bpo-39413: Implement os.unsetenv() on Windows (GH-18163)
The os.unsetenv() function is now also available on Windows.
diff --git a/Doc/library/os.rst b/Doc/library/os.rst
index 4fec647..de3e560 100644
--- a/Doc/library/os.rst
+++ b/Doc/library/os.rst
@@ -645,6 +645,9 @@
.. availability:: most flavors of Unix, Windows.
+ .. versionchanged:: 3.9
+ The function is now also available on Windows.
+
.. _os-newstreams:
diff --git a/Doc/whatsnew/3.9.rst b/Doc/whatsnew/3.9.rst
index 9b5b4fb..751562e 100644
--- a/Doc/whatsnew/3.9.rst
+++ b/Doc/whatsnew/3.9.rst
@@ -224,6 +224,9 @@
:data:`os.P_PIDFD` (:issue:`38713`) for process management with file
descriptors.
+The :func:`os.unsetenv` function is now also available on Windows.
+(Contributed by Victor Stinner in :issue:`39413`.)
+
poplib
------
diff --git a/Lib/test/test_os.py b/Lib/test/test_os.py
index 82c441c..dbdc00c 100644
--- a/Lib/test/test_os.py
+++ b/Lib/test/test_os.py
@@ -953,17 +953,44 @@
value_str = value.decode(sys.getfilesystemencoding(), 'surrogateescape')
self.assertEqual(os.environ['bytes'], value_str)
+ @unittest.skipUnless(hasattr(os, 'putenv'), "Test needs os.putenv()")
+ @unittest.skipUnless(hasattr(os, 'unsetenv'), "Test needs os.unsetenv()")
+ def test_putenv_unsetenv(self):
+ name = "PYTHONTESTVAR"
+ value = "testvalue"
+ code = f'import os; print(repr(os.environ.get({name!r})))'
+
+ with support.EnvironmentVarGuard() as env:
+ env.pop(name, None)
+
+ os.putenv(name, value)
+ proc = subprocess.run([sys.executable, '-c', code], check=True,
+ stdout=subprocess.PIPE, text=True)
+ self.assertEqual(proc.stdout.rstrip(), repr(value))
+
+ os.unsetenv(name)
+ proc = subprocess.run([sys.executable, '-c', code], check=True,
+ stdout=subprocess.PIPE, text=True)
+ self.assertEqual(proc.stdout.rstrip(), repr(None))
+
# On OS X < 10.6, unsetenv() doesn't return a value (bpo-13415).
@support.requires_mac_ver(10, 6)
- def test_unset_error(self):
+ @unittest.skipUnless(hasattr(os, 'putenv'), "Test needs os.putenv()")
+ @unittest.skipUnless(hasattr(os, 'unsetenv'), "Test needs os.unsetenv()")
+ def test_putenv_unsetenv_error(self):
+ # Empty variable name is invalid.
+ # "=" and null character are not allowed in a variable name.
+ for name in ('', '=name', 'na=me', 'name=', 'name\0', 'na\0me'):
+ self.assertRaises((OSError, ValueError), os.putenv, name, "value")
+ self.assertRaises((OSError, ValueError), os.unsetenv, name)
+
if sys.platform == "win32":
- # an environment variable is limited to 32,767 characters
- key = 'x' * 50000
- self.assertRaises(ValueError, os.environ.__delitem__, key)
- else:
- # "=" is not allowed in a variable name
- key = 'key='
- self.assertRaises(OSError, os.environ.__delitem__, key)
+ # On Windows, an environment variable string ("name=value" string)
+ # is limited to 32,767 characters
+ longstr = 'x' * 32_768
+ self.assertRaises(ValueError, os.putenv, longstr, "1")
+ self.assertRaises(ValueError, os.putenv, "X", longstr)
+ self.assertRaises(ValueError, os.unsetenv, longstr)
def test_key_type(self):
missing = 'missingkey'
diff --git a/Misc/NEWS.d/next/Library/2020-01-24-10-10-25.bpo-39413.7XYDM8.rst b/Misc/NEWS.d/next/Library/2020-01-24-10-10-25.bpo-39413.7XYDM8.rst
new file mode 100644
index 0000000..a185ab5
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2020-01-24-10-10-25.bpo-39413.7XYDM8.rst
@@ -0,0 +1 @@
+The :func:`os.unsetenv` function is now also available on Windows.
