Issue #10755: Add the posix.fdlistdir() function. Patch by Ross Lagerwall.

Doc/library/os.rst

@@ -733,6 +733,16 @@ as internal buffering of data.
       This function is not available on MacOS.
 
 
+.. function:: fdlistdir(fd)
+
+   Like :func:`listdir`, but uses a file descriptor instead and always returns
+   strings.  After execution of this function, *fd* will be closed.
+
+   Availability: Unix.
+
+   .. versionadded:: 3.3
+
+
 .. function:: fpathconf(fd, name)
 
    Return system configuration information relevant to an open file. *name*

Lib/test/test_posix.py

@@ -285,6 +285,18 @@ class PosixTester(unittest.TestCase):
         if hasattr(posix, 'listdir'):
             self.assertTrue(support.TESTFN in posix.listdir())
 
+    @unittest.skipUnless(hasattr(posix, 'fdlistdir'), "test needs posix.fdlistdir()")
+    def test_fdlistdir(self):
+        f = posix.open(posix.getcwd(), posix.O_RDONLY)
+        self.assertEqual(
+            sorted(posix.listdir('.')),
+            sorted(posix.fdlistdir(f))
+            )
+        # Check the fd was closed by fdlistdir
+        with self.assertRaises(OSError) as ctx:
+            posix.close(f)
+        self.assertEqual(ctx.exception.errno, errno.EBADF)
+
     def test_access(self):
         if hasattr(posix, 'access'):
             self.assertTrue(posix.access(support.TESTFN, os.R_OK))

Misc/NEWS

@@ -35,6 +35,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #10755: Add the posix.fdlistdir() function.  Patch by Ross Lagerwall.
+
 - Issue #4761: Add the *at() family of functions (openat(), etc.) to the posix
   module.  Patch by Ross Lagerwall.
 

Modules/posixmodule.c

@@ -2678,6 +2678,76 @@ posix_listdir(PyObject *self, PyObject *args)
 #endif /* which OS */
 }  /* end of posix_listdir */
 
+#ifdef HAVE_FDOPENDIR
+PyDoc_STRVAR(posix_fdlistdir__doc__,
+"fdlistdir(fd) -> list_of_strings\n\n\
+Like listdir(), but uses a file descriptor instead.\n\
+After succesful execution of this function, fd will be closed.");
+
+static PyObject *
+posix_fdlistdir(PyObject *self, PyObject *args)
+{
+    PyObject *d, *v;
+    DIR *dirp;
+    struct dirent *ep;
+    int fd;
+
+    errno = 0;
+    if (!PyArg_ParseTuple(args, "i:fdlistdir", &fd))
+        return NULL;
+    Py_BEGIN_ALLOW_THREADS
+    dirp = fdopendir(fd);
+    Py_END_ALLOW_THREADS
+    if (dirp == NULL) {
+        close(fd);
+        return posix_error();
+    }
+    if ((d = PyList_New(0)) == NULL) {
+        Py_BEGIN_ALLOW_THREADS
+        closedir(dirp);
+        Py_END_ALLOW_THREADS
+        return NULL;
+    }
+    for (;;) {
+        errno = 0;
+        Py_BEGIN_ALLOW_THREADS
+        ep = readdir(dirp);
+        Py_END_ALLOW_THREADS
+        if (ep == NULL) {
+            if (errno == 0) {
+                break;
+            } else {
+                Py_BEGIN_ALLOW_THREADS
+                closedir(dirp);
+                Py_END_ALLOW_THREADS
+                Py_DECREF(d);
+                return posix_error();
+            }
+        }
+        if (ep->d_name[0] == '.' &&
+            (NAMLEN(ep) == 1 ||
+             (ep->d_name[1] == '.' && NAMLEN(ep) == 2)))
+            continue;
+        v = PyUnicode_DecodeFSDefaultAndSize(ep->d_name, NAMLEN(ep));
+        if (v == NULL) {
+            Py_CLEAR(d);
+            break;
+        }
+        if (PyList_Append(d, v) != 0) {
+            Py_DECREF(v);
+            Py_CLEAR(d);
+            break;
+        }
+        Py_DECREF(v);
+    }
+    Py_BEGIN_ALLOW_THREADS
+    closedir(dirp);
+    Py_END_ALLOW_THREADS
+
+    return d;
+}
+#endif
+
 #ifdef MS_WINDOWS
 /* A helper function for abspath on win32 */
 static PyObject *
@@ -8599,6 +8669,9 @@ static PyMethodDef posix_methods[] = {
     {"link",            posix_link, METH_VARARGS, posix_link__doc__},
 #endif /* HAVE_LINK */
     {"listdir",         posix_listdir, METH_VARARGS, posix_listdir__doc__},
+#ifdef HAVE_FDOPENDIR
+    {"fdlistdir",       posix_fdlistdir, METH_VARARGS, posix_fdlistdir__doc__},
+#endif
     {"lstat",           posix_lstat, METH_VARARGS, posix_lstat__doc__},
     {"mkdir",           posix_mkdir, METH_VARARGS, posix_mkdir__doc__},
 #ifdef HAVE_NICE

configure

@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.in Revision: 88608 .
+# From configure.in Revision: 88624 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.65 for python 3.3.
 #
@@ -9311,8 +9311,8 @@ $as_echo "MACHDEP_OBJS" >&6; }
 
 # checks for library functions
 for ac_func in alarm accept4 setitimer getitimer bind_textdomain_codeset chown \
- clock confstr ctermid execv faccessat fchmod fchmodat fchown fchownat fork \
+ clock confstr ctermid execv faccessat fchmod fchmodat fchown fchownat \
- fpathconf fstatat ftime ftruncate futimesat \
+ fdopendir fork fpathconf fstatat ftime ftruncate futimesat \
  gai_strerror getgroups getlogin getloadavg getpeername getpgid getpid \
  getpriority getresuid getresgid getpwent getspnam getspent getsid getwd \
  initgroups kill killpg lchmod lchown linkat lstat mbrtowc mkdirat mkfifo \

configure.in

@@ -2534,8 +2534,8 @@ AC_MSG_RESULT(MACHDEP_OBJS)
 
 # checks for library functions
 AC_CHECK_FUNCS(alarm accept4 setitimer getitimer bind_textdomain_codeset chown \
- clock confstr ctermid execv faccessat fchmod fchmodat fchown fchownat fork \
+ clock confstr ctermid execv faccessat fchmod fchmodat fchown fchownat \
- fpathconf fstatat ftime ftruncate futimesat \
+ fdopendir fork fpathconf fstatat ftime ftruncate futimesat \
  gai_strerror getgroups getlogin getloadavg getpeername getpgid getpid \
  getpriority getresuid getresgid getpwent getspnam getspent getsid getwd \
  initgroups kill killpg lchmod lchown linkat lstat mbrtowc mkdirat mkfifo \

pyconfig.h.in

@@ -229,6 +229,9 @@
 /* Define if you have the 'fdatasync' function. */
 #undef HAVE_FDATASYNC
 
+/* Define to 1 if you have the `fdopendir' function. */
+#undef HAVE_FDOPENDIR
+
 /* Define to 1 if you have the `finite' function. */
 #undef HAVE_FINITE
 
@@ -533,6 +536,9 @@
 /* Define if the OS supports pipe2() */
 #undef HAVE_PIPE2
 
+/* Define if the OS supports pipe2() */
+#undef HAVE_PIPE2
+
 /* Define to 1 if you have the `plock' function. */
 #undef HAVE_PLOCK