Mini Shell

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

# Copyright (c) 2009, Giampaolo Rodola'. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""
Notes about unicode handling in psutil
======================================

Starting from version 5.3.0 psutil adds unicode support, see:
https://github.com/giampaolo/psutil/issues/1040
The notes below apply to *any* API returning a string such as
process exe(), cwd() or username():

* all strings are encoded by using the OS filesystem encoding
  (sys.getfilesystemencoding()) which varies depending on the platform
  (e.g. "UTF-8" on macOS, "mbcs" on Win)
* no API call is supposed to crash with UnicodeDecodeError
* instead, in case of badly encoded data returned by the OS, the
  following error handlers are used to replace the corrupted characters in
  the string:
    * Python 3: sys.getfilesystemencodeerrors() (PY 3.6+) or
      "surrogatescape" on POSIX and "replace" on Windows
    * Python 2: "replace"
* on Python 2 all APIs return bytes (str type), never unicode
* on Python 2, you can go back to unicode by doing:

    >>> unicode(p.exe(), sys.getdefaultencoding(), errors="replace")

For a detailed explanation of how psutil handles unicode see #1040.

Tests
=====

List of APIs returning or dealing with a string:
('not tested' means they are not tested to deal with non-ASCII strings):

* Process.cmdline()
* Process.connections('unix')
* Process.cwd()
* Process.environ()
* Process.exe()
* Process.memory_maps()
* Process.name()
* Process.open_files()
* Process.username()             (not tested)

* disk_io_counters()             (not tested)
* disk_partitions()              (not tested)
* disk_usage(str)
* net_connections('unix')
* net_if_addrs()                 (not tested)
* net_if_stats()                 (not tested)
* net_io_counters()              (not tested)
* sensors_fans()                 (not tested)
* sensors_temperatures()         (not tested)
* users()                        (not tested)

* WindowsService.binpath()       (not tested)
* WindowsService.description()   (not tested)
* WindowsService.display_name()  (not tested)
* WindowsService.name()          (not tested)
* WindowsService.status()        (not tested)
* WindowsService.username()      (not tested)

In here we create a unicode path with a funky non-ASCII name and (where
possible) make psutil return it back (e.g. on name(), exe(), open_files(),
etc.) and make sure that:

* psutil never crashes with UnicodeDecodeError
* the returned path matches
"""

import os
import shutil
import traceback
import warnings
from contextlib import closing

from psutil import BSD
from psutil import OPENBSD
from psutil import POSIX
from psutil import WINDOWS
from psutil._compat import PY3
from psutil._compat import u
from psutil.tests import APPVEYOR
from psutil.tests import ASCII_FS
from psutil.tests import bind_unix_socket
from psutil.tests import chdir
from psutil.tests import CI_TESTING
from psutil.tests import copyload_shared_lib
from psutil.tests import create_exe
from psutil.tests import get_testfn
from psutil.tests import HAS_CONNECTIONS_UNIX
from psutil.tests import HAS_ENVIRON
from psutil.tests import HAS_MEMORY_MAPS
from psutil.tests import INVALID_UNICODE_SUFFIX
from psutil.tests import PsutilTestCase
from psutil.tests import PYPY
from psutil.tests import safe_mkdir
from psutil.tests import safe_rmpath
from psutil.tests import serialrun
from psutil.tests import skip_on_access_denied
from psutil.tests import spawn_testproc
from psutil.tests import terminate
from psutil.tests import TESTFN_PREFIX
from psutil.tests import UNICODE_SUFFIX
from psutil.tests import unittest
import psutil


if APPVEYOR:
    def safe_rmpath(path):  # NOQA
        # TODO - this is quite random and I'm not sure why it happens,
        # nor I can reproduce it locally:
        # https://ci.appveyor.com/project/giampaolo/psutil/build/job/
        #     jiq2cgd6stsbtn60
        # safe_rmpath() happens after reap_children() so this is weird
        # Perhaps wait_procs() on Windows is broken? Maybe because
        # of STILL_ACTIVE?
        # https://github.com/giampaolo/psutil/blob/
        #     68c7a70728a31d8b8b58f4be6c4c0baa2f449eda/psutil/arch/
        #     windows/process_info.c#L146
        from psutil.tests import safe_rmpath as rm
        try:
            return rm(path)
        except WindowsError:
            traceback.print_exc()