diff --git a/Modules/clinic/posixmodule.c.h b/Modules/clinic/posixmodule.c.h
index 13a69cd..0f5995e 100644
--- a/Modules/clinic/posixmodule.c.h
+++ b/Modules/clinic/posixmodule.c.h
@@ -6125,7 +6125,43 @@
#endif /* ((defined(HAVE_SETENV) || defined(HAVE_PUTENV)) && !defined(MS_WINDOWS)) */
-#if defined(HAVE_UNSETENV)
+#if defined(MS_WINDOWS)
+
+PyDoc_STRVAR(os_unsetenv__doc__,
+"unsetenv($module, name, /)\n"
+"--\n"
+"\n"
+"Delete an environment variable.");
+
+#define OS_UNSETENV_METHODDEF \
+ {"unsetenv", (PyCFunction)os_unsetenv, METH_O, os_unsetenv__doc__},
+
+static PyObject *
+os_unsetenv_impl(PyObject *module, PyObject *name);
+
+static PyObject *
+os_unsetenv(PyObject *module, PyObject *arg)
+{
+ PyObject *return_value = NULL;
+ PyObject *name;
+
+ if (!PyUnicode_Check(arg)) {
+ _PyArg_BadArgument("unsetenv", "argument", "str", arg);
+ goto exit;
+ }
+ if (PyUnicode_READY(arg) == -1) {
+ goto exit;
+ }
+ name = arg;
+ return_value = os_unsetenv_impl(module, name);
+
+exit:
+ return return_value;
+}
+
+#endif /* defined(MS_WINDOWS) */
+
+#if (defined(HAVE_UNSETENV) && !defined(MS_WINDOWS))
PyDoc_STRVAR(os_unsetenv__doc__,
"unsetenv($module, name, /)\n"
@@ -6157,7 +6193,7 @@
return return_value;
}
-#endif /* defined(HAVE_UNSETENV) */
+#endif /* (defined(HAVE_UNSETENV) && !defined(MS_WINDOWS)) */
PyDoc_STRVAR(os_strerror__doc__,
"strerror($module, code, /)\n"
@@ -8773,4 +8809,4 @@
#ifndef OS__REMOVE_DLL_DIRECTORY_METHODDEF
#define OS__REMOVE_DLL_DIRECTORY_METHODDEF
#endif /* !defined(OS__REMOVE_DLL_DIRECTORY_METHODDEF) */
-/*[clinic end generated code: output=6f42d8be634f5942 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=0348cbdff48691e3 input=a9049054013a1b77]*/
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 6a68752..3a8e6aa 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -10083,6 +10083,64 @@
#ifdef MS_WINDOWS
+static PyObject*
+win32_putenv(PyObject *name, PyObject *value)
+{
+ /* Search from index 1 because on Windows starting '=' is allowed for
+ defining hidden environment variables. */
+ if (PyUnicode_GET_LENGTH(name) == 0 ||
+ PyUnicode_FindChar(name, '=', 1, PyUnicode_GET_LENGTH(name), 1) != -1)
+ {
+ PyErr_SetString(PyExc_ValueError, "illegal environment variable name");
+ return NULL;
+ }
+ PyObject *unicode;
+ if (value != NULL) {
+ unicode = PyUnicode_FromFormat("%U=%U", name, value);
+ }
+ else {
+ unicode = PyUnicode_FromFormat("%U=", name);
+ }
+ if (unicode == NULL) {
+ return NULL;
+ }
+
+ Py_ssize_t size;
+ /* PyUnicode_AsWideCharString() rejects embedded null characters */
+ wchar_t *env = PyUnicode_AsWideCharString(unicode, &size);
+ Py_DECREF(unicode);
+
+ if (env == NULL) {
+ return NULL;
+ }
+ if (size > _MAX_ENV) {
+ PyErr_Format(PyExc_ValueError,
+ "the environment variable is longer than %u characters",
+ _MAX_ENV);
+ PyMem_Free(env);
+ return NULL;
+ }
+
+ /* _wputenv() and SetEnvironmentVariableW() update the environment in the
+ Process Environment Block (PEB). _wputenv() also updates CRT 'environ'
+ and '_wenviron' variables, whereas SetEnvironmentVariableW() does not.
