From 161e7b36b1ea871a1352ccfc1d4f4c1eda76830f Mon Sep 17 00:00:00 2001 From: Victor Stinner Date: Fri, 24 Jan 2020 11:53:44 +0100 Subject: [PATCH] bpo-39413: Implement os.unsetenv() on Windows (GH-18163) The os.unsetenv() function is now also available on Windows. --- Doc/library/os.rst | 3 + Doc/whatsnew/3.9.rst | 3 + Lib/test/test_os.py | 43 ++++-- .../2020-01-24-10-10-25.bpo-39413.7XYDM8.rst | 1 + Modules/clinic/posixmodule.c.h | 42 +++++- Modules/posixmodule.c | 127 +++++++++++------- 6 files changed, 160 insertions(+), 59 deletions(-) create mode 100644 Misc/NEWS.d/next/Library/2020-01-24-10-10-25.bpo-39413.7XYDM8.rst diff --git a/Doc/library/os.rst b/Doc/library/os.rst index 4fec647828e..de3e5603e10 100644 --- a/Doc/library/os.rst +++ b/Doc/library/os.rst @@ -645,6 +645,9 @@ process and user. .. 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 9b5b4fb3785..751562e875e 100644 --- a/Doc/whatsnew/3.9.rst +++ b/Doc/whatsnew/3.9.rst @@ -224,6 +224,9 @@ Exposed the Linux-specific :func:`os.pidfd_open` (:issue:`38692`) and :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 82c441c2048..dbdc00c2fea 100644 --- a/Lib/test/test_os.py +++ b/Lib/test/test_os.py @@ -953,17 +953,44 @@ class EnvironTests(mapping_tests.BasicTestMappingProtocol): 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 00000000000..a185ab5efe2 --- /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 13a69cd5f0e..0f5995ec640 100644 --- a/Modules/clinic/posixmodule.c.h +++ b/Modules/clinic/posixmodule.c.h @@ -6125,7 +6125,43 @@ exit: #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 @@ exit: 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 @@ exit: #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 6a687529df0..3a8e6aacb2a 100644 --- a/Modules/posixmodule.c +++ b/Modules/posixmodule.c @@ -10082,6 +10082,64 @@ posix_putenv_dict_setitem(PyObject *name, PyObject *value) #endif /* PY_PUTENV_DICT */ +#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 @@ static PyObject * 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 @@ os_putenv_impl(PyObject *module, PyObject *name, PyObject *value) #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 @@ static PyObject * 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