def try_unicode(suffix):
    """Return True if both the fs and the subprocess module can
    deal with a unicode file name.
    """
    sproc = None
    testfn = get_testfn(suffix=suffix)
    try:
        safe_rmpath(testfn)
        create_exe(testfn)
        sproc = spawn_testproc(cmd=[testfn])
        shutil.copyfile(testfn, testfn + '-2')
        safe_rmpath(testfn + '-2')
    except (UnicodeEncodeError, IOError):
        return False
    else:
        return True
    finally:
        if sproc is not None:
            terminate(sproc)
        safe_rmpath(testfn)


# ===================================================================
# FS APIs
# ===================================================================


class BaseUnicodeTest(PsutilTestCase):
    funky_suffix = None

    def setUp(self):
        if self.funky_suffix is not None:
            if not try_unicode(self.funky_suffix):
                raise self.skipTest("can't handle unicode str")


@serialrun
@unittest.skipIf(ASCII_FS, "ASCII fs")
@unittest.skipIf(PYPY and not PY3, "too much trouble on PYPY2")
class TestFSAPIs(BaseUnicodeTest):
    """Test FS APIs with a funky, valid, UTF8 path name."""

    funky_suffix = UNICODE_SUFFIX

    @classmethod
    def setUpClass(cls):
        cls.funky_name = get_testfn(suffix=cls.funky_suffix)
        create_exe(cls.funky_name)

    @classmethod
    def tearDownClass(cls):
        safe_rmpath(cls.funky_name)

    def expect_exact_path_match(self):
        # Do not expect psutil to correctly handle unicode paths on
        # Python 2 if os.listdir() is not able either.
        here = '.' if isinstance(self.funky_name, str) else u('.')
        with warnings.catch_warnings():
            warnings.simplefilter("ignore")
            return self.funky_name in os.listdir(here)

    # ---

    def test_proc_exe(self):
        subp = self.spawn_testproc(cmd=[self.funky_name])
        p = psutil.Process(subp.pid)
        exe = p.exe()
        self.assertIsInstance(exe, str)
        if self.expect_exact_path_match():
            self.assertEqual(os.path.normcase(exe),
                             os.path.normcase(self.funky_name))

    def test_proc_name(self):
        subp = self.spawn_testproc(cmd=[self.funky_name])
        name = psutil.Process(subp.pid).name()
        self.assertIsInstance(name, str)
        if self.expect_exact_path_match():
            self.assertEqual(name, os.path.basename(self.funky_name))

    def test_proc_cmdline(self):
        subp = self.spawn_testproc(cmd=[self.funky_name])
        p = psutil.Process(subp.pid)
        cmdline = p.cmdline()
        for part in cmdline:
            self.assertIsInstance(part, str)
        if self.expect_exact_path_match():
            self.assertEqual(cmdline, [self.funky_name])

    def test_proc_cwd(self):
        dname = self.funky_name + "2"
        self.addCleanup(safe_rmpath, dname)
        safe_mkdir(dname)
        with chdir(dname):
            p = psutil.Process()
            cwd = p.cwd()
        self.assertIsInstance(p.cwd(), str)
        if self.expect_exact_path_match():
            self.assertEqual(cwd, dname)

    @unittest.skipIf(PYPY and WINDOWS, "fails on PYPY + WINDOWS")
    def test_proc_open_files(self):
        p = psutil.Process()
        start = set(p.open_files())
        with open(self.funky_name, 'rb'):
            new = set(p.open_files())
        path = (new - start).pop().path
        self.assertIsInstance(path, str)
        if BSD and not path:
            # XXX - see https://github.com/giampaolo/psutil/issues/595
            return self.skipTest("open_files on BSD is broken")
        if self.expect_exact_path_match():
            self.assertEqual(os.path.normcase(path),
                             os.path.normcase(self.funky_name))