+
+ Prefer _wputenv() to be compatible with C libraries using CRT
+ variables and CRT functions using these variables (ex: getenv()). */
+ int err = _wputenv(env);
+ PyMem_Free(env);
+
+ if (err) {
+ posix_error();
+ return NULL;
+ }
+
+ Py_RETURN_NONE;
+}
+#endif
+
+
+#ifdef MS_WINDOWS
/*[clinic input]
os.putenv
@@ -10097,47 +10155,7 @@
os_putenv_impl(PyObject *module, PyObject *name, PyObject *value)
/*[clinic end generated code: output=d29a567d6b2327d2 input=ba586581c2e6105f]*/
{
- const wchar_t *env;
- Py_ssize_t size;
-
- /* Search from index 1 because on Windows starting '=' is allowed for
- defining hidden environment variables. */
- if (PyUnicode_GET_LENGTH(name) == 0 ||
- PyUnicode_FindChar(name, '=', 1, PyUnicode_GET_LENGTH(name), 1) != -1)
- {
- PyErr_SetString(PyExc_ValueError, "illegal environment variable name");
- return NULL;
- }
- PyObject *unicode = PyUnicode_FromFormat("%U=%U", name, value);
- if (unicode == NULL) {
- return NULL;
- }
-
- env = PyUnicode_AsUnicodeAndSize(unicode, &size);
- if (env == NULL)
- goto error;
- if (size > _MAX_ENV) {
- PyErr_Format(PyExc_ValueError,
- "the environment variable is longer than %u characters",
- _MAX_ENV);
- goto error;
- }
- if (wcslen(env) != (size_t)size) {
- PyErr_SetString(PyExc_ValueError, "embedded null character");
- goto error;
- }
-
- if (_wputenv(env)) {
- posix_error();
- goto error;
- }
- Py_DECREF(unicode);
-
- Py_RETURN_NONE;
-
-error:
- Py_DECREF(unicode);
- return NULL;
+ return win32_putenv(name, value);
}
/* repeat !defined(MS_WINDOWS) to workaround an Argument Clinic issue */
#elif (defined(HAVE_SETENV) || defined(HAVE_PUTENV)) && !defined(MS_WINDOWS)
@@ -10186,7 +10204,23 @@
#endif /* defined(HAVE_SETENV) || defined(HAVE_PUTENV) */
-#ifdef HAVE_UNSETENV
+#ifdef MS_WINDOWS
+/*[clinic input]
+os.unsetenv
+ name: unicode
+ /
+
+Delete an environment variable.
+[clinic start generated code]*/
+
+static PyObject *
+os_unsetenv_impl(PyObject *module, PyObject *name)
+/*[clinic end generated code: output=54c4137ab1834f02 input=4d6a1747cc526d2f]*/
+{
+ return win32_putenv(name, NULL);
+}
+/* repeat !defined(MS_WINDOWS) to workaround an Argument Clinic issue */
+#elif defined(HAVE_UNSETENV) && !defined(MS_WINDOWS)
/*[clinic input]
os.unsetenv
name: FSConverter
@@ -10199,16 +10233,13 @@
os_unsetenv_impl(PyObject *module, PyObject *name)
/*[clinic end generated code: output=54c4137ab1834f02 input=2bb5288a599c7107]*/
{
-#ifndef HAVE_BROKEN_UNSETENV
- int err;
-#endif
-
#ifdef HAVE_BROKEN_UNSETENV
unsetenv(PyBytes_AS_STRING(name));
#else
- err = unsetenv(PyBytes_AS_STRING(name));
- if (err)
+ int err = unsetenv(PyBytes_AS_STRING(name));
+ if (err) {
return posix_error();
+ }
#endif
#ifdef PY_PUTENV_DICT