._exit(1)
     225              else:
     226                  debug("os.setsid() succeeded! (bad!)")
     227                  os._exit(2)
     228              os._exit(4)
     229          else:
     230              debug("Waiting for child (%d) to finish." % pid)
     231              # In verbose mode, we have to consume the debug output from the
     232              # child or the child will block, causing this test to hang in the
     233              # parent's waitpid() call.  The child blocks after a
     234              # platform-dependent amount of data is written to its fd.  On
     235              # Linux 2.6, it's 4000 bytes and the child won't block, but on OS
     236              # X even the small writes in the child above will block it.  Also
     237              # on Linux, the read() will raise an OSError (input/output error)
     238              # when it tries to read past the end of the buffer but the child's
     239              # already exited, so catch and discard those exceptions.  It's not
     240              # worth checking for EIO.
     241              while True:
     242                  try:
     243                      data = os.read(master_fd, 80)
     244                  except OSError:
     245                      break
     246                  if not data:
     247                      break
     248                  sys.stdout.write(str(data.replace(b'\r\n', b'\n'),
     249                                       encoding='ascii'))
     250  
     251              ##line = os.read(master_fd, 80)
     252              ##lines = line.replace('\r\n', '\n').split('\n')
     253              ##if False and lines != ['In child, calling os.setsid()',
     254              ##             'Good: OSError was raised.', '']:
     255              ##    raise TestFailed("Unexpected output from child: %r" % line)
     256  
     257              (pid, status) = os.waitpid(pid, 0)
     258              res = os.waitstatus_to_exitcode(status)
     259              debug("Child (%d) exited with code %d (status %d)." % (pid, res, status))
     260              if res == 1:
     261                  self.fail("Child raised an unexpected exception in os.setsid()")
     262              elif res == 2:
     263                  self.fail("pty.fork() failed to make child a session leader.")
     264              elif res == 3:
     265                  self.fail("Child spawned by pty.fork() did not have a tty as stdout")
     266              elif res != 4:
     267                  self.fail("pty.fork() failed for unknown reasons.")
     268  
     269              ##debug("Reading from master_fd now that the child has exited")
     270              ##try:
     271              ##    s1 = os.read(master_fd, 1024)
     272              ##except OSError:
     273              ##    pass
     274              ##else:
     275              ##    raise TestFailed("Read from master_fd did not raise exception")
     276  
     277      def test_master_read(self):
     278          # XXX(nnorwitz):  this test leaks fds when there is an error.
     279          debug("Calling pty.openpty()")
     280          master_fd, slave_fd = pty.openpty()
     281          debug(f"Got master_fd '{master_fd}', slave_fd '{slave_fd}'")
     282  
     283          self.addCleanup(os.close, master_fd)
     284  
     285          debug("Closing slave_fd")
     286          os.close(slave_fd)
     287  
     288          debug("Reading from master_fd")
     289          try:
     290              data = os.read(master_fd, 1)
     291          except OSError: # Linux
     292              data = b""
     293  
     294          self.assertEqual(data, b"")
     295  
     296      def test_spawn_doesnt_hang(self):
     297          pty.spawn([sys.executable, '-c', 'print("hi there")'])
     298  
     299  class ESC[4;38;5;81mSmallPtyTests(ESC[4;38;5;149munittestESC[4;38;5;149m.ESC[4;38;5;149mTestCase):
     300      """These tests don't spawn children or hang."""
     301  
     302      def setUp(self):
     303          self.orig_stdin_fileno = pty.STDIN_FILENO
     304          self.orig_stdout_fileno = pty.STDOUT_FILENO
     305          self.orig_pty_close = pty.close
     306          self.orig_pty__copy = pty._copy
     307          self.orig_pty_fork = pty.fork
     308          self.orig_pty_select = pty.select
     309          self.orig_pty_setraw = pty.setraw
     310          self.orig_pty_tcgetattr = pty.tcgetattr
     311          self.orig_pty_tcsetattr = pty.tcsetattr
     312          self.orig_pty_waitpid = pty.waitpid
     313          self.fds = []  # A list of file descriptors to close.