    @unittest.skipIf(not POSIX, "POSIX only")
    def test_proc_connections(self):
        name = self.get_testfn(suffix=self.funky_suffix)
        try:
            sock = bind_unix_socket(name)
        except UnicodeEncodeError:
            if PY3:
                raise
            else:
                raise unittest.SkipTest("not supported")
        with closing(sock):
            conn = psutil.Process().connections('unix')[0]
            self.assertIsInstance(conn.laddr, str)
            # AF_UNIX addr not set on OpenBSD
            if not OPENBSD:  # XXX
                self.assertEqual(conn.laddr, name)

    @unittest.skipIf(not POSIX, "POSIX only")
    @unittest.skipIf(not HAS_CONNECTIONS_UNIX, "can't list UNIX sockets")
    @skip_on_access_denied()
    def test_net_connections(self):
        def find_sock(cons):
            for conn in cons:
                if os.path.basename(conn.laddr).startswith(TESTFN_PREFIX):
                    return conn
            raise ValueError("connection not found")

        name = self.get_testfn(suffix=self.funky_suffix)
        try:
            sock = bind_unix_socket(name)
        except UnicodeEncodeError:
            if PY3:
                raise
            else:
                raise unittest.SkipTest("not supported")
        with closing(sock):
            cons = psutil.net_connections(kind='unix')
            # AF_UNIX addr not set on OpenBSD
            if not OPENBSD:
                conn = find_sock(cons)
                self.assertIsInstance(conn.laddr, str)
                self.assertEqual(conn.laddr, name)

    def test_disk_usage(self):
        dname = self.funky_name + "2"
        self.addCleanup(safe_rmpath, dname)
        safe_mkdir(dname)
        psutil.disk_usage(dname)

    @unittest.skipIf(not HAS_MEMORY_MAPS, "not supported")
    @unittest.skipIf(not PY3, "ctypes does not support unicode on PY2")
    @unittest.skipIf(PYPY, "unstable on PYPY")
    def test_memory_maps(self):
        # XXX: on Python 2, using ctypes.CDLL with a unicode path
        # opens a message box which blocks the test run.
        with copyload_shared_lib(suffix=self.funky_suffix) as funky_path:
            def normpath(p):
                return os.path.realpath(os.path.normcase(p))
            libpaths = [normpath(x.path)
                        for x in psutil.Process().memory_maps()]
            # ...just to have a clearer msg in case of failure
            libpaths = [x for x in libpaths if TESTFN_PREFIX in x]
            self.assertIn(normpath(funky_path), libpaths)
            for path in libpaths:
                self.assertIsInstance(path, str)


@unittest.skipIf(CI_TESTING, "unreliable on CI")
class TestFSAPIsWithInvalidPath(TestFSAPIs):
    """Test FS APIs with a funky, invalid path name."""
    funky_suffix = INVALID_UNICODE_SUFFIX

    @classmethod
    def expect_exact_path_match(cls):
        # Invalid unicode names are supposed to work on Python 2.
        return True


# ===================================================================
# Non fs APIs
# ===================================================================


class TestNonFSAPIS(BaseUnicodeTest):
    """Unicode tests for non fs-related APIs."""
    funky_suffix = UNICODE_SUFFIX if PY3 else 'è'

    @unittest.skipIf(not HAS_ENVIRON, "not supported")
    @unittest.skipIf(PYPY and WINDOWS, "segfaults on PYPY + WINDOWS")
    def test_proc_environ(self):
        # Note: differently from others, this test does not deal
        # with fs paths. On Python 2 subprocess module is broken as
        # it's not able to handle with non-ASCII env vars, so
        # we use "è", which is part of the extended ASCII table
        # (unicode point <= 255).
        env = os.environ.copy()
        env['FUNNY_ARG'] = self.funky_suffix
        sproc = self.spawn_testproc(env=env)
        p = psutil.Process(sproc.pid)
        env = p.environ()
        for k, v in env.items():
            self.assertIsInstance(k, str)
            self.assertIsInstance(v, str)
        self.assertEqual(env['FUNNY_ARG'], self.funky_suffix)


if __name__ == '__main__':
    from psutil.tests.runner import run_from_name
    run_from_name(__file__)