gh-85984: Add POSIX pseudo-terminal functions.

Doc/conf.py

@@ -97,19 +97,24 @@
  ('c:func', 'free'),
  ('c:func', 'gettimeofday'),
  ('c:func', 'gmtime'),
+ ('c:func', 'grantpt'),
  ('c:func', 'localeconv'),
  ('c:func', 'localtime'),
  ('c:func', 'main'),
  ('c:func', 'malloc'),
  ('c:func', 'mktime'),
+ ('c:func', 'posix_openpt'),
  ('c:func', 'printf'),
+ ('c:func', 'ptsname'),
+ ('c:func', 'ptsname_r'),
  ('c:func', 'realloc'),
  ('c:func', 'snprintf'),
  ('c:func', 'sprintf'),
  ('c:func', 'stat'),
  ('c:func', 'strftime'),
  ('c:func', 'system'),
  ('c:func', 'time'),
+ ('c:func', 'unlockpt'),
  ('c:func', 'vsnprintf'),
  # Standard C types
  ('c:type', 'FILE'),

Doc/library/os.rst

@@ -1122,6 +1122,20 @@ as internal buffering of data.
  .. versionchanged:: 3.12
  Added support for pipes on Windows.
 
+
+.. function:: grantpt(fd, /)
+
+ Grant access to the slave pseudo-terminal device associated with the
+ master pseudo-terminal device to which the file descriptor *fd* refers.
+ The file descriptor *fd* is not closed upon failure.
+
+ Calls the C standard library function :c:func:`grantpt`.
+
+ .. availability:: Unix, not Emscripten, not WASI.
+
+ .. versionadded:: 3.13
+
+
 .. function:: isatty(fd, /)
 
  Return ``True`` if the file descriptor *fd* is open and connected to a
@@ -1429,6 +1443,23 @@ or `the MSDN <https://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Windo
  .. versionadded:: 3.3
 
 
+.. function:: posix_openpt(oflag, /)
+
+ Open and return a file descriptor for a master pseudo-terminal device.
+
+ Calls the C standard library function :c:func:`posix_openpt`. The *oflag*
+ argument is used to set file status flags and file access modes as
+ specified in the manual page of :c:func:`posix_openpt` of your system.
+
+ The returned file descriptor is :ref:`non-inheritable <fd_inheritance>`.
+ If the value :data:`O_CLOEXEC` is available on the system, it is added to
+ *oflag*.
+
+ .. availability:: Unix, not Emscripten, not WASI.
+
+ .. versionadded:: 3.13
+
+
 .. function:: preadv(fd, buffers, offset, flags=0, /)
 
  Read from a file descriptor *fd* at a position of *offset* into mutable
@@ -1486,6 +1517,21 @@ or `the MSDN <https://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Windo
  .. versionadded:: 3.7
 
 
+.. function:: ptsname(fd, /)
+
+ Return the name of the slave pseudo-terminal device associated with the
+ master pseudo-terminal device to which the file descriptor *fd* refers.
+ The file descriptor *fd* is not closed upon failure.
+
+ Calls the reentrant C standard library function :c:func:`ptsname_r` if
+ it is available; otherwise, the C standard library function
+ :c:func:`ptsname`, which is not guaranteed to be thread-safe, is called.
+
+ .. availability:: Unix, not Emscripten, not WASI.
+
+ .. versionadded:: 3.13
+
+
 .. function:: pwrite(fd, str, offset, /)
 
  Write the bytestring in *str* to file descriptor *fd* at position of
@@ -1738,6 +1784,19 @@ or `the MSDN <https://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Windo
  .. availability:: Unix.
 
 
+.. function:: unlockpt(fd, /)
+
+ Unlock the slave pseudo-terminal device associated with the master
+ pseudo-terminal device to which the file descriptor *fd* refers.
+ The file descriptor *fd* is not closed upon failure.
+
+ Calls the C standard library function :c:func:`unlockpt`.
+
+ .. availability:: Unix, not Emscripten, not WASI.
+
+ .. versionadded:: 3.13
+
+
 .. function:: write(fd, str, /)
 
  Write the bytestring in *str* to file descriptor *fd*.