     314          self.files = []
     315          self.select_input = []
     316          self.select_output = []
     317          self.tcsetattr_mode_setting = None
     318  
     319      def tearDown(self):
     320          pty.STDIN_FILENO = self.orig_stdin_fileno
     321          pty.STDOUT_FILENO = self.orig_stdout_fileno
     322          pty.close = self.orig_pty_close
     323          pty._copy = self.orig_pty__copy
     324          pty.fork = self.orig_pty_fork
     325          pty.select = self.orig_pty_select
     326          pty.setraw = self.orig_pty_setraw
     327          pty.tcgetattr = self.orig_pty_tcgetattr
     328          pty.tcsetattr = self.orig_pty_tcsetattr
     329          pty.waitpid = self.orig_pty_waitpid
     330          for file in self.files:
     331              try:
     332                  file.close()
     333              except OSError:
     334                  pass
     335          for fd in self.fds:
     336              try:
     337                  os.close(fd)
     338              except OSError:
     339                  pass
     340  
     341      def _pipe(self):
     342          pipe_fds = os.pipe()
     343          self.fds.extend(pipe_fds)
     344          return pipe_fds
     345  
     346      def _socketpair(self):
     347          socketpair = socket.socketpair()
     348          self.files.extend(socketpair)
     349          return socketpair
     350  
     351      def _mock_select(self, rfds, wfds, xfds):
     352          # This will raise IndexError when no more expected calls exist.
     353          self.assertEqual((rfds, wfds, xfds), self.select_input.pop(0))
     354          return self.select_output.pop(0)
     355  
     356      def _make_mock_fork(self, pid):
     357          def mock_fork():
     358              return (pid, 12)
     359          return mock_fork
     360  
     361      def _mock_tcsetattr(self, fileno, opt, mode):
     362          self.tcsetattr_mode_setting = mode
     363  
     364      def test__copy_to_each(self):
     365          """Test the normal data case on both master_fd and stdin."""
     366          read_from_stdout_fd, mock_stdout_fd = self._pipe()
     367          pty.STDOUT_FILENO = mock_stdout_fd
     368          mock_stdin_fd, write_to_stdin_fd = self._pipe()
     369          pty.STDIN_FILENO = mock_stdin_fd
     370          socketpair = self._socketpair()
     371          masters = [s.fileno() for s in socketpair]
     372  
     373          # Feed data.  Smaller than PIPEBUF.  These writes will not block.
     374          os.write(masters[1], b'from master')
     375          os.write(write_to_stdin_fd, b'from stdin')
     376  
     377          # Expect three select calls, the last one will cause IndexError
     378          pty.select = self._mock_select
     379          self.select_input.append(([mock_stdin_fd, masters[0]], [], []))
     380          self.select_output.append(([mock_stdin_fd, masters[0]], [], []))
     381          self.select_input.append(([mock_stdin_fd, masters[0]], [mock_stdout_fd, masters[0]], []))
     382          self.select_output.append(([], [mock_stdout_fd, masters[0]], []))
     383          self.select_input.append(([mock_stdin_fd, masters[0]], [], []))
     384  
     385          with self.assertRaises(IndexError):
     386              pty._copy(masters[0])
     387  
     388          # Test that the right data went to the right places.
     389          rfds = select.select([read_from_stdout_fd, masters[1]], [], [], 0)[0]
     390          self.assertEqual([read_from_stdout_fd, masters[1]], rfds)
     391          self.assertEqual(os.read(read_from_stdout_fd, 20), b'from master')
     392          self.assertEqual(os.read(masters[1], 20), b'from stdin')
     393  
     394      def test__restore_tty_mode_normal_return(self):
     395          """Test that spawn resets the tty mode no when _copy returns normally."""
     396  
     397          # PID 1 is returned from mocked fork to run the parent branch
     398          # of code
     399          pty.fork = self._make_mock_fork(1)
     400  
     401          status_sentinel = object()
     402          pty.waitpid = lambda _1, _2: [None, status_sentinel]
     403          pty.close = lambda _: None
     404  
     405          pty._copy = lambda _1, _2, _3: None
     406  
     407          mode_sentinel = object()
     408          pty.tcgetattr = lambda fd: mode_sentinel
     409          pty.tcsetattr = self._mock_tcsetattr
     410          pty.setraw = lambda _: None
     411  
     412          self.assertEqual(pty.spawn([]), status_sentinel, "pty.waitpid process status not returned by pty.spawn")
     413          self.assertEqual(self.tcsetattr_mode_setting, mode_sentinel, "pty.tcsetattr not called with original mode value")
     414  
     415  
     416  def tearDownModule():
     417      reap_children()
     418  
     419  
     420  if __name__ == "__main__":
     421      unittest.main()