Lib/test/test_os.py

@@ -4536,13 +4536,46 @@ def test_dup2(self):
  self.assertEqual(os.dup2(fd, fd3, inheritable=False), fd3)
  self.assertFalse(os.get_inheritable(fd3))
 
- @unittest.skipUnless(hasattr(os, 'openpty'), "need os.openpty()")
+@unittest.skipUnless(hasattr(os, 'openpty'), "need os.openpty()")
+class PseudoterminalTests(unittest.TestCase):
+ def open_pty(self):
+ """Open a pty fd-pair, and schedule cleanup for it"""
+ main_fd, second_fd = os.openpty()
+ self.addCleanup(os.close, main_fd)
+ self.addCleanup(os.close, second_fd)
+ return main_fd, second_fd
+
  def test_openpty(self):
- master_fd, slave_fd = os.openpty()
- self.addCleanup(os.close, master_fd)
- self.addCleanup(os.close, slave_fd)
- self.assertEqual(os.get_inheritable(master_fd), False)
- self.assertEqual(os.get_inheritable(slave_fd), False)
+ main_fd, second_fd = self.open_pty()
+ self.assertEqual(os.get_inheritable(main_fd), False)
+ self.assertEqual(os.get_inheritable(second_fd), False)
+
+ @unittest.skipUnless(hasattr(os, 'ptsname'), "need os.ptsname()")
+ @unittest.skipUnless(hasattr(os, 'O_RDWR'), "need os.O_RDWR")
+ @unittest.skipUnless(hasattr(os, 'O_NOCTTY'), "need os.O_NOCTTY")
+ def test_open_via_ptsname(self):
+ main_fd, second_fd = self.open_pty()
+ second_path = os.ptsname(main_fd)
+ reopened_second_fd = os.open(second_path, os.O_RDWR|os.O_NOCTTY)
+ self.addCleanup(os.close, reopened_second_fd)
+ os.write(reopened_second_fd, b'foo')
+ self.assertEqual(os.read(main_fd, 3), b'foo')
+
+ @unittest.skipUnless(hasattr(os, 'posix_openpt'), "need os.posix_openpt()")
+ @unittest.skipUnless(hasattr(os, 'grantpt'), "need os.grantpt()")
+ @unittest.skipUnless(hasattr(os, 'unlockpt'), "need os.unlockpt()")
+ @unittest.skipUnless(hasattr(os, 'ptsname'), "need os.ptsname()")
+ @unittest.skipUnless(hasattr(os, 'O_RDWR'), "need os.O_RDWR")
+ @unittest.skipUnless(hasattr(os, 'O_NOCTTY'), "need os.O_NOCTTY")
+ def test_posix_pty_functions(self):
+ mother_fd = os.posix_openpt(os.O_RDWR|os.O_NOCTTY)
+ self.addCleanup(os.close, mother_fd)
+ os.grantpt(mother_fd)
+ os.unlockpt(mother_fd)
+ son_path = os.ptsname(mother_fd)
+ son_fd = os.open(son_path, os.O_RDWR|os.O_NOCTTY)
+ self.addCleanup(os.close, son_fd)
+ self.assertEqual(os.ptsname(mother_fd), os.ttyname(son_fd))
 
  @unittest.skipUnless(hasattr(os, 'spawnl'), "need os.openpty()")
  def test_pipe_spawnl(self):

Misc/NEWS.d/next/Library/2023-03-15-03-21-18.gh-issue-85984.Xaq6ZN.rst

@@ -0,0 +1,2 @@
+Add POSIX pseudo-terminal functions :func:`os.posix_openpt`,
+:func:`os.grantpt`, :func:`os.unlockpt`, and :func:`os.ptsname